Overhauling marine propulsion systems

URN: SEMME3118
Business Sectors (Suites): Marine Engineering Suite 3
Developed by: Enginuity
Approved on: 31 Mar 2019

Overview

This standard identifies the competences you need to carry out a complete overhaul of marine propulsion systems, in accordance with approved procedures. The equipment to be overhauled will have been removed from the vessel or craft and the overhauling activities may take place in a shipyard or manufacturer's workshops. The marine propulsion equipment covered by this standard includes alternating and direct current motors, steam turbines, gas turbines, two-stroke and four-stroke internal combustion engines. The overhauling activities will involve stripping the equipment down to component level, cleaning and inspecting the components for wear, replacing all defective and `lifed' components and rebuilding the equipment in line with the overhauling specification.

The marine propulsion units to be overhauled will include turbo blowers, air intakes, combustion system, engine control units/nozzle boxes, fuel systems, fire detection systems, exhaust units and other associated mechanical equipment. The overhauling activities will include making all necessary checks and adjustments to ensure that components are correctly replaced, positioned, aligned, adjusted, torque loaded, locked and fastened and that the correct sealants are used.

Your responsibilities will require you to comply with organisational policy and procedures for the marine equipment overhauling activities undertaken and to report any problems with these activities, or with the tools and equipment used that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You must ensure that all tools, equipment and materials used in the overhauling activities are removed from the work area and equipment on completion of the activities and that all necessary job/task documentation is completed accurately and legibly. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.

Your underpinning knowledge will provide a good understanding of your work and provide an informed approach to applying overhauling procedures to marine propulsion equipment. You will understand the dismantling and reassembly methods and procedures used and their application. You will know how the equipment functions, the purpose of the individual components and associated defects, in adequate depth to provide a sound basis for carrying out the overhauling activities to the required specification. In addition, you will have sufficient in-depth knowledge of these components, to ensure that they are fit for purpose and meet the specifications, thus providing a sound basis for carrying out reassembly.

You will understand the safety precautions required when carrying out the overhauling activities associated with marine propulsion equipment, especially those for lifting and handling the equipment. You will be required to demonstrate safe working practices throughout and will understand your responsibility for taking the necessary safeguards to protect yourself and others in the workplace, both ashore and afloat.


Performance criteria

You must be able to:

  1. work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
  2. follow the relevant maintenance schedules to carry out the required work
  3. carry out the maintenance activities within the limits of your personal authority
  4. carry out the maintenance activities in the specified sequence and in an agreed time scale
  5. report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
  6. complete relevant documentation in line
    with organisational procedures, 
    and pass them on to the appropriate person
  7. dispose of waste materials in accordance with safe working practices and approved procedures

Knowledge and Understanding

You need to know and understand:

  1. the health and safety requirements of the area in which the overhauling activity is to take place and the responsibility they place on you
  2. the specific health and safety precautions to be applied during the overhaul procedure and their effects on others
  3. hazards associated with carrying out overhaul activities on marine propulsion equipment (such as using lifting and handling equipment, handling oils, greases, release of stored pressure/force, misuse of tools, using damaged or badly maintained tools and equipment, not following laid-down maintenance procedures)
  4. the importance of wearing protective clothing and other appropriate safety equipment (PPE) during the overhaul
  5. how to obtain and interpret drawings, specifications, manufacturers' manuals and other documents needed in the overhauling process
  6. how to carry out currency/issue checks of the specifications you are working with
  7. the procedure for obtaining replacement parts, materials and other consumables necessary for the overhaul
  8. company policy on the repair/replacement of components during the overhauling process
  9. the sequence to be adopted for the dismantling/reassembling of various types of assemblies
  10. the methods and techniques used to dismantle/reassemble marine propulsion systems (such as release of pressures/force, proof-marking, extraction, pressing, alignment)
  11. methods of checking that components are fit for purpose, how to identify defects and wear characteristics and the need to replace `lifed' items (such as seals, belts and gaskets)
  12. how to make adjustments to components/assemblies to ensure that they function correctly (such as bedding in of white metal bearings, laser alignment of propeller shafts, balancing of rotating components such as armatures and turbines, setting working clearance, setting travel, setting backlash in gears, pre-loading bearings)
  13. the basic principles of how the equipment functions, its operating sequence, the working purpose of individual units/components and how they interact
  14. the identification, application, fitting and removal of different types of bearings (such as roller, ball, thrust, shell)
  15. methods and techniques of fitting keys and splines
  16. the identification, application, fitting and removal of different types of gears
  17. how to set up timing marks and position and set the tension of belts and chains, correctly
  18. the identification and application of different types of locking devices 
  19. the uses of measuring equipment (such as micrometers, verniers, expansion indicators and other measuring devices)
  20. how to check that tools and equipment are free from damage or defect, are in a safe and usable condition and are configured correctly for the intended purpose
  21. the generation of technical documentation and/or reports following completion of the overhauling activity
  22. the equipment operating and control procedures to be applied during the overhauling activity
  23. how to use lifting and handling equipment in the overhauling activity
  24. the problems associated with the overhauling of marine propulsion equipment and how they can be overcome
  25. the organisational procedure to be adopted for the safe disposal of waste of all types of materials
  26. the extent of your own authority and to whom you should report if you have a problem that you cannot resolve

Scope/range


Scope Performance

  1. Carry out all of the following during the overhaul of the marine propulsion equipment:

    1. use the correct issue of company and/or manufacturers' drawings and overhauling documentation
    2. adhere to risk assessment, COSHH and other relevant safety standards
    3. ensure the safe isolation of equipment (such as mechanical, electricity, gas, air or fluids, steam)
    4. provide safe access and working arrangements for the overhauling area
    5. use lifting and handling equipment, in accordance with health and safety guidelines and procedures
    6. carry out the overhauling activities using appropriate techniques and procedures
    7. comply with organisational requirements with regard to renewal or replacement of existing components
    8. ensure that the overhauled equipment meets the required specification
    9. ensure that there are no foreign objects left in the completed equipment
  2. Carry out overhauling activities on one of the following types of marine propulsion equipment:

    1. direct current electric motor              
    2. steam turbine
    3. alternating current electric motor
    4. gas turbine                                           
    5. two-stroke turbine/mechanically/naturally aspirated diesel engine
    6. four-stroke turbine/mechanically/naturally aspirated diesel engine
  3. Carry out overhauling activities on four of the following marine propulsion system components:

    1. air Intake                                    
    2. engine control unit               
    3. air start system
    4. air charger
    5. cylinder head                                
    6. fuel system                          
    7. shafts
    8. combustion system                  
    9. turbine                             
    10. fire extinguishing system
    11. bearings                                 
    12. exhaust system                      
    13. electrical start system
  4. Carry out eighteen of the following activities on the equipment being overhauled:

    1. dismantling equipment to unit/sub-assembly level
    2. draining fluids
    3. flushing out and cleaning
    4. removing and refitting cylinder liners
    5. dismantling units to component level                        
    6. bedding in of white metal bearings
    7. proof-marking/labelling of components                       
    8. lapping in valves
    9. checking components for wear and serviceability          
    10. pre-loading bearings
    11. replacing all `lifed' items (such as seals, bearings, gaskets)  
    12. setting backlash in gears
    13. replacing all damaged or defective components           
    14. electrical bonding of components
    15. setting timings and adjusting replaced components         
    16. applying gaskets and sealant/adhesives
    17. re-assembling components to sub-assembly level           
    18. tightening fastenings to the required torque
    19. balancing of rotating components (such as armatures and turbines)
    20. re-assembling sub-assemblies to unit level
    21. carrying out crankshaft deflection
    22. re fill system fluids to the correct level
    23. securing components using mechanical fasteners and threaded devices
    24. applying bolt locking methods (such as split pins, wire locking, lock nuts, stiff nuts, swage nuts)
    25. carrying out any required tests on the completed equipment
  5. Replace a range of propulsion system components, to include sixteen of the following:

    1. shafts                                  
    2. shell bearings               
    3. slides
    4. couplings                         
    5. bearing housings    
    6. rollers
    7. gears                               
    8. fitting keys                 
    9. static and dynamic seals
    10. clutches                            
    11. springs                    
    12. housings
    13. brakes                               
    14. diaphragms                      
    15. actuating mechanisms
    16. valves and seats
    17. injectors
    18. pumps
    19. burners
    20. chambers (such as combustion)             
    21. cams and followers    
    22. structural components
    23. pistons                                
    24. chains and sprockets      
    25. wire thread inserts
    26. splines                                
    27. pulleys and belts             
    28. shims and packing
    29. roller or ball bearings          
    30. levers and links             
    31. pipes and unions
    32. locking and retaining devices (such as circlips, pins)   
    33. other specific components
  6. Overhaul marine propulsion equipment, in compliance with one of the following standards:

    1. BS or ISO standards and procedures
    2. customer (contractual) standards and requirements
    3. company standards and procedures
    4. specific system requirements
    5. recognised compliance agency/body's standards
    6. other accepted international standards
  7. Complete the relevant documentation in line
    with organisational procedures, 
    to include one of the following and pass it to the appropriate people:

    1. job cards
    2. permit to work/formal risk assessment
    3. overhaul log or report
    4. chart of dimensional inspection
    5. other specific reporting method

Scope Knowledge


Values


Behaviours

Behaviours:

You will be able to apply the appropriate behaviours required in the workplace to meet the job profile and overall company objectives, such as:

  • strong work ethic
  • positive attitude
  • team player
  • dependability
  • responsibility
  • honesty
  • integrity
  • motivation
  • commitment

Skills


Glossary


Links To Other NOS


External Links


Version Number

3

Indicative Review Date

30 Mar 2021

Validity

Current

Status

Original

Originating Organisation

Semta

Original URN

SEMME3118

Relevant Occupations

Marine Engineering Trades

SOC Code

5235

Keywords

engineering; marine; overhaul; propulsion system; DC motors; AC motors; steam turbines; gas turbines; two stroke diesel; four stroke diesel