This new publication, the second in a series on loss prevention subjects, focuses on marine engineering issues and procedures related to the prevention of loss of propulsion. Its purpose is to provide general guidance and practical advice to marine engineers and ship owners on blackout and main engine failures, the risks associated with loss of propulsion, and the precautions that can be taken to limit and prevent them.

As explained, the consequences of third party claims may be substantial – in time, expense and reputation. The implications of propulsion loss may be significant either affecting or stopping navigation altogether in ports and their approaches, in canal systems, in waterways for days, weeks and months. Claims as a result of collisions, groundings, consequential pollution and ‘offhire’, transhipment costs – all in addition to any repair costs - as well as claims from shore based facilities operators of loading and discharge equipment and facilities are all likelihoods in the event of damage. Media and stakeholder interests will all need to be addressed.

Possible causes of main engine failure 

  1. Blackout
  2. Fuel oil poor quality or contamination (e.g. fines, water or bacteria inside the tank)
  3. Insufficient attention to proper fuel changeover procedure when entering or exiting SECA
  4. Failure of starting air (insufficient pressure in the bottle). High or excessive numbers of engine starts and stops while manoeuvring will deplete pressure in the main engine start bottles. This may lead to the engine failing to start with a consequent loss of navigational control at critical times, such as when docking. It is important that the start air pressure is monitored while the ship is being manoeuvred and also vital that the pilot and bridge team are made aware of the maximum number of consecutive engine starts they can demand.
  5. Insufficient or ineffective maintenance of electronic and pneumatic control systems (for example, filters in pneumatic control systems are often
  6. Loss of control air pressure
  7. Loss of lubrication
  8. Engine automated shut down or even slow down at a critical time
  9. Shaft intermediate bearing failure
  10. Stern tube bearing failure


  • Ensure correct maintenance of all equipment
  • Ensure that no maintenance is carried out on filters and fuel systems when on standby or approaching restricted navigational areas.
  • Ensure fuel oil viscosity and temperature control equipment is accurate and fully operational.
  • Ensure that all engineers are aware of how to isolate one cylinder on the main engine in the event of failure
  • Wait for the results of tests on newly supplied fuel oil to ensure that the fuel is ‘on spec’ before changing-over to the new one.
  • Do not mix bunkers from two different suppliers in the same tanks.
  • Ensure water is regularly drained from fuel oil tanks, to avoid bacterial contamination.
  • Ensure that system temperature and pressure alarms, fuel filter differential pressure transmitters, etc. are accurate, tested and operational.
  • Ensure that engineers are fully familiar with all engine room systems and their pipelines.
  • Establish ‘failure to start’ / blackout procedures / checklist as well as emergency response manual / procedures / checklist / instructions.
  • Ensure the manning level / team composition in the engine (control) room is compliant with the international (e.g. STCW convention), national and local regulations.
  • Ensure that any loss of power and/or propulsion incident is investigated and a root cause determined, by properly trained personnel.
  • Ensure that weekly tests of the emergency generator are carried out with the battery charger disconnected from the mains.
  • Ensure that all means of starting the emergency generator are tested and that all crew members are familiar with them.
  • Ensure that the emergency generator is operated on load as close to the maximum capacity as possible, for at least one hour, every month.
  • Ensure the starting air pressure is monitored by the watchkeeping engineers when manoeuvring and ensure that the deck department is aware of the limitations of starting air availability.
  • During manoeuvring operations or when on standby, run two (or more) generators in parallel whilst ensuring sufficient power availability should one either stop or trip. Monitor and balance switchboard power loads equally.
  • Test the astern operation of the main engine prior to arriving at the pilot station and, if practical, before approaching the berth.
  • Establish procedures to ensure that there is adequate electrical capacity available before starting up lateral thrusters, mooring equipment or other heavy equipment, bearing in mind that simultaneous starting of large electric motors will lead to a large power surge and possible overload.
  • Tests of the lateral thrusters and mooring equipment should be carried out well before entering restricted waters and undertaking critical manoeuvres.
  • Ships fitted with shaft generators should, where appropriate, switch to auxiliary generator power well before entering restricted waters and well before undertaking critical manoeuvres.
  • Engineers should change over to manoeuvring mode and be standing by in the Engine Control Room (ECR) prior to the vessel entering the port’s seaward approaches.
  • Over-current tests for the vessel’s main generator breakers have to be carried out to the satisfaction of the classification society during periodic surveys.
  • A regular thermographic survey of the switchboard should be carried out to monitor for loose connections or overheating equipment.
  • The alarm printer, where fitted, should be maintained correctly, such that the printout is legible

London P&I Club loss prevention manager Carl Durow says: “The Club has seen an increase in the number of machinery failure-related cases in recent years. In most cases, it is the timing and location of the incident which dictates the severity of the claim. This publication is aimed at raising awareness of the necessary good practices and post-incident investigation activities which in combination can result in significantly reducing the risk of major claims.” 

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