40th Anniversary Journal Awards Results

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Effect of end shape on blast from cylindrical charges

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March 2014THE JOURNAL OF THE I NST I TUTE OF EXPLOS IVES ENG INEERS

ExplosivesEngineering

Professional Affiliate of the Engineering Council UK

The Institute ofExplosives Engineers

The Institute of Explosives Engineers Suite 3, 7–8 Mill Street, Stafford ST16 2AJTelephone and fax: 01785 240154Email: secretariat@iexpe.orgwww.iexpe.org

Institute of Explosives Engineers Registered Office: 141 Victoria Road, Swindon SN1 3BUCompany No. 07905911Company limited by guarantee

EditorDiane Hall Telephone: +44 (0)1729 840765Mobile: +44 (0)7778 063373Email: editor@iexpe.org DianeTHall@aol.com

Design and Print/Production and Advertising ManagerGordon Hunt Gordon Hunt DesignTelephone: +44 (0)1726 832594Email: design@gordon-hunt.co.uk

Explosives EngineeringDistributed quarterly to all members of the Institute of Explosives Engineers. To non-members or for additional copies to members, including p&p. Single copies:- UK £8.80, EU £11.20, World £12.40.Annual subscription:- UK £34.50, EU £44.10, World £48.90

To obtain copies, contact Explosives Engineering Subscriptions at the Institute address above.Cheques should be made payable in sterling to the Institute of Explosives Engineers.

Papers, articles and letters to the Editor are welcome and should be sent to the Editor at her emailaddress, or by post to the Institute address.

Opinions expressed in the Journal are those of the authors concerned. They do not necessarily represent the views of the Institute

The IExpE logo is a UK registered trade mark owned by IExpE

Professional Affiliate of ECUK

Contents

Front cover picture: Imagesthrough SEM (scanning electronmicroscope) of blackpowder(left) and SEM of sphericalagglomerate of gun propellantgrade n-guanylureadinitramide (GuDN/Fox-12)(Centre for DefenceChemistry, CranfieldUniversity).

Regulars

Institute News 2

Tech Spec 34

The Bennett file 36

Sidney Alford column 37

Industry News 38

Conference/Exhibition Diary 40

In a flash - Ben Hoge BA (Criminal 40Justice) I.A.A.I CFI CFEI MIExpE

ContentsFeaturesBest practice for Commercial Explosive Ordnance 8Disposal (EOD) in Great BritainKen Cross MBE CEng MSc BSc(Hons) FIExpE

Critical review of novel detection 12methods for buried explosivesHolli Kimble MEng MSc MIExpE

A cost effective method for preliminary 16explosive characterisationAndrew Envy BEng AIExpE

D10 dozer recovered from a 21high wall using blastingTristan Worsey BSc MSc MISEE

A history of explosives: as they 26relate to the UKIan McKay CEng MPhil BSc DipH&S FIMM FIExpE

Effect of end shape on blast from cylindrical charges 28 Scott Bradley BEng MSc(EOE)

01

ThePresident

speaks

I hope that when you opened this edition ofthe journal you noticed that it was slightlydifferent. Our Journal Committee haveupdated the design, typeface and paper tomark our 40 years as an Institute and tomodernise the style we launched for the30th Anniversary. The Institute was formedin 1974 and this is included in a history ofexplosives in this journal. Since our formationwe have come a long way and we must bevery grateful to our founding fathers forsetting up the Institute. We should be veryproud that we are now a ProfessionalAffiliate of the Engineering Council andthose members who wish to do so can seekprofessional registration with theEngineering Council.

I recently represented the Institute at aprofessional engineering forum at the MODsite at Abbey Wood and I was approachedby several graduates and apprentices whowere interested in professional registrationbut were unsure where to start. We need tokeep pushing the message to those startingoff in their careers that if they are interestedin professional registration then join anInstitute and start recording their CPDactivities.

To commemorate our forty years we heldthe 40th Anniversary Journal Awardscompetition to encourage those interestedto write and submit a paper on aspects ofexplosives engineering. There were fourcategories, Fellows, Members, Associatesand Non-members. We had responses in all

categories and so thank you to all those whoentered. The winning articles from eachcategory are elsewhere in the journal as aredetails of the Awards presentation.

At the end of January we hosted a visit ofour counterparts from EUExcert Sweden.The last EUExcert project ended with 8 outof 10 partner nations agreeing to adopt andadapt the UK National OccupationalStandards (NOS) as the basis for certificationof explosives workers. As there have beenmany changes in people and structures inSweden, it was agreed that the aim of theweek was to provide an introduction to theNOS and their implementation as the basisof qualifications and also as managementtools. The week was a great success and welook forward to the next phase ofcollaboration across Europe in this area.

Members of the Institute have also beeninvolved with the GEMS meeting. GEMSstands for Group of Experts in MitigationSystems. It was formed in December 1999and held its inaugural meeting at COTEC(Cranfield Ordnance Test and EvaluationCentre). The group is managed by CPNI(Centre for the Protection of NationalInfrastructure) and has expanded over theyears to include embedded members acrossGovernment departments and agencies.Individual members are encouraged tonetwork, communicate challenges andpresent their findings and questions to thewider Group. The Group meets each Januaryin a different location; this year AWE hostedthe meeting and next year DSTL will beinviting GEMS members along to one oftheir establishments.

In an industry as diverse as explosives,networking is very important and so I drawyour attention to the Linkedin group we run.It is also very important to have the ability tofind information that you need and it is not

always available on the web. The Instituteholds a range of documents which havenow been catalogued by Dr Ian Barnes andwe intend to put that list on the website somembers can see what we hold. We areconsidering exactly which documents toretain and where they will be held. It is a sadfact of life that as establishments haveclosed libraries have too often been closedand their contents destroyed. If anymembers have documents they think wouldbe worth keeping please let the Secretariatknow and we will consider finding a homefor them.

Looking forward to the AGM and after therequest at last year’s you will have seen thatwe have moved the venue to Scotland thisyear and we hope that those in Scotland andthe North of England will take theopportunity of a shorter journey to supportboth functions. Details are to be found onpage 7 and if you have not yet booked in, donot delay and I look forward to seeing youall in Scotland.

Finally to Council matters, first it is withsadness that I have to inform you that PeterNorton has had to resign from Councilbecause of his other commitments andthrough the pages of the Journal I wouldlike to thank him on your behalf for the workhe has done as Technical Officer and for thearticles he has written. As I step down fromthe Presidency at the AGM, the President fornext year will be John Wolstenholme andthe two Vice Presidents will be Mike Bollandand Paul Harris. We are looking for newmembers of Council and I encourage you allto vote for those you would like to see onCouncil. Thank you for your support overthe last two years, it has been a greatprivilege to have been the President of sucha vibrant and growing Institute.

A J Morley MSc BSc MIExpE

Institute News

Professional Registration updateProfessional Registration statistics as at February 1st 2014:

CEng IEng EngTechQUALIFIED 16 4 3IN PROGRESS 7 1 0

PRI Assessor training: on 27th February 2014, Col Gareth Collett andDr Chris Owen will attend the Society of Environmental Engineers PRIAssessor training to be held at Lockheed Martin's facility in Ampthill.

Professional Registration. All Members and Fellows of the Instituteshould give serious consideration to professional registration in oneof the grades available (EngTech, IEng, CEng). Professional registrationis your personal quality mark that demonstrates to others in theprofession and potential employers or clients that you are committed

to maintaining a high quality of working, continuous professionaldevelopment, and compliance with a professional code of ethics,environmental and safety standards. It is not an onerous task andthose who are already registered will testify to its value in theirprofessional lives.

To apply for professional registration call or email the Institute office:Tel +44 (0)1785 240154; Email secretariat@iexpe.org

For more information, contact Ken Cross: Tel +44 (0)7805 053791Email: registrar@iexpe.org

Ken Cross MBE CEng MSc BSc(Hons) FIExpE

02

EUExcert type of project. The Key Actions ofErasmus+ are described in full on the IExpEwebsite. Key Action 1 of Erasmus+ is tosupport mobility visits for learners and stafffrom programme nations, of which both UKand SWE are part. Key Action 2 is to fosterco-operation and innovation for goodpractices, which is clearly at the core of theEUExcert aims. It is important to note that allorganisations will need to be registered onthe European Commission’s onlineregistration facility in order to apply forfunds. The Council of IExpE has agreed outof committee that they will register in theircapacity as the National Node for EUExcert.Members of EUExcert UK who might wish todraw down EC funds through this schemewill also need to register.

International Conference onExplosive Education and Certificationof Skills 2014 This year’s ICEECS is likely to take place on11-12 June in Karlskoga, Sweden and thecall for papers will be published soon.

EUExcert UK Actions1. Maintain a link to the UK National Agency

for Erasmus+. 2. Members wishing to draw down

Erasmus+ funds for Key Action 1 mobilityvisits should register with Erasmus +.

3. Prepare to support the creation of aproject team to write the bid for the nextEUExcert project.

4. Prepare to support the organisation ofthe 2014 International Conference onExplosives Education and Certification ofSkills.

K A Cross MBE CEng MSc BSc(Hons) FIExpEChairman EUExcert UK

Institute News

Branch reportsSouth (Central and West) BranchMatthew Tosh presented to the branch on10th December 2013 in Bristol. This was aninformative and enjoyable presentationincluding some pyrotechnic demonstrationsfor good measure. Matthew provided aninteresting insight into the chemistry andphysics of pyrotechnic effects. He talkedabout how he has used his teaching and

03

Matthew Toshpresenting to

the Branchmeeting.

Swedish (SWE) mobility visit 27th to 31st January 2014The long-awaited visit of our counterpartsfrom EUExcert SWE took place from 27th to31st January 2014. The last EUExcert projectended with 8 out of 10 partner nationsagreeing to adopt and adapt the UKNational Occupational Standards (NOS) asthe basis for certification of explosivesworkers and, as there have been manychanges in people and structures in Sweden,it was agreed that the aim of the week wasto provide an introduction to the NOS andtheir implementation as the basis ofqualifications and also as management tools.

Seven members of EUExcert SWE and sevenfrom EUExcert UK participated over theweek. My thanks go to all those fromEUExcert UK who put so much time andeffort into providing a well-structuredprogramme that was pitched at exactly thelevel our guests wanted.

Next EUExcert project The final sessions provided the opportunityto discuss the next EUExcert project. Weoutlined our position, that although wehave resisted taking the leadership role forthe next project in the EUExcert Programme,expecting (in concert with other EUExcertpartners) that KCEM will continue to do soand in order that the programme is not seenas UK-centric, we must consider thepossibility that the benefits for sustainabilityof skills in the UK explosives sector andmobility of UK explosives workers requireEUExcert UK to form a project team to eitherlead or support the next phase. All membersare invited to suggest options/models forsetting up this team. The topic of the nextproject was discussed in outline and it is

hoped that it will include partnerparticipation in implementing the NOS to acertain (to be determined) level such as atleast one explosives worker in one or twocompanies in the partner nation havingqualified in a vocational qualification, withthe partner nation and supportingcompany(ies) having created andimplemented policies and processes, usedthe NOS to create Role Profiles and createdand used supporting information systems.

The Chairman of the Board of KCEMdiscussed the leadership of the next projectwith his board in the week beginning 3rdFebruary 2014, with the fallback optionbeing that they should lead a virtual projectteam made up from the partners. At thesame time, the Chairman of the EUExcertAssociation, Chairman of EUExcert SWE andmembers of EUExcert UK considered thepracticalities of writing the bid for fundingthe project in line with the strategy that wasproposed at the final meeting of theEUExcert SWE visit: to bid for funds toenable staff and learner mobility visitsbetween UK and SWE, and other partnernations within the constraints of Erasmus+Key Action 1 and to bid for funds for thenext EUExcert project within the terms ofErasmus+ Key Action 2.

Erasmus+ The Chairman of EUExcert UK and DOES PM(IExpE) attended the Erasmus+ briefingsession in London on 10th December 2013.The UK National Agency for Erasmus+ willbe a consortium led by the British Councilwith Ecorys UK as a key partner. In outline,Erasmus+ has some 14.7 Billion EURO tosupport projects over the period 2014-2020,some 75%+ of which is available for the

EUExcert UK report

presenting backgrounds, along withprofessional firework experience, to engageaudiences of all ages in the applications ofscience. Matthew explained why he hatesbangs for the sake of bangs and some of thechallenges he's encountered so far. Thepresentation also raised interestingreminders about why procurementmanagers and safety managers of explosivearticles should take care when applying‘read across’ from one system to another, asthe smallest of changes can createsignificantly different explosive results. Tofind out more about Matthew, visitwww.matthewtosh.com.

Please get in touch, through the InstituteSecretariat, if you wish to attend any of themeetings or to be added to the emaildistribution list

Rob Hart CEng AIEMA MIExpE Branch Secretary

Certifying Expertise inEuropean Explosives Sector

As a means of celebrating the 40th anniversary of the Institute, theEditorial team created a new competition calling for original technicalpapers/articles for publication in the journal. The competition waspublicised widely both in our journal and others and through leafletsdistributed to selected universities and industries; internationalentries were received over an eight month period. The competitionwas open to all members and to non-members. The prize for eachwinner is a glass tankard and a cheque for £500. It had been intendedto award two prizes for the Member’s category but as the entriescame it became apparent that only one was required.

We selected a judging panel of people who have been involved in theexplosives sector for a long time and, to maintain the independenceof the panel, the judges were not allowed to enter the competition.The judges were asked to grade the articles according to their quality,the technical application, explosives content, layout and interestgenerated by the paper.

The judges wish to commend all the entries but in particular singledout the entries from the Associate Members for the high quality anddepth of the articles. The winning entries in each category are:

Fellows – Ken Cross“Best practice for Commercial Explosive Ordnance Disposal (EOD) inGreat Britain”

Members – Holli Kimble“Critical review of novel detection methods for buried explosives”

Associate Members - Andrew Envy“A cost effective method for preliminary explosive characterisation”

Non Members – Tristan Worsey“D10 dozer recovered from a high wall using blasting”

The winning entries from each category are published in this journaland the remaining entries will be used in future journals at theEditor’s discretion. Papers are published as entered with minortypographical changes.

It is hoped that all the prize winners will be able to attend the dinnerafter the AGM on 1st May to be presented with their prizes.

We are now considering whether to run another journal competitionor to run one in a slightly different form. The subjects for thiscompetition were left fairly open; should we tighten the selection ofsubjects, for instance? If anyone has views about this please let theEditor know.

Details of any future competition, if it is decided to run one, will benotified in the journal.

Institute News

04

Award WinnersCongratulations

to the winners inthe JournalAwardsCompetition -2014

Development officefor explosives skillsAt the time of writing this update I have been fully involvedwith the EUExcert Swedish explosives employers mobility visitto the UK to share best practice and find out how the UKexplosives sector has taken forward the use of ExplosivesSubstances and Articles (ESA) National Occupational Standards(NOS). The trip has included visits to QinetiQ, CranfieldUniversity, ISSEE with presentation by employers, HSQ, AVCTS,Cogent, MPQC and myself, including the use of an excellentpresentation by Air Cdre Mike Quigley to the PARARI conferencein Australia. This explained how the UK and DE&S are tacklingthe ‘Sustaining WOME Sector Skills’ and the SQEP issue (SuitabilityQualified Experienced Personnel) and was well received.

The Sector Skills Strategy Group (SSSG) board will be reviewingthe achievement and outcomes of the DOES project at theirnext board meeting in February 2014 and will be deciding onhow they will take the project forward in the future and keepthe momentum, we will keep you informed. I continue to assistthe SSSG employers via the Expert Working Groups (EWG) tosign-post training opportunities and collaboration of training,as well as my other priority areas.

I have been involved in the HSE EIDAS database workshopslooking at ‘Trials’ and ‘Disposal’ sub-sectors, which have been ledby SSSG Expert Working Groups (EWG) members and willprovide industry with a ‘Lessons Learnt’ database of pastaccidents and incidents, which will be held on the SSSG portalpage.

I can report that the Explosives Apprenticeship frameworks forLevel 2 and 3 are now published and available for use with earlyindications that some employers will start using these fromApril 2014 and others with their September intake.

I would like to remind members about the next Ordnance,Munitions and Explosives Symposium at Cranfield University,Shrivenham - ‘Design for Safety’ which will be held from 30thSeptember to 1st October 2014 and a call for abstracts/papers isbeing made now.

If any IExpE member has any questions, please feel free tocontact me for details.

Allan Hinton FinstLM MCMI MCILT AIExpE DOESProgramme Manager

Email: doespm@iexpe.org or secretariat@iexpe.orgMobile: 07866 429559 Tel: 01785 240154

Institute Awards 2013-2014A call for nominations for the following awards:• MSc Award• Nobel Lecture Award• Harold Swinnerton Award• Rosenthal Salver Award• Examination Award• Journal Award• Student AwardNominations to secretariat@iexpe.org (See page 38).

Institute News

05

Inaugural gathering ofPast PresidentsA lunch will be held on 26th March at the Special ForcesClub in London to reaquaint old colleagues and Presidents.Further details : membership@iexpe.org.

Please note Ken Cross is hoping to arrange a similar eventfor Fellows of the Institute

We thank the Past Presidents and Membersfor their contribution to the success andgrowth of the Institute and look forward tocontinued expansion and professionalism.

Picture taken at an IExpE Council Meeting in January 1985 includes thefollowing Members: Dr Sidney Alford, Brook Foster, Nick Daniels, MarkHatt, Fred Ogden, Jeffrey Rosenthal, Roger Hughs, Bill Fowler, Dr GourSen, not identified, John Butterworth, John Mackenzie, Terry White,Barry Lawe, Terry Digges.

1984. R P Hughes BSc CEngAMIMinE MIExpE.

2004. Charles Moran FiExpE

2010. Ken Cross MBE CEngMSc BSc(Hons) FIExpE

2006. Richard Vann MIExpE

2008. Malcolm Ingry MIExpE

1998. Ian McKay CEng MPhilBSc DipH&S FIMM FIExpE

2012. Alan Morley MSc BScMIExpE

1993. Mike Groves MIExpE.

1985. Fred Ogden FIExpE.

2002. Jim Hackett MIQ MIExpE.

2000. Andy Pettit BSc MScMIMinE FIExpE

1996. Peter McGoff MIMine CEngMIExpE.

1994. Mark Hatt MIPE FIExpE.

1989. Terry Digges FIExpE.

1979. Bill Fowler TD FIExpE.

Ken Broadhurst, MBIM FIExpE, (1987President) congratulates Terry White,BSc CEng MIMinE FIExpE, onbecoming Vice President. Terry wenton to be President in 1991.

Marking the 40th Anniversary of the Institute

Note: Not all photographs of Past Presidents were available.

Institute News

06

The 2014 AGM and Conference will be taking place on 1st and2nd May 2014 at the Westerwood Hotel and Golf Resort(Cumbernauld, Nr. Glasgow, G68 0EW) with the AGM and dinneron 1st May and the Conference on 2nd May.

The theme for the 2014 Conference is “Developing Competencein Explosives Skills”, with various provisional industry speakersalready selected. Should you wish to be considered to present atthe Conference, please contact Dave Welch or Hannah Mellishby calling: 01329 226 156 or emailing events@iexpe.org.

It is proposed that the 2014 programme will remain the same asfor 2013, following a positive response, with a shorter day andan extended open forum after the symposium to allow fordelegate participation. However the conference will commenceslightly later this year at 09.30 to allow consideration forattendees' and presenters' travel constraints.

Thus, outline timings for the programme are below:1st May 2014 13:30 – 15:30 CouncilMeeting1st May 2014 16:00 – 18:00 AGM1st May 2014 19:30 – 20:00 DrinksReception1st May 2014 20:00 – 23:00 AGM Dinner2nd May 2014 09:30 – 15:45 Conference2nd May 2014 15:45 onwards Open Forum/

Networking

All Members of the Institute are entitled to attend the AGM andConference at no cost, other than travel expense and overnightaccommodation. Non-members will find the associated event costson the AGM and Conference Booking Form, which should becompleted by all attendees (including Members) and returned toevents@iexpe.org or via post to Chairman for IExpE AGM andConference, Shogun House, Fielder Drive, Fareham, PO14 1JE, at theearliest convenience. If you require a new copy of the form, pleasecontact Dave Welch or Hannah Mellish on 01239 226 156 orevents@iexpe.org. Accommodation should be booked directlythrough the hotel by calling: 01236 457 171, quoting “IExpE” as areference to obtain the associated discount. As always, partners areencouraged to attend the Dinner and Conference and theirattendance should be detailed on the Booking Form also.

A number of sponsors have already been confirmed, however, thereare packages still available due to the new restructured and tieredlevels allowing for further sponsorship opportunities. Allsponsorship packages are detailed in the Sponsorship BookingForm which can be obtained through Dave Welch or HannahMellish by calling: 01329 226 156 or emailing events@iexpe.org.

07

IExpE AGM and Conference 2014Institute News

SummaryThe changing framework of EOD operationsin Great Britain, especially in the latter partof the ‘noughties’, prompted the HSE to askthe IExpE to write a guidance note oncommercial EOD operations to inform EODcontractors, their clients, the regulators andthe authorities on best practice in the field.In 2009, the HSE published an articleoutlining the challenges that needed to beaddressed. The “Guidance Notes forCommercial Explosive Ordnance DisposalOperations“ is due to be published inDecember 2013 and this paper shows thateach of the challenges is properly addressedand that the final version of the GN achievesits aims.

In short, best practice for commercialexplosive ordnance disposal (EOD) in GreatBritain comes down to EOD organisationsbeing demonstrably competent across allthe requisite skills at all levels of theorganisation, identification of UXO andtherefore the hazards and risks associatedwith them, compliance with regulationswherever possible and offering timelyALARP solutions to the regulators whencircumstances are not covered in theregulations.

BackgroundIn 2009, Paul Rushton of the UK Health andSafety Executive’s Explosives Inspectorate

published an article in the journal of theInstitute of Explosives Engineers entitled“Legal Requirements for Commercial EODOperations”. The intention of his paper was toflag up the issues that commercial EODoperators must address with respect toexplosives licensing, preventingunauthorised access to explosives, and howexplosives may be transported, includingboth the explosives to be used in disposaland the less well characterised explosives tobe disposed of. The paper addressed thebackground to the issue, identified the keylegal duties and raised some questions abouthow the UK might take the issues forward. Indoing this it highlighted four particular

Institute News

Best practice for Commercial Explosive OrdnanceDisposal (EOD) in Great Britain

Award WinnerCategory: Fellows of IExpE

08

By Ken Cross MBE CEng MSc BSc(Hons) FIExpE

PICRITE Ltd, UK

AbstractThis paper outlines the background to, and development of, a newguidance document for contracting and delivering commercialEOD operations in Great Britain. It describes the changingframework for provision of EOD support from MOD-only to a blendof Defence and commercial operators. The booklet ‘GuidanceNotes for Commercial EOD Operations’ is described as providingguidance on best working practices for dealing with potentiallyunexploded munitions discovered on the landmass of Great Britainor in its territorial waters. The Guidance Note is not a substitute forofficially recognised training and qualifications but is intended toassist all involved in fulfilling their responsibilities for the safety ofemployees, contractors and service personnel, as well as the safetyof people living or working in the vicinity of the EOD Operation. It isintended as a reference document for regulators, local authorities,engineering/construction contractors and commercial EODorganisations, to ensure that each understands the roles andresponsibilities of the others.

challenges that UK EOD companies face inmeeting their legal obligations.

The particular challenges identified were:

• Can the UXO be destroyed on-site?• On-site licensed storage.• Is the UXO safe to move or transport?• Carriage to disposal site.

Having presented the paper at the IExpE AGMand published it in the journal, HSE and IExpEobserved that the number of commercialEOD companies was growing to fill the gapsleft as the Ministry of Defence (MOD) waspulling back from its hitherto ubiquitouspresence in all disciplines of EOD across theUK due to its increasing commitments inAfghanistan and its reducing budget. It wasfelt that it was only right and proper toenable the burgeoning companies to havethe best chance of staying on the right side ofthe multi-faceted regulatory requirements byproviding a single guidance note that shouldat least ensure that the directors andemployees of these companies, as well aspotential clients were aware of the relevantlaws and processes involved in conductingEOD in a commercial environment.

The changing EOD frameworkin GBSince before the Second World War, theMOD provided all EOD services forgovernment and police forces across the UK.For some types of clearance, MOD wasentitled to charge the recipient of theservice directly, for example the EODclearance of a scrap yard and in the 1990s itbecame common practice to cross-chargepolice authorities for the provision of pre-emptive EOD cover at major events.

The combination of changes to civilengineering standards and regulations,requiring detailed risk assessments andenvironmental assessments, withconsequent mitigation policies andprocesses incorporated in the project plan,with reducing availability of MOD EODsupport, provided opportunities forcommercial EOD organisations to offer theirservices. In the maritime environment, theMOD moved away from providing regularEOD support to aggregate yards that wouldfrequently find unexploded ordnance (UXO)in the loads brought ashore by theirdredgers. This resulted in the publication inMarch 2010 of a Guidance Note “Dealingwith munitions in marine sediments”1.

The current MOD policy on the provision ofEOD support is that “Defence provides EODsupport to the civil authorities within the UK

under Military Aid to the Civil Authoritiesprinciples2. The geographical dispersal ofand response time for military EOD teams isformally agreed between the Home Officeand the Ministry of Defence in a ServiceLevel Agreement. Defence will respond atshort notice where there is deemed to be athreat to life or potential for unacceptableeconomic damage. Outside these criteria,Defence will clear unexploded ordnance andconsider requests for assisting in theclearance of other types of explosive.However, should there be a realisticexpectation of encountering munitionsduring a commercial operation or privateworking, a competent commercial EODcontractor should be employed. TheMetropolitan Police Service and a number ofUK commercial companies maintain a rangeof EOD capabilities. The latter may also beengaged to support civil authorities.”

It was also around this time that the MOD,along with all other governmentdepartments, began to implement austeritymeasures to reduce the UK’s financial deficit.The austerity measures included makingmany service personnel redundant and, ofcourse, that was expected to include EODoperators who would look to make use oftheir skills in the commercial marketplace.

This prompted the HSE’s concern that suchnew entries to the commercial EOD spaceshould not fall foul of the law, havingworked within a highly regulated andcontrolled environment within the MODthat enshrined the multiple complexregulatory requirements within one or twoJoint Service Publications, or as they areseen by the HSE - ‘Safe Systems of Work’.

What was needed was a guide forCommercial EOD Operations that wouldinform newcomers to EOD provision, thoseorganisations wishing to employcommercial EOD companies, those workingwithin EOD companies and the authorities.

Guidance notes for commercialexplosive ordnanace disposaloperationsThe aims of the Guidance Notes (GN) are:

• To provide practical advice to localauthorities, the emergency services,possible contracting organisations and,EOD contractors on the measures to betaken to reduce the risk to people andproperty when suspected munitions arediscovered.

• To outline the potential risks and safety

measures that need to be considered.• To enable a contracting organisation to

specify EOD Operations as a means toachieving their overall intent.

• To enable a commercial EOD companyto meet the various operational andlegislative requirements demanded of itin conducting EOD operations withinthe United Kingdom.

• To assure the regulator that commercialEOD companies working within the UKknow the framework of explosiveslegislation within which they mustoperate and that implementation ofcommercial EOD Operations complywith that legislation and best practice.

• To outline the procedures to be followedwhen suspected munitions areencountered.

• To remind companies, individuals andorganisation that the risks from theiroperations should be As Low asReasonably Practicable3 (ALARP).

The GN does not relieve individuals,companies or organisation from their duty tomeet the legislative requirements of the Law.

It provides guidance on best workingpractices for dealing with potentiallyunexploded munitions discovered on thelandmass of Great Britain or in its territorialwaters. The GN is not a substitute forofficially recognised training andqualifications but is intended to assist allinvolved in fulfilling their responsibilities for:

• The safety of employees, contractors andservice personnel.

• The safety of people living or working inthe vicinity of the EOD Operation.

Meeting the challengesChallenge 1 - Can the UXO be destroyedon-site?From a risk-reduction perspective, i.e. notexposing more people and property to thehazard than is absolutely necessary, thismust always be the preferred option. Thesimple answer to the challenge is that it willdepend on the location of the site, proximityof surrounding buildings and the nature ofthe UXO. These then are the ‘so what?’questions – what are the hazards associatedwith the destruction of the UXO and is thesite safe and suitable for the destructionoperation?

The GN provides guidance on the conductof site surveys, UXO Risk Assessments, noiseand vibration monitoring and the overallconduct of an EOD operation from planningthrough to remediation.

Award Winner

09

As the subject matter expert (SME), the EODorganisation is expected to be able todemonstrate competency (that combinationof knowledge, experience, skills andattitude) at all levels of the organisation toundertake all the relevant processes andprocedures: site survey, identification ofUXO, siting of disposal area, advising andimplementing mitigation, movement,storage and use of explosives, advising andimplementing remediation.

Training and maintenance of competence isessential to the business and safe conduct ofEOD operations. In order to operate in theUK, all EOD Operators must holdqualifications that are mapped against theNational Occupational Standards forExplosive Substances and Articles (NOS forESA), Key Role 1245 at the level appropriateto the task in hand. It is expected that thesenior EOD operator on site will betechnically qualified and, in order to provideassurance to local authorities and clients ofhis capability to conduct dynamic riskassessments, must hold a recognisedqualification in the management of an EODor Munitions Clearance operation.

EOD can be carried out at many levels - fromthe neutralisation of large bombs andmissiles to the destruction of grenades andsub-munitions. EOD qualifications should beappropriate to the hazard and the munitionsmost likely to be found. As a guide thefollowing levels are appropriate6:

• EOD Level 1. Level One operators arecompetent to locate, identify anddestroy under appropriate supervision,single items in-situ on which they havebeen specifically trained.

• EOD Level 2. Level Two operators arecompetent to locate, identify, move,transport and destroy multiple items onwhich they have been specificallytrained.

• EOD Level 37. Level Three operators arecompetent to conduct render-safeprocedures and final disposal of anytype of explosive ordnance with theexception of specialisations listed underlevel four.

• EOD Level 4. Level Four operators arecompetent to carry out specialist tasks inthe following categories provided thatthey have the relevant training8:- Disposal of specific Guided Weapons;- Demilitarisation of ExplosivesOrdnance;

- Chemical, Biological, Radiological andNuclear weapons;

- Improvised Explosive Device Disposal;- Disposal of weapons with specific fuelhazards;

- Logistic disposal.

Challenge 2 – On-site licensed storage.On a pre-planned EOD operation, there aretwo reasons why an explosives store mightbe required: to store the serviceableexplosives required for the destruction ofUXO on-site or for the temporary storage ofUXO if they cannot be destroyed on the daythey are found. When UXO are disposed ofon the day they are found, no storagelicence is required, however the potential forunforeseen delays should be considered.Delays could be due to finding a largequantity that cannot be disposed of quicklyenough or due to weather conditions oravailability of explosives or perhaps otherfactors external to the site. It is thereforesensible to have a licensed store on the sitewhere UXO may be temporarily kept until itcan be disposed of.

The GN provides an outline of the GBexplosives licensing regime – HSE, Police orLocal Authority, depending on theorganisation’s required holdings. It isincumbent on the EOD contractor to identifya suitable location on the site for anexplosives store in their Method Statementand to arrange proper licensing.

Challenge 3 - Is the UXO safe to move ortransport?This is the most critical question in the EODoperation. As Paul Rushton noted in hisoriginal article “This is only an issue if it isunsafe to undertake the disposal on site. Butit is potentially a very big one”. In actual fact,there are two elements to this: is the UXOsafe to move within the site, i.e. to the on-site disposal area; is the UXO safe to move toan off-site disposal area?

The emphasis in the GN on the competenceof individuals at all levels in the EODorganisation, regular validation ofcompetence and an insistence onidentification of the UXO all contribute toproviding the level of assurance required bythe regulators. This particular issue was themost debated in all the development of theGN but an agreement was reached such thatHSE Explosives Inspectorate (HSE XI) expectsUXO to be destroyed in-situ wheneverpossible and when safe to do so; occasionswhen UXO are moved from the site ofdiscovery should only be considered wherethe risks of on-site disposal cannot bemitigated to an acceptable level. Themovement of any explosive comes with itsown risks and therefore the overridingconstraint is that the UXO has been assessedand is considered safe to transport, this willbe largely dictated by the condition in whichthe UXO is found.

Challenge 4 – Carriage to disposal site.The challenge was originally articulated as“Contractors cannot classify the UXOthemselves, and HSE would not classify UXOwithout test evidence. Classification istherefore not appropriate. However HSE hasthe power to authorise carriage ofexplosives that is contrary to theprohibitions or requirements of the CarriageRegulations. Authorisations must be timelimited, specify the purpose for which theyare issued, and set out the conditions ofcarriage.

“Authorisations have most often been usedto permit the carriage of unclassifiedfireworks from an unlicensed location to alicensed store. Before authorising suchcarriage, HSE needs to be convinced that thecarriage is safe, i.e. that there is no risk ofignition during the transport operation. Forundamaged explosives that are similar toexplosives that have already been classified,this can be relatively straightforward, but forunexploded ordnance of unknowncondition and unknown provenance it couldbe very difficult.”

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Annex D of the GN describes the approval process for packagingand movement of EOD arisings with the aim of providing EODorganisations the process for applying for either an annual permit topackage and move EOD arisings from the site of discovery of anitem of UXO to an off-site disposal area in a pre-planned EOD task,or for a one-off move of UXO in a reactive EOD scenario.

The GN requires that outer packaging must be of wooden or othernon-metallic construction and must display a UN Packaging Codethat shows the package can be accepted for transport. Where this isnot practicable a justification as to the suitability of the proposedpackaging will need to be made. Outer packaging must carryappropriate markings:

• UN Ser 0354, Articles Explosive N.O.S.• Hazard Classification Symbol – 1.1L• Gross Weight• NEQ (Estimate)• Quantity• Name – “Unexploded Ordnance for Disposal by Open

Detonation”• Date packaged

Given the non-standard nature of the UXO, inner packaging must besafe and suitable, i.e. it must prevent the UXO from movementwithin the outer package and must neither add to the effects of anunexpected explosion nor the initiation of such an event e.g. byincreasing the risk of electrostatic discharge. Suitable materialsinclude, but are not limited to: anti-static bubble-wrap, corrugatedcard, polystyrene chips no smaller than combined outer dimensionsof 5cm.

Normal ADR/CDG regulations apply with regard to approved vehicletype, placarding, training of drivers and escorts etc. UXO are not tobe carried in the same vehicle as the serviceable explosives requiredfor their destruction, hence the use of the hazard classification code1.1L. It is recognised that this requirement adds to the logisticburden on the EOD organisation but it is imperative that the hazardof the unclassified, packaged UXO is isolated from other explosivehazards that could add to the overall hazard in the event of anunplanned explosion or fire.

1. ISBN 978-1-906410-14-82. Joint Doctrine Publication 02 (2nd Edition) - Addendum: Operations in the UK: A Guide

for Civil Responders, published February 20103. Defined by Judge Asquith in Edward v. the National Coal Board (1949) as “ ‘Reasonably

practicable’ is a narrower term than ‘physically possible’, and seems to me to imply thatcomputation must be made by the owner in which the quantum of risk is placed on onescale and the sacrifice involved in the measures necessary for averting the risk (whetherin time, money or trouble) is placed in the other, and that, if it be shown that there is agross disproportion between them – the risk being insignificant in relation to thesacrifice – the defendants discharge the onus on them.”

4. http://www.cogent-ssc.com/education_and_qualifications/NOS.php 5 http://www.homelandsecurityqualifications.co.uk/wp-content/uploads/2010/03/ESA-

NOS-KR-12-Munition-Clearance-Search-interactive-version.pdf 6 CWA 15464-1, Humanitarian Mine Action - EOD Competency Standards - Part 1: General

requirements7 CWA 15464-5, Humanitarian Mine Action - EOD Competency Standards - Part 5:

Competency for EOD level 38 CWA 15464-4, Humanitarian Mine Action - EOD Competency Standards - Part 4:

Competency for EOD level 4

Further information: kencross@picrite.co.uk

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Editorial Programme –2014-2015

June Quarrying & mining

Major Majendie and the Explosives Act of 1875

September Pyrotechnics, special effectsand forensics

December EOD/IEDD and area clearance

March SOLAS (Safety of Life at Sea)equipment

Explosives used insafety equipment

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Critical review of novel detectionmethods for buried explosivesBy Holli Kimble MEng MSc MIExpE, Ministry of Defence.

AbstractA critical review of different optical andolfactory methods for the detection of buriedexplosive devices shows that none of the novelmethods examined are likely to yield a goldensolution. The combination of honeybeepassive sampling and bioreporting bacteriacould be used to detect a range of devicescontaining different explosives. It is ofteneasier to detect by-products of manufacture,decomposition products or taggants addedduring manufacture, and many of the noveltechniques search for these chemical clues.

IntroductionThe detection of emplaced explosives isbecoming increasingly important to ensurethe security of the British population, civilianand military, at home and abroad.Technology is being developed in a numberof different branches to identify the threatsfaced in specific areas such as in airports, oldminefields or the improvised explosivesdevices (IEDs) faced in-Theatre.

This critical review focuses on developingtechnologies that could be used to detectburied devices (mines and IEDs). Detectiontechnologies will be broken into two mainareas: optical methods and olfactorymethods. Of particular interest aretechniques that indirectly detect explosivesby searching for compounds that are onlyfound in the presence of explosives (and aregenerally easier to detect).

BackgroundOne major issue with the detection of mostmilitary explosives is that they have lowvapour pressures (meaning that a lowamount of gaseous emissions are released innormal atmospheric conditions), makingthem hard to detect outright. Despite thelow vapour pressure of explosives, there areoften by-products of manufacture that havea significant vapour pressure.1 This meansthat the best way to detect a given explosivemay be to search instead for a more easilydetectable compound related only to theparticular explosive (manufacture by-product, decomposition product ortaggant). This is possible for trinitrotoluene(TNT), where a by-product dinitrotoluene(DNT) has a higher vapour pressure and ismuch easier to detect. Explosives with a lowvapour pressure tend to linger for longerperiods of time than high vapour pressure

substances, so if an object or a surface hasbeen in contact with the explosive, it can bedetected for longer.2

Taggants are added to compounds to allowthem to be detected and identified – theytend to be volatile and very difficult tomanufacture. They are only associated withexplosive compounds, making them asgood, if not better, for detecting militaryexplosives than the low vapour pressureexplosive. Taggants can also be added tomake explosives difficult to replicate,showing that they have been made outsidea qualified laboratory. They are addedduring manufacture and as they are anintended additive, the detection methodcan be developed alongside the taggant toensure adequate detection.3

Explosive compounds have a tendency todecompose over time. Often thedecomposition products have higher vapourpressures than the explosive, so searchingfor these products is a common method ofdetecting the presence of an explosive.

Conventional explosives detection requireseither direct contact or the ability to closelyapproach the target being sampled.4 Someof the novel methods examined have theadvantage that they have been developed,or have the potential, for stand-offdetection, thereby reducing the risk topersonnel and equipment.

Optical methodsLuminescence-based methods of explosivedetection cover a range of novel opticalmethods. Explosive compounds are notnaturally fluorescent and in order to detectexplosives using fluorescence, one can makean explosive compound fluoresce; induce a

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chemical reaction causing fluorescence;quench the fluorescence of otherfluorophores or cause fluorescent excitationin other species.5,6

While explosive compounds are notinherently fluorescent, it is possible to excitethem with high-energy x-rays or gammarays. High energy X-ray fluorescence (XRF) isa technique which can be used to identifyTNT, RDX, PETN, CE, C4, Comp B, blackpowder, smokeless powder, flash powderand ANFO.[7] Blair and Poteet also claim thatthe method is not affected by wind orvegetation and that it is currently possible todetect these explosives from a 2m stand-off.Nitrated explosives can be used in a redoxreaction with other compounds to producehighly fluorescent species.3 The majordrawback to this method is that it is alaboratory-based experiment – the amineproducts of the redox reaction must becombined with a solution containing aRubidium compound (there are numerousmethods) which must then be reduced toform the fluorophore. This is impractical inthe field as it requires handling of theexplosive and therefore knowledge of wherethe devices can be found. It could be auseful identification tool, however, it is time-consuming and the chemicals involved areexpensive.

Another direct luminescence method is toinduce the decomposition of an explosiveresulting in the formation of NO thatfluoresces under UV stimulation, thisfluorescence can then be measured todetermine the explosive. Detection isreported to be possible in the laboratorysetting,5 but is not sensitive enough for usein the field. It is also difficult to detect RDXand PETN using this method, as they bothpreferentially decompose to NO2 ratherthan NO. At present, this technique does nothave the versatility to detect buriedexplosives.

An indirect method of detecting thepresence of explosives is a fluorescencequenching method, where the fluorescenceof a fluorophore is reduced by the presenceof an explosive. It has been noted that thedecrease in fluorescence is proportional tothe concentration of the explosive. Thistechnique is not of practical use at this stage– there are currently requirements forsolution or solid phase explosives andfluorophores, making this unsuitable fordetecting buried explosives and thismethod is limited to the detection ofnitrated explosives, so it would be necessaryto know the type of explosive used in the

buried devices before attempting to detectthem. Future developments could lead to ausable detection method if the quenchingcan occur with vapour-phase explosives. Ageneral idea of the location for the devicewould be needed before this short-rangetechnique could be used.

A crossover between optical and olfactorymethods is the use of bioreporter bacteria:the genetically engineered bacteria detectcues from the presence of an explosive andtranslate this in a visual way (as do dogs)which humans can detect. Two differenttypes of glowing response have beencreated: bioluminescence, the production ofvisible light by the bacterium; andfluorescence, a green glow in response toUV stimulation.6 The mechanisms are verydifferent and the bioluminescence isrelatively weak and requires sensitivedetection equipment. The fluorescence iscreated using a protein found in a species ofjellyfish which fluoresces under UV light, theglowing response turns on and off with UVexposure, allowing the distinction betweenthe glow of the bacteria and ambient light.As shown in Figure 1, the bacteria can begrown in large drums and then sprayed overa suspected buried explosives site, oncenight falls, a UV light can be used to induceregions of fluorescence which correspond toa buried device. The UV lamp can only beused at night, or the glow will not bedetectable by eye, it may also be necessaryto use an electronic detector to see theglow. The bacteria only fluoresce in thepresence of one explosive, however, it is notinconceivable that a batch could be grownwhich contains several different types of

bacteria suited for different explosives.Currently, it is also not possible to usegenetically modified bacteria without verystrict control, making it unlikely that suchtechnology would be readily embraced.

One major implication with the use of thistechnology is that the rough location ofnumerous devices (i.e. a minefield) is known;it would not be appropriate to begin coatingthe entire countryside with bioreporterbacteria and then sending out an army tosearch the area by night. This method alsohas limitations in detection based on theprobability of slow release of the chemicalsto the surface from buried devices – thismakes it useful for humanitarian de-mining,but may reduce the tempo of militaryoperations.

The novel optical methods examined arelargely at the laboratory testing stage, andthe majority would be unsuitable for thedetection of unknown buried explosives asthey are only able to detect specificexplosive compounds. Another severelimitation in their use would be the lack ofstand-off detection; only the XRF andbioreporter bacteria techniques have astand-off which may be of use. The use ofelectromagnetic waves in the detection ofexplosives avoids disturbance byenvironmental factors such as wind,however, detection is only possible for abare charge at the surface as although the x-ray may penetrate to a depth, the responseis not likely to be visible from a buried, caseddevice. The bioreporting bacteria show mostpromise of the optical methods examined,but the sensitivity of such bacteria would

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Figure 1: Procedure for explosive detection using bioreporter bacteria6.

require testing to see how long it takes afterburial before the bacteria can detect theexplosive. In the longer term, a brighterglow or variety of colours to indicatedifferent explosives may increase the utilityof this technique.

Olfactory methodsSniffer dogs are certainly the best knownolfactory method of explosives detectionand have been used in a military settingsince 1971 by the US Air Force.2 It is still notfully understood how dogs sense thepresence of explosives, and the performanceof dogs against modern sensing equipmenthas not been fully tested. There are pros andcons to the use of dogs compared toequipment in detection, including:

Training – the dog requires long andexpensive training to detect explosives. Ahuman must be trained for many years todevelop the technology required to detectexplosives, an operator must then be trainedwho must take the equipment to the frontline (if possible).Mobility – dogs are highly mobile;specialised vehicles exist to transport thedog and handler to the required location,the dog can move on its own once it reachesthe site, it can follow plumes of vapour tothe source with its nose without delay. Mostdetection systems are not man-portable,many require samples, and others are onlyable to detect a single explosive withoutlengthy recalibration. Some detectionsystems are more accurately identificationsystems which give a negative result unlessthe target explosive is present; dogs can betrained to detect many explosives.Calibration – machines and dogs bothrequire recalibration. In both cases, effortmust be made to ensure that the calibrationsamples do not become contaminated withother substances, explosive stocks arenormally replaced yearly for this reason.2

Reliability – dogs are limited to working forbrief durations, as they may have attentionand sensitivity issues after longer shifts.Dogs are also unable to communicate thetype of explosive they have detected.Detection equipment may have otherreliability issues, likely to involve sensitivity.Sensitivity – difficult to compare, as dogsand machinery may not be detecting thesame substance, but dogs are able to detectcertain explosives in the parts per trillionrange in a laboratory setting2 and detectorequipment ranges from similar detectionlimits to a requirement for higherconcentration. Dogs do not have to decide

which type of explosive they are samplingfor before setting out – this is a majordrawback to most portable detectionequipment.

The use of dogs is well established, but thereare questions over the accuracy of canineolfactory detection. The development ofelectronic noses known as “sniffers” is tryingto harness the power of detection in ascientific measurement device. It is heldback, however, by a lack of clearunderstanding of exactly how a dog is ableto detect the presence of an explosive – wejust know that it can. Much research is goingon to establish the mechanism for detection.

A downside to the use of dogs is that thisvaluable asset must be within the dangerzone of an explosive device in order tocommunicate its location; this leads to ahigh risk to an asset that is difficult toreplace.

The immediacy of feedback for caninedetection is a huge advantage over the useof electronic equipment which can takeminutes to process data to determinewhether an explosive is in the vicinity. Thismakes real-time use of sensing equipment aproblem, as sensing equipment for stand-offdetection could potentially be flownthrough the area of interest, but this is not alikely solution for systems with slowprocessing.

Another olfactory method of detectionbeing developed involves the training anduse of honeybees. There are passive andactive methods with honeybee detection.

Passive – based on the principle that thereare 45,000 to 60,000 bees in a colony

making thousands of foraging trips eachday, covering around 2km2,4 the bees comeinto contact with anything in that regionand return to a fixed hive location. Samplingat the hive allows a snapshot to be taken ofany explosives present in the vicinity of thehive. The method behind locating anexplosive device relative to a number ofhives is shown in Figure 2, where the closerhives become most contaminated.

Active – bees can be trained to search forexplosives (liquid, solid, vapour, particulate).Bees could be effective in the detection oflandmines4 as 90% of landmines have TNTas the main filling, a decomposition productof which is the more easily detectable DNT.Training a bee uses similar methods totraining a dog – conditional training, wherebees learn to associate a particular odourwith a reward. With a dog it may take manymonths to train, whereas bees can betrained on-site and sent out to search in thesame day.

A nectar feeder is set up close to the colonyand a sample of the explosive to bedetected in placed within 6 inches of thereward. The bees then associate the scent ofthe explosive with the reward of nectar. Dueto the foraging nature of bees, they willbegin to search for other locations with thatodour and will gather at areas where theydetect that odour. Experiments performedby Sandia National Laboratories discoveredthat if bees from a trained hive finduntrained bees from a different hive, theywill teach them to associate the explosiveodour with the reward and thereby recruitother bees to search for the explosives. Fieldtrials have been performed which show thatthe bees prefer to visit nectar targets thathave the explosive residue nearby rather

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Figure 2: Detection of explosive using passive detection by honeybees.

than ordinary nectar. The concentration forthe targets was between 0.74 and 0.8 ppb.4

Detection of explosives using honeybeesshows promise – compared to dogs they arecheaper to train or replace, do not require ahighly trained handler and are effective atdetecting explosives at low concentrations.They are only sensitive to the explosive thatthey have been trained to detect, and it isunlikely that bees could be trained to detectnumerous explosives (including taggants orby-products), so there would be limitationsto their detection capability in a real-worldscenario involving unknown explosives inunknown locations. Bees do not fly at night,in the rain or in cold weather,1 they mustalso be taken to the area of interest. Withthis in mind, honeybees could not be usedon their own as an effective method ofdetection. Another drawback to the use ofbees is tracking them – it has been proposedthat tiny radio transmitters could beattached to bees to report where theylanded (Figure 3).1 The utility of radiotransmitters seems unrealistic, as there arethousands of bees in a colony and any oneof those bees is disposable as this detectiontechnique is based on foraging behaviour.Another limitation to this technique issimilar to many others – the time taken for aburied explosive device to leak detectabletraces to the surface, though the sensitivityand mobility of bees is an advantage in thiscase.

Although cheaper and easier to train thandogs, bees are limited to the detection ofone explosive at present and it is notpossible to direct them to a suspectedsource as it is with a dog. The passivemonitoring of an area could be useful todetect changes in the chemicals present anddetect explosives in an area. It is alsopossible that bees passing to and fro in anarea would go unnoticed, whereas the

trained bees may amass in an area and drawattention to themselves and this method ofdetection, leading to spoofing attempts.

ConclusionThe detection of buried explosive devices iskey. In order to improve on currentcapabilities, it may be necessary to embracesome of the novel technologies that areemerging in this sector. As can be seen fromthis review, none of the methods examinedwould be suitable on their own, but acombination of techniques may yield animprovement.

The passive detection using honeybeescould be combined with specific detectionusing bioreporter bacteria. This combinationcould improve the accuracy and theefficiency of resource usage when comparedto either of these techniques alone. It wouldallow a sweep of a wide area and wouldprovide a more focussed region to targetwith the bacteria – thus reducing bacteriaand manpower detection requirements.

In general, the examined optical techniquesare slow, bulky and unsuitable for militaryuse in the detection of explosives, however,as the sensing technology improves, manyoptical methods could be used to detectexplosives at a greater stand-off, reducingthe risk to personnel. These methods arealso expensive, meaning that they aregenerally out of reach for both civilian andmilitary applications at this point.

The olfactory techniques include the use ofdogs, which are currently the best methodfor the detection of explosives. It isimportant to note that there may come atime when the benefits of using novelsensing equipment outweigh thelimitations, but at this point in time, theflexibility of canine detection is superior tothe expensive, bulky and (comparatively)

slow equipment on offer. The instantprocessing, sensitivity at range and mobilityof dogs are their greatest advantages, soefforts focussed on fast, lightweight stand-off detection would close the gap.

Bibliography[1] Guill, J., 2009. The Nose Knows: Developing

Advanced Chemical Sensors for the RemoteDetection of Improvised Explosive Devices in2030. US Air Command Staff College, Maxwell AirForce Base, Alabama.

[2] Beveridge, A., ed. 1998. Forensic Investigation ofExplosions. London: Taylor & Francis.

[3] Leahy-Hoppa, M., Fitch, M. and Osiander, R.,2009. Terahertz spectroscopy techniques forexplosives detection. Analytical andBioanalytical Chemistry, 395(2), 227-257.

[4] Rodacy, P. et al, 2002. The Training andDeployment of Honeybees to Detect Explosivesand Other Agents of Harm, Detection andRemediation Technologies for Mines andMinelike Targets VII, Orlando, Florida, USA, April2002. SPIE Vol 4742.

[5] Meaney M. and McGuffin V., 2008.Luminescence-based methods for sensing anddetection of explosives. Analytical andBioanalytical Chemistry, 391(7), 2557-2576.

[6] Kercel, S.W. et al, 2007. Novel Methods forDetecting Buried Explosive Devices, (CONF –970465 - - 8). Oak Ridge, Tennessee: Office ofScientific and Technical Information.

[7] Blair, H.M. and Poteet, W.M., 2000. Proc SPIE IntSoc Opt Eng 4129:494-502

[8] Layton, J., 2007. How can you train honeybees tosniff for bombs?,http://science.howstuffworks.com/bomb-sniffing-bees.htm

Further information: Holli.Kimble994@mod.uk

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Figure 3: Honeybeesready to be fitted withradio transmitters8.

IntroductionExplosives safety and performancetestingWhen an explosive formulation is beingdeveloped for whatever purpose theformulation is required to undergo a largevariety of testing to establish the explosivesafety and performance characteristics ofthat particular formulation. A performancetest is required to bridge the gap betweenthe safety and performance testing onexplosive to provide approximateperformance data prior to upscale inproduction. It is important that performancetesting is carried out on new explosiveformulations and even on new batches ofold material manufactured to a newspecification. The tests carried out for thispaper are a combination of two tests, thecylinder test, and the flyer plate test, fromthese tests several performance propertiesthat can be measured including velocity ofdetonation (VoD), brisance, detonationpressure and the JWL equation of statevalues.

The cylinder test, as described by Suceska19951, consists of a hollow copper cylinderfilled with an explosive down its entirelength detonated at one end and thedetonation wave runs down the cylinderforcing the copper wall outwards. Thedisplacement or velocity of the expandingcopper wall is recorded with respect to time.

The flyer plate test, as described by Suceska19951, consists of a explosive material beingdetonated while in contact with a metalplate. The velocity of the metal plate is thenrecorded and the detonation pressure, PCJ,can be calculated.

This is a report about the development of aone-shot test to determine the performanceproperties of an explosive at a smaller scaleof production, which will highlight if theexplosive being tested has the desiredperformance properties before a costly upscale in manufacture. The test being

developed is essentially a small scale, costeffective combination of the cylinder testand flyer plate test. An array of diagnosticswill be used to measure the velocity-timehistory of the expanding cylinder wall and ofthe flyer plate, positioned at the oppositeend of the tube to the detonator, and thevelocity of detonation of the explosive. Thedata recorded from these outputs can thenbe manipulated to give a good indication ofthe explosive performance properties of anexplosive. This report will look at the effectthat variations in the density, with respect tothe percentage of the maximum theoreticaldensity of the explosive that is achieved, andstandoff between the outer diameter of theexplosive cylinder and the inner diameter ofthe copper tube have on the resultsachieved by this type of test. These two testsare carried out in an attempt to understandhow a small assembly or manufacturingerror can affect the results during this typeof test.

Experimental methodsExplosive formulationThe explosive composition that was usedduring the development of the Mini cylindertest was a HMX based explosive that will benamed Composition A for the purposes ofthis report. The composition is made up of90% HMX, with energetic plasticiser. Thisexplosive has been well characterised in thepast using standard cylinder tests makingthis the ideal explosive to use to developthese tests as this will give some indicationas to whether the Mini Cylinder Test isproducing comparable data.

The cylinders were filled with seven 10mm(nominal) diameter and length pressedpellets of three different densities of 98.5%,97% and 95% (densities are given withrespect to the theoretical maximum density,TMD, of the explosive composition).Following the pressing of each pelletdimensions of the pellets were measured

using a micrometer. Due to availability ofmaterial only enough pellets for two shotsof the 97% and 95% TMDs were pressed butit was decided that this would still provideenough data for a comparison with the98.5% TMD pellets.

After the pressing and metrology stage ofthe explosive pressing were complete thepellets density was measured accuratelyusing the Archimedes method. Table 1shows the statistical analysis of the pelletdensity measurements.

The pellets were then cooled and insertedinto the hollow copper cylinders, seven percylinder. Cooling of the pellets was donedue to the interference fit between thepellet and the cylinder wall, the coolingshrinks the pellet and allows for insertioninto the cylinder.

Figure 1 shows how a gap is introducedbetween the copper cylinder and theexplosive pellet.

Figure 1 Image of gap between pellet and cylinder

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A cost effective method for preliminary explosive characterisationBy Andrew Envy BEng AIExpE, AWE Aldermaston

Nominal Average Range Standard deviation

95% 95.39% 94.57-95.95% 0.5%97% 97.35% 96.57-97.75% 0.32%98.5% 98.44% 98.12-98.71% 0.12%

Table 1. Statistical analysis of the pellet density measurements.

Pellet

Cylinder wall

Pellet

Gap

Cylinder wall

No Gap

Gap

The cylinders that were made for the gaptests had the internal diameter increased to10.1mm and 10.2mm for 0.05mm and0.1mm gap respectively. To ensure thatthere is a consistent gap between the pelletsand the cylinder the pellets were insertedalong with 3 equally spaced 2mm widestrips of shim.

Experimental set upThe experimental rig was made from lasersintered rapid prototype material. Thismaterial was chosen for its high strengthand low weight properties, while also beingcost effective. Figure 2 shows a picture ofthe engineering model of the experimentalrig while Figure 3 shows a picture of theexperimental rig in position in the firing chamber.

Figure 2. Engineering model of experimental rig.

Figure 3. Photograph of experimental rig.

detonation of the explosive being tested isalready known therefore the resultsgathered by the probes can be compared tothe known V.o.D. giving an idea of theaccuracy of the results.

ResultsCopper wall expansionFigure 5. Spectrogram of shot 2 radial velocity.

Figure 5 shows a spectrogram of velocityplotted against time for the data taken fromshot 2, due to the programming constraintsthe axis label cannot be increased in size.

Figure 6 (over page), is a graphicalrepresentation of the spectrogram, thefollowing are key points taken from theresults.

• It can be seen that the velocity risessharply at the initial point of movement,climbing to a velocity of approximately700-800m/s almost instantaneously as theshock front from the detonating explosiveimpacts the inner wall of the cylinder.

• At this point a characteristic of thecylinder test radially expanding cylinderoccurs where the velocity of the cylinderdecreased sharply for a short time beforerapidly increasing again. This is called pullback and occurs 5-7 times while the shock

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Space for boosterDet holder

Flyer plate

Det holder

Copper cylinderfilled with HE

HetV Probeposition

The prefilled copper cylinders then alignedwith the laser diagnostics and the velocity ofdetonation probes and initiated in the firingchamber by a Number 8 detonator andtetryl booster added to the set up directlyprior to firing.

Each test was designated a number from 1to 13, Table 3 shows the numberdesignations.

Test Number Test Type1-3 98.5% TMD, close wall4-6 98.5% TMD with 0.05mm gap7-9 98.5% TMD with 0.1mm gap10-11 97%, close wall12-13 95% TMD, close wall

Table 3. Test numbers.

DiagnosticsHeterodyne velocimetryThe primary diagnostic that was used during these experiments was theHeterodyne Velocimetry (HetV)laser diagnostic. HetV is a laserdiagnostic that directly measuresthe velocity of a moving reflectivesurface. This is achieved using acontrol signal along with thereflected signal from the movingtarget, the change in frequencyfrom the reflected signal, due to theDoppler shift, is mixed with thecontrol signal causing a ‘beatfrequency’. This beat frequency isrecorded and used to determine thevelocity of the moving surface, asdescribed by Bowden 2007 2.

For these tests the two channels of HetVwere used, one channel was used tomeasure the radial expansion of the coppercylinder and the other was used to measurethe free surface velocity of the brass flyerlocated at the bottom of the cylinder.

Velocity of detonation probesTo accurately measure velocity of detonation(VoD) down the copper cylinder a line ofionisation type probes, spaced approximately1mm from the cylinder wall, was positioneddown the length of the cylinder wall. A 32pin ribbon cable was used to perform thistask, as shown in Figure 4.

By knowing that each probe was spaced1.5mm to the next probe and the time atwhich the probe was impacted the resultscan be plotted on a position-time graph andthe gradient of the line of results producedis the velocity of detonation. The velocity of

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Figure 4. Velocity of Detonation probes prior to firing.

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It has been found that the pedigree materialfor the shims of 5mm and 10mm thicknesscould not be guaranteed and it could becopper, this will affect the calculation of thedetonation pressure. Below the detonationpressure is calculated for both materials.

Figure 8. Free surface velocity graph thickness of shimversus velocity.

By extrapolating the polynomial curve fittedto the data back to zero it is found that thefree surface velocity of the explosive isfound to be approximately 2274m/s. Theparticle velocity is known to be half of thefree surface velocity of the flyer, this canthen be inputted into equation 2 below.The equation for shock hugoniot for brass isgiven below [4]:

(2)

The equation for shock hugoniot for copperis given below [4]:

(3)

The shock velocity can then be used withremainder of the known variables forequation 45 below is known and thedetonation pressure can be calculated.

(4)

calculate show a value higher than that evenof pure HMX (2970m/s). The Gurneyconstant therefore cannot be used reliablycalculated when there is a gap betweenexplosive and cylinder wall.

Flyer plate velocityOnly the peak (free surface) velocity wasneeded for the analysis of the flyer plateresults, seen in Figure 7 at the top of thevelocity spike.

Table 5. Shows the peak velocities read from thedigitisation of the spectrograms.

Figure 8 is a plot of velocity and shimthickness. The value taken for the 2mm shimis the average of the values recorded forshots 2, 4, 8 and 9. The values for these shotswere used because the quality of the datarecorded was superior.

wave reverberates through the cylinder asthe cylinder accelerates. This effectdiminishes as the shock reflections losetheir energy.

• Once the cylinder has accelerated rapidlyfor approximately 2µs the velocity beginsto rise less steeply and plateaus to itsmaximum speed. The maximum velocity isdependent on a number of factorsincluding the gurney constant of theexplosive and the confinement of theexplosive within the copper material.

Gurney constantEquation 13 shows the Gurney equation fora thin walled hollow cylinder filled withexplosives.

(1)

Gurney equation for a cylinder.

The final peak velocity of the cylinder can beused to calculate the Gurney constant of theexplosive. Table 4 shows the Gurneyconstants calculated from the data.

The Gurney constants show that for the highTMD, close wall tests the Gurney constant isconsistent with PBX 9404, an explosivesimilar to that of composition A. However forthe tests with gaps the Gurney constants

Figure 6. Digitised results for shot 2 radial velocities.

Time (µs)

Dis

plac

emen

t (m

m)

Velo

city

(ms-

1 ), A

ccel

erat

ion

(ms-

1 µs-

1 ) Velocity

Acceleration

Displacement

Shot 2 3 4 5 6 7√2E (m/s) 2813.47 2866.92 2911.84 3096.79 2802.29 3032.15Shot 8 9 10 12 13 PBX 9404√2E (m/s) 2813.47 2866.92 2969.39 2750.58 2940.62 2900

Table 4. Gurney constants calculated from experimental data.

Figure 7. Spectrogram for shot 3 flyer plate velocity.

Shot ID Thickness Peak Free (mm) Surface Velocity (m/s)

2 2 1945

3 5 1478

4 2 1927

5 10 839

6 2 1678

7 2 1784

8 2 1924

9 2 1951

10 2 1875

12 2 1784

Flyer thickness (mm)

Velo

city

(m/s

)

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result is that this means that the explosivesfor this type of test do not need to bepressed to as high a TMD as possible usinghigher temperatures and isostatic pressuretechniques reducing cost and timeconstraints.

Shots 7-9 are the results of the intended0.1mm gap test. The main differencesbetween the 0.1mm gap shots and no gapshots are:1. The already discussed stronger

reverberations, especially on the firstthree ‘pull backs’. The velocity of the initialrise in velocity prior to ‘pull back’ is alsohigher for the 0.1mm gap shots.

2. The cylinder wall appears to level off at ahigher velocity for the gap tests. Thishappens for all three of the gap tests andseems to be higher than the no gap testsby approximately 50-75m/s.

There are two reasons why the cylinder wallvelocity has increased for the gap tests. Thefirst theory involves the gurney constantequation for explosively driven cylinders,Equation 1. The cylinder wall thickness wasreduced as the outer diameter of thecylinder will have remained the same for alltests while the inner diameter was increasedto allow for the gap. This decrease in wallthickness would increase the velocity of thecylinder wall according to the Gurneyequation.

DiscussionRadial expansionIn order to compare the early expansiontime of the different types of test thedigitised cylinder expansion data is plottedon Figure 10 with separated time bases.

The first thing that can be seen from theresults that have been recorded is that thedata from these tests are very consistent andreproducible. All of the results from eachtest show a sharp instantaneous rise to thefirst ‘pull back’ with a consistent number of‘pull backs’ of diminishing strength beforethe copper wall velocity levels to a constantvelocity of between approximately 1650 and1850m/s. With the exception of the 0.05mmgap shots the traces from each of thedifferent types of shot almost overlay eachother showing very good reproducibility.The results for shot 2 show that there wereweaker reverberations between this shotand that of the gap type tests. Althoughthere does seem to be some enhancementof the reverberation for the gap shots themost likely reason for apparent lack of ‘pullback’ is lack of resolution due a smallmisalignment of the laser during set up.The effects of small density variations in theexplosives observed by these tests are small.The rise to similar peak velocities with thetraces for the lower densities being shownon the same time base show very littlenotable difference. The significance of this

Brass Copper

up 1.137km/s 1.137km/s

ρm 8.3g/cc 8.96g/cc

Us 5.34317km/s 5.62687km/s

ρ0 1.84g/cc 1.84g/cc

D 8.75km/s 8.75km/s

Pcj 34.35GPa 37.81GPa

Where:

Table 6. Detonation pressure calculation.

The results recorded from these testsalthough not without error have proved thatthis method works. The literature value forthe detonation pressure of this explosive is38GPa6 putting the detonation pressurescalculated above within 10% of the actualvalue.

Velocity of detonationThe data from the velocity of detonationprobes were recorded using a logic analyserthat detected the completion of the circuitfor each probe as the copper impacted theprobes. The time of arrival of each signal canthen be plotted as shown below in Figure 9.

Figure 9 Velocity of detonation results for shot 1

The velocity of the advancing detonationwave as it accelerates the copper cylinder isthe slope of the curve fitted to the data, asshown in Figure 9. Table 7, below, shows thevalues of the velocity of detonationobtained using the gradient of the curve.

Shot Velocity of detonation (km/s)

1 8.496

3 8.952

9 8.595

10 9.798

11 9.115

12 7.701

Known V.o.D. ~8.7-8.8

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Table 7. Velocity of detonationresults for all tests.

Figure 10. Variable time visualisation of the radialvelocities for all shots.

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batches of the same explosive material orto directly compare with other explosivematerials.

• The effects of a gap and of lowerdensities were studied and comparedwith data for no gap at a maximumvelocity. It was found that for thedifferences in density that the explosivematerial was pressed to be negligiblemeaning that the method of pressing canbe relaxed reducing the costs. The gapproduced interesting data that warrantsmore research to be carried out, theincreased ringing of the cylinder duringexpansion and the higher velocity aretwo effects of note.

• The loss of control over some of the testcomponents lead to some inaccuracies inthe results. These included the materialchoice of the flyer shim.

References1. Suceska, M. (1995), Test Methods for Explosives,

Springer-Verlag New york.2. Bowden, M.D. And Maisey, M.P. (2007)

Development of a Heterdyne Velocimeter Systemfor use in the Sub-Microsecond Time Regimes,Proceedings SPIE – The International Society forOptical Engineering, 7162.

3. Cooper, P. (1997) Introduction to DetonationPhysics, Contained within Explosive Effects andApplications, Edited by Zukas, J. A. And Walters,P. Springer-Verlag New york.

4. March, S.P. (1980), LASL Shock Hugoniot Data,University of California Press.

5. Stennett, C. And Goldsmith, M. (2011),Diagnostic Methods for DetonatorCharacterisation, Cranfield University DefenceAcademy Project Report, Reference:DEAS/CS/1608/11-v1.1.

6. Merchant, P.W., White, S.J. And Collyer, A.M.2002. A WBL-consistent JWL equation of statefor the HMX-based explosive EDC37 fromcylinder tests, AWE Aldermaston TechnicalReport.

7. J. W. Ferguson, Internal communication, July2013

8. Ferguson, J.W. And Taylor, P. 2013 Application ofHeterodyne Velocimetry and pyrometry asdiagnostics for explosive characterisation,American Physical Society conference on ShockCompression of Condensed Matter (APS SCCM)Seattle 2013.

Further information: andrew.envy@awe.co.uk

test. The release of the pressure at an earlierpoint means that the copper is being drivenharder for longer in the standard cylindertest.

Velocity of detonationThe results from the V.o.D. probes were notcompletely accurate but the method forobtaining the V.o.D. used on these tests issound and with some refinement in themethod in future tests better data will berecorded.

Considerations for future workThe tests carried out for this paper are agood start for the ‘A Cost Effective Methodfor Preliminary Explosive Characterisation’. The methods used in the tests are sound butcould be improved on in the following ways:

• The method used for measuring thevelocity of detonation of the explosivematerial needs to be improved upon.

• The explosive rig needs to bereengineered to aid in the positioningand alignment of the HetV diagnostic, alot of time was spent carrying out thisoperation and at times still provided lessthan perfect results.

ConclusionsThis work has shown:• That scaling down or miniaturising the

cylinder test can be used as a ‘A CostEffective Method for PreliminaryExplosive Characterisation’. The dataproduced has proved to be repeatableand in good agreement with the resultsseen on standard cylinder tests. Althoughthe results are not 100% accurate themini cylinder test could be used as ascreening test as a comparison toprevious data recorded for previous

The second theory is that as the air gapbetween the explosive and cylinder wallallows the detonation wave to straightenradially decreasing the vertical componentof the velocity and therefore increasing theradial velocity.

Comparison with standard cylindertest resultsAn important test as to whether it truly givesa rough reflection of the standard cylindertest is to directly compare the radialexpansion history recorded by the minicylinder with that of the standard cylindertest for the same material. Figure 11 showsthe radial expansion history from shot 2 ofthe mini cylinder tests plotted on the datafrom a standard cylinder test for the samematerial. The data provided for Figure 11was taken following a privatecommunication with Dr Ferguson, the datawas presented at A.P.S. Conference in 2013by Ferguson et al 7,8.

The graph shows radial velocity on the y axisand displacement of the cylinder along the xaxis. As can be seen there is goodcomparison between the two results, thetwo don’t completely overlay but there arereasons for the discrepancies seen. These arein the main part due to the thicker wall ofthe copper in the standard cylinder test asthe material properties of the copper have amore prominent affect on the results. Ahigher peak velocity is observed from thestandard cylinder test. The most likelyreason for the higher velocity is that thethinner copper wall will break up earlierthan the thicker standard cylinder test wallallowing the pressure to escape from thecylinder earlier than the standard cylinder

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Figure 11 Comparison of mini cylinder test with standardcylinder test radial velocities6.

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D10 dozerrecovered froma high wallusing blastingBy Tristan Worsey BSc MSc MISEE, Newmont MiningCorporation, Nevada, USA

IntroductionA dozer operator during night shift drove a D10dozer up a berm and off the edge of the high wall.The dozer fell down the high wall 18.3 m (60 ft)before the front blade dug into a catch bench. Thedozer operator high tailed it out of the dozer andclimbed to safety after the dozer came to a stop onthe catch bench. The high wall the dozer drove offwas at a 65 degree angle but the dozer sat on thecatch bench at a 40 degree angle. Figure 1 shows aphotograph of the dozer caught on the catchbench.

At first hooking onto the dozer’s tool bar anddragging it out was suggested, but this was deemedunsafe and damaging to the dozer. Bringing in acrane to lift the dozer was also suggested but inorder to access a sufficient tie off point the tool barwould have to be removed. It was deemed unsafefor personnel to do any work on the dozer in themiddle of the high wall. The decision was made toexcavate down to the bench elevation in order forpersonnel to be able to work on the dozer from thesafety of bench elevation.

At first they tried to free dig the material but it soonturned too hard to dig. The blast tech team knewthat blasting would be an option if we changed ournormal blast design. When excavation was nolonger possible the idea of specialized blasting wascasted out and management took the bait.

AbstractA dozer operator at a surface gold mine accidentally drove a D10 offthe side of a high wall. The blade of the dozer caught on the lip of acatch bench 18.3 m (60 ft), down, stopping its descent. The operatorscrambled to safety in fear that the dozer would not hold.Engineering and management looked at multiple dozer recoveryoptions, with safety the overriding consideration. The initial plan wasto rent a crane to lift the dozer out. However, Caterpillar would notsanction tying off on the tool bar. This meant that personnel wouldhave to remove the tool bar on the high wall, which was deemedunsafe. For work to be done at the dozer level an access bench wasnecessary. Mechanical excavation was initially attempted, but onlyhad success several feet down before the rock was no longer digable.The only option other than abandoning the dozer was blasting theaccess bench down to the elevation of the dozer blade.

The drill and blast team had discussed blasting solutions and cameup with a sound approach that was presented when mechanicalexcavation failed. Normal mine production blasts use 200 mm (77/8th in.) holes drilled 7.0 m (23 ft) and loaded with 2.1 m (7 ft) ofpowder, with 30 to 40% hole utilization and a PF of 0.2 Kg/tonne (0.4lbs\ton). Down the hole detcord and surface delays are used andblasts can be violent. The problem was three fold: damaging thedozer with flying rock, knocking the dozer down the high wall, andvibrations causing cascading material to bury and damage thedozer. Fortunately the ground was mostly waste rock, which meantthere were few constraints on blasting. The plan involved increasingboth powder factor and hole utilization to send more of the energyinto breaking the rock and casting it away from the dozer whilsteliminating flyrock and minimizing ground vibrations. Blasts as nearas 24 m (80 ft) away from the dozer were designed using one of thehighest powder factors ever used at the mine of 0.4 kg/tonne(0.8lbs/ton) or 0.9 kg/m3 (1.6lbs/yd3) and a 63% hole utilizationusing the timing precision of electronic detonators with the process,philosophy and designs described in detail in the paper. The processwas documented using video, seismograph and laser profilingmovement monitoring.

The D10 dozer was successfully extracted with none of the windowsdamaged and no damage from the blasting. It was back inoperation at the mine after a thorough inspection and maintenance.

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Figure 1. The day after the dozer drove off the high wall.

double the powder factor to 0.4 kg/tonne(0.8 lbs/ton) for the special panel shots bydecreasing the burden and spacing to 4 x4.6 m (13 x 15 ft) and increasing depth to19.2 m (63 ft). The weight of explosives waslimited in the 19.2 m (63 ft) face by using a171 mm (6.75 in.) hole instead of normal 200mm (7.875 in.) hole. A buffered blend with adensity of 1.15 g/cc was used due to reactiveground potential. Unfortunately gettingnice crushed stone wasn’t an option forstemming so drill cuttings were used forstemming the holes. The quality of the drillcuttings for stemming was decent due to

came up with 33 ms hole to hole and 62 msrow to row for the 12.2 m (40 ft) bench and25 ms hole to hole and 53 ms row to row forthe 18.3 m (60 ft) bench. These situationssimulated well at 30.5 m (100 ft) and 61.0 m(200 ft) locations from the blast hole.

Normal production patterns used at themine site are 4.9 x 5.5 x 7.0 m (16 x 18 x 23 ft)(Burden x Spacing x Depth) in ore and 5.5 x5.5 x 13.4 m (18 x 18 x 44 ft) in overburden.The average powder factor on site is around0.2 kg of explosives per tonne of material(0.4 lbs/ton). The decision was made to

MethodologyThe whole idea of the design was to put asmuch of the explosive energy into breakingand casting the rock as possible to reducethe amount of vibrations escaping the blastpattern. Explosive energy likes to take thepath of least resistant. The less contained ablast is the more energy goes into breakingand casting the rock in the direction of thefree face than goes into the material behindthe blast. The bigger the bench height toburden ratio is the more tensile stress isexerted onto the rock. Rock tends to breakbest under tensile stress. This is like trying tobreak a tall skinny pencil in half and a shortfat pencil in half. The tall skinny pencil is alot easier to break. The plan was to increasethe powder factor by decreasing burden andspacing and increasing face height. This intheory would increase movement of thematerial, increase fragmentation, anddecrease ground vibrations.

DesignThe bench elevation that the dozer drove offwas on the 1750 m (5740 ft) elevation. Thefront dozer blade caught on the 1731 m(5680 ft) catch bench below. This meant theblast would have to fragment 18.3 m (60 ft)of material to be excavated to create a padto work on the dozer. Two types of blastingwere designed for creating the pad, onebeing for the initial drop and the other forremoving the material closest to the dozer.

Since we had to drop down 18.3 m (60 ft),the drop cut was made by shooting twolevels. The first level was drilled to 1736 m(5697 ft) and the second was drilled to the1730 m (5677 ft). This was because we usednormal production design for the dropbecause it was far enough away to not be asconcerned with moving or hurting thedozer. This helped out the speed of themining cycle.

Signature hole analysis was done on a 12.2m (40 ft) bench using normal productionpractice of down hole cord and on a 18.3 m(60 ft) bench using a down hole electronicdetonator. An explosives supplier was usedto analyze the signature hole data and they

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Shot type Burden (ft) spacing (ft) hole Hole bench PF lbs/ton PF lbs/cyd Stemming lbs/hole Blenddepth (ft) diameter (in) height (ft) (ft) (% emulsion)

40 ft drop 17 18 43 7.875 40 0.54 1.10 24 500 15

20 ft drop 16 18 23 7.875 20 0.34 0.84 16 180 15

60 ft panel 13 15 63 6.75 60 0.8 1.62 23 700 15

Metric (m) (m) (m) (mm) (m) Kg/tonne Kg/m^3 (m) Kg/hole %

40 ft drop 5.2 5.5 13.1 200 12.2 0.27 0.61 7.3 227 15

20 ft drop 4.9 5.5 7.0 200 6 0.17 0.43 4.9 82 15

60 ft panel 4 4.6 19.2 171 18.3 0.4 0.90 7.0 318 15

Figure 3. 5680 shot map.

Table 1. Pattern designs.

Figure 2. 5700 bench shot map.

The next two blasts were on the same benchas the first with the same design and timing.These blasts are outlined in pink (5-12-2013)and teal (6-12-2012) in Figure 2. The secondshot had 161 holes (8 dead) and was 161 m(529 ft) away from the dozer. This shot had apeak particle velocity of 5.334 mm/s (0.210in/s) at 9.3 Hz with the lowest frequencybeing 8.9 Hz at 4.572 mm/s (0.180 in/s).Little to no movement was reported fromthe scans for the material around the dozerand the dozer itself. In Figure 5 the blastshows a little stemming ejection. This is verycommon when using detcord down the holeas an initiator. The stemming ejectioncauses quite a bit of fly material that isunwanted once we get closer to the dozer.The third shot had 102 holes (6 dead) andwas 77m (251 ft) away from the dozer. Thisshot had a PPV of 34.544 mm/s (1.360 in/s)at 17.0 Hz with the lowest frequency being10.2 Hz at 34.544 mm/s (1.360 in/s). Thescans reported little to no movement of thedozer from before the blast. In Figure 6 theblast shows a little more violent stemmingejection.

had 127, 13.1 m (43 ft) holes, and 227 kg(500 lbs) of explosives per hole. Theseismograph reading next to the dozer hada peak reading of 53.848 mm/s (2.120 in/s)at 26.9 Hz with the lowest frequency of 21.3Hz at 46.736 mm/s (1.840 in/s). It was notedthat normal blasting practices did sendquite a bit of material down the high wall. Ifthis design was shot by the dozer it wouldhave covered the dozer with material andpotentially dislodged the dozer. See Figure2 for the location of the blast on 4-12-2012.It is the blast bordered in red.

the damp conditions of winter andstemming ejection was minimal.

The panel shots were limited to three rowsto minimize constipation of the shot. Afterthree rows, relief caused by the row timingand material moving, starts to decrease.This causes an increase in vibrations goingback into the wall. The pattern designs ofthe drop cuts and panel shots are shown inTable 1. Figures 2 and 3 show a plane view ofthe pattern designs.

ResultsUnfortunately there are no regulations on themaximum vibrations for a D10 dozer sittingon the edge of a high wall. The engineershad no starting place besides trial and error.Since the material with the dozer didn’t faildue to weather conditions changing, it wasassumed that the dozer could take quite a bitmore than the regulation for structures of50.8 mm/s (2 in/s). Table 2 shows thedistances away from the blast of theseismographs and seismograph data. Noticethat the last three blasts had significantlymore ground vibrations. This was due to theproximity of the blasts. From data collectedvs. what was estimated, vibrations near thedozer were significantly reduced by usingsignature hole data and increasing powderfactor by decreasing burden and spacing andincreasing hole length. Now in a perfectworld the hole diameter would have beendrastically reduced. This would havedecreased weight per hole to be less thanproduction and still doubled the powderfactor. With this operation going lower than171 mm (6.75 in.) diameter this was not anoption.

The first blast went well. Laser profile scanswere taken before and after the blast andshowed minimal movement. Figure 4 showsa picture of the blast. Notice the dozer inthe lower right hand corner. The dozer was50.6 m (166 ft) away from the blast. We didnot decide to bring the next pattern backfrom the crest edge because the scans didn’tshow any movement in the materialbetween the dozer and the blast. The blast

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Table 2. Seismograph distance from blast and data.

Figure 4. First dozer shot.

Figure 5. Second

dozer shot.

Figure 6. Third

dozer shot.

Blast Seis Seis PPV (ips) PPV (mm/s) Frequency Calculated PPV Calculateddistance(ft) distance(m) (Hz) (ips) (k factor PPV (mm/s)

of 1140)

1st (12-4-12) 157 48 2.12 53.85 26.9 47.23 1199.64

2nd(12-5-12) 493 150 0.21 5.33 9.3 7.57 192.28

3rd(12-6-12) 220 67 1.36 35.54 17 27.53 699.26

4th(1-2-13) 153 47 1.52 38.61 22.2 22.14 562.36

5th(1-24-13) 170 52 1.88 47.75 13.4 58.95 1483.23

6th(2-1-13) 72 22 ips>5 mm/s>127 N/A 233.05 5919.47

7th(2-14-13) 92 28 N/A N/A N/A 157.44 3998.98

8th(2-27-13) 84 26 8.8 223.52 28.4 182.11 4625.59

front of the blast. One thing to note fromthis scan is that the material next to wherethe blast was located is unaffected. Thismeans that this is a safe distance (43m/140ft) from the high wall to put the blast oncewe get to patterns directly behind the dozer.Figure 9 shows a photograph of the blast.This blast had the least amount of flymaterial and only one stemming ejectionthat was from a hole plugging duringstemming.

Shot number six was the second panel shotnext to the dozer. The blast had 12, 19 m (63ft) holes (0 dead), and 318 kg (700 lbs) ofexplosives per hole. The teal pattern (1-2-13) in Figure 3 shows shot number six. Thispattern was only 33 m (108 ft) away from thedozer and had more burden than designeddue to the failure. This pattern also hadsome short holes in the middle of thepattern. This shot gave a PPV greater than127 mm/s (5 in/s). Unfortunately theseismograph was set to a max of 127 mm/s(5 in/s) so data was not received. The scanshowed little to no movement on andaround the dozer. This was a good sign thatthe dozer was pretty well set in the catch

Shot number five next to the dozer was thefirst panel shot. There was a failure in thewall that split the pattern up into two shots.In Figure 3 there is a gap in-between thepink and teal shots that was the area thatfailed. The pink pattern (24-1-13) was thepanel shot we shot first. The blast had 53, 19m (63 ft) holes, and 318 kg (700 lbs) ofexplosives per hole. The closest hole to thedozer was 67 m (219 ft). This shot gave aPPV of 47.752 mm/s (1.880 in/s) at 13.4 Hz,which was the lowest frequency. The beforeand after dozer scans came back negativefor significant movement. Figure 8 shows apicture of what the before and after scanslooked like. All of the scans looked verysimilar except for one so only two scans willbe shown in the paper. In the scan anythingthat is in blue is up to 0.3 m (1 ft) of materialgain, grey is zero movement, and orange isup to 0.3 m (1 ft) of lost material. The greencolor means it went out of the range of -0.3m (-1 ft) to 0.3 m (1 ft). The scan shows thatthe material near the dozer was basicallyunaffected. The material that is right next tothe free face shows a little bit of loss but itwas right in front of the blast and it wasexpected to see a little bit of movement in

Blast number four next to the dozer was a6m (20ft) drop pattern to get the 1737 m(5700 ft) down to the 1731 m (5680 ft)elevation to fully free face the panel shot.Since this shot had less than half theexplosives per hole than the 12 m (40 ft)drop it was decided to shoot all 402 holes(11 dead) in one shot. This is the blast shoton 2-1-13 outlined in red in Figure 3. Theclosest hole to the dozer was 48 m (158 ft)and gave a seismic reading of 38.608 mm/s(1.520 in/s) max at 22.2 Hz and the lowestfrequency 13.0 Hz at 32.512 mm/s (1.280in/s). The dozer scans did not show anysignificant movement near or around thedozer. This blast (2-1-13) is outlined in red inFigure 3. This blast had less groundvibrations than the first shot that was similarin distance but this shot had less than halfthe kgs per delay. This blast had a lot ofstemming ejection and was also quiteviolent as can be seen in Figure 7. Quite abit of material was cascaded down the sideof the high wall and there was some flymaterial that could have hit the dozer if ithad been closer. There was a little bit ofsnow that fell down the high wall in front ofthe dozer but no actual material fell.

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Figure 7. Fourth dozer shot. Figure 8. Before and after scan of the first panel shot.

Figure 9. Fifth dozer shot.

Figure 10. Dozerscan of the sixth

shot.

frequency of 4.7 Hz at 152.4 mm/s (6.00in/s). The scans showed little to nomovement of the dozer or the materialaround it. Figure12 shows a photograph ofthe eighth dozer blast. This shot had somestemming ejection that was caused by usingdrill cuttings and holes plugging.

After the eighth shot the bench was downto the dozer blade elevation and there wasenough room for equipment to operate.The 15 m (50 ft) buffer zone ended up beingeasy to dig. This was due to the shock wavefrom the blast creating micro fractures in therock. This was expected, but wasn’texpected to work as well as it did. Figure 13shows the dozer after final excavation of thebuffer zone. The removal of the dozer wasdone by strapping onto the tool bar with theshovel and digging the material out fromunder it with a backhoe then dragging it tomore stable ground. The dozer had no blastdamage and all of the glass was intact. Oncethe fluids were changed this dozer was outin the pit again working.

ConclusionThe dozer rescue using blasting to excavatethe bench to the level of the dozer was asuccess. Although vibrations were

bench and as long as the material in thecatch bench didn’t get casted the dozerwould be fine. One thing from this blast thatwas noticed was the material in-betweenthe dozer and the blast did show a little bitof movement, as seen in Figure 10 below. Itwas then decided to pull the rest of thepanels 15 m (50 ft) back. Figure 11 shows aphoto of the shot. This shot had no flymaterial and no stemming ejection.

Shots 7 (14-2-13) and 8 (27-2-13) weresimilar in design to the first panel shot andcan be seen in Figure 3 in green and yellowrespectively. Shot 7 was 39 m (128 ft) awayfrom the dozer. This blast was done whilethe blasting engineers were at the 2012 ISEEconference and the seismograph monitorswere improperly set up and a valid readingwas not obtained. The video was alsomissed, but the before and after dozer scansshowed little to no movement of the dozerand the surrounding material. This shot wasslightly north behind the dozer. Shot 8 wasthe last dozer shot needed for equipmentspace to retrieve the dozer and was slightlysouth behind the dozer. This shot had 53, 19m (63 ft) holes (0 dead), and 318 kg (700 lbs)of explosives. This shot gave a PPV of 223.52mm/s (8.80 in/s) at 28.4 Hz with the lowest

25

significantly more at the dozer with thepanel shots than the drop cuts, using regularproduction blasting design would havecaused even more vibrations in the samelocation and would have cast material ontothe dozer and disturbed the catch benchmaterial that the dozer was sitting on,resulting in dozer loss. Using the techniqueof increasing the powder factor bydecreasing burden and spacing andincreasing face height, while casting therock away from the dozer, did significantlyreduce the impact of blasting near thedozer.

ReferencesUnknown. (2012). Service Manual for a Cat D10Dozer. Peroria, IL, United States of America:Caterpillar Inc.

Unknown. (2012). Orica Pocket Blast Guide.Melbourne, VIC, Australia: Orica Mining Services.

Walker, J. (2010). AutoCAD Civil 3D. San Rafael, CA,United States of America: Autodesk.

Further information:Tristan.Worsey@newmont.com

Award Winner

Figure 11. Sixth dozer shot.

Figure 12. Eighthdozer shot.

Figure 13. Dozer after final excavation.

1846

First synthesis of nitroglycerine

by Ascanio Sobrero in a laboratory

in Turin.

1859

W G Armstrong perfects the world's first

successful breech-loading system of field

artillery that fired elongated, fused

projectiles through a polygroove rifled

steel barrel.

1860

Gunpowder and Fireworks Act covers

making and keeping.

1861

Gunpowder and Fireworks (Amendment)

Act covers carriage.

1865

Nobel devises the first reliable detonator.

1865

January 21st - first use of explosives in oil well

shooting by Roberts in Pennsylvania.

1866

First oil well perforating charge,

a "torpedo" used in USA.

1867Dynamite invented by Nobel.

Produced in UK at Ardeer from 1871.

1867Ammonium nitrate added to

dynamite by Swedish chemistsOhlsson and Norrbein.

1860sA series of serious explosions, killing

many, mainly in the Midlandsmunitions trade, raise public

concerns about the explosives industry

in UK. 1869

Nitroglyerin

e Act covers

importa

tion.

1874

Vivian Derin

g Majendie, a

Major in

the Royal A

rtille

ry,

commiss

ioned to m

ake investi

gations a

nd to w

rite a

Report to

the Secre

tary of State w

hich addresse

d the

Necessi

ty for t

he Amendment of th

e Law relatin

g to

Gunpowder and oth

er Explosiv

es with

suggesti

ons

for a new Act.

1875

The Explosives A

ct passe

d . This A

ct was m

odelled by

Crown co

lonies and dependencie

s aro

und the globe.

It covered m

anufacturin

g, keeping, se

lling, c

arrying

and importi

ng Gunpowder, N

itro-G

lycerin

e, and

other e

xplosive su

bstance

s but n

ot use

. It c

ame into

force on 1 Ja

nuary 1876. Majendie is

appointed the

first H

M Insp

ector, l

ater Chief In

specto

r, of E

xplosives.

1878

Alexander Redgrave appointed as fi

rst

HM Chief Insp

ector o

f Facto

ries.

1888

The first te

sting galle

ry in th

e UK fo

r explosiv

e

testing fo

r safety in

flammable atmosp

heres in co

al

mines constr

ucted at Hebburn

by the N

orth of

England Insti

tute of M

ining and

Mechanica

l Engineers

and used

1888 - 1896. E

xplosives

safety in

flammable

atmosp

heres

achieved.

1 ©

Gunpowder appears

to have been disc

overed by

the Chinese

during th

e first ce

ntury AD.

668

"Greek fire” -

a form

of napalm

?

- use

d in battl

e.

13 ©

Gunpowder intro

duced in

to Euro

pe

by Berthold Sch

wartz.

1242

Roger Baco

n knows a fo

rmulatio

n for g

unpowder

and conce

als it in

cypher to pro

tect it.

1346

Cannon used at B

attle of C

recy.

Feature

1951

Fireworks Act comes into force.

This is an Act to confer powers of

seizure where dangerous fireworks are found,

and powers to determine or amend licences or

certificates for explosives factories where fireworks

are made.

1956

First version of the UN "Orange Book" - the

Recommendations on the Transport of Dangerous

Goods. This sets up the system for codifying

dangerous goods and is the cornerstone of much

succeding explosives and hazardous

materials legistlation.

1972

European Communities Act.

1972

Lord Robens delivers his report to Parliament in

July. This Report was demanded as it was found that

about 1000 persons died each year and half a

million were hurt at work in the UK, with 23 milion

working days lost annually. It says that "there is too

much law .... it is badly structured...,. (and)

unintelligible." the existing legislation was

"haphazard" and "a mass of intricate detail".

A radical overhaul is proposed. There was to be a

consolidated Act covering health and safety.

A history ofexplosives:as they relate to the UKBy Ian McKay CEng MPhil BSc Dip H&S FIMM FIExpE

26

1974Institute of Explosives Engineers

holds its inaugural meeting in Birmingham on 22 May at which fifty persons attend and formally

establish the Institute.

1974Health and Safety at Work etc. Act drafted and enacted. TheExplosives Inspectorate, long

part of the Home Office istransferred to become part of

newly formed Health and SafetyExecutive and ceases formally toexist as a separate entity after 31

December 1974.

1970s

ANFO, slurri

es and emulsi

on explosives d

eveloped. .

These ca

n be made to

be non self-s

ensitise

d and not

cap se

nsitive. A

long with

a range of im

provements

in

detonato

r desig

n and with

the in

troductio

n of

advanced a

nd relia

ble inita

tion m

ethods b

y shock

tube, th

ese re

present a

significa

nt potentia

l incre

ase

in safety in

transp

ort, handlin

g and use.

1975

Health and Safety Exe

cutiv

e form

ally esta

blished.

1985

The Royal Ord

nance fa

ctorie

s in th

e UK are so

ld off

to beco

me Royal Ord

nance plc

on January 2,

ending the State co

ntrol o

f munitio

ns of w

ar which

was begun in

1640.

1986

Single European Act a

mends Treaty of R

ome. The

Community now empowered to

set m

inimum

standard

s for h

ealth and sa

fety of workers.

Numbers

of Dire

ctives e

nsue, d

ealing w

ith lif

ting, w

ork

equipment, manual h

andling, d

isplay sc

reens, etc.

1986

NCVQ (Natio

nal Council

for V

ocatio

nal

Qualifica

tions)

first in

troduce

d NVQs,

some of w

hich apply to

the

explosives s

ector.

Roger Bacon.

Ascanio Sobrero.W G Armstrong.

Berthold Schwartz.

Alexander Redgrave.

Example of a Hazard diamond.

Vivian Dering Majendie.

1804

The first fatality in coal mining known to be due

to shotfiring fumes, recorded by Desgrange.

1807

Fulminate of mercury used in the first

percussion cap for use by the armed forces.

1831

Bickford develops a safety fuse.

1833

Enacted, “An Act to Regulate

the Labour of Children and young

Persons in Mills and Factories of the

United Kingdom” – the first of a series of

Factory Acts. Fundamentally and crucially, this is

the first Act under which the appointment of

Inspectors of Factories could be made in order

that the provisions of the Act could be

enforced.

1833

Alfred Nobel born 23 October.

1845

Nitrocellulose discovered and

developed as an explosive.

1896

Alfred N

obel died 10th

Dece

mber.

1898

Sir Vivian M

ajendie dies 24 April.

1911

The Coal Mines A

ct use

s the phrase

s "so

far a

s

possible" a

nd "so fa

r as p

racticable" i

n relatio

n to

safety pro

visions.

1914 to 1918

World W

ar I. The fa

ilure of th

e Battle of A

ubers Ridge

on May 9, 1

915 was a

ttributed by Sir J

ohn French th

e

British

C-in-C

, to a la

ck of s

hells. T

his was “

The Shell

Scandal,"

reported by th

e Times, a

s “The w

ant of a

n

unlimite

d supply of h

igh explosives w

as a fa

tal bar t

o

our succ

ess." S

hortage of c

ordite

, made fro

m aceto

ne,

most of w

hich ca

me from abro

ad, was n

ow acute.

Schoolch

ildren exhorte

d to co

llect h

orse ch

estnuts

to

be used by W

ar Office

to fe

rment in

to ace

tone. "E

very

chestn

ut is of u

se to

the co

untry".

In 1917 there w

ere

produce

d 183,000 tonnes o

f shells

in th

e UK. B

y the

end of the w

ar, the Brit

ish arm

y alone had fired 170

million sh

ells, m

ost of w

hich hit F

rance or B

elgium.

1930s

Reliable delay deto

nators

developed, prim

arily in

Germany and U

K.

1415

Battle of A

gincourt

on 25 Octo

ber. This i

s a m

ajor

victory against

the French

in th

e Hundred years War.

Follo

wing this,

Henry V establish

ed the Board

of

Ordnance

to su

pply guns and ammunitio

n to th

e

Navy. In th

e fulln

ess of ti

me the O

rdnance

Board

would become th

e Defence

Ord

nance Safety Group.

1605

Guy Fawkes (

1570 - 1606) in

tends to use

about

36 barrels o

f gunpowder t

o blow up the H

ouse

of Parlia

ment in London on 5 N

ovember.

Betrayed, th

e attempt fa

ils and Fa

wkes and

others

are tortu

red and execu

ted.

1630 and onwards

Gunpowder reco

rded as b

eing used in

, resp

ectively,

the Endon co

pper mines in

Staffordsh

ire (1

630), in

the M

endips (1683)and in

Cornwall (

1689).

1640

Gunpowder pro

duction begins a

t Walth

am Abbey.

1641

The first UK st

aute relatin

g to explosiv

es is passe

d on

3 August. This i

s An Act fo

r the fre

e bringing in

of

Gunpowder and Salt-p

etre fro

m Foreign Parts

, and

for the fre

e making of G

unpowder in th

is Realm

.

1772

The Gunpowder A

ct bans e

dge runner m

ills.

This is t

he first st

atute aim

ed at contro

lling

conditio

ns in explosiv

es manufactu

re.

Feature

1800Fulminates discovered.

1802The Health and Morals of

Apprentices Act is the first statuteaimed specifically at control of

working conditions. It becomeslaw on 22 June.

1935Massive explosion of ammonium

nitrate and other ammonium saltstakes place on 21 October inOppau, Germany. Somethingapproaching 5000 tonnes of

material explodes, killing over 500persons. Workmen were using

dynamite to loosen the materialwhich had caked in a silo.

1937

O in C No. 30 to the 1875 Act Classes

Acetylene as an explosive and prohibits it

under certain conditions.

1939 to 1945

World War ll. Many explosives devices developed and

improved - typical of wartime. The Munroe effect

(first described in 1792) used in the Bazooka and,

later, in countless oil well perforating charges. By

1943/1944, the peak annual UK output had reached

20,023 naval guns, 10.2 million rounds of large

diameter ammunition, 233,206 mines and depth-

charges, 7039 torpedoes, 3,046,000,000

rounds of small diameter ammunition,

and 21,584,000 grenades in addition to

300 thousand tons of explosives. About

5 million persons, over 16 % of the

workforce, were employed in production

of munitions of war.

1945

United Nations organisation founded after World War

II to replace the rather discredited League of Nations.

Its stated aims were to stop wars between countries,

and to provide a platform for dialogue. It contains

multiple subsidiary organisations to carry out its

missions. There are 193 Member States including

every internationally recognised sovereign state in

the world excepting the Vatican

City.

27

1992

Management of H

ealth and Safety at

Work Regualtions in

corp

orate the pro

visions

of the fra

mework Dire

ctive 89/3

91, when re

quired

employers to

contro

l risk

, into

UK la

w.

1994

Heather S

later of H

SE Buxton Laborato

ries (

later H

SL)

becomes t

he 1000th M

ember of th

e Insti

tute w

hen

she jo

ins on 16 N

ovember.

2000

The Standards S

etting Body (S

SB) for

Explosives, M

unitions a

nd Search O

ccupatio

ns

was esta

blished to

develop Natio

nal

Occupatio

nal Standard

s and N

ational

Vocatio

nal Qualifi

catio

ns for t

hose in

volved in

munitions c

learance and se

arch activ

ities.

2005

Many of the re

maining require

ments of th

e 1875

Explosives A

ct are sw

ept away by th

e Manufactu

re

and Storage of E

xplosives R

egulations (

MSER).

2008

The Insti

tute is

formally

reco

gnised as a

Professi

onal

Affiliate o

f the Engineerin

g Council o

n 24 July.

2011

Allan H

inton appointed as t

he Development O

ffice

for Explosiv

es Skills

Programme (D

OES) Manager

with th

e resp

onsibilit

ies to su

pport th

e Sector S

kills

Strategy G

roup (S

SSG) in su

staining U

K skills

in

Explosives S

ubstance

s and Arti

cles (

ESA).

2012

The Insti

tute ce

ases t

o be a trading

associa

tion and is

registered as a

Limite

d Company. The Certi

ficate of

Incorp

oration is

dated 11 January.

William Bickford.Alfred Nobel.

Guy Fawkes.

Coal minesexplosives testgallery.

WW I.

Oppau.

One of the first 10 ton bombs,photographed in 2009.

UN logo.

Further information: ipmckay@btinternet.com

“minor changes in the shape of the end havea seemingly disproportionate effect on theproperties of the end effect”. Research byWisotski and Snyer [14] examined blast fromplane and hemispherical ended charges,also concluding that "it is interesting to notehow unquestionably the slope of thepressure-distance curve changes with onlyminor changes to the end contour of thecylinder".

Still, despite these early findings and thepotential significance to current quantity-distance based safety standards and lowcollateral warhead development, littlerecent research has been directedspecifically at comparatively assessing theeffect of changes in end geometry ofcylindrical charges on the resulting blastfield generated.

ScopeA programme of work was undertaken toinvestigate the near-field blast effectsproduced from detonation of six cylindrical400g PE4 charges of Length/Diameter(L/D)≈2 with varying end profiles (see Figure3). A combination of hydrocode modellingand experimental firings were conducted toprovide Pressure-Time data at distances of1m to 3m from the end of the charge and atangles varying from 0° to 90° from thecentral axis. In addition, High Speed Video(HSV) of experimental firings was employedto augment modelling results and enablevisualisation of the shock wave systemproduced.

A variety of factors may necessitate that theend geometry of an explosive chargedeviates from that of a simple plane endedcylinder. The incorporation of a cavity in theend of an explosive charge (hollow charge)in order to increase axial blast effectivenesswas noted as early as 1792 [13]. Laterstudies, documented by Bawn [2], usedSchlieren imagery to examine the shockwave system around cylindrical charges withvarying end geometries, confirming that

IntroductionThe concept of "TNT Equivalence" is usedextensively throughout the explosivesindustry to compare the specific outputcharacteristics of an energetic material tothat of TNT. It is a fundamental parameterused in evaluating the damaging effect of aparticular charge on buildings, structures andpersonnel and forms the basis for severalgovernment regulatory criteria including thestorage and transportation of explosives.

However, the data used in the determinationof TNT Equivalence is based mainly onexperimental results from detonation ofspherical charges, despite that most militarycharges are more nearly cylindrical. Anumber of studies have shown that the near-field blast effects from plane-endedcylindrical charges1 exhibit quite differentcharacteristics from those of sphericalcharges of similar mass [4; 6; 7; 8; 9; 11; 14].Free-air detonation of cylindrical chargesresults in a complex blast field comprising ofprimary, secondary and bridge shock waves[5] which is "obviously far from spherical"[10]. A number of fundamental studies haveinvestigated the blast field generated fromthe detonation of plane-ended cylindricalhigh explosive charges [3; 6; 10; 12; 14; 15].These have illustrated that Mach interactionof the blast waves produced from the sidesand ends of the charge produces bridgewaves off the corners, and that secondary orreflected waves are generated from the endsof the bridge wave due to reflection of theprimary waves (see Figure 1). This results in amultiple shock phenomenon which isevident in blast gauge histories in the nearfield (see Figure 2).

As the blast wave propagates away from thecharge, the reflected waves tend to overtakethe primary and bridge waves such that, aftersome distance, the blast wave resembles thatproduced by a spherical charge and is said tobe 'healed'. This is because the velocity of theshock wave is related to the local ambienttemperature, pressure and density of themedium. Hence, the reflected waves travelmore quickly through the pre-shocked air.

28

Feature

Effect of end shape on blastfrom cylindrical chargesBy Scott Bradley BEng MSc (EOE), System Design Evaluation LtdProject Supervisors: Dr N. Davies, Dr C. Knock, Cranfield University

Figure 1: Schematic of the Blast Field around aCylindrical Charge [14].

Figure 2: Near Field P-T Gauge History from a Cylindrical Charge.

Figure 3. Cylindrical Charge Geometries.

determine the key characteristics of the blastwave recorded at each gauge, namely Timeof Arrival, Peak Overpressure and PositiveImpulse. Positive Impulse was calculated byintegration of the pressure trace, from thearrival of the shock front to the time at whichthe curve crossed the x-axis.

HSV from the trial was found to be unreliable.Problems with triggering of the cameraprevented capture of the initial firings andlater efforts were hampered by inclementweather. Overall the quality of the HSV datathat was gathered was poor, predominatelydue to difficulties associated with providingsufficient natural light to the camera.

Pressure contour plots were created from thesimulation results, at various intervals, toprovide a visualisation of the development ofthe shock wave system around each charge.Figure 7 illustrates the shock wave systempredicted from MSC Dytran simulationsaround the Intrusive Cone Ended Charge(Type II) after 0.32µs.

Figure 7. MSC Dytran Pressure Contour Plot for Intrusive Cone Ended Charge at 0.32µs.

mounted atop a steel post, at a height of 2mfrom the ground to prevent interferencefrom reflected waves.

Computer modellingHydrocode modelling of each charge typewas conducted using ANSyS Autodyn. Forcomparison purposes, further modellingwas later conducted by MSC Software usingMSC Dytran and found to correlate well withthe Autodyn results.

Where possible, models were simplifiedusing 2D axial symmetry. An Euler solverwas used to model the explosive charge andsurrounding air medium. The main chargeexplosive was represented by C4, but thedetonator and booster charges were notmodelled. The Euler domain was graded togive a cell size of 1mm in proximity to thecharge, increasing to 3.5mm at theextremities. Flow-out boundary conditionswere applied to all off-axis edges of theEuler domain and a gauge array, similar tothat used in the experimental firings, wasadded around the charge including fiveadditional gauges (see Figure 5). Allsimulations were solved to a time of 10ms.

ResultsExperimental and modelling P-T gaugehistory data was collated and plotted. Apreliminary analysis was conducted to

Only the findings from the Intrusive andProtuberant Cone Ended charges (Type IIand Type V) are discussed here.

ExperimentalA series of experiments were conducted toinvestigate the blast field produced from atotal of 18 charges with 6 different endgeometries. Trials were conducted at theExplosive Research and Demonstration Area(ERDA) of the Defence College ofManagement and Technology (DCMT),Shrivenham, UK, December 2011.

Charge designGeometry for the explosive charges wasdetermined using Computer-Aided-Designsoftware based on a target charge mass of400g and L/D of 2. The charges wereprepared by hand pressing of PE4, using apurpose designed moulding system, into alight cardboard tube casing with a 3mm SX2booster. An L2 Electrical Detonator wasinserted into the end of the charge andlocated centrally by a low density pinewoodDetonator Support. Figure 4 illustrates across-section of a fully assembled charge.

Figure 4. Cross-Section of a Fully Assembled Charge.

Experimental setupTo capture the near field blast wavesgenerated, an array of blast gauges werepositioned around the charge. HSV (HighSpeed Video)was also used to provide avisual indication of the shape of the blastfield. Figure 5 shows the generalarrangement of the HSV, blast gauges andcharge at the ERDA range.

Each charge was mounted on a steel postwith an ionisation probe attached to thecharge casing to provide a trigger pulse forthe data acquisition systems (see Figure 6).Blast gauges were mounted within circularbaffle plates to ensure that only the side-onpressure component of the blast wave wasmeasured. Each gauge/baffle assembly was

29

Feature

Figure 5. ERDA Generalarrangement of HSV,blast gauges andexplosive charge.

Figure 6. Mounted explosive charge and blast gauges.

30

Feature

Figure 8. Development of shock wave system around Intrusive cone ended charge (Type II).

Figure 9. Development of shock wave system around protuberant cone ended charge (Type V).

31

phenomenon which is responsible for adouble peak in the blast wave, the generalform of the predicted shock wave funnelwas verified by comparison with theexperimental P-T gauge data.

For example, for the intrusive cone endedcharge, Gauges 5 and 9 are located outsideof the bridge and bow wave funnels, in the90° direction. As expected, the experimentaldata for these gauges shows only a singlepeak. Gauges 6 and 10 also lie outside, butare in close proximity to, the upperbounding surface of the bridge wave funnel.The experimental results show that a doublepeak occurs at Gauge 6 but not at Gauge 10.This is because, as indicated on the shock

bridge waves become less pronounced untileventually the blast wave ‘heals’ and theshock front resembles that from a sphericalcharge.

Similar to those presented by Bawn [2], thepredicted shock wave systems around eachcharge can be summarised as shock wavefunnel diagrams; produced by tracing thelocus of the intersection of the bow/bridgewaves with the primary shock waves2, basedon the hydrocode modelling results (seeFigure 10 and Figure 11).

Since, as stated, a reflected wave isgenerated at the point of intersection of theprimary and bridge wave and it is this

Analysis and discussionShock wave systemSince the quality of the experimental HSVdata was found to be poor, analysis of theshock wave system around each charge isbased primarily on the review of modellingresults.

Figure 8 illustrates the predicteddevelopment of the shock wave systemaround the Intrusive Cone Ended Charge.Shortly after initiation, primary blast wavesare produced from the end and curvedsurfaces of the charge. A projectile-likedisturbance is evident, emerging from theaxial primary wave, with an associated bowshock wave.

Sometime later, a bridge wave can be seendeveloping at the intersection between thetwo primary waves, similar to that for planeended charges. The axial bow shock wavebecomes more pronounced and asecondary shock wave can be seentravelling behind. This may be as a result ofMach interaction between the axial primaryshock wave and bow wave although, sinceno additional bridge wave is apparent, it islikely that it is simply a continuation of theprimary axial wave which has beenovertaken by the bow shock.

As the shock system continues to propagate,reflected waves form from the triple point.Along the axis, three regions of highpressure are apparent, corresponding to thebow, secondary and reflected shock waves.

Eventually the lateral primary and bridgewave ‘heal’ to form a smooth, almostspherical shock front. The axial primary andbow wave also become superimposed at theshock front to form a single disturbance, asnoted by Bailey and Murray [1].

For the Protuberant Cone Ended Charge(Type V), the shock wave system produced isfound to be more complex than that from aplane ended cylindrical charge (see Figure9). In accordance with the findings of Bawn[2] and Bailey and Murray [1], modellingresults show that primary waves aregenerated from the plane surfaces of thecharge and that these are connected by abridge wave which forms at the intersection. Also evident, is that an additional bridgewave forms along the axis of the charge, dueto Mach interaction of the primary wavesgenerated from opposing surfaces of theconical end. As the blast wave propagatesthe separate identities of the primary and

Feature

Figure 10. Intrusive ConeEnded Charge Shock WaveFunnel Plot.

Figure 11. Protuberant ConeEnded Charge Shock WaveFunnel Plot.

funnel plot by the transition from a solid tobroken line, prior to reaching Gauge 10 theprimary lateral and bridge wave shock frontsmerge, meaning that no reflected shockwave is generated. Gauge 7 lies just belowthe lower boundary of the bridge wavefunnel, within the path of the mergedprimary axial and bridge wave, and doesexhibit a double peak response. WhereasGauge 11 is exposed to only the mergedprimary lateral and bridge shock waves andshows only a single peak. The form of the P-Tcurve for the axial gauges is more complex,with both Gauges 8 and 12 showingmultiple peaks corresponding to thepassage of a bow, secondary and reflectedshock wave, as discussed previously.

Positive impulseA quantitative examination of theexperimental and modelling P-T data foreach charge was undertaken. For thefollowing reasons, the analysis was confinedto the positive impulse of the blast wave only:

Firstly, the positive impulse “is generally amore useful indicator of blast damagepotential” [10]. It is a function of both theoverpressure and the positive phaseduration and thus better characterises theblast wave than peak overpressure alone,particularly when multiple peaks areobserved;

Secondly, whilst consistency of theexperimental data for the key blastparameters was generally good, givingrelative standard deviations3 of below 10%.Modelling results for first and second peakoverpressure were found to give errorsaveraging 20% and 50%, respectively, andcould therefore not be used to reliablysupport the analysis. However, correlation ofboth time of arrival and positive impulse wasmuch improved, being generally below 10%.

Figure 12 and Figure 13 illustrate theexperimental and modelling positiveimpulse data for the intrusive andprotuberant cone ended charges relative tothe plane ended charge.

Intrusive cone ended charge(Type ll)ExperimentalAt 2m from the charge, experimental resultsfor the intrusive cone ended charge show anoticeable reduction in positive impulsealong the charge axis (approximately 18%).This decrease in axial impulse is perhapssomewhat surprising, considering thathollow charges are often used to increase

axial effect. However, previous analysis ofthe predicted shock wave system illustratesthat along the axis the blast wave comprisesof a series of multiple shocks. Inspection ofthe P-T data collected shows that, despitethe peak overpressure remaining similar tothat of the plane ended charge, each of theindividual shocks is of relatively shortduration and hence the positive impulse ofthe wave is reduced.

In the 30° and 60° directions, small increasesover the plane ended charge are found(1.8% and 7.2%, respectively). In the 30°direction this may be attributed to the factthat Gauge 7 was located just below thelower boundary of the bridge wave funnel,whereas for the plane ended charge it wascontained within it. As such, the P-T trace forthe intrusive cone ended charge shows adouble shock phenomenon which increasesthe positive phase duration and, hence, thepositive impulse of the blast wave.

At 3m, the axial positive impulse appears tohave recovered, then showing a 2.6%increase over the plane ended charge. Thismay be due to the ‘feeding-in’ of energyfrom higher pressure regions of the blastwave, as proposed by Wisotski and Snyer[14], or due to an increase in the positivephase duration, owing to the secondary andreflected waves receding from the primaryshock front. However, at all angles a generalincrease of between 0.7% and 2.8 is found.

ModellingAt 1m from the charge, modelling resultsshow greatly enhanced positive impulsealong the axis (166% in comparison to theplane ended charge). However, what isparticularly interesting is that in the 30° to90° directions, positive impulse is also foundto have increased by 16.1%, 18.3% and28.2%, respectively. In fact, it wasconsistently the greatest of all cylindricalcharge types investigated.

Contrary to the experimental data, at 2m,modelling results continue to showsignificantly increased positive impulsealong the axis (128% greater than for theplane ended charge). It is thought that thelack of correlation with trial results can beattributed to the complex axial shock wavesystem which exists and accumulation oferrors in the prediction of peak overpressurefor the bow, secondary and reflectedshockwave components. In the 30° to 90°directions, results also appear tooverestimate the positive impulse showingincreases of 22.5%, 18.2% and 17.9%respectively, when compared to theexperimental data; albeit by a lesser extent.It is most likely that this is due to energy fedin from the high impulse, axial region of theblast wave. With this in mind, it is consideredthat the predictions for positive impulse at1m may also be exaggerated.At 3m, results show that the axial impulsehas decayed somewhat, then only giving a26.4% improvement over the plane endedcharge. However, at greater angles similar

Feature

32

Figure 12. Relativepositive impulse forintrusive coneended charge.

Figure 13. Relativepositive impulse forprotuberant coneended charge.

Feature

33

increases as at 2m are observed.Comparison with experimental data doesillustrate that the model continues tooverestimate the magnitude of the positiveimpulse at all angles; although, there isgeneral agreement that an increase in blasteffectiveness occurs at all angles.

Protuberant cone endedcharge (Type V)ExperimentalAt 2m, experimental results show anincreasing, approximately linear relationshipbetween the magnitude of the positiveimpulse and angular displacement from thecharge axis. At all angles between 0° and60°, the positive impulse is reducedcompared to the plane ended charge, withthe greatest reductions occurring in the 0°and 30° directions (13% and 14%,respectively). The presented area theory [10;14] may explain the reductions in impulsecompared to the plane ended charge, and‘feeding-in’ of energy could account forgreater positive impulse in the 60° direction.At 3m, positive impulse along the axisappears to have recovered; showing anincrease of 6% at both 0° and 90°, whilstremaining suppressed in the 30° and 60°directions by 3% and 5%, respectively. Infact, in the 60° direction the positive impulsewas found to be the lowest of all six chargetypes investigated.

ModellingAt 1m, modelling results for the protuberantcone ended charge show a 30% reduction inaxial positive impulse, compared to theplane ended charge. At 30° the impulseremains marginally reduced (7%), but at 60°an increase of 14% is observed. In theperpendicular direction, positive impulse isalmost identical to the plane ended charge. At 2m, axial, 30° and 90° positive impulse isreduced, in comparison to the plane endedcharge, by 5%, 2% and 3%, respectively;whilst in the 60° direction an increase of 1%is found. Correlation of the modelling andexperimental data was reasonable witherrors across all angles not exceeding 10%.However, the increase in positive impulsenoted in the 60° direction is not observed inthe experimental results, and in the otherdirections the model tends generally topredict lower attenuation of the blast effect.At 3m, the axial positive impulse hasrecovered to give a 1% increase over theplane ended charge but remains identical inthe 30° direction. At greater angles areduction of 2% is apparent. Comparisonwith the experimental results does reveal

some discrepancies in the predicted trend,despite that absolute errors in the positiveimpulse predictions remain within 10%.Whilst the axial increase, and 30° and 60°decreases in positive impulse are observed inthe experimental results, in all cases themodel tends to marginally underestimatethe magnitude of these effects. However, therelative increase in perpendicular positiveimpulse is not captured at all by the model.

ConclusionThe effect of varying end shape on the blastproduced from 400g cylindrical charges ofPE4, with L/D=2, has been investigatedusing a combination of experimental andhydrocode modelling methods. The resultshave clearly supported the findings ofprevious authors, showing that relativelyminor changes to the end shape of thecharge can have a significant effect on boththe shock wave system produced and thepositive impulse of the blast wave at varyingangles around the charge.

The presence of an intrusive conical endprofile produces an axial projectile effectwhich results in a complex shockwavesystem consisting of a bow, secondary andreflected shock wave. In other directions thecomponents of the blast wave are similar tothat from a plane ended cylindrical charge.At small scaled distances, significantlyenhanced positive impulse is generatedalong the axis. This phenomenon is welldocumented and is used commonly in avariety of applications (breeching charges,rock blasting, etc.) to increase near-field axialeffect. What is most interesting is that, whilstthis axial increase tends to decay quitequickly, both experimental and modellingresults agree that a general increase in theblast effectiveness of the charge, at all otherangles and stand-off distances, is achievedby incorporation of the conical cavity.

A protuberant cone ended charge generatesprimary waves which propagate in aperpendicular direction from the surfaces ofthe cylinder and conical profile, and areconnected by a bridge wave. However, incommon with the findings of previousauthors, a further bridge wave is formedalong the charge axis due to Mach interactionof the primary waves produced from theopposing surfaces of the conical end.

A protuberant cone ended charge generatesa definite near-field attenuating effect alongand in proximity to the axis at small scaleddistances, without materially affecting blasteffects in the perpendicular direction. Atgreater distances, the axial and

perpendicular impulse shows smallenhancements, but at the intermediateangles the impulse remains suppressed incomparison to a plane ended charge ofsimilar dimensions.

References1. Bailey, A. and Murray, S. G. (1989), Explosives,

Propellants and Pyrotechnics, 1st ed, Brassey's,UK.

2. Bawn, C. E. H. and Rotter, G. (1956), Science ofExplosives, 1st ed, Her Majesty's StationaryOffice, UK.

3. Cybulski. (Safety in Mines Research and TestingBranch), (1943), Unpublished Work Buxton, UK.

4. Das, J. (2009), Blast Effects and Equivalency ofHollow Cylindrical Charges (Masters of Sciencein Explosive Ordnance Engineering thesis)Cranfield University, Shrivenham, UK.

5. Held, M. (1983), "TNT - Equivalent", Propellants,Explosives, Pyrotechnics, vol. 8, pp. 158-167.

6. Ismail, M. M. and Murray, S. G. (1993), "Study ofthe Blast Wave Parameters from Small ScaleExplosions", Propellants, Explosives,Pyrotechnics, vol. 18.

7. Knock, C. and Davies, N. (2011), "Predicting theImpulse from the Curved Surface of DetonatingCylindrical Charges", Propellants, Explosives,Pyrotechnics, vol. 36, pp. 105-109.

8. Knock, C. and Davies, N. (2011), "Predicting thePeak Pressure from the Curved Surface ofDetonating Cylindrical Charges", Propellants,Explosives, Pyrotechnics, vol. 35.

9. Plooster, M. N. (1978), Blast Front Pressures fromCylindrical Charges of High Explosives, NWC TM3631, Naval Weapons Center, US.

10. Plooster, M. N. (1982), Blast Effects fromCylindrical Explosive Charges: ExperimentalMeasurements, NWC TP 8382, Naval WeaponsCenter, US.

11. Reeves, T. (2010), Determination of BlastParameters - Along the Axis of a CylindricalCharge (L:D of 4:1) (Masters of Science inExplosive Ordnance Engineering thesis)Cranfield University, Shrivenham, UK.

12. Titman. (Safety in Mines Research and TestingBranch), (1947), S.M.R.T.B Annual ReportLondon, UK.

13. Walters. (US Military Academy), (2003), AnOverview of the Shaped Charge Concept(unpublished Report), Westpoint, US.

14. Wisotski, J. and Snyer, W. H. (1965),Characteristics of Blast Waves Obtained fromCylindrical High Explosive Charges, DenverResearch Institute, US.

15. Woodhead. (Safety in Mines Research andTesting Branch), (1947), Unpublished WorkBuxton, UK.

1 A plane-ended cylindrical charge is a solid explosivebounded by two parallel planes and such a surfacehaving a circle as its directrix.

2 At the point where the intersection of the primary andbow/bridge waves was no longer clear, the boundaryhas been extended by use of a polynomialextrapolation, as indicated by the transition from asolid to broken line.

3 Relative Standard Deviation (%) = (Standard Deviation/ Mean) x 100

Further information: scott.bradley@sde-uk.com

34

Dynamo explodersDynamo types are the oldest and do notrequire any form of stored energy, such asbatteries. They work by convertingmechanical energy into electrical energy.8

The operator either twists a handle ordepresses a rack bar – that T handle plungerof my cartoon based ambitions - which inturn operates a dynamo comprising copperbrushes and a commutator.

Most are designed so that the contacts to thefiring circuit close at the end of the stroke.This is to ensure that current is released whenthe electric energy generated is at its peak.9

However, some simple generators do nothave this feature, comprising simply agenerator and a rotating handle.10

Rack bar machines could typically firebetween 20 and 200 detonators in series,while a twist handle machine might beexpected to fire up to 20 in a series.11 Theoutput of a machine depends on its condition,which deteriorates over time, and the effortexpended by the firer. Because mostexploders are designed to only fire at the endof the stroke, it is important to vigorouslyoperate the handle through its full range ofmovement in order to reliably fire the series.

The rack bar exploder illustrated is a BritishExploder Dynamo Mk V, made in 1918. It ishoused in a sturdy wooden box, measuring13 x 8 x 6 inches which was usually paintedwhite. The top is fitted with two brass outputterminals for the firing leads. It was probablyone of these machines that Lawrence wasreferring to and it is entirely typical of earlydynamo exploders. To operate it, the rackwas fully withdrawn, the leads wereconnected to the terminal, then the handlewas smoothly and swiftly pushed down,which operated the dynamo and, when theend of the stroke was reached, closed thecontacts and released the charge.12 Whatcould be simpler or more satisfying?

The standard military exploder of the SecondWorld War was the Exploder Dynamo Mk 7which was also a rack bar machine. Thiscontinued in British service well into the1950s alongside more modern condensertypes. The Mk 7 was a more compact versionof the Mk V and was capable of firing 42shots in series over a cable length of 880yards13 and through a resistance of 150ohms.14

Twist handle machines are smaller andlighter than their rack bar counterparts,although they operate along the sameprinciples. The example pictured is a Drake,

“The exploder was in a formidable lockedwhite box, very heavy. We split it open,found a ratchet handle, and pushed it downwithout harming the ship. The wire was aheavy rubber insulated cable. We cut it inhalf, fastened the ends to screw terminals onthe box and transmitted shocks to oneanother convincingly. It worked.”6

Not knowing that special electric detonatorswere needed, he initially tried to insert hisfiring leads into the open end of a plaindetonator and was puzzled by its apparentfailure to explode.7

One of my greatest disappointments onjoining the explosives fraternity wasdiscovering that the initiation of electricdetonators was no longer achieved byplunging an imposing T shaped handle intothe bowels of a great wooden box. I shouldsay that, at that point, most of my explosivesknowledge had been gleaned from cartoons.

When I took over as Troop Warrant Officer atNortholt Troop, 11 EOD Regiment RLC. I wasmost gratified to find in the Troop museuman exploder of the sort that Lawrence ofArabia and Wiley Coyote had used, completewith an impressive T handle plunger.

Alongside it was a twist handle exploder,and next to that sat an Exploder DynamoCondenser. Along with the Shrike Exploderon the EOD van, these provided a prettygood representative sample of the types ofexploder available and offered a pottedhistory of exploder development.

The role of the exploder (or blasting machine,as they are called in some sectors of industryand in some overseas countries) is to providesufficient current over a distance to initiateone or more detonators or other electricalinitiator.

Exploders must be portable enough to becarried to remote locations, robust enoughto survive the journey and the conditionsencountered, and safe.

They can be divided into two groups,according to their method of operation.These are dynamo types (also referred to asgenerator or magneto types) and condensertypes (also known as capacitor types). Thedifference between the two is that adynamo exploder creates an electric chargeand releases it immediately, while acondenser exploder stores an electriccharge in a capacitor before discharging intothe firing circuit.

ExplodersIt is a New year and a new, but somewhatless aesthetically pleasing, face peers outfrom the header on the Tech Spec page. Onbehalf of everyone who has enjoyed hiscolumn, I would like to thank Pete Nortonfor the splendid work he has done over thelast three years. I know Pete well from ourformer careers as Ammunition Techniciansin the Royal Logistic Corps (RLC) and this isnot the first time that I have found myselfgazing upon the absurdly high standards hehas set and wondering how I am ever toapproach them, let alone meet them.

Back in the June 2012 Journal, Pete wrote afascinating piece on the various types ofdetonators1 and this article follows on fromthat by looking at the means of initiatingelectric detonators. Here I am referring tolow voltage detonators of the type that, Isuspect, most of us are familiar with, and notthe high voltage varieties such as ElectricBridgewire, Exploding Foil or Slapperdetonators. As Pete noted, Henry JuliusSmith patented the electric detonator in1868 and they were in use by the 1880s2. Inthe Saar mining region, between 1907 and1909, it was found that the cost perelectrical shot was higher than those usingigniferous means, but the overall blastingcosts per ton of coal extracted wereconsiderably lower.3

Despite the benefits of electrical initiation,the British army was slow to adopt it. Nomention was made of it in the demolitionssection of the Manual of Field Engineering,published in 1911.4 This all changed duringthe First World War. Writing in The SevenPillars of Wisdom, TE Lawrence ‘of Arabia’discussed using electric detonators insabotage attacks on the Hejaz railway,beginning in 1915.5 Describing theexploder he used, Lawrence said:

Tech Spec

Tech SpecBruce Cochrane MPhil MIExpE

35

to a resistor and is fully discharged.17

An example of an old, but very simple,battery powered machine is the FemcoMulti Shot Condenser Exploder. In this, theoperator inserts and holds down a key,which causes the batteries to charge thecapacitor. A lamp indicates when they arefully charged. When the operator removesthe key, the capacitors discharge into theexternal firing circuit.18

More typical of a modern battery poweredexploder is the Exploder, DC, ElectronicHandheld. This is more familiar to soldiersand engineers the world over as the Shrikeexploder and has found widespread militaryand civilian applications.

I started this article with a thanks and Ishould like to end with some as well. I amindebted to Harry Lewis and Dave Parkes atEODTIC, and to Malcolm Holden at theDefence Explosives Munitions and SearchSchool for supplying much of the technicalinformation which informed this piece.

I hope to look at commercial explosives inmy next few pieces, so if you work in theexplosives industry, please do not be toosurprised if I contact you, begging forinformation. Alternatively, if you have ideasor information on a subject that couldbenefit from the Tech Spec treatment,please do not hesitate to contact methrough the Institute or via email atbtcochrane@hotmail.com.

1 Norton P, Explosives Engineering, June 2012 pp 26-27. 2 Ibid.3 Marshall A, Explosives: Their Manufacture, Properties,

Tests and History, J & A Churchill, London, 1915, p 445.4 Manual of Field Engineering, HMSO, 1911, pp 84 – 96.5 Lawrence TE, Seven Pillars of Wisdom, Jonathan Cape,

London, 1935, p351.6 Ibid.7 Ibid.8 Manual of Field Works (All Arms) 1921 (Provisional),

HMSO, 1921, p 183.9 Blasters’ Handbook, Canadian Industries Limited,

Montreal, 1964. p 63.10 For example, the dynamo exploder included in the

Kit, Rapid Cratering L16A1.11 Blasters’ Handbook, Canadian Industries Limited,

Montreal, 1964. pp 63 – 65 and Marshall, Op Cit, p 446.

12 Manual of Field Works (All Arms) 1921 (Provisional),HMSO, 1921, p 183.

13 AP.1661G. Vol. 1 (2nd Edn.), Sect 6, Chap 1, para 98,EODTIC Bicester.

14 DWS Notes on Ammunition, Issue 6A, sect II, 1942,para 26.

15 Email H Lewis, EODTIC, 21 Jan 2014.16 Blasters’ Handbook, Canadian Industries Limited,

Montreal, 1964. p 63.17 AP.1661G. Vol. 1 (2nd Edn.), Sect 6, Chap 1, EODTIC

Bicester.18 Blasters’ Handbook, Canadian Industries Limited,

Montreal, 1964. p 65.

The exploder illustrated is the Mk II version.It is housed in a moulded synthetic resincase and has a plastic window on top whichcovered a neon lamp. The exploder wasfitted with two output terminals at one endand a firing button and safety switch flap atthe other.

Inside there is a generator which suppliesalternating current to an auto-transformer,an 0.5 microfarad condenser and two metalrectifiers which are arranged in a voltage-doubler circuit and convert the AC currentto DC. This then charges a 6 microfaradcapacitor to between 1100 and 1500 volts.

The neon lamp is connected between tapson the auto-transformer and limits thevoltage to which the capacitor can becharged. It also indicates when thecapacitor is fully charged.

To operate the exploder, the firing leads areconnected to the output terminals. Thesafety switch flap is moved to expose thedynamo armature spindle. This alsoremoves a resistor shunt across thecapacitor. The dynamo handle is crewedonto the spindle and briskly rotatedclockwise to produce AC current, which isconverted to DC and passed to thecapacitor. The neon lamp flashescontinuously when the capacitor is fullycharged.

With the dynamo handle left in position, thefiring button is pressed. This switches thecapacitor connections from the chargingcircuit to the output terminals. Current isreleased into the external circuit and theseries is fired.

If the handle is removed before the firingbutton is pressed, the capacitor is connected

made by ICI. This was a capable of firing sixshots in series.15

The dynamo has given – and still gives -reliable service the world over, especially inplaces where batteries and/or rechargingfacilities are not available. I worked withGreek army EOD teams in 2011 and wassurprised to see them using a 1950s vintagetwist handle dynamo exploder to fire theirrecently purchased and cutting edge EODweapons. It worked perfectly. However, inmost applications, the generator has beenreplaced by condenser machines, thusconsigning the satisfying twist or plunge tohistory and the tender care of WarnerBrothers.

Condenser explodersIn condenser exploders, a charge is stored inone or more capacitors and then released bythe operator pressing a button or carryingout some other action. There are two groupsof condenser machines: those with batteriesand those with a manually operateddynamo. In some cases the low voltageenergy provided by the batteries or dynamois converted to high voltage by a converteror transformer, before being passed to thecapacitors. In others, the batteries orgenerator charge the capacitors directly. Inmost cases, when the capacitors are fullycharged a lamp illuminates. 16

The Exploder Dynamo Condenser was thestandard British military exploder from the1940s to the 1970s. It is typical of acondenser machine in which the capacitorswere charged by the manual operation of adynamo and is similar in concept tocommercial machines such as theBeethoven exploder, which is still available.

Tech Spec

Exploder Dynamo CondensorMk ll, 1950s.

Exploder Dynamo Mk V, 1918. ICI Drake Dynamo Exploder, 1960s.

36

Having previously confessed in these pagesto the guilty secrets of a mis-spent youth, Iam about to open wider the door to thecupboard in which the skeletons are kept.yes, I searched the streets after Guy Fawkes’Night to try to find those delightfully smellyremnants – mostly rockets and aeroplanesbut, if on adjacent fields and allotments,fireworks not normally prone to leaving theground. Now, of course, I know that, far frombeing alone in this activity, there were fellowaficionados all over the country hiding inshadowy corners ready to leap out when thecoast was clear to secure another artefact forthe collection. It is a practice of which I am,now, rather proud since it resulted in acollection of labels still extant. Should I sayothers are envious that certain items (albeitpossibly dirty) are in my collection (andthose of other seekers after unconsideredtrifles) and not in theirs?

No, that can be admitted and few readingthis publication and none reading Fireworkswill turn a hair. But what of using yourchildren as an excuse for such searches indifficult to locate corners? I can rememberthe rockets from our own Guy Fawkes’ partywhich landed in the industrial estatecompound behind our house and whichwould have, otherwise, been difficult toretrieve: ‘I am sorry; my daughter likes tohave the rockets that we fired. Would youjust let us in to…?’ It worked every time. ‘Ofcourse she can come in; now where exactlywas it?

Given that, while perfectly acceptable,firework hunting is not a normal activityamong the uninitiated, such methods wereuseful to get back fireworks which landed inother gardens – in fact I often had knocks on

the door when another find was made by adiligent child working on ‘our’ behalf. Welltrained children (and my daughter washappy to retrieve fireworks and indeedeagerly awaited the following day’sexcursions) are a god-send. you can walkalong whistling while exhibiting a smilewhich tells all who pass by – ‘I do like toindulge my children – don’t you?’ andanother rocket is secured.

While fireworks are not universally loved (it’sa funny world) many use expressions whichhave them as their theme. I wonder howmany who describe a disappointingoutcome as a ‘damp squib’ really know whata squib is. While readers will doubt this, it ismany years since that particular fireworkwas available in this country, or indeedanywhere. There is even disagreement onhow they should be fired. Our squibs wereused like stickless rockets: they would actlike a saucisson, a firework which worms itsway round the garden before (unlike asaucisson) emitting what was always knownas a ‘report’. The curious thing is that I neversaw a squib with instructions on it. Othersinserted them in the ground so that theeffect was one of a gerbe emitting a finalebang.

Ron Lancaster recalled, in an early edition ofFireworks the use of squibs in Huddersfield:‘Squibs were sold when I was a boy inHuddersfield for removing soot in the topsof ovens in old cast iron kitchen ranges. Thesoot collected over the top of the oven andthere was a little door where you couldinsert a flue brush or a squib. It was a handrolled tube funnel and wired with agunpowder charcoal mix and had a grainbounce at the bottom.’ Few would know thatnow.

If we get ejected we ‘get a rocket’. yes, itcould be an allusion to a space craft but theexpression has been around for a long time– long before space travel was an everydaytopic. An old car which emits explosivenoises as it jumps along is called ‘an oldbanger’. A good looking lady is a ‘firecracker’;a bouncing object is like a ‘jumping jack’.Literary references to Roman candles aremany and we are delighted to have a‘cracker’ of a party.

Fireworks are used in advertising – inanything that presages an exciting event.They give meaning to important scenes –are used as a background to a love scene.While the lovers kiss at the end of a film,shells fill the background.

While no longer acceptable subject matterfor comic stories and children’s magazines,exploding shells and cakes illustrateliterature for the young. While Beano wouldno longer tell the story of our hero’s use offireworks, books for children – like FireworkMaker’s Daughter – are still in vogue. I wellremember cartoon strips where fireworkswere used to foil a burglary or do all mannerof good deeds, while misbehaviour withthem was also a topic. Now it is all a bit moreresponsible.

But, like it or not, fireworks are part of life –acceptable in the main. And thoroughlyenjoyable!

John Bennett is editor of Fireworks, a magazine forenthusiasts and the trade. It is obtainable, by creditcard on the website www.fireworks-mag.org or, bypost, from Fireworks, PO Box 40, Bexhill TN40 1GX Telephone: 01424 733050; email: editor@fireworks-mag.org. £10 annual subscription payable to FireworksMagazine.

The Bennett file

The Bennett fileOur columnist John Bennett reflects onthe fireworks references in our language

37

Sidney Alford Column

On trying to be an expertReaders may recall my comments on theProsecution’s case in which my services asan Expert Witness for the Defence had beenrequested1 and in which the seriousness ofthe evidence was indicated by a remarkableweight of about 2.7kgs of printed paperwhich, rumour had it, had generated a bill ofabout £3,000,000. More recently I wascontacted by another firm of InstructingSolicitors about another case and, afterhearing the bones of the allegations, andfeeling that another injustice might behovering, I agreed to cast an eye over theProsecution evidence. This weighed in atjust under 8.7kgs, correspondingproportionally to a hypothetical rumour of£9,666,666. After a couple of days of perusal,I was asked what fees I would charge for myservices.

In April of last year I had read2 of thegovernment’s intention to save money (andget tough on susceptible alleged criminals?)by denying a defendant the right to choosetheir own lawyer but, instead, to beallocated a representative, therebycontributing to a cut of £220,000,000 fromthe billion pound annual budget for criminallegal aid and, incidentally but moresinisterly, no doubt augmenting theconviction rate. On 6th January of this yearcourts fell silent around the country asbarristers, for the first time ever, stayed awayand demonstrated publicly their profounddisapproval.

Being somewhat out of touch with suchmercenary matters, and wondering whatmight constitute a reasonable charge for myservices, I corresponded on the subject withDr Chris Pamplin, Editor of the UK Register ofExpert Witnesses, who kindly gavepermission for the reproduction of datafrom a table from its Expert Witness Survey2013 which presented average chargingrates for report writing and courtappearances according to speciality. Thislisted a series of professions and the averagehourly rates for the writing of reports by hisresponders. These ranged from experts inmedicine (£207), accountancy (£193)3,building (£157), surveying (£152),engineering (£145) and science (£134).

I then corresponded with the Legal ServicesCommission, which classified me as an“Explosives Expert”, and informed me that Icould charge for no more than twenty twohours of preparation - apparentlyregardless of the weight of prosecutionevidence - at £90 an hour, giving a total of£1,980. Thus my efforts were rated at only47% of those of an accountant, 57% ofthose of a builder and 67% of those of a“scientist”.

They presumably considered an “explosivesexpert” to be any one of the thousands ofpeople who have been taught the correctway to label boxes of safety fuse, to blow upunwanted munitions in situ or to pourammonium nitrate slurries from a tankerdown a shot-hole. They paid no heed to thefact that this case related to the allegedpreparation and properties of home madeexplosives (HMEs), and devicesincorporating them -- subjects in which theacquisition of practical experience isforbidden in most places in whichchemistry may be otherwise lawfullypracticed and conventional explosiveslawfully handled or used. This means that"home made" explosives are almostexclusively the domain of criminals and ofthe DSTL (Defence Science & TechnologyLaboratory) Forensics Laboratory which, itso happens, provides the Experts whocompile the Prosecution’s evidence. Thusthe evidence is heavily loaded withallusions to “explosives” even when onecharacteristic of the compositions involvedis to emit hot gas very fast but, for example,as a rocket fuel, definitely not to explode. Itmay be that DSTL’s care for its employees’welfare is such that they are permitted verylittle practical acquaintance with the actualbehaviour of these naughty, naughtysubstances.

One most regrettable aspect of suchprosecutions is that, from the originalExplosives Act of 1875 onwards, the use ofthe word “explosive” was extended fromgunpowder and dynamite to include “everyother substance ... used ... to produce ... apyrotechnic effect”, but which no genuineexpert would dream of describing in reallife as an explosive. Consequently, withoutany malicious intent, any device capable offizzing until it goes pop is likely to bedescribed as an IED (Improvised explosiveDevice) – a term properly applied to bombs– and introduced into Prosecutionstatements related to pyrotechniccompositions in contexts quite unrelated toharmful intent.4

In the recent case I accepted the request toact an Expert Witness for the Defence notfor the paltry payment but in the hope ofseeing justice done. Suffice it to note that,when I had driven three quarters of the wayto the Crown Court with the intention ofdisabusing the Prosecuting Council ofcertain misunderstandings from the dock, amessage informed me that the Prosecutionhad dropped all related charges. The dutyof an Expert Witness is to the Court, not theDefendant, but I saw no reason to quarrelwith their Expert's eventual wisejudgement. They and the police would stillhave found that the case was a nice littleearner.

In his Reflections5, marking his retirementas HSE Chief Inspector of Explosives, NeilMorton commented that, “When I firstencountered HSE in 1977, it was a neworganisation, bringing together inspectorsfrom different backgrounds, with anExplosives Inspectorate staffed by people withsignificant hands-on explosives experience”.As he left, however, “the ExplosivesInspectorate can no longer rely solely onrecruiting experienced people from theexplosives sector”.

If the HSE finds it difficult to recruitinformed experts then so will lawyers.Moreover, there may well be a dearth ofcompetent people willing to argue for theDefence: those who have the expertisetend, inevitably, to feel loyalty to themilitary or civil services whence theyacquired their expertise.

And what does it take to be an “expert”?Why, keeping outwardly calm whenconfronted by such legal statements6 as“The following explosives, together withsmokeless powder, do not require anexplosives certificate” and “Explosive articleswhich ... are intended to be used for thepropulsion of model rockets”.7

1 vide JIExpE, December, 20112 The Law Society Gazette, 8th April 2013 3 A year earlier accountants had headed the list at

£220 an hour: bankers were, alas, not listed.4 See ref. 1 5 vide JIExpE, September, 20136 Control of Explosives Regulations 1991 (as

amended) 7 In reality, smokeless powders, if treated like high

explosives, usually behave like high explosives androcket motors, believe it or not, are designed not toexplode.

The views expressedare those of the author:Our columnist Sidney Alford MSc PhD

reflects on mercenary matters and thedearth of competent people

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The independent educational charity The Smallpeice Trusthas launched a new course timetable for 2014 and is seekinghundreds of 12 to 17 year old students to sample theirengineering taster courses. Any student can apply to attenda wide range of subsidised residential courses which takeplace at universities nationwide. These are designed forstudents with an interest in or natural flair for Science,Maths, Design or Technology with a view to encouragingthem to consider a career in engineering.

The Smallpeice Trust will be running an EngineeringExperience course at the University of Nottingham from14th to 16th April 2014. The course offers one hundredstudents aged 12 to 14 (years 8 and 9) an opportunity toexplore the subject of engineering through a series of real-life challenges. Competing in teams, students will also workon design-and-build projects with young role modelengineers from companies such as Babcock, Jaguar LandRover, Rolls-Royce and the Royal Navy, who will guide themthrough every stage of product development, from initialconcepts to final testing.

Throughout the process, students will be confronted withreal-life issues including the need to work within a budget tomake the project commercially viable. All Smallpiece coursesare linked to the National Curriculum and are designed toimprove core skills such as team building, financialmanagement, communication and problem solving.

Further information:www.smallpeicetrust.org.uk

CamborneSchool ofMinescelebrates125 yearanniversaryA centre of miningexcellence which haspioneered the verybest in industry-led teaching, research and technological advances hasbeen celebrating a truly special landmark. 2013 marked the 125thanniversary of the Camborne School of Mines (CSM) one of the world’sforemost mining and minerals engineering institutions, with eventsthroughout the year.

To celebrate, CSM organised a series of events to help share the passion,enthusiasm and excellence that has become the hallmark over theyears. These included a distinctive Live Wall, an interactive forumdesigned to showcase the highlights, milestones and achievements sinceits inception in 1888. The Live Wall features memories and anecdotesfrom alumni based across the globe, interesting facts and figures aboutthe industry and its relevance and importance to today’s society, andfascinating insights into the history of CSM. It brings togethercontributions from the CSM community, with regular updates andadditions.

Professor Frances Wall, Head of CSM, said: “We are all very excited aboutcelebrating this landmark occasion with the most important part of ourhistory: our staff, students, alumni, collaborators and supporters. CSMhas grown from fairly humble beginnings to now be regarded, quiterightly, as one of the best mulitdisciplinary mining schools anywhere inthe world. Our achievements over the past 125 years are a source ofpride, inspiration and motivation for everyone who is part of the CSMcommunity, past and present. We are sure that the celebrationshighlighted just what we have achieved together so far, and also ourplans for the future.”

Camborne School of Mines has developed an enviable reputation ofproducing pioneering research, focusing on the key challenges ofresource sustainability, environmental production and mine health andsafety.

CSM is recognised as having had a global impact on the mining andminerals industry, by training graduates who are now leading thesector in new and exciting ways. It has also built close relationshipswith local, national and international business, and these collaborationshave helped to promote advances in sustainable mining, geologicalexploration and renewable energy.

2013 was the 20th anniversary of CSM’s association with the Universityof Exeter. It is now located in purpose-built facilities on the PenrynCampus. Anyone associated with CSM who would like to share anyvideos of their work, or messages for the celebrations can upload themto youTube using the hashtag #CSM125.

Further information:www.exeter.ac.uk

Industry News

IndustryNews

Educational charity seeksone hundred 12-14 yearolds for engineeringexperience

“Major Miner”Professor Gour Sen’s book in new editionEngineers Australia have published a new and enlargededition of Professor Sen’s book “Major Miner” in an e-book format at a cost of A$20 per copy.

(See review Explosives Engineering March 2013).

Further information: gour.sen@gmail.com

The Institute ofExplosives EngineersAwards 2013-2014A timely reminder to you all to think about those you havecome into contact with in the explosive-related world. Hereis the opportunity for those individuals to be recognised bytheir peers and receive one of the following awards, whichwill be presented at the annual AGM and Conference heldin Glasgow 1st to 2nd May.

Nobel Lecturer Award: member or non member who is recognisedto have done exemplary work in the field of explosives.

Harold Swinnerton Award: member or non member who hasdone the most for services to the industry.

Rosenthal Silver Salver Award: member who has committed anoutstanding service to the Institute.

Examination Award: for the best student in the EntranceExamination.

Journal award: For the best article in the calendar year published inExplosives Engineering.

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The government's role has causeddiplomatic embarrassment and as recentlyas late last year British embassies wereinstructed to warn host governments that"these systems are not effective … haveeither no working parts or no power source"and to "exercise extreme caution if thesedevices are in use to protect life".

The devices are known to have been sold inThailand, Mexico, Lebanon, the Philippinesand several African countries. In 2001 awarning was circulated across governmentby a senior Home Office scientist who testedan early version of Bolton's bomb detector.Tim Sheldon, of the Defence Science andTechnology Laboratory, said the results werecirculated to about 1,000 officials.

His warning concluded: "Although the ideaof security forces forking out thousands ofpounds for a useless lump of plastic seemsincredible or even funny, a surprisingnumber of people have been taken in. If theyare relying on such devices to detect terroristbombs, the implications are deadly serious."

The government has denied any knowledgethat the equipment was useless and, despiteits own trials, has argued it could not haveknown it was backing a scam. “It is right thatin some circumstances UK Trade &Investment will seek reimbursement forpromotional and advisory services," agovernment spokesman said. "When UKTIbecomes aware that a company has actedfraudulently it will withdraw its support andrefer matters to the appropriate authorities.UKTI has an important job to do in

Industry News

The government accepted thousands of pounds from a fraudster to assist a globaltrade in fake bomb detectors despite aWhitehall-wide warning that such deviceswere "no better than guessing" and could bedeadly.

The Kent businessman Gary Bolton paid thegovernment to enlist serving soldiers and aBritish ambassador in what turned out to bethe fraudulent sale of bomb detectors basedon novelty golf ball finders. Bolton, 48,was sentenced to seven years in jail lastyear for fraud after claims that use of hishandheld devices cost lives and resulted inwrongful convictions.

The ability of UK firms to hire top diplomatsto arrange introductions for as little as £250 atime, and serving soldiers to act as salesmenfor £109 a day plus VAT, without checks onthe authenticity of products, is revealed inWhitehall documents about Bolton's dealingswith the UK government released to theGuardian under the Freedom of InformationAct. The government accepted more than£5,000 in payments from the fraudster tosupply uniformed Royal Engineers topromote the bogus kit at international tradefairs in the Middle East and Europe, and tosecure the backing of Giles Paxman, thebrother of the BBC presenter Jeremy Paxmanand then UK ambassador to Mexico, who setup sales meetings for Bolton's firm withsenior Mexican officials engaged in thecountry's bloody drugs war. The Britishembassy in Manila also helped, and Whitehalltrade bodies took money to support GlobalTechnical at least 13 times from 2003 to 2009as Bolton made up to £3m a year. SentencingBolton last year, an Old Bailey judge said thescam "materially increased the risk ofpersonal injury and death".

One of the devices sold by the fraudster Gary Bolton.Photograph: PA

supporting British business across the worldand is aiming to help 50,000 businesses nextyear. UKTI cannot undertake a test orassessment of all products and services forevery business it supports."

Giles Paxman, who is now retired, said therehad been no reason "to suspect that[Bolton's] activities were in any wayuntoward", but questioned whether thegovernment had the right procedures toalert embassies about dubious products. "Iam sure that I would have very careful not toprovide any specific endorsement of MrBolton's products," he said.

Campaigners against the trade have calledfor officials to be held responsible for theirsupport for Bolton's equipment. Humanrights activists in Thailand have identifiedtwo bombings that killed four people afterthe device was used to check suspiciousvehicles. In Mexico where an estimated1,000 of the devices were sold, campaignerssay they have resulted in convictions ofinnocent people.

In 2009, Bolton paid UKTI's Mexico branch toarrange for Paxman to send introductoryletters on his behalf to officials in statesfighting drug cartels. Diplomats set up salesmeetings, offered to take officials out forlunch as part of Bolton's sales drive, andsuggested using the imprimatur of theembassy for a public relations drive forBolton's equipment.

At arms fairs in Kuwait and Bahrain,corporals in the Royal Engineers were hiredby Bolton to promote the GT200 device, aswell as at security and weapons shows inEurope. Bolton paid the Royal EngineersExport Support Team and UKTI £5,631.93,the trade minister Lord Green has admitted.

Further information: The Guardian, 26thJanuary 2014,

www.theguardian.com/politics.2014

Conman hired soldiers in bomb detector scam

Appreciation awards: In recognition of support of the Instituteor Branch.

Further details are available on the website.

I would really appreciate a flurry of nomination. There are well-deserving people out there that should be congratulated for ajob well done. Please email the secretariat with your nominationsat secretariat@iexpe.org and Vicki will forward those for ourconsideration.'

Fiona Smith AIExpE, IExpE Awards Committee

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your age: 51

Occupation: I am employed by ProNet Group, Inc., aleading forensic engineering firm.

Current position: I am the lead Fire and Explosion Investigatorfor the firm's United States Western Region.

Responsibilities in job/work activities: I determine the origin, cause andresponsibility of fires and explosions. I adviseand participate in the collection of forensicevidence at fire and explosion scenes, andprovide expert testimony regarding fireinvestigation and explosion analysis.

Why are you involved in IExpE? The Institute of Explosive Engineers allowsme to associate with many explosivesprofessionals from diverse backgrounds anddisciplines. In my former public safety firecareer, I was assigned to the department'sarson bomb squad for 18 of my 24 years’service. Prior to retiring as the ChiefInvestigator and Bomb Squad Commander, Iwas certified as a bomb technician for 17years performing basic and advancedtechniques in improvised explosive devicedefeat while specializing in explosives safety,explosives disposal and explosives storageoperations. My current position, when calledfor, allows me to consult and provide an arrayof explosive related analysis.

What are the benefits for you of theIExpE? The ability to participate and network withnumerous explosives professionals in amanner that provides education about allexplosives disciplines while being updatedabout current explosives technologicaltrends. I am proud to be a Member of anorganization which does a superb job ofcommunicating the needs and benefits forthe safe and professional use of explosives intoday’s modern society.

What are your main goals in the next10 years? I am not a scientist, but as a formerexplosives handling practitioner, my goal isto continue to read and study appliedresearch that documents the physics ofexplosive properties, or, a term I personally

Conference / Exhibition Diary

ConferencesExhibition Diary

In a flash:Ben HogeBA (Criminal Justice) I.A.A.I CFICFEI MIExpE

like to describe as "The speed of energy". AsMembers, we are all involved in the businessof using explosives energy to accomplishwork in some form, and currently my jobentails examining explosion scenes todetermine what happened. Understandingexplosives energy and the speed at which itfunctions is critical for both our analysis ofhow to use explosives for good purpose inaddition to evaluating that energy whensomething goes wrong.

What alternative career might youhave followed?My friends know I am a cowboy at heart. Igrew up in the western state of Nevada.Given the opportunity, I would have majoredin agriculture instead of criminal justice andprobably developed a large cow ranchoperation.

Who do you most admire on thecurrent world stage and why? Christine Lagarde, Managing Director of theInternational Monetary Fund (IMF). She tookthe helm of an international organization in2011 amid a crisis with vision and strongleadership acumen. I am always an admirerof those who believe in themselves andultimately triumph in the face of adversity asthey make the best leaders.

Who would you most like to meetfrom any century and why? Raffaello Sanzio da Urbino, also known asRaphael. He was an artist and painter duringthe Renaissance. I studied his works incollege. My favorite work of his is The Schoolof Athens, a fresco. He lived during anenlightening time, and although he is knownprimarily for his sketches and paintings, hiswork in architecture and engineering wasextraordinary for that era.

What are your favouriteactivities/hobbies? Spending time with my family, westernhorsemanship trail riding, camping in themountains and leather craft, which is mypersonal form of art expression.

What is your ideal holiday? My wife finally convinced me to take a 10 daycruise to the Caribbean for our 20th weddinganniversary 4 years ago. I have come toenjoy the cruise vacations as there are somany different destinations to choose fromand the food is just incredible.

What is your favourite type of food? Enjoying a great cut of beef at a good SteakHouse.

GAS, VAPOUR AND DUST EXPLOSIONHAZARDSFaculty of Engineering, University of Leeds,24th to 28th March 2014Protection, mitigation and prediction.Further information: www.engineering.leeds.ac.uk,Email: cpd@engineering.leeds.ac.uk

COUNTER TERROR EXPO 2014Olympia, London, 29th to 30th April 2014The premier international event for theentire security sector, Government, military,law enforcement, emergency services,private sector and security services.Further information:www.counterterrorexpo.com email: counterterrorexpo@clarionevents.com

IExpE AGM AND CONFERENCE 2014Westerwood Hotel and Golf Resort,Cumbernauld, Nr.Glasgow, 1st to 2nd May 2014The theme of the conference is “Developingcompetence in explosives skills”.Further information: email:events@iexpe.orgSee details on page 7.

XVlll SAFEX CONGRESSWarsaw Marriott Hotel, Warsaw, Poland,19th to 24th May, 2014Further information: secretariat@safex-international.org

INTERNATIONAL CONFERENCE ONEXPLOSIVE EDUCATION ANDCERTIFICATION OF SKILLS 2014Karlskoga, Sweden, 11th to 12th June 2014Further information: www.euexcert.org

HILLHEAD 2014Lafarge Tarmac’s Hillhead Quarry, nearBuxton, 24th to 26th June 2014www.hillhead.com

ORDNANCE MUNITIONS ANDEXPLOSIVES SYMPOSIUMDefence Academy of the United Kingdom,Shrivenham, 30th September to 1st October,2014On behalf of the Sector Skills StrategyGroup (SSSSG) of the explosives Industryand Cranfield Defence and Security, thetheme will be “Design for safety ofordnance, munitions and explosives andtheir associated facilities”. There will befour strands to this theme: equipment,facilities, people and policy.Further information: www.symposiaatshrivenham.comSee details on page 7.

IExpE Journal calls for papersDeadline for June 2014 issue is April 30th.

1500 - 3000 word articles and papers will beconsidered for publication and should beaccompanied by digital illustrations eg.photographs, drawings and tables. E mail the Editor: editor@iexpe.org

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