external logbook gdc

JOMO KENYATTA UNIVERSITY

OF

AGRICULTURE AND TECHNOLOGY

(JKUAT)

SCHOOL OF ELECTRICAL AND ELECTRONICS ENGINEERING

DEPARTMENT: ELECTRICAL AND ELECTRONIC ENGINEERING

STUDENTS EXTERNAL ATTACHMENT LOG-BOOK

DURATION: 8 WEEKS MINIMUM

JKUAT is ISO 9001:2008 Certified Setting Trends in Higher Education, Research and Innovation

JKU/2/33/11

THE LOG BOOK

1. INTRODUCTION This book is to assist the student to keep record of the training. It will show the departments and sections in which the student has worked and the periods of time spent in each.

2. DAILY REPORT The daily work carried out during the periods of training is to be recorded clearly with sketches and diagrams where applicable.

3. WEEKLY REPORT This is a summary of work done in a week and should cover theory/practical report on the work covered.Students are required to present the log-book weekly to the industry based supervisor for assessment of content and progress. The Supervisor can use any page for his comments where necessary.

4. CHANGE OF ATTACHMENT A student is expected to start and finish his industrial attachment in one establishment. If it becomes absolutely necessary that he must change his place of attachment, the student should first secure permission in writing from the college.His application for change of place of attachment should indicate the name and the address (not just Post Office Box) of the Company or industry to which he wishes to transfer. Any attachment not properly authorized will be canceled.

5. COLLEGE SUPERVISOR'S VISIT The training Supervisor of the JKUAT will check the log-book when he/she visits the project to ensure that the proper training is being received, and record his/her comment on the paper provided for this purpose, towards the end of the book.

6. SPECIAL REQUEST FOR THE INDUSTRY-BASED SUPERVISOR Please assess the student as per assessment form provided.

7. REPORT WRITING In addition to the daily and weekly record the student should submit a summary report of the work done during the attachment duration e.g. full coverage of the course, problems encountered. Suggest improvements to make the programme worthwhile.The report should contain a summary of activities of the organization, manufacturing services processes the student was involved in.This co includes the highlights of the project the student was involved in. The student is expected to point out the weak and strong points of the attachment.

8. REPORT SUBMISSION The log-book and report must be submitted to the relevant departmental Attachment Co-coordinator at the end of the attachment


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S T U D E N T ‘S P A R T I C U L A R S

Name of Student: ..........JEFF M. WANJALA..

(Surname First)

Registration No. of the student:....EN271-C007-0046/2010...

Department: ...... ELECTRICAL AND ELECTRONIC ENGINEERING.

Course of study: ....Bsc. ELECTRICAL AND ELECTRONIC ENGINEERING.

Year of course: ....... 5TH YEAR.........................................

Name and Address of Company/Establishment Attached: THE GEOTHERMAL DEVELOPMENT COMPANY (GDC)

P. O. BOX 100746, 00101 NAIROBI KENYA

Name of Industry-Based Supervisor: .......................................

...................................................................................................

...................................................................................................

Duration: From: .......9TH January 2015.

To : ..........20TH April 2015.


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AG. MANAGING DIRECTOR & CEO

CORPORATE AFFAIRS DIVISION

CONSULTANCY, RESEARCH & DEVELOPMENT TECHNICAL SERIVICES

LEGAL AFFAIRS AND COMPANY SECRETARY HUMAN RESOURCE

REGIONAL OPERATIONS

DRILLING SERVICES

COMMERCIAL SERVICES

Planning and Logistics

Operations

MANAGING DIRECTOR'S OFFICE

Equipment Maintenance

JKU/2/33/11

The student could draw the organization chart of industry attached hereunder.


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ATTACHMENT TIME-PLAN

(The student should draw a time-table indicating time to be sent on each task/section).


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WEEKLY PROGRESS CHART (WEEK ENDING...13TH FEB..........)

DAY DESCRIPTION OF WORK DONE

Mon.

Introduction to GDC drilling department of technical services.Orientation was done and training module was given with the aim of getting one to understand the sole role of the drilling department in GDC.

Tue.

THE OCCUPATIONAL SAFETY & HEALTHThe health general provision entails cleanliness, overcrowding, lighting, drainage of floors and sanitary conveniences.Personal safety by ensuring all times wearing the right protective gear.

Wed

Cleanliness. Every workplace shall be kept in a clean state, and free from effluvia arising from any drain, sanitary convenience or nuisance, and, without prejudice to the generality of subsection. Accumulations of dirt and refuse shall be removed daily by a suitable method from the floors and benches of workrooms, and from the staircases and passages; the floor of every workroom shall be cleaned at least once in every week by washing or, if it is effective and suitable, by sweeping or by any other method;

Thur.

Overcrowding.

(1) An occupier shall ensure that his workplace shall not, while work is carried on, be so overcrowded as to cause risk of injury to the health of the persons employed therein.

(2) Without prejudice to the generality of subsection (1) a workplace shall be of sufficient size for work to be carried out with ease and shall further have the necessary free space and , having regard to the nature of the work ,an adequate amount of air for each employee , the minimum permissible being ten cubic metres per person:

Frid.

Lighting.

(1) An occupier shall ensure that effective provision is made for securing and maintaining sufficient and suitable lighting, whether natural or artificial, in every part of his workplace in which persons are working or passing.

(2) All glazed windows and skylights used for the lighting of workrooms shall, so far as practicable be kept clean on both the inner and outer surface and free from obstruction:

Provided that this subsection shall not affect the white-washing or shading or windows and skylights for the purpose of mitigating heat or glare.


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TRAINEE'S WEEKLY REPORT

I reported to GDC on 9th February 2015 were I was given the company’s rules, regulation, safety standards and my training ,annual that shows what was going to be covered during my entire period for the industrial attachment.Operation and maintenance of rigs, Operation and maintenance of motors, Operation and maintenance of generators were the sub topics of my curriculum. In order to appreciate the importance of the above system in relation to workshop practice we were familiarized with QMS, EMS, and OHS.

1. Cleanliness.

(1) Every workplace shall be kept in a clean state, and free from effluvia arising from any drain, sanitary convenience or nuisance, and, without prejudice to the generality of subsection (1)—

Accumulations of dirt and refuse shall be removed daily by a suitable method from the floors and benches of workrooms, and from the staircases and passages;

The floor of every workroom shall be cleaned at least once in every week by washing or, if it is effective and suitable, by sweeping or by any other method;

all inside walls and partitions, and all ceilings or tops of rooms, and all walls, sides and tops of passages and staircase, shall: Where they have a smooth impervious surface, at least once in every period of twelve

months, is washed with hot water and soap or cleaned by other suitable method; where they are kept painted with oil paint or varnished, be repainted or varnished at

least once in every period of five years, or such other period as the director may deem necessary, and at least once in every period of twelve months be washed with hot water and soap or cleaned by other suitable method; and

Provided that where it appears to the Minister that in any class or description of workplaces or part thereof any of the provisions of this section are not required for the purpose of keeping the workplace in a clean state, or are by reason of special circumstances inappropriate or inadequate for such purpose, he may, if he thinks fit, by order direct that those provisions shall not apply to any workplace, or part of a workplace, of that class or description, or shall apply as varied by the order.

(2) An occupier who contravenes the provisions of this section commits an offence.

2. Overcrowding.

i. An occupier shall ensure that his workplace shall not, while work is carried on, be so overcrowded as to cause risk of injury to the health of the persons employed therein.

ii. Without prejudice to the generality of subsection (1) a workplace shall be of sufficient size for work to be carried out with ease and shall further have the necessary free space and , having regard to the nature of the work ,an adequate amount of air for each employee , the minimum permissible being ten cubic metres per person:

iii. Provided that, in determining, for the purposes of this sub-section the amount of cubic space in any room, no space more than four point five metres from the floor shall be taken into account, and, where a room contains a gallery, the gallery shall be treated for the purposes of this subsection as if it were partitioned off from the remainder of the room and formed a separate room.

iv. Every workroom shall be not less than three metres in height, measured from the floor to the


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NOTE: USE BACK PAGE FOR THE CONTINUATION OF THE REPORTFOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ...13THE FEB..................(Additional drawings, may be attached where necessary)The student may also use this space for additional reports.

Lowest point of the ceiling or, where there is no ceiling, to the lowest point of the roofing material:

Provided that, if the Director is satisfied that owing to the special conditions under which the work is carried on in any workroom the application of the provisions of this subsection to that workroom would be inappropriate or unnecessary, he may by certificate in writing except the work room from those provisions subject to any conditions specified in the certificate.

(4) An occupier who contravenes the provisions of this section commits an offence.

1. Ventilation.

An occupier shall ensure that effective and suitable provision is made for securing and maintaining, by the circulation of fresh air in each workroom, the adequate ventilation of the room.

The Minister may by rules, prescribe a standard of adequate ventilation for workplaces or for any class or description of workplaces or part thereof and for any other places of work.

An occupier who contravenes the provisions of this section commits an offence.

2. Lighting.

(1) An occupier shall ensure that effective provision is made for securing and maintaining sufficient and suitable lighting, whether natural or artificial, in every part of his workplace in which persons are working or passing.

(2) All glazed windows and skylights used for the lighting of workrooms shall, so far as practicable be kept clean on both the inner and outer surface and free from obstruction:

Provided that this subsection shall not affect the white-washing or shading or windows and skylights for the purpose of mitigating heat or glare.

Student's Signature: .................................... Date: ..16th February 2016...……………......

Comments by Lecturer/Supervisor: ......................................................................................................

.......................................................……………………………………………………………..........

Name: ...................................................………………………………………………………........

Signature: ........................... Date: .............……………………………………………………....


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WEEKLY PROGRESS CHART (WEEK ENDING: ...20TH Feb.................)


Mon.MACHINERY SAFETY

Safe use of plant, machinery and equipment. All plant, machinery and equipment whether fixed or mobile for use either at the workplace or as a workplace, shall only be used for work which they are designed for and be operated by a competent person.

Tue.

Prime movers.

(1) Every flywheel directly connected to any prime mover and every moving part of any prime mover, except prime mover referred to in subsection (3), shall be securely fenced, whether the flywheel or prime mover is situated in an engine-house or not.

(2) The head and tailrace of every water wheel and of every water turbine shall be securely fenced.

(3) Every part of an electric generator, motor and rotary converter, and every flywheel directly connected thereto, shall be securely fenced.

Wed.Transmission machinery.

(1) Every part of transmission machinery shall be securely fenced.

(2) Efficient devices or appliances shall be provided and maintained in every room or place where work is carried on by which the power can promptly be cut off from the transmission machinery in that room or place.

Thur.Other machinery.(1) Every dangerous part of any machinery, other that prime movers and transmission

machinery shall be securely fenced:(2) Every workplace shall be kept in a clean state, and free from effluvia arising from any

drain, sanitary convenience or nuisance, and, without prejudice to the generality of subsection. Accumulations of dirt and refuse shall be removed daily by a suitable method from the floors and benches of workrooms, and from the staircases and passages; the floor of every workroom shall be cleaned at least once in every week by washing or, if it is effective and suitable, by sweeping or by any other method;

Frid.Hand held and portable power tools and equipments.

(1) Every employer shall——

(a) be responsible for the safe condition of tools and equipment used by his employee s, including tools and equipment which may be furnished by the employees;

(b) Ensure that no equipment or portable power tools shall be used in an environment that contains or is likely to contain flammable vapours or substances unless they are intrinsically safe for such environments.

Sat


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TRAINEE'S WEEKLY REPORT MACHINERY SAFETY

1. Safe use of plant, machinery and equipment.

All plant, machinery and equipment whether fixed or mobile for use either at the workplace or as a workplace, shall only be used for work which they are designed for and be operated by a competent person.

2. Prime movers.

Every flywheel directly connected to any prime mover and every moving part of any prime mover, except prime mover referred to in subsection (3), shall be securely fenced, whether the flywheel or prime mover is situated in an engine-house or not.

The head and tailrace of every water wheel and of every water turbine shall be securely fenced.

Every part of an electric generator, motor and rotary converter, and every flywheel directly connected thereto, shall be securely fenced.

3. Transmission machinery .

Every part of transmission machinery shall be securely fenced. Efficient devices or appliances shall be provided and maintained in every room or place

where work is carried on by which the power can promptly be cut off from the transmission machinery in that room or place.

Every machine intended to be driven by mechanical or any other type of power shall be provided with an efficient starting and stopping appliance, the control of which shall be in such a position as to be readily and conveniently operated by the person operating the machine.

No driving-belt when not in use shall be allowed to rest or ride upon a revolving shaft which forms part of the transmission machinery.

Suitable striking gear or other efficient mechanical appliances shall be provided and maintained and used to move driving-belts to and from fast and loose pulleys which form part of the transmission machinery and any such gear or appliances shall be so constructed, placed and maintained as to prevent the driving-belt from creeping back on to the fast pulley.

The Director may by certificate in writing grant, subject to any conditions specified in the certificate, exemption from compliance with any of the requirements of subsections (2), (3), (4) and (5) in any case where he is satisfied that compliance with the requirement is unnecessary or impracticable.

4. Other machinery .

Every dangerous part of any machinery, other that prime movers and transmission machinery shall be securely fenced:

Provided that, in so far as the safety of a dangerous part of any machinery cannot by reason of the nature of the operation be secured by means of a fixed guard, the requirements of this subsection shall be deemed to have been complied with if a device is provided which automatically prevents the operator from coming into contact with the part.


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NOTE: USE BACK PAGE FOR THE CONTINUATION OF THE REPORTFOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ........20TH FEB.............

(Additional drawings may be attached where necessary)The student may also use this space for additional reports.

(2) Any part of a stock-bar which projects beyond the head-stock of a lathe shall be securely fenced.

1. Hand held and portable power tools and equipments.

(1) Every employer shall——

Be responsible for the safe condition of tools and equipment used by his employee s, including tools and equipment which may be furnished by the employees;

Ensure that no equipment or portable power tools shall be used in an environment that contains or is likely to contain flammable vapours or substances unless they are intrinsically safe for such environments.

(2) All power driven portable and hand held tools shall have their operating controls so located as to minimise the possibility of their accidental operation if such an accidental operation would constitute a hazard to the worker or other persons.

Student's Signature: ................................................. Date: …23rd February 2016……

Comments by Lecturer/Supervisor: ......................………………………………………...........

...............................................................………………………………………………………...

..........................………………………………………………………........................................

Name: .......................……………………………………………………...................................

Signature: ........................... Date: ......…………………………………………………...........


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WEEKLY PROGRESS CHART (WEEK ENDING: ...27TH Feb..........)


Mon.Power SystemThe power system of the drilling rig ZJ70 is made up of main diesel generating set, auxiliary diesel generating set and generator room

Tue.Generator parallel operation• For generator sets to operate in parallel and balance the system load between them, these basic conditions must be met.• All engines must be running at the same speed.• The voltage of the alternators must be the same.• The response of the AVR and governor control must be the same.When the voltages are rising and falling at the same time they are said to be in synchronization and connections can be made by safely closing the generators circuit breaker in this state to put the generator on line.

Wed.

Putting the generator on lineThe circuit breaker is made ready (charged) by whatever method it is designed for. Either by mechanical charging using the lever, which will normally need to be operated several times until the spring is charged. This action will disengage automatically to prevent overcharging the spring. Or it will be charged by an internal electric motor, in the same way, ready for the circuit breaker to close at the push of a button, or automatically by the system.

Thur.Synchronizing procedureSynchronization is the act of bringing a generator on line, connecting it to the live electrical system. The actual synchronizing procedure is the adjustment of the generator frequency (speed) to match that of the generators on the switchboard. The incoming generator’s speed pot, on the switchboard, is used to adjust the frequency or speed of that machine to the speed of the machines already on the switchboard.

Frid.Rule of thumbAs a rule of thumb with the generator to be put on line, it should be running slightly faster than the machines already on line, and the breaker is closed at roughly the 5-to-12 position, and by the time breaker closes the generator will be exactly in sync with the system. To ensure the incoming generator will be generating a small load when the circuit breaker is closed it should be running slightly faster than the switchboard.

Sat.


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TRAINEES' WEEKLY REPORTThe main diesel generating set of 4 generators CAT3512B are installed in 4 main generator rooms. According to requirements of the operated conditions, the generating set is under SCR electric drive system control, which can make each of the generating set running singly or in parallel, to distribute the network load equally and make the voltage frequency normal and steady. For the detailed information of the main diesel generating set, please see the “Operation and Maintenance Manual” of the generator CAT3512B.The auxiliary diesel generating set is made up of the diesel engine, the generator, the matching substructure and the systems of electricity, control, cooling and exhaust. This set is installed independently in a generator room, providing long-term excellent and steady alternating current power, realizing the automatic long distance monitoring without watchman. See the “operation and maintenance manual of diesel generating set CAT” for detail.Main generator room consists of 5 machine rooms. Four main generators CAT3512B are respectively installed in the four rooms, in which the auxiliary generator unit and air system are installed in No. 5 room and tools cabinet and file bench are equipped in suitable place. The 5 generator rooms form closed entirety after distribution in well field; and rain-proof cover plates are connected between various room roofs. And power cables of all the rooms are located on the top of roofs and are introduced into the electric control room via Cable Bridge.1) The Equipment and Structure Feature of the Generator Room

The main generator room is made up of substructure, column, roof, valve, sliding door, smoke evacuation system, air passage, fuel and lubricant passage, distribution and lighting system, cable channel and hanging ladder, etc.

To facilitate the installation and maintenance of the generating set, the column and the substructure, the column and the roof are connected with bolts

There is a discharge outlet at the lower part of the substructure. On the surface of the substructure near the water tank is the connecting threaded hole for the grounding cable, and on the same side is the faucet for fixing the hanging ladder

There are smoke evacuation and water nozzles on the roof of each generator room, and the water nozzle is equipped with funnel for the infusion of cooling fluid.

The fuel, lubricant and air passages are set under the walkway pad of each generator room. The oil and gas input and output ends between the generator rooms are connected with dismountable tube, and equipped with valve according to the requirement.

To facilitate the operation, maintenance ventilation and radiating of the diesel generating set, the valve and sliding door of the side wall can be dismantled, and the operator can decide whether dismantle them or not according to the factor of drilling period.

The roof of each generator room is equipped with cable channels, which are fixed on the cross-beam of the roof with bolts. Before hoisting the roof, the upright cable channels should be dismantled, in case the cable channels are damaged.

In order to prevent the rain and the sand, connecting boards are used to cover between the generator rooms and between the generator rooms and the SCR electrical control room

NOTE: USE BACK PAGE FOR THE CONTINUATION OF THE REPORT


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FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ....27th FEB.............(Additional drawings, may be attached where necessary)The student may also use this space for additional reports.

Figure 1 - Generators in engine room of a jack-up rig.

Student's Signature : ............................................. Date: .2nd march 2016…………......

Comments by Lecturer/Supervisor: .......……………………………………….........................

............................................................………………………………………………………......

............................................................……………………………………………………….....

Name: ....................................................…………………………………………………........

Signature: .............................. Date: .................……………………………………………..


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WEEKLY PROGRESS CHART (WEEK ENDING...6th march.......)

DAY DESCRIPTION OF WORK DONE ON MAINTENANCE IF SCR

Mon

ACTION RESULT1. Preliminarya) Ensure that SCR Unit to be a) SCR On light will glow.tested will not be assigned from b) Blowers under the SCR bridge will switch on.the Control Console.


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b) Energise the AC bus, if required. c) On DC Control Module, Power On and Zero Throttle Interlock lights will glow.

c) Close the SCR circuit breaker.

Tue.

2. SCR Bridge Checka) On the DC Module, set the Observe the front panel DC voltmeter. The voltage will climb

smoothly to 750 VDC as the knob is rotated clockwise, and return to 0 as the knob is rotated counterclockwise.

spring-loaded Manual Voltsswitch to “on”.b) Rotate the Manual Volts knobslowly clockwise to “Max.” andback down to “Min.”

Wed.

3. Contactor and Throttle Checka) Trip the SCR breaker. This will allow us to close the assignment contactors without

applying power to the motors. In each position, check contactor (CONT) and Throttle Reference (REF) signals from

b) Jumper the auxiliary contact ofthe breakerc) Set the Control Consoleassignment switch to variouspositions.d) Remove aux. contact jumperwhen all CONT and REF signalsare checked out.

Thur.

Firing Pulse Checka) Ensure that SCR Unit under test SCR On light will glow and blowers will switch on. Check firing pulses to each of the 6 SCRs with an

oscilloscopewill not be assigned at theDriller’s Console.b) Open the SCR circuit breaker.c) Set the spring-loaded ManualVolts switch to “On” and turn the

Manual Volts knob a ½ turn.

Frid.4. After completing the test close SCR breaker. Be sure Manual Volts switch is off.Example: Place the ground lead on K terminal of the Firing Pulse transformer and Probe on the G terminal.

Sat.

TRAINEES' WEEKLY REPORT During this week specific functional test were carried out to assure proper operation of the SCR unit. The tests were carried out after recalibration of the unit assemblies.

THEORY OF OPERATION SCR Bridge


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A 3Ø AC supply from the bus is applied to the SCR bridge through a circuit breaker. Each AC phase is connected to two SCRs. One SCR feeds positive AC portion to the DC (+) bus and the other SCR feeds the negative AC portion to the DC (-) bus. For example, 3ØAC is connected to A+ and A- SCRs. A + SCR feeds the DC (+) bus while the A- SCR feeds the DC (-) bus.DC (+) and DC (-) buses are connected to loads via assignment contactors. The SCRs are switched on and off to vary the DC level through firing pulses applied across the GATE (G) and CATHODE (K) terminals of each SCR. The firing pulses are generated in the DC Control Module

Circuit Breaker.The breaker is equipped with a set of auxiliary contacts. A normally open contact is interlocked with the front panel SCR ON light. Another normally open contact is a part of the Assignment Contactor logic.The breaker also has an undervoltage (UV) trip coil. The breaker is tripped automatically if the power supply to the coil is interrupted. Positive terminal of the coil is permanently connected to a +14Vdc power supply. The negative terminal is connected to a -14Vdc supply through various normally closed switches which signal the following hazardous conditions.

SCR Overtemperature. There are two temperature sensors. Sensor TS11 is mounted on the DC (+) bus and TS21 is mounted on the DC (-) bus. The sensor contact is designed to open when the SCR junction temperature exceeds 220°F (125°C).

Blown SCR Fuse. Fuse protection for the SCR consists of high speed indicating silicon fuses. The UV Trip circuit is wired through trigger fuse microswitches of all the SCRs.

o A trigger fuse is connected across each Main fuse assembly. If a main fuse blows, the micro-switch trigger activates. The trigger fuse has a long plunger which is set close to the micro-switch arm. When the fuse blows, the plunger pushes into the arm, causing the micro-switch contact to open.

Emergency Off. The UV Trip circuit is also interlocked with normally closed EMERGENCY OFF button on the Driller’s Console.

Firing PulseA pulse transformer is used to invert and double the SCR firing pulse supplied by the DC control module. The current pulse rises in less than 20 n Sec. to approximately 1 amp to “hard fire” the SCR. It then descends to a 0.5 amp “backporch” to force more and more of the SCR to turn on through a regenerative process

DC Foot Throttle OperationA Foot Throttle is provided for the Drawworks for quick response from the SCR bridge during tripping. The DW Foot Throttle reference (pin 114) is applied directly to the current regulator summing the junction, skipping the speed feedback junction. Therefore, it acts as a current NOTE: USE BACK PAGE FOR THE CONTINUATION OF THE REPORT

FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ............6TH MARCH……...

(Additional drawings, may be attached where necessary)The student may also use this space for additional reports.


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Command. When the Driller presses the foot throttle, current to the Drawworks motors rises quickly and the voltage follows.The DW speed reference from the Driller’s Console hand wheel (pin 117) and the DW foot throttle reference are auctioneered through D10 and D59 to select the higher (more negative) throttle command. When the driller begins a tripping operation, he first sets the Drawworks to cathead speed by slightly cranking the hand throttle. This enables the foot throttle via a microswitch on the hand throttle. When the driller presses the foot throttle to lift a heavy load, the foot throttle reference quickly supersedes the DW speed reference.The foot throttle reference goes to zero when the driller removes his foot from the throttle.As a result, the DW speed reference takes over, and the motor speed and torque return to cathead values

Student's Signature: .................................................... Date: ....9th march 2016....

Comments by Lecturer/Supervisor: ............………………………………....................

..............................................................………………………………………………...

...............................................………………………………………………..................

Name: ................................................…………………………………………............

Signature: ....................... Date: ..................………………………………………...

WEEKLY PROGRESS CHART (WEEK ENDING ...13th march........)

DAY DESCRIPTION OF WORK DONEMon. Sensors

Audit of sensors on the rig: this includes H2S gas sensors, water level sensors, temperature sensors, speed sensorsLocating the sensors on the rig and testing if they are still functional.

The H2S gas sensors that were faulty were replaced with new ones. As to avoid being


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Tue. choked by the gas.

Wed.The water level sensors were found to be fully working after checking then by sending a signal from the control panel and a feedback was received. This helps in knowing how much water is used, left and needed for the drilling.

Thur.The speed sensors at the mud pumps were found to be faulty as they gave strokes per minute that differ.

Frid.Calibration of all the sensors at the rig.

Sat.

TRAINEES' WEEKLY REPORT

During this week of my attachment I was surprised how possible sensors are still used at large in drilling and learnt the integral part they play. How to service them also gave me an eye opener.

A sensor is often defined as a device that receives and responds to a signal or stimulus.This definition is broad. In fact, it is so broad that it covers almost everything from a human eye to a trigger in a pistol.The sensors do not function by themselves; it is always a part of a larger system that may incorporate many other detectors, signal conditioners, signal processors, memory devices, data recorders, and actuators. The sensor’s place in a device is either intrinsic or extrinsic. It may be


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positioned at the input of a device to perceive the outside effects and to signal the system about variations in the outside stimuli. Also, it may be an internal part of a device that monitors the devices’ own state to cause the appropriate performance. A sensor is always a part of some kind of a data acquisition system. Often, such a system may be a part of a larger control system that includes various feedback mechanisms.For calibration, it was noted that if the sensor’s manufacturer’s tolerances and tolerances of the interface (signal conditioning) circuit are broader than the required system accuracy, a calibration is required. To calibrate sensors, it was essential to have and properly maintain precision and accurate physical standards of the appropriate stimuli.

Nothing is perfect in this world, at least in the sense that we perceive it. All materials are not exactly as we think they are. Our knowledge of even the purest of the materials is always approximate; machines are not perfect and never produce perfectly identical parts according to drawings. All components experience drifts related to the environment and their aging; external interferences may enter the system and alter its performance and modify the output signal. Workers are not consistent and the human factor is nearly always present. Manufacturers’ fight an everlasting battle for the uniformity and consistency of the processes, yet the reality is that every part produced is never ideal and carries an uncertainty of its properties. Any measurement system consists of many components, including sensors. Thus, no matter how accurate the measurement is, it is only an approximation or estimate of the true value of the specific quantity subject to measurement, (i.e., the stimulus or measurand). The result of a measurement should be considered complete only when accompanied by a quantitative statement of its uncertainty. We simply never can be 100% sure of the measured value.

NOTE: USE BACK PAGE FOR THE CONTINUATION OF THE REPORTFOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ......13TH MARCH...........(Additional drawings, may be attached where necessary)The student may also use this space for additional reports.


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Water level sensor Fire gases sensor H2S sensor

Student's Signature: ............................................................ Date: .........16th march 2016.

Comments by Lecturer/Supervisor: .........................…………………………………......

...................................................………………………………………………….............

.................................................…………………………………………………................

Name: ...........................................………………………………………………...............

Signature: ................................................... Date: .………………………….................

WEEKLY PROGRESS CHART (WEEK ENDING...20th march........)



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Mon. Motors Audits of the motors were carried out; this includes shale shaker motors, pump motors tank motors. This was to give a visual of what motors on the rig count and type.

Tue.Testing motors for rewinding and bearingRecommended the faulty motors either for rewinding or bearing replacement.

Wed.

Testing motors for rewinding and bearingRecommended the faulty motors either for rewinding or bearing replacement.Cleaned the functioning motors.

Thurs.Testing motors for rewinding and bearingRecommended the faulty motors either for rewinding or bearing replacement.Cleaned the functioning motors.

Frid.Testing motors for rewinding and bearingRecommended the faulty motors either for rewinding or bearing replacement.Cleaned the functioning motors.

Sat.


We started with Operation and maintenance of motors. The type of motor that was to be repaired


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was an induction motor. It was important to note that the induction motors are popularly used in the industry. Focusing on three phase induction motor; its main features are cheap and low maintenance despite this advantages its speed control is not easy.

Induction motors are used in pumps, fans, conveyer and mixers in the company.The basic parts of an AC motor are the rotor, stator and enclosure. The stator and rotor are electrical circuits that perform as electromagnets. The stator is stationary consisting of laminations stacked together to form a hallow cylinder. Coils of insulated wire are inserted into the slots of the stator core. The stator winding were connected directly to the power source.The rotor is the rotating part of the electromagnetic circuit. It can be of either squirrel caged or wound rotor. The squirrel cage type is composed of copper bars embedded in rotor slots and shorted at both end by end rings. It is simple, cheap, and robust and needs little maintenance. While the wound rotor type, the rotor winding is wound by wires. Winding terminals can be connected to the external circuit through slip rings and brushes. It is easy to control speed but makes it expensive.

The enclosure consist of a yoke and two end brackets that protects the electrical and operating parts from harmful effects also the fans fitted is used for cooling. Another important component is the name plate that is attached onto the motor. It shows the type of motor, current rating, horse power rating, and speed in revolution per minute, frequency, voltage rating and name of the constructing company.Information from the name plate provides important data needed for motor rewinding that would be taken elsewhere for rewinding.

NOTE: USE BACK PAGE FOR CONTINUATION OF THE REPORT FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ...20TH MARCH..............(Additional drawings, may be attached where necessary)The student may also use this space for additional reports.


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The different types of motors used.

Student's Signature: ............................................. Date: .....…23rdmarch 2016.

Comments by Lecturer/Supervisor: .............................………………………....

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Name: ....................................................……………………………………......

Signature: ....................... Date: ..........…………………………………...........

WEEKLY PROGRESS CHART (WEEK ENDING: 27th march.2016..)


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DAY DESCRIPTION OF WORK DON

Mon.Lighting system. Audits of the lighting system were carried out since the visibility at night was poor.This was to give a visual of what luminaires on the rig count and type. Including those in the containers.

Tue.Battery back-up emergency lights Testing the emergency backup lights for their ability to stay illuminated for the period specified in the manufactures specifications and to comply with the HSE requirements

Wed.Safety restraints The safety chains were checked to stop a loose fitting from falling from height.

Thur.Lamp replacement Both fluorescents and mercury vapour lamps degrade over time and the lighting value falls so slowly that it is hard to see the difference unless a new lamp is installed and then a great difference will be seen in the output. During the drilling break it was a good idea to change some of the old lamps for new ones to upgrade the lighting output

Frid.Lighting control Usually in the machinery areas, there was no local light switching; the only isolation for these circuits will be back at the distribution panel, which was in a non hazardous area such as the switchboard, MCC or accommodation. There should be dual lighting circuits in these areas so that there is always light if one circuit should fail.

Sat.



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There is a variety of lighting types to be found around the rig. The rig floor is the most important area on the rig. The driller and drill crew need to be able to see clearly to conduct the drilling operation safely at all times, and in all conditions.Lighting distribution normally starts at the lighting distribution panel, which will be situated in a non hazardous area such as an SCR room, MCC, or accommodation depending on the size of the rig. The Distribution Panel is normally supplied from a 480/208-volt transformer which is delta connected on the primary side to a 480 VAC supply from the switchboard or the MCC by a breaker or switchgear which will protect the supply to the distribution panel. On the secondary side the transformer will be star- or -Y-connected to produce 120 volts phase to neutral for lighting and small power, and 208 volts phase to phase will be available so that three phase 208 VAC can be obtained from the distribution panel.Since, Rig power installations vary considerably, depending on the country standards used by the design and building teams. Acceptable American standards, which are commonly used, do not always ground the neutral of the secondary of the transformer used in lighting circuits, indeed the neutral is often at 120 VAC with respect to ground.A single pole breaker is used on the live side only. This means that a 208/230 VAC fixture can be used. In this case although the light will go out when switched off all power is not removed from the fixture and 120 VAC still remains on the neutral side. Great care must be taken when maintaining these fixtures as electric shock is possible from the ungrounded neutral side. Do not assume the fixture is totally "dead" without thoroughly checking first with a multimeter.Any lighting circuit in a hazardous area needs to have both the live and the return broken by a switch or other device before it enters the Hazardous area. For this reason most lighting in hazardous areas are supplied by double pole circuit breakers.All of the lighting circuits are brought back to a distribution panel for termination. The circuits can be isolated at this panel for repair or fault finding by opening the breaker for that particular circuit and locking it out for safety. This method can also be used when looking for a ground fault on the main switchboard by turning off the breakers one by one until the ground/earth detection lights go out when the breaker is opened to the faulty circuit.Note: Please see above paragraph and thoroughly check the fixture before assuming it is "dead" as the neutral may still be alive, and can only be deenergised by disconnecting the neutral it at the distribution panel from the "neutral" terminal strip, this will need to be done with care as the terminal strip will be alive as well, not grounded as it would be in other systems.On larger rigs there will be many distribution panels. The distribution panels will be found in the area being catered for such as the galley, mess room or accommodation, where there may be many outlets, and the main breaker to supply that distribution panel will be back at the switchboard or MCC.

NOTE: USE BACK PAGE FOR CONTINUATION OF THE REPORT


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FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: 27TH MARCH............... (Additional drawings, may be attached where necessary)The student may also use this space for additional reports.

Different luminaries at the rigStudent's Signature: ........................................................ Date: ...…30th march 2016.

Comments by Lecturer/Supervisor: ..................................………………………………..

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Name: .................................................……………………………………………..........

Signature: ............................................ Date: ....................…………………………...WEEKLY PROGRESS CHART (WEEK ENDING: 3rd April.........)

DAY DESCRIPTION OF WORK DONEEarthing system


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Mon. Generally maintenance required is the inspection of the earthing system for broken or damaged earth-bonding cables or straps and replacing them if required. A check was made for corrosion damage of the cables or terminations where it will be necessary to change damaged earthing cables, lugs, or securing bolts to maintain the earth/ground link for earth continuity

Tue.Assorted earth cablesThe only spares one can keep for this system is cable of the required sizes. On a land rig this will be some fairly long lengths from structure to structure to keep all the separate modules and structures linked to and tied down to a common earth.

Wed.Assorted cable lugsA selection of cable lugs will be required to suit the various sizes of cable used. There should be only two or three for all the different earthing connections around the rig.

Thur.Earth stakes and terminatorsA stock of earth stakes and terminators are always required. In some locations where a good earth is hard to find due to very dry ground, you may require earth stakes that can be extended by screwing them together with connectors or couplings until the rods reach the water table or damp ground.

Frid.Testing motors for rewinding and bearingRecommended the faulty motors either for rewinding or bearing replacement.

Sat.


In electricity supply systems, an earthing system defines the electrical potential of the conductors relative to that of the earth's conductive surface. The choice of earthing system has implications for


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the safety and electromagnetic compatibility of the power supply. Note that regulations for earthing (grounding) systems vary considerably between different countries.

Grounding Fundamentals

Equipment connected to earth - Potential equalized.

A protective earth (PE) connection ensures that all exposed conductive surfaces are at the same electrical potential as the surface of the earth; this avoids the risk of electrical shock if a person touches a device in which an insulation fault has occurred. It ensures that in the case of an insulation fault to ground, a very high current flow, will trigger an overcurrent protection device (fuse, circuit breaker) that disconnects the power supply.Earthing is the system of connections to the general mass of the earth/ground. Earthing systems are usually installed for one or more of the following purposes:

As part of implementation of protective earthing of the power distribution system. For conducting lightning discharge currents to earth. As part of control power supply which is referenced to ground.

It is important that all electrical equipment is securely earthed. This includes all parts that may be separated by gaskets, flanges, valves or steel frames. Any part where a potential difference will be created should a fault occur will need a bonding cable or strap attached to carry any fault current. All these points will need to be bridged with cable and terminated correctly either side of the joint to ensure that the fault current will not cause an arc or spark across the joint, such as the mounting feet of the motor to the mounting frame, or the mounting frame to the deck.

Maintenance proceduresAn inspection of a major drilling contractor's maintenance system shows no dedicated earthing routine. This may look strange but the inspection of the earthing of individual equipment and systems is part of that equipment. What about the earthing for the rig after a rig move? Or the earthing of the structures? When would you inspect these? An inspection of these points should be done as you walk round.

NOTE: USE BACK PAGE FOR CONTINUATION OF THE REPORT FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: ...3rd April..............



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A missing earth is of no consequence as it still not stop any equipment working. It will however reduce the effectiveness of the electrical protection. The other thing it will not do is protect people. To put it another way it will increase the possibility of injury to people.Injury to people may not just be the electrical shock. If the person who gets the shock is in a position where they could fall into moving equipment downstairs or lose their grip on the heavy loads they are carrying all cause injury.

Fig. Earth bonding of equipment.

Student's Signature: .......................... Date: ....6th April 2016....……………………

Comments by Lecturer/Supervisor: ........................………………………………….......

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Name: ......................................……………………………………………......................

Signature: ............................................. Date: .......………………………………...........

WEEKLY PROGRESS CHART (WEEK ENDING: ...10th April........)



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Mon.The water level sensors were found to be fully working after checking then by sending a signal from the control panel and a feedback was received. This helps in knowing how much water is used, left and needed for the drilling.

Tue.PLC The basic PLC consists of a chassis, a central processing unit (CPU), a power supply module, and input and output modules. The PLC will also have an operator interface and connection port for a programming device, such as a laptop computer, so that the CPU can be programmed or the input/output functions manipulated if required (forced).

Wed.Input module The input module is designed to accept a variety of digital and analogue signals from various controls and sensors and convert them to logic signals that can be used by the CPU. The CPU will then make decisions based on those signals and execute control decisions based on the programmed instructions in the memory.

Thur.Output module The output modules will convert the control instructions from the CPU into digital or analogue signals that will be used by various field devices to act upon those instructions, such as the contactor in a starter.

Frid.Laptop connection To program the PLC, a laptop computer is often used because it serves various functions and it can be used to download the instructions which will determine what the PLC will do with a specific input signals from the sensors. The programming can be displayed on the monitor to indicate changes, and new parameters can be entered or changes made to the programme as required

Sat.


Before the introduction of the PLC, the majority of equipment control on rigs was with the use of relays and contactors to start and stop various motors during drilling operations. This in general was


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known as a hardwired control system, where wiring was run from the MCC to the start/stop stations and from the MCC to the motor to give control over that motors operation.With this introduction the wiring changed so that the start/stop buttons are now connected to the input modules of the PLC, and the start/stop buttons became input sensors. The coil supply of the motor starter contactor is now connected to the output module connections of the PLC which then becomes an actuator. The functions of the input/output modules (I/Os) can be changed in the PLC programming if required, so that normally closed contacts can be changed into normally open contacts and vice versa. Therefore it is now easier to modify control commands in the PLC than it was in the old, hardwired systems.Changes to the functionality of the equipment can be easily made by reprogramming the PLC. Most PLCs have integrated diagnostic and override functions. Applications can be easily documented and duplicated much more quickly and with less cost.The PLC is a computer and will store information in the form of ON or OFF conditions (1 or 0), referred to as binary digits (bits). Sometimes the binary digits are used individually and sometimes to represent numeric values. Various number systems are used in PLCs, and all the numbering systems have the same characteristics: digits, base, and weight. It is the same decimal system that is used in everyday life.

The heart of the PLC is the central processing unit (CPU), which is a microprocessor unit that contains the system memory. The CPU is the PLC's decision-making unit, as it monitors the inputs and makes decisions based on the programme stored in the memory to activate outputs. The CPU performs various functions such as scanning, counting, timing, data comparison and sequential operations.

Figure - Ladder logic on the PLC CPU.

Early PLCs were designed to be used by electricians who would learn PLC programming on the job. These PLCs were programmed in "ladder logic", which strongly resembles a schematic diagram of relay logic. Modern PLCs can be programmed in a variety of ways, from ladder logic

NOTE: USE BACK PAGE FOR CONTINUATION OF THE REPORT

FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: .....10TH April............



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to more traditional programming languages such as BASIC and C. Another method is State Logic, a very high-level programming language designed to program PLCs based on state transition diagrams.Recently the international standard IEC 61131-3 has become popular. IEC 61131-3 currently defines five programming languages for programmable control systems: FBD (Function Block Diagram), LD (Ladder Diagram), ST (Structured Text, similar to the Pascal programming language), IL (Instruction List, similar to assembly language) and SFC (Sequential Function Chart). These techniques emphasize the logical organization of operations.While the fundamental concepts of PLC programming are common to all manufacturers, differences in I/O addressing, memory organization and instruction sets mean that PLC programmes are never perfectly interchangeable between different OEMs. Even within the same product line of a single manufacturer, different models may not be directly compatible

The PLC programming is achieved through a repetitive process called scan. A PLC scan will start with the CPU reading the inputs. The application programme is performed using the status of the inputs. Once programming is completed, the CPU will perform internal and diagnostic tasks. The scan cycle will end by updating the outputs and the restart. The cycle time will depend on the size of the programme, the number of I/Os and the amount of communication required.

Scan cycle being processed by CPU.

Student's Signature: ..................................... Date: ......13th April 2016..……………


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Name: ......................................……………………………………………......................

Signature: ....................... Date: ...........…………………………………………...........WEEKLY PROGRESS CHART (WEEK ENDING: 17th April.........)



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Mon.Cable typesMany of the cables used on oil and gas exploration rigs are of the flexible type. There are many manufacturers around the World who produce high current, high voltage cable suitable for supplying power to items such as DC traction motors, This cable is produced by companies such as Olex, Beldon and Helukabel, and one that is well patronized, Rockbestos Surprenant Cable, which produces the heavy single-core DC-type cables, as well as the Exane cables for the lighter applications.

Tue.Cable traysThe only inspection normally required is to check that the cable tray covers are not loose, that the earth bonding is intact, that there are no securing bolts missing or loose, and that there are no broken cable ties, particularly on the vertical runs. On older facilities you may have to inspect occasionally for corroded or broken brackets, clamps, or damage from other operations such as overhead cranes, where loads have hit the cable trays while the loads are being moved around the rig.

Wed.CablingThe condition of the cables that are supported by the cable tray is of importance, especially where exposed to direct sun light. Plastic cable ties may have deteriorated to a point where they are no longer effectively attaching the cable to the trays and will need replacing. This will be more obvious on sections of cable tray that are hung vertically or transverse bulkheads on their side.

Thur.The water level sensors were found to be fully working after checking then by sending a signal from the control panel and a feedback was received. This helps in knowing how much water is used, left and needed for the drilling.

Frid.Testing motors for rewinding and bearingRecommended the faulty motors either for rewinding or bearing replacement.

Sat.


Normally the only maintenance required will be the trays that are damaged, this often occurs when they have been hit by a crane load. In this case it will all need to be put back to its original condition by removing any damaged sections and installing new sections in their place. If this is has to be


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done, then the grounding will need to be checked around the damaged area. The earth bonding for the cable trays will have to be checked for damage and replaced with new cable and lugs if required. Also a check of all the cables on the tray for damage at the same time would be advised.Very little maintenance is required to the cabling unless it is damaged. Serious damage will require the cable to be replaced. Light sheath damage can be repaired with use of the correct type of insulating tapes. In a situation where severe damage has occurred and the cable cores are broken, then this type of damage can be repaired with a "Scotchcast" splicing kit. Normally only considered when no spare cable is available or a long down time will be needed to completely replace the cable.When the cores can be repaired and insulated satisfactorily, then the whole repair can be encapsulated in a polycarbonate mould on which the ends can be cut to suit the size of the sheath. These moulds come in two halves that click together and can be taped to seal any leaks. There is a satchel of two part epoxy resin which can be mixed and pored into the mould and left to set. These have been known to work well under water on deep-well pump cables where the cable is often not long enough to reach a power supply.

Maintenance proceduresMajor drilling contractor has no dedicated cable maintenance routines. This may look strange but the inspection of the cable of individual equipment and systems is part of that equipment.The cable that is not part of the equipment needs to be looked at as part of the daily and weekly rounds. After all, every cable cannot be identified inside a cable tray so look at them all as you do your rounds.

Fault finding at times on rig cables can present several types of problems, as cables can be cut, crushed or pulled apart during drilling operations.Cut cablesProviding the cables have been cut cleanly and the appropriate breakers have tripped open to protect the cable, then these can be repaired with a "Scotchcast" splicing kit until new cable can be installed. If used with mastic, these joins can also be considered water tight if prepared in the right way.Stretched cablesThe same problem exists with cables that have been pulled apart or stretched until cores have broken. It will only be the loss of a control circuit that will indicate that there is a problem. If the cores have not been pulled out of the plugs or receptacles, only continuity and core-to-core testing will expose broken or shorted wires. This makes the decision to replace the cable fairly obvious.

NOTE: USE BACK PAGE FOR CONTINUATION OF THE REPORT FOR SKETCHES, DIAGRAMS AND GRAPHS DATE: 17th April...............



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Figure - Signs of a stretched cable.

Umbilical cablesIn the case of umbilical cables in facilities such as platform and tender rigs where these can be 20-core control cables or more, it is better to have spare cables already made up to install in the event of a failure, complete with plugs and receptacles to be run out and plugged in at short notice.

Student's Signature: .......................... Date: .....20th April 2016...………………


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Name: ......................................……………………………………………......................

Signature: ....................... Date: ...........…………………………………………...........FOR THE USE OF INSTITUTION SUPERVISOR ONLY

General comments on first/second/third (Delete as appropriate) Visit


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Name of Supervisor: ...........................................………………………………………..…..

Signature of Supervisor: ....................................………………………………………….

Date: ......................................................…………………………………………………..


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Documents

external logbook gdc