Norwegian Hull Club is one of the leading Hull and Machinery Underwriters. In order to avoid similar situations, we would like to share our experience of incidents which have occurred to vessels in our underwritten fleet.
Malfunction of emergency generators occurs quite frequently, and in rare occasions we have experienced a total loss of electrical power leaving the vessel completely helpless.
We want to share the following ”lessons learned”:
Water accumulation in the emergency generator caused corrosion to wiring impeding electrical connections.
Prevent these problems by keeping the generator dry at all times. Ensure that there are no undesired routes of ingress and that drains are maintained clear, withspace heaters and internal electrical heaters operable. Ensure ventilation is adequate and operates satisfactorily. Periodic inspections of the emergency generator cabling, emergency switchboard and auxiliary electrical equipment should be carried out and incorporated into the vessel’s planned maintenance systems. Particular care should be paid to avoid and remove the presence of moisture and corrosion deposits and for signs of insulation breakdown or overheating, which should be rectified.
Poor fuel quality caused combustion problems resulting in erratic running and production of abnormal smoke.
Be sure to always use the manufacturer’s specified fuel quality and to purchase this from a reliable source. Consideration should be given to the use of low temperature fuel in colder environments. Regular checks should be carried out for possible water contamination of the fuel and ensure that a sufficient reserve of fuel is available both in the service tank and otherwise on board.
The emergency generator suffers breakdown under high and continuous load.
It is recommended to test the emergency generator at least once a month such that it is used to solely supply emergency services via the emergency switchboard. This should be carried out under controlled conditions. It should be verified that the generatorstarts and connects to the emergency switchboard automatically. Ensure that several of your officers and crew are able to manually start and connect the emergency generator to the switchboard. Alternative and secondary methods of starting the emergency generator should also be fully verified, for example the use of a first start compressor to charge an air receiver and/or electrical start by batteries with their charger/rectifier switched off. Ability to maintain reserves of starting energy should be verified including the electrical charge of batteries and the pressure in air receivers and hydraulic systems.
In addition, and this has proved critical on a few occasions.
The emergency generator is seldom really used, and annually it should be run at constant high load at minimum 85% of rated capacity and for a minimum of one hour. When the generator is operated, running parameters, such as lubricating oil pressure and temperature and cooling water temperature, should be checked and verified as satisfactory.
Necessary maintenance is ignored due to limited running hours of the unit.
Planned maintenance should include mechanical overhaul work for the emergency generator diesel engine in accordance with manufacturer’s recommendations, and obviously NOT based on running hours. Such work should be carefully scheduled and planned to avoid extended periods whereby the emergency generator is not available for required service. Lubricating oil and coolant should be maintained in reasonable condition and regularly checked including the use of antifreeze solution if operating in cold climates.
The emergency generator failed to start due to contamination of the fuel system resulting in blockages of pipes and filters.
When routinely starting the emergency generator pre-starting checks including levels of fuel, draining of the fuel filter and checking of lubricating oil and coolant according the manufacturer’s recommendations. If the generator spuriously starts, connects, disconnects or fails to provide a steady electrical output, the relevant electrical connections, circuits and auxiliaries should be checked as a priority.
The annual classification test failed to determine the actual condition of the emergency generator.
Your classification society will survey the emergency generator on an annual basis. They will carry out a black out test in order to prove satisfactory operation. You should not solely rely on testing by the classification society to verify ongoing reliable operation. Your emergency generator is as important as your anchors in a distress situation. Make sure that it is properly maintained.