SSPA Highligts 58/2013

PAGE8 –9

Highlights.Issue 58/2013

Brash ice growth - full scale ice testsin the Gulf of Bothnia for the Port of Sabetta

Page 10–11 Page 12 –13 Page 14–16

Page 2–3 Page 4 –5 Page 6–7

City planningusing SEAMANsimulation toolNew bridge, Hisingsbron

Voyage optimisation on the shallow waters of the Baltic SeaThe MONALISA project

Ports prepare forSECA 2015 in LNGinfrastructure projectA validated approach

A proposed design methodology for success-fully developing ESDs Energy Saving Devices

Cutting edge tankerdesign requires outof the box thinkingHolistic optimisations of ships

Ship trafficscheduling in theGöta RiverThe GOTRIS project

2 Highlights 58/ 2013 – Ports prepare for SECA 2015 in LNG infrastructure project

Long-term relationshipsAs a company SSPA is growing, both in size and in adding new knowledge. Our main focus areas are:

• acting as a bridge between research and implementation in the maritime industry• optimisingforenergyefficiencywhile keepingenvironmental,financial,human and technological factors in mind and• ensuring sustainable development through proper risk management.

Our vision remains unchanged as we strive to be recognised as your most rewarding partner for innovative and sustainable maritime development. In order to achieve this vision wehavedefinedfourcorevaluesthatweasacompany believe in and live by. One of them is long-term relationships, which is why our clients’ aims and visions are important to us.

Ever since SSPA was founded in 1940, we have supported our clients with services and expertise in the hydrodynamic sphere. Over the years, the scope of our services has increased and now covers most facets of maritime technology. We believe that long- term relationships, in combination with a high level of integrity, are the most solid founda-tion for gaining clients’ trust. A client must be abletoconfidentlyrealiseitsvisionswithus.New technologies need to be tested, new ideas demonstrated and validated, and SSPA offers the arena, tools and methods to do this. SSPA acts as a bridge between theory and practice, research and implementation, the present and the future.

In this issue of Highlights you will find a selection of articles describing some of our on-going projects. Do not hesitate to contact us, with feedback, comments or questions. We hope you enjoy issue 58 of SSPA Highlights.

I would also like to pass on Seasons Greetings and my best wishes for a Happy New Year to all of SSPA’s clients, partners and colleagues in the maritime society. Thank you all for the opportunitiesgivenandtheconfidenceshownin 2013.

Susanne Abrahamsson

Susanne AbrahamssonPresident

Highlights 58.

Major role enables a validation platformOf seven ports involved, SSPA Sweden AB is responsible for carrying out the pre-investment studies on behalf of Copenhagen – Malmö, Stockholm and Aarhus, and thus plays a major role in the BPO project. The studies of the two former ports are expected to be finalised by Q4 2013, while the study of the latter continues until the end of 2014. For each of the ports the expected deliverables is a report functioning as a decision support, in order to be able to decide if further measures need to be taken for an LNG infrastructure. The studies for each of the ports have varied in extent, from a feasibility study with a first step market analysis, localisation study and investment analysis for Copenhagen Malmö Port to a more extensive study for Aarhus, that, above the feasibility study, also includes getting approval from the authorities, a process

In line with the IMO’s decision on Sulphur Emission Control Areas to be established by 1 January 2015, the Baltic Ports Organization has initiated the “LNG in Baltic Sea Ports” project, co-financed by the EU TEN-T Multi- Annual Programme, with the aim of finding the prerequisites for a harmonised approach on LNG bunker filling infrastructure in the Baltic Sea Area. On the basis of SSPA’s extensive involvement as experts in the introduction of LNG, SSPA has been commissioned to analyse the best options for locations of LNG terminals in Scandinavian ports.

Ports prepare for SECA 2015 in LNG infrastructure project

including a risk analysis, and furthermore developing a pre-design and subsequent design of the planned infrastructure. For Stockholm the initial feasibility study was followed by the preparation of plans on how to arrange LNG bunkering at Stadsgården, in the passenger area. The final part of the Stockholm activity is to prepare a safety manual for bunkering and use of LNG in port areas. The scope of each port activity has differed and running three separate studies within a larger project frame has added to the SSPA in-house expertise in the field of LNG- related projects and provided the opportunity of setting up a validation platform for methods used in these kinds of projects. For the ports involved this means the project set up and methods have been subject to a constant review, which in turn has enabled cross-checking and validating results.

Methods usedAll of the feasibility studies started with market studies and volume estimations, where the use of AIS data for traffic flows in a certain area has given the chance to isolate facts needed for volume estimations. By looking at the number of passages, number of individual vessels and type of vessels, it is possible to gather valid data on traffic patterns. Furthermore, gathering statistics on vessel segments and age structures, combined with outlooks on new building schemes from shipyard order books, makes it possible to predict future changes in certain fleets or traffic flows in various areas. Sensitivity analysis is used as a validation tool for predicting volume estimations, formula-ting high and low LNG scenarios for each individual port, with short- and long-term perspec- tives included, relieving final findings or scenario layouts, also weighing in scenarios of LNG

Density plot of ship traffic in the Kattegat. The plot is created in IWRAP with AIS-data from the Swedish Maritime Administration.

Ulrika RoupéProject Manager. She has an MBA in Environmental Economics, and graduated from Gothenburg University

in 1995. She joined SSPA in 1999 where she works as project manager in environ-mental, development co-operation and transport development projects, both in Sweden and internationally. She mainly works with environmental projects on transports and shipping, environmental economic analysis, risk analysis, coastal zone management, and international cooperation.

Contact informationE-mail: [email protected]

Maria BännstrandProject Manager. She has an M.Sc. in Shipping Systems and Technology with a Major in Shipping

Management and Logistics from Chalmers University of Technology from 2003. She also graduated as a Master Mariner in 1999. She has been employed at SSPA since April 2012, working primarily with simulation studies and with projects linked to alternative fuels. Previous employments includes working at sea and as a ship’s operations manager and as a hull insurance underwriter.


Risk analysis based on case by case.

Rules and regulations process from an EU perspective.

LNG fuelled vesselLNG fuelled vessel

Max radius of heat radiationfrom fire scenarioMax radius of heat radiationfrom fire scenario

Residential buildingsResidential buildings

Public terminal areaPublic access OK during LNG bunkering

Public terminal areaPublic access OK during LNG bunkering

r industrial businessOtherricted accessRestrii

Other industrial businessRestricted access

Hazardouss iinndustrysafety zoneHazardous industrysafety zone

Hazardous industrial activityHazardous industrial activity

Terminal areah restricted accesswith h

Terminal areawith restricted access

Pooteeential conflict zozoonneeoOOveOverOverlapping safety zonenesnPotential conflict zoneOverlapping safety zones

Bunkering safety zoneBuBuncted from heat radiationprotectecte

Bunkering safety zoneprotected from heat radiation

b ib ib ib ibarrierbarrierbarrierbarrierb ibarrierH t di tiH t di tiH t di tiH t di tiHeat radiationHeat radiationHeat radiationHeat radiationH di iHeat radiation bbbbbHeat radiation barrier

Bunkering safety zoneBunkering safety zone

oneoneoneoneoneoneoneoneEx-zEEEEEx zEx zEx zEEx-zEx-zEx-zEx-zzozoEx-zone

Public roadPublic road

LNGG bunker vesG ssssssselsssLNG bunker vessel

price development. Methodology for localiza-tion studies typically includes acquiring infrastructure data, e.g. on land-based users, industries, possibilities of accessing a future terminal with various means of transport and interviews with strategic partners and regional planning authorities. Combining estimated volumes with costs of the various ways of storage, distribution and means of transporta-tion, gives clear indications about suitable locations and choice of terminal from a cost and market analysis perspective. When it comes to risk analysis methods, SSPA follows the FSA methodology (Formal Safety Assessment, adopted and approved by the UN International Maritime Organization). Since, for the Port of Aarhus, the approval process included carrying out a risk analysis, the scope of this risk analysis was based on the legal requirements of the authorities and the EIA procedure. The risk analysis focused on the facility, the terminal and the operational situation, specifically the bunkering procedure. For approval processes, in an overall perspective,

Harmonisation and disseminationIn the “LNG in Baltic Sea Ports” project, the harmonisation and dissemination of results will be secured via a stakeholder platform where key players will be gathered from both the Baltic ports and outside the region. Another important step in the dissemination process is to develop an LNG handbook, which will include a suggested approach for LNG bunkering infrastructure and guidelines on how to set up LNG infrastructure in a port.

it is vital to follow relevant regulations and laws. For LNG implementation these laws differ between countries. In the main, specific national laws apply for the Port of Aarhus, apart from relevant international laws and directives, such as the Seveso EU directive.

EU -Regulations

Parliament - LawEU directive

Government - Regulations

Authorities - Regulations

4 Highlights 58/ 2013 – Voyage optimisation on the shallow waters of the Baltic Sea

Voyage optimisation on the shallow waters of the Baltic SeaThe MONALISA project is focusing on efficient, safe and sustainable maritime transport. A Sea Traffic Coordination Centre, similar to that in the aviation sector, will coordinate vessels by offering them fuel-optimised routes. These green routes are calculated using algorithms developed by SSPA, utilising the legacy of knowledge in hydrodynamics and testing thousands of ships, combined with novel optimisation methods. Evaluations were made on real routes, collected from historical AIS data compared with new optimised routes. The potential of a 12% saving was found in a case study on transit traffic through the shallow waters of the Kattegat.

The STCC conceptWhen a vessel is approaching a sea area under control of a Sea Traffic Coordination Centre (STCC), the captain is offered to send his intended route to the STCC for optimisation. The STCCwill make appropriate changes to the route, e.g. insert constraints like a No Go Area. Since SSPA acts as a service provider the route is sent to the SSPA server via the internet. The SSPA service will deliver an optimised route back to the STCC fulfilling the constraints, and desired time of approach (ETA) with the lowest fuel consumption. The STCC will check the route and then send it back to the vessel. The concept was successfully demonstrated with the vessel POUL LØWENØRN in the Great Belt, communicating with a prototype STCC, which then accesses the server at SSPA.

The SSPA route optimisation routineThe route optimiser is a cloud-based web service that will optimise the route by adding, moving and removing waypoints, ensuring the ETA is still preserved. The route optimiser will also set the optimum speed for each leg in order to minimise fuel consumption. These are the optimisation components:

The geo component• Includes forecasts and depth data.• Continually takes into account the shift in time and place of the weather forecast during optimisation.

The ship component• Calculates the fuel consumption in a 20 m x 20 m resolution grid.• Calculation depends on wind, waves, currents and depth and the interaction with the hull and propulsion characteristics.

The route component• Traversing the area from start to finish to determine the most fuel-efficient way.• Finally it simplifies the route, reducing the number of waypoints and adjusting speed. The depth information is of course essential for optimising a route with sufficient Under Keel Clearance (UKC), but it is also vital for calculating the increased hull resistance due to the squat effect, which should be considered in shallow waters like the Baltic Sea and many other European waters. The optimisation kernel was developed together with the Fraunhofer-Chalmers Research Centre for Industrial Mathematics.

Case study of green routes in the KattegatTo investigate the effect of green routes on the traffic pattern, a study was made of the transiting vessels through the Kattegat based

on actual AIS data compared with simulated AIS data from the route optimisation. The following delimitations were set:• AIS data from one month, January 2012, with about 1,700 vessel movements.• AIS-class 60-89, i.e. passenger ships, cargo ships and tankers.• Transiting between the areas: Skaw, Gothenburg, Great Belt or The Sound.• Vessels must make speed all the time.• Draught greater than 5.3 m.• Wind, waves and current set to predominant values for the region.

The vessel POUL LØWENØRN in the Great Belt, exchanging routes with the STCC ashore in Gothenburg. Geographic scope of the study. The outer

boundary is for the current main traffic in the Kattegat. The green zones are used to identify the present main transit traffic through the Kattegat.

Photo: Jesper T Andersen / jtashipphoto.dk

Highlights 58/ 2013 – Voyage optimisation on the shallow waters of the Baltic Sea 5

The optimisation is free to find new routes without considering today’s routing while still adhering to Traffic Separation Schemes (TSS). The UKC was set at 20% of the draught or at least 1 meter, which is in line with recom-mendations set by HELCOM for vessels in the Baltic Sea. A Safety Ellipse, suggested by Fuji, surrounds the vessel with a semi major axis, four times the ships’ length. The optimisation is made on one specific ship model with the assumption that the relative fuel consumption as a function of speed is around the same for most vessels.

Traffic analysisThe optimised routes generally show a more concentrated traffic pattern. This is not surpri-sing, since a shorter route is beneficial for any vessel. Finding a shorter route also means that the speed can be reduced, which has a heavy impact on the optimisation. In some areas traffic has a wider lateral spread, often an effect from vessels of a higher draught need more depth. Some optimised routes are placed in new areas that must be further investigated in terms of nautical considerations. A significant change in the traffic pattern is the removal of the two “doglegs” in the old pattern route. These doglegs emerge from recom-

mended routes on the chart, but it is possible to take a straighter route. Considering the traffic volume, approximately 20,000 nm could be saved on an annual basis when avoiding the doglegs. The average saving for the transit traffic with optimised routes is generally around 12%. Although this study is limited to a specific region, we have demonstrated a novel voyage optimisation tool suitable for use in shallow waters that are common in Europe and other parts of the world.

Density plot for the current main transit traffic through the Kattegat. Carried out with the IWRAP risk assessment tool, based on Helcom’s AIS data for January 2012. (Recalculated to one year.)

Density plot for the optimised routes. Carried out with the IWRAP risk assessment tool, based on SSPA’s simulated AIS traffic data from optimised routes. (Recalculated to one year.)

The depth information is vital for optimising a

route taking into account the increased hull

resistance due to squat, which should be considered in

shallow waters like the Baltic Sea and many other

European waters.

Project Manager. He graduated from Chalmers Technical University with an M.Sc. in Mechanical Engine-

ering and later gained a B.Sc. in Nautical Science. He has several years’ experience from R&D in the automotive industry. He joined SSPA in 2012 and manages research projects in the e-navigation field and related risk analysis.


Lars Markström

Project Manager. He studied the Masters program Complex Adaptive Systems, in the Engineering Physics

Department, at Chalmers University of Technology. Previously he worked as Product Manager at Playscan AB and as Software Architect at Avail Intelligence, both in Gothenburg, Sweden. Since starting at SSPA in January 2013, he has been involved in various research projects developing route optimisation and mathematical modelling.


Henrik Holm

Facts about MONALISA

MONALISA (Motorways & Electronic Navigation by Intelligence at Sea) started in early 2010 aimed at improving safety and optimisation of ship routes in line with the EU’s Baltic Sea Strategy. MONALISA is co-financed by the EU, Trans-European Transport Network (TEN-T) and the Västra Götaland Region. The project is coordinated by the Swedish Maritime Administration and partners include SSPA Sweden AB, the Danish Maritime Administration, Finnish Transport Agency, Chalmers University of Technology, SAAB TransponderTech AB and GateHouse A/S. The project ends in December 2013 and is followed by MONALISA 2.0, where SSPA will implement a concept of traffic coordi-nation into the green routes and carry out risk analysis tasks.

Read more at: www.monalisaproject.eu

6 Highlights 58/ 2013 – Cutting edge tanker design requires out of the box thinking

Cutting edge tanker design requires out of the box thinkingKeep the cargo flow constant, fulfil the IMO regulations set by the Energy Efficiency Design Index (EEDI) and respect limitations set by harbours and docks. These are just a selection of requirements for a state of the art tanker new building project, all of which must be met with the same hull design. SSPA takes bigger steps towards these targets by thinking out of the box and by applying unconventional concepts and dimensions to a new Panamax Tanker.

Identifying the big gainsOne of the common problems in naval architecture and ship design is that the main deci-sions, those that have the most influence on what the ship will look like and how it willperform, are made at a point in time wherealmost no knowledge of the design’s behaviour,appearance, and characteristics are available.The more time spent on the project, the moreknowledge is gathered but less room is available for changes and improvements. A ship’s power consumption, for example, is primarily influenced by the main dimensions selected, which is done at a very early stage of the project and mainly driven by financial constraints and the dimensions of existing vessels. A commonly carried out hull form optimisation might gain some 5% in power

saving as well as the application of state-of-the-art energy saving devices, but neither can provide the larger gains that can be achieved by optimising the main dimensions.

Hull designers workbenchThe previously mentioned problems can besolved in two ways. The first is to adopt the traditional and well-known design spiral, i.e.repeating every step and every decision untilthe results are sufficient. This way of workingrequires a lot of time and money since everystep in the design process is repeated severaltimes. Finally the optimal result will only bereached if every decision is questioned afterevery single design loop. The second way is to gather as much know-ledge as possible at the very start of the project.

This way of working requires a huge amountof information available from other ships andthe opportunity of using state-of-the-art toolsfor hull design and evaluation, but will ensurean optimised result with fewer working steps by making the necessary information availablewhen the important decisions have to be made. Having a database with several thousand ships’ hulls of varying size, shape and type,SSPA can easily predict the performance of aship with certain dimensions using in-housetheoretical prediction programs. Additionally,SSPA recently introduced simulation-drivendesign to commercial design projects. Theclose coupling of various in-house tools, parametric geometry modelling, and SSPA’s main CFD tool SHIPFLOW, through the cutting edge CAE program FRIENDSHIP-

The chart above depicts the relative importance and performance improvement possible at each individual step in the design process. The first step of selecting the ship’s basic characteristics and form – where the funnel’s diameter is greatest – is also the step in the design process that has the greatest impact towards improving (and impairing) the ship’s overall performance. As the design progresses through each successive step the funnel grows increasingly narrow as more and more of the design is finalized and the performance improvement and impairment potential similarly decreases.

Ship Dimensional Parameter Study

Energy saving devicesPropeller design Rudders

Hull lines optimisation CFD & tank tests (including sea-keeping tests)

Main dimensions

Hull shape

Details

Project Manager. He received his engineering diploma in Naval Architecture and Ocean Engineering at

Berlin University of Technology in 2010. He has been employed at SSPA Sweden AB since 2010 and since then has been involved in various projects in the areas of hull design, model testing and full scale evaluation.


Fabian Tillig

Highlights 58/ 2013 – Cutting edge tanker design requires out of the box thinking 7

Tran

spor

t effi

cien

cyBlock coefficient

Ship A

Ship B

Ship C

Fleet average

Model 1 2 3

Beam (m) 32.2 40 40

cB 0.84 0.84 0.87

speed (kn) 14.6 13.1 12.5

delta (EEDI) 0% -13.8% -13.4%

Framework, allows SSPA to investigate various design approaches and dimensions in a very cost and time-effective manner providing the opportunity for large energy savings even before designing the hull lines.

Future design targetOnly a few months ago ships’ performanceswere measured by their speed at a certain power or a power at a certain speed. The class’s best ship was the fastest. With the introduction of the Energy Efficiency Design Index (EEDI)the measure of a ship’s performance is about tochange. Reduced to its absolute simplest formand assuming that the quality of the engines andthe required auxiliary engines are the same forseveral ships, the EEDI is defined as the installed power divided by the transported cargo, which is represented by speed times deadweight.

Unconventional design approachesAssuming the EEDI as the target function, a ship’s main dimension optimisation can be performed in two different directions. Firstly, one can perform a classic optimisation towards the lowest achievable power for a given dead-weight and installed power. The second app-roach would be to keep the power constant and try to increase the deadweight relatively to thereduction of speed. Additional constraints, such as a maximum length might be applied in orderto meet harbour requirements. Since such anoptimisation might lead to extreme dimensions,like very high B/T ratios, the designer must beopen minded towards unconventional designapproaches, i.e. twin skeg designs for largetankers.

EEDI optimised Panamax Tanker designRecently carried out comparison tests of a twinskeg and a single skeg conventional Panamax

Tanker showed that the delivered power of thetwin skeg design is about 5% lower than that of the single skeg design. These results show that the unconventional approach of a twin skeg tanker seems favourable. Applying the afore-mentioned methods, a study of five different beams and three block coefficients was carried out to optimise the main dimensions to reach the lowest EEDI. In order to simplify the scope of the study the power and length were kept constant. The speed at the given power for each of the 15 designs was evaluated using theoreticalprediction methods based on SSPA’s database.The predictions were checked and calibratedusing full viscous CFD resistance and self- propulsion simulations. The results show that an increase in beam of about 20% can gain up to 13.8% in EEDI, even though the hull form used for the CFD computations of the wider ship was only a scaled version of the original one and thus not optimised for the new dimensions.

The picture shows the transport efficiency (defined by DWTD* VS /PDT) of three single ships and the fleet average as a function of the block coefficient. The graphic shows, that a ship with comparably poor hull lines (Ship B) can be as good as a ship with superb hull lines (Ship C), if the main dimensions are selected in a better way. Ship A combines favourable main dimensions and high quality hull lines and turns out to be outstanding with regard to transport efficiency.

The table shows the attained gains in EEDI. By increasing the beam a reduction in the EEDI of about 13.8% was realized, assuming the power (engines) and the added resistance in a seaway is the same for all three ships.

Visualisation of CFD results for a Twin Skeg Tanker. Pressure distribution and flow lines help the designer to judge the quality of the hull design and find possible areas of improvement.

The tools are available and these exemplary studies prove the validity of this approach: SSPA is ready for holistic optimisations of ships at the earliest design stages. Are you?

8 Highlights 58/ 2013 – Brash ice growth - full scale ice tests in the Gulf of Bothnia for the Port of Sabetta

Brash ice growth - full scale ice tests in the Gulf of Bothnia for the Port of Sabetta

Brash ice forms quickly during frequent passages in an ice channel filling the channel behind the vessel. As the broken ice consolidates between each passage, new brash ice is successively produced resulting in increased brash ice thickness meaning increased vessel resistance. With a lack of additional ice reducing resources like warm wastewater outlets, no alternative fairways and a full operational demand, optimised ice manage-ment and parallel channels are required. However, limited depth in the approach and port area requires dredging and the overall question for the Port of Sabetta was: How many parallel channels are needed to be able to maintain full operation? The field project, initiated to gain knowledge on brash ice growth, started with a pre-defined channel traffic frequency and a maximum acceptable brash ice thickness. The measurement campaign in Luleå was formed by SSPA in cooperation with Luleå Technical University, Luleå Bogserbåts AB and Bertin Technology.

The test channel of approximately ½ nm in the port of Luleå. Inserted is a general example of channel profile. Channel edge depths up to several meters were measured.

Comprehensive measurements; full seasonal variationBrash ice growth and thickness is affected by several parameters such as channel passage frequency, air temperature and radiation. With harsh conditions, seasonal variation and several affecting variables the ability to estimate brash ice thickness was necessary for the Yamal LNG project. In the development work of the brash ice growth model input was needed.

Brash ice profile measurements; input and validationTo gain more knowledge about the phenomenon and give input for validation to a brash ice growth model the dedicated test channel was established in sheltered waters in the Port of Luleå. Channel profiles were measured once a week and controlled passages by the harbour icebreaker m/s Viscaria were carried out twice a week.

SSPA has successfully taken advantage of the easily accessible Gulf of Bothnia, this time for full scale brash ice tests. Brash ice growth and accumulated channel thickness was investigated in an extensive measurement campaign carried out in Luleå during the winter of 2012/2013 on behalf of Yamal LNG and TOTAL.

Photo: Victor Westerberg

Jim Sandkvist

BRASH ICE

Accumulation of small pieces of ice produced by nature or due to repeated breaking by vessels, e.g. in an ice channel.

Seasonal variation of engine load

Jan-1335

40

45

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55

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Feb-13 Mar-13 Apr-13

Channel [%]

Ice free water [%]

Level ice (h = 40cm) [%]

Engine load for each channel passage and corresponding reference tests in level ice and ice free water. Note where channel load crosses the level ice load, hence a parallel channel favourable.

Several ice core samples were taken during the campaign which were analysed in the ice lab at Luleå Technical University. Compression tests and ice analysis under cross-polarised light were some of the tests that were carried out. In addition to the ice and vessel measurements, continuous metocean data such as air temperature, wind speed and radia-tion data etc. were collected. In all, 14 measured channel profiles, about 30 measured channel passages and a vast amount of metocean data providing a well-founded basis for analysing the phenomenon and validation of the brash ice growth model was collected.

Harbour icebreaker m/s Viscaria played a key role in the project performing passages twice a week in the test channel. All relevant variables on-board were monitored and logged by the SSPA Datalogger system.

Increased Vessel resistanceTo make progress in ice, the thrust produced by the prime mover system needs to bridge the total resistance of the vessel. During the controlled passages in the channel, added ice resistance due to increased brash ice thickness was investigated aided by reference tests in level ice and ice free water. By monitoring the engine load during the season and comparing with level ice and ice

Project Manager. He graduated from the Royal Institute of Technology in 2012 with an M.Sc. in Naval

Architecture and joined SSPA after gradua- tion. He is active in Arctic oil spill response as well as ice management, winter naviga- tional projects and simulations. He is a member of the 27th ITTC Ice specialist committee.


Victor Westerberg

In all, 14 measured channel profiles, about 30 measured channel passages and a vast

amount of metocean data was collected providing a

well-founded basis for analysis.

free water loads for the corresponding speed, seasonal variation is obvious. Maximum ice growth and ice extension in the northern part of Sweden usually peaks in March, which corre-lates well with the last winter measurements. If parallel channels are suitable a new channel is preferably opened when channel resistance exceeds level ice resistance, see figure below (marked). Note however that only one level ice thickness is shown in the graph

and channel resistance is shown for various brash ice thicknesses during the season.

Gulf of Bothnia; test area suitable for Arctic mattersThe brash ice measurement campaign is yet another example on the possibilities of the Gulf of Bothnia as a test area for navigation in ice and Arctic operations. A wide variation of ice conditions at a reasonable distance from the ice lab at Luleå Technical University is available. This time the sheltered area with shallow water in the port of Luleå was a perfect location for the measurements. Earlier in 2010, deeper water and pack ice was needed when measurements with a typical Arctic ice management vessel were performed. The Gulf of Bothnia was suitable and the location was used to perform acoustic measurements which are described in Highlights 51/2010.

A proposed design methodology for successfully developing ESDsSSPA has long experience with testing most Energy Saving Devices (ESDs) available on the market and has also been involved in many joint research projects developing energy saving solutions. SSPA, and also other parties within the community, has recognised that there can be a risk if ESDs are developed and applied in a standard routine process only based on model scale, not taking into account the full scale flow effect. This article describes additional steps needed in the development process of ESDs and propose a design methodology for successfully developing ESDs. In order to test and evaluate the proposed design methodology two generic research devices have been created: Generic Device GD-OK and GD-GK.

10 Highlights 58/ 2013 – A proposed design methodology for successfully developing ESDs

Most feasible ESDs to be selectedMost ESDs are used to enhance the flow into propulsion devices, and aimed at increasing propulsive efficiency as well as reducing energy loss. The ESD should be designed based on optimum trade-off between power reduction (favourable effect) and maximum allowable resistance increase/cavitation risk (unfavourable effect). SSPA’s experience has shown that the design of ESDs is specific for a given ship and that the best gain can be reached if the hull/propeller/ESD is optimised together for each specific ship. It is a well-known phenomenon that the flow characteristics in model scale differ from the full scale flow field in the wake. This has been taken into consideration for long time in an experience-based manner by e.g. propeller designers, working both for design, evaluation and extrapolation. Today it is common practice that the performance of ESDs is measured in the towing tank and evaluated with standard extrapolation methods developed for hulls and propellers.

Even though there is a lack of validation studies of Computational Fluid Dynamics (CFD) RANS simulations for full scale ship flow and the results are not yet reliable enough to fully predict global quantities, CFD codes can still be used to under- stand the full scale flow and thereby provide means for better ESD optimisation. As CFD simulations can be conducted at full scale, the scaling problem inherent in model tests can be avoided and the prediction of full scale performance of ESDs can be improved by a combination of model tests and CFD prediction.

Proposed design methodology In order to achieve the best possible result, SSPA proposes a design methodology that makes use of all available technical resources in the most effective way to its full extent, but within the limits of its capabilities. The methodology is presented in three steps below.Step 1: Optimisation of ESD in full scaleThe optimum configuration obtained from model tests/model scale CFD simulation might not be the optimum in full scale. Therefore, the

In order to test and evaluate the proposed design methodology two generic research devices have been created: Generic Device GD-OK and GD-GK.

optimisation of the ESD should be carried out for full scale performance from the beginning. A wide range of design parameter variation studies are performed using full scale CFD simulation. Typical design adjustments can be dimensioning, positioning and shaping parameters of the ESD. Step 2: Confirmation by model testingBased on the evaluation of power gain and detailed analysis of flow characteristics, the most promising ESDs will be selected and tested for confirmation. As the ESD has been designed in full scale, it cannot be expected that it will perform too well in model scale. Normal towing tank testing is necessary though, both for baseline performance without ESD, but also for validation of the CFD in model scale (to be compared to model scale CFD simulations of the proposed ESD). Step 3: Full scale wake dummy hullAs the flow characteristics in model scale differ from actual flow fields around the ship in full scale in the wake region, the efficiency gain prediction from model tests is not sufficient for reliable correlations of power saving between

Keunjae Kim

Michael Leer- Andersen

Project Manager. He graduated from Chalmers University of Technology in 1989 with a Ph.D. in Naval

Architecture. Before joining SSPA in 2002 he had more than 20 years’ experience in ship design at the DSME (Daewoo Shipbuilding & Marine Engineering Co., Ltd.) in South Korea. He coordinates large research projects at SSPA and is currently leading the CFD working group at SSPA Research.


Project Manager. He received his M.Sc in Naval Architecture from Denmark’s Technical

University in 1996. He started at SSPA in 1997 at Research, and has mainly worked in the area of CFD, specifically optimisation, wash wave prediction and friction on rough surfaces, including code development.


Highlights 58/ 2013 – A proposed design methodology for successfully developing ESDs 11

Model and full scale wake in plane of an ESD.

The figure above indicates that an approximate 5~6% power reduction can be achieved by different types of ESDs in model scale as compared to the baseline design. SHIPFLOW computations were able to correctly predict the relative ranking for the ESDs tested. Test cases investigated so far indicates that full scale CFD predicts lower power gains than model test full scale predictions.

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model and full scale. On the other hand, the absolute accuracy by CFD computation is still limited, particularly for predicting global quanti-ties such as speed power performance. To address these issues, and to bridge the Reynolds number range, an additional step intro-duced is the design of a full scale wake dummy hull, which can create a wake which resembles the full scale wake (non-dimensionally). This idea allows for model testing aiming at higher

confidence in the design, both for full scale perfor-mance prediction and possible cavitation/vibration risks. Substantial work has been conducted for the first two steps described above. In order to investigate full potential of the proposed design methodology, a research initiative is ongoing in which the method will be applied to the two test examples. This will investigate the complete design methodology and its potential for the future.

Model scale Full scale

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VelocityX10.950.90.850.80.750.70.650.60.550.50.450.40.350.3

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Ship traffic scheduling in the Göta RiverSSPA participates in the GOTRIS (Göta älv River Information System) project, which aims at optimising the route for ships travelling on the Göta River with respect to planned bridge and lock openings as well as ship meeting places. The project’s aim is to develop a prototype system that makes all information about ship traffic on the Göta River available to all modes of transport that are affected by bridge openings and ship port arrivals. By bringing in the stakeholders and having rail, sea and road traffic sharing information and services in a River Information Service (RIS) system, the project demonstrates how traffic can be controlled regarding the passage of bridges and locks, so that disturbances in rail and road traffic can be minimised, while ship traffic is optimised. SSPA’s role has been to develop the scheduling module that takes into account all of the constraints for the route on the river. These are typically train traffic, bridge maintenance, other ships as well as speed limits.

GOTRIS projectThe GOTRIS project includes a number of partners, with Viktoria Swedish ICT, The Swedish Transport Administration (Trafikverket), InPort and SSPA being the main players in the process of the prototype system development. Viktoria Swedish ICT handles project management, InPort handles the compilation of vessel routes from Safe Sea Net Sweden as well as the graphical user interface for pilots and rail traffic control. The Swedish Transport Administration’s main responsibility is to act as a centre for all data sources, such as train timetables, AIS data and more. SSPA’s role is to develop a scheduling module that can handle the many constraints imposed on traffic on the river. Ideally the algorithm would give each ship a scheduled route from its current position to the next port and also continue to schedule routes to all ports listed in the Safe Sea Net Sweden’s list of ports for the ship.

12 Highlights 58/2013 – Ship traffic scheduling in the Göta River

Testing the prototype systemThe prototype will be tested on pilots, bridge supervisors and rail traffic control. They will each be given a tablet computer with a graphical interface, see figure above. The interface shows estimated arrival times along the river as well as bookings for bridges. This will give the actors more advance notice, thus better ability to plan ahead for incoming traffic.

Scheduling algorithmThe Swedish Transport Administration’s server delivers all input data to the SSPA scheduling module. Data consists of train timetables, weather information, pilot bookings, departure times from ports etc. The module schedules all traffic and for each ship it returns a list of holding times at a number of positions along the river. The scheduling module consists of two chained algorithms. The first one is a basic

deterministic rule-based approach that computes a baseline route. The baseline route fulfils all ship-related constraints, such as speed limits and bridge bookings, but it doesn’t take into account inter-ship related constraints, such as meetings and overtaking. The second step is an evolutionary algorithm that, based on the baseline route, handles the more advanced inter-ship related restrictions and also, if necessary, reduces the number of speed changes along the route.

Evolutionary algorithmsAn evolutionary algorithm is an optimisation technique based on Darwinian principles, i.e. survival of the fittest. For a given problem, the input values are expressed as a genome with a fitness function constructed for evaluating the problem with the genome input. If it’s a maximisa-tion problem then the higher the value returned from the fitness function the better that set of genes solves the problem. A large population of input values, i.e. individuals, are created and in each generation all individuals are tested with the fitness function. The best ones continue to the next generation, hence Darwinian. The task for the evolutionary algorithm is to find the individual (in our case the vessel) that either maximises or minimises the fitness, depending on the type of problem being solved. Evolutionary algorithms have their advantages. They are well-suited when the problem at hand has many viable solutions and a large number of variables and in the case when there is no deterministic algorithm that solves the task optimally. In more casual terms they are usually a good approach when the solution is more easily defined in terms of what it shouldn’t be than how it’s supposed to be.

Pilot user interface in the GOTRIS prototype.

GOTRIS evolutionary algorithmIn the scheduling module, the Göta River is divided into a long list of segments and the genome is the speed on each of those, so a ship with a route that spans 30 segments has a genome with 30 speed values. In each generation hundreds of route candidates are created, all of them initially a small variation of the base line route. The fitness function evaluates each route and calculates a value of how well that particular route solves the problem. It is a combination of calcula- tions, a set of sub-functions, one for each restric- tion. In general, fitness functions are continuous, meaning that a very small variation of the genome will generate a small change in the fitness value. However, there are situations where binary elements are inevitable, e.g. in the case of GOTRIS when the route tries to pass a blocked bridge, then the fitness function will return a very large fixed amount, to indicate that the route is not a good solution.

Objectives of the GOTRIS fitness functionThe objective is to reduce fitness according to the following criteria:• proportional to comfort speed deviation• if speed is below the ship’s minimum speed• proportional to the deviation from near segment’s speed• if the ship tries to pass a bridge that is blocked• if the ship doesn’t pass the bridge when it has a booking• if the ship has a meeting outside of the desig- nated meeting zones.In this context it is easier to discard routes that do not fulfil all constraints than it is to actuallycalculate a route that does.

AssessmentThe benefit of using an evolutionary method is that it finds solutions that would be hard to calculate with a deterministic set of rules. This is especially true in GOTRIS when it comes to reducing the number of speed changes on the route. It handles this while still taking bookings and meetings into account. Another advantage is that special logical cases don’t need any separate handling, instead the route is simply discarded when it breaks the constraints. This however comes with a penalty: computational time is long. There are other alternatives for optimisation, such as the Simplex method, but the fact that evolutionary algorithms always return a solution and that it is possible to further refine a solution by continuing for more generations, makes it a very suitable approach in the GOTRIS project.

Next stepsThe system for scheduling and the ability to get an overview of the upcoming 24 hours of rail and ship traffic makes it possible to utilise resources, such as bridges, more effectively. It also means that planned maintenance can be carried out with less impact on infrastructure and potentially allowing it to put a figure on the capacity of the system as a whole. The environmental impact is also addressed, since the pilot receives an early overview of the speed required to arrive on time for bridge bookings. The next steps for the GOTRIS project is to evaluate the prototype, getting feedback from pilots and traffic control on how well GOTRIS performs. This input will be used in the design of a future fully operational system.

Peter GrundevikVice President, Head of SSPA Research. He received his Ph.D. in physics from the University of Göteborg/

Chalmers University of Technology in 1982. He then worked at Ericsson Radio Systems developing sensor techniques. In 1993 he became president of Dyning Utveckling, developing communication systems. He joined SSPA in 1997 and has worked with telematics, navigation technologies, and intermodal transport as well as project co-ordination.


Henrik HolmProject Manager. He studied the Masters program Complex Adaptive Systems, in the Engineering Physics Department, at Chalmers

University of Technology. Previously he worked as Product Manager at Playscan AB and as Software Architect at Avail Intelligence, both in Gothenburg, Sweden. Since starting at SSPA in January 2013, he has been involved in various research projects developing route optimisation and mathematical modelling.


Schematic of the GOTRIS area. Graphic: Viktoria Swedish ICT

The GOTRIS project is funded by

• Swedish Governmental Agency for Innovation Systems• The Swedish Transport Administration • City of Gothenburg• Region Västra Götaland • Kristinehamn Municipality• Karlstad Municipality• Region Värmland

Read more at www.gotris.se

14 Highlights 58/2013 – City planning using the SEAMAN simulation tool

City planning using the SEAMAN simulation toolDesigning a new bridge over a river passed by inland vessel traffic will always be a challenge, both for the visual look as well as for the safety of vessels passing under and traffic on the bridge. SSPA is contributing to the design process of the new bridge, Hisingsbron, being built in the city of Gothenburg. It is doing this using the SEAMAN simulator. Clients such as the Gothenburg city architect, the design team from COWI and stakeholders from the shipping industry have been able to evaluate the bridge to be built.

A situationThe pilot leans back in his chair. He has safely navigated the ship from Lilla Edet, has just passed the Marieholmsbron bridge and there are only two bridges left to pass until this journey will end for him. He can see the newly built bridge “Hisings-bron” slowly opening its leaves in front of him as he is approaching it. Suddenly the bridge leaves stop dead with the bridge only half open. After a short moment the bridge-watch announces over the radio that there is a malfunction in the bridge’s machinery, and it will stay in its current state until further notice. The pilot realises immediately that he will not be able to pass under the bridge in its present state, and as the ship is travelling with the current it will be too much of an effort to simply stand-by in front of the bridge. He will have to rest the ship against the fenders on the bridge

guard designed for precisely this type of event. But is such a manoeuvre possible, and is it safe? Can the pilot trust that the design of the bridge guards is sound? Fortunately the situation above is taking place on a SEAMAN simulator at SSPA. Hisingsbron is not yet built, and before COWI decides on the design of the bridge guards they will take every measure to ensure that the guards can pass scenarios like the one described above. One measure that has been taken is to set up a SEAMAN simulation to test the design’s safety.

The bridgeThe new river connection will form a connecting link between the north and south bank of the river and contribute to the transformation of the Freeport and Gullbergsvass areas. The connection is not

Is the manoeuvre possible and is it safe? Different situation alternatives were created on the SEAMAN simulator at SSPA.

only a transportation link, but also a major urban development project and an attractive symbol for the City’s future. Hisingsbron is to replace the existing Götaälvbro and to go into operation

Through SEAMAN and SSPA’s manoeuvring

experts, knowledge is brought to clients in a way that answers the questions

that each specific client may have. SEAMAN is designed from the start

to be flexible.

Screenshot from the simulation. Before the final design of the Hisingsbron will be decided, every measure will be taken to ensure that the guards can pass scenarios like the one described in the article.

around 2020. The project’s total construction period is planned to be approximately five years. A program outline was drafted and consultations were held in autumn 2009. The height of the new bridge will be 13 meters and it will be located just upstream of the existing Götaälvbron. To start with, at least 80,000 public transport users, 5,000 cyclists and pedestrians, and 30,000 drivers will be using the bridge on a daily basis.

The challengeSSPA continually works as a partner with large design and construction companies, as well as municipalities in city planning. SSPA’s contribu-tion in the close cooperation with clients is usually to provide logistic best practice, design collision avoidance measurements, ice management, evaluate maritime risks and simulate vital

Götaälvbron in the City of Gothenburg as it is today. Hisingsbron will replace the existing bridge around 2020.

hazardous situations during construction and operation. In this specific project SSPA worked closely with COWI and the Municipality of Gothenburg to evaluate maritime risks and the nautical effects of the new bridge’s design.

The main parts of the mission were:• To verify safe ship passage of the new bridge• During construction work: • To verify safe passage of the construction site and old bridge. • To eliminate or reduce risks introduced to shipping during all stages of construction, which was done by simulating identified critical steps in construction.• To form a documentation to enhance existing risk analysis focusing on injuries onboard passing vessels.

Highlights 58/ 2013 – City planning using the SEAMAN simulation tool 15

All has been done to maintain safe and effective vessel traffic during the construction and during operation.

The simulationsSEAMAN is a simulation framework designed in-house at SSPA. It draws upon SSPA’s 70 years of experience of hydrodynamics and ship manoeuvring. Through SEAMAN and SSPA’s manoeuvring experts that knowledge is brought to clients in a way that answers the questions that each specific client may have. Since each client is unique, and each question is unique, SEAMAN is designed from the start to be flexible. In this particular case the visual cues gained from the bridge opening and closing was important for the client. SSPA modelled the bridge so that the

Photo: Jim Sandkvist

Johan GahnströmSenior Project Manager and Business Developer. He has a B.Sc. Nautical Science from 1987 and holds an unrestricted

master license. Captain Gahnström recently rejoined SSPA again after having started up a new gas and chemical terminal as CEO/harbor master. Previous experience range from setup of a new LNG terminal in Soyo, Angola, work in Ras Laffan, Qatar and Swedish Maritime Administration. His background includes work with LNG, VTS, marine piloting, management, ISPS and cargo control.


Linus AldebjerProject Manager. He studied Engineering Physics at Chalmers University of Technology. Previously he worked as Software Architect at

Saab Underwater Systems, Motala, Sweden. Since he was employed at SSPA in January 2011, he has been leading the work to upgrade SSPA’s simulation tool, SEAMAN. He has also been involved in various research projects developing route optimisation and mathematical modeling.


opening times were close to those in reality, which enabled the previously described simulation to be carried out realistically.

The resultsWhat happened with the pilot and the malfunctio-ning bridge in the situation? The pilot successfully manoeuvered the ship to the bridge guard, from which he could proceed once the bridge was functioning again. The bridge design proved sound, at least for this scenario. During the two days when the simulations were conducted, 64 other scenarios were simulated, discussed by the

65 scenarios were simulated, discussed by the pilots and SSPA’s manoeuvering experts, and then graded for safety. This will help ensure that there will be fewer surprises once the bridge is actually built.

16 Highlights 58/2013 – City planning using the SEAMAN simulation tool

pilots and SSPA’s maneuvering experts, and then graded for safety. This will help ensure that there will be fewer surprises once the bridge is actually built. Considering that the bridge is expected to last for 120 years, those days in the SEAMAN simulator can be considered time well spent.

SSPA Highlights is published by:SSPA SWEDEN ABBox 24001, SE- 400 22 Göteborg, Sweden.Phone: +46 31 772 90 00 Fax: +46 31 772 91 24E-mail: [email protected] Web: www.sspa.seMH100890-01-00-A

SSPA’s vision is to be recognised as the most rewarding partner for innovative and sustainable maritime development. To always offer the latest knowledge and best practices, about 20 per cent of the compa-ny’s resources are engaged in research and development. The Swedish government founded SSPA in 1940 and in 1984 it was established as the limited company SSPA Sweden AB. The company has been owned by the Foundation Chalmers University of Technology since 1994.

SSPA offers a wide range of maritime services, including ship design, energy optimisation, finding the most effective ways to interact with other types of transportation, and conducting maritime infrastructure studies together with safety and environmental risk assessments. Our customers include shipowners, ports, shipyards, manufacturers and maritime authorities worldwide.

Our three focus areas are:

• SSPA acts as a bridge between theory and practice, research and imple mentation, the present and the future. The foundation is the ability to provide unbiased expertise, advice, and services to our customers and other stakeholders.

• SSPA ensures sustainable development through proper risk management in close cooperation with the customer.

• SSPA has the financial, environmental, human and technological factors in mind for optimal energy efficiency.

Our head office is located in Gothenburg and we have a branch office in Stockholm.

You can also download Highlights at www.sspa.se

Documents

SSPA Highligts 58/2013