Integration of Non-Marine specific components

30th September 2003

Integration of Non-Marine specific components

Initial Report

This issue relates to the integration of marine engines into the vessel and in particular to the terminal connections for fuel and lubricating oil.

Failure of the threads securing the fuel pressure regulating valve to the fuel manifold adapter caused a quantity of gas oil to be sprayed over the running engine. Fortunately, the engine was stopped immediately and the fuel did not ignite. A combination of engine vibration and side loading from a poorly fitted hose connection is likely to have caused the threads to wear on one side and eventually allow fuel leakage.

When the vessel is being built, pipework supplied as part of the engine “package” has to be connected to ancillary equipment, e.g. pumps, coolers, filters etc. The point raised is that the engine manufacturer should take a greater role in specifying exactly how their connections are to be made to the engine system pipework. It is not sufficient to assume that the ship builder is competent to do this.

In service, badly specified and / or fitted connections can lead to premature failure with potentially catastrophic consequences.

The engine manufacturer should specify maximum allowable misalignment, the type, size and securing arrangements for flexible pipe connections/couplings so as to reduce side loading and vibration on the terminal connection. This would ensure that failures due to fatigue cracking and fretting of threads etc are reduced to a minimum.

 

The incident described could easily have resulted in a serious fire.  The engine room was only manned because of other technical difficulties, had it been unmanned, as designed, the result would probably have been far worse.  CHIRP has become aware of an incident involving a similar engine which did result in a serious fire and is keeping the relevant investigation body informed.

The Maritime Safety Committee at IMO has raised concerns with respect to engine room oil fuel systems in the past and in MSC/Circ.851 states, with respect to installation:

“One person should be designated as responsible for co-ordinating the initial on-board installation of the complete fuel system.

The co-ordinator must be able to understand the overall design criteria and ensure that the design intent is fully implemented at the time of installation.”

Does this happen in practice and who is the co-ordinator?

Class might be the appropriate body, but if the manufacturer does not design the engine terminal connections with adequate tolerances, or does not specify the tolerances and installation requirements adequately, then the shipyard is left to do its best and Class left to say that it has done so.

This would appear to be a rather imprecise process that risks leaving the engineers onboard to discover any defects through operation and take their chances on whether there is a fire or not!

CHIRP would like to gather more views on this issue before approaching organisations that may be able to do something about it.

More reports please!

 

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