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Horror Stories

Engine Fires Caused By Missing Erosion Plugs

 

 

The jerk type fuel pumps as fitted to the majority of marine diesel engines are often fitted with erosion plugs in the casing opposite the spill ports in the barrel. These erosion plugs are replaceable once they erode due to the velocity of the fuel as it spills back at the end of injection.

 

Whilst in place they should be tightened to the recommended torque and locked using locking wire.

 

 

In two recent cases on vessels fitted with similar engines, a plug worked loose and came out. The fuel under pressure then sprayed on to a hot surface causing a fire. In one case a major fire caused extensive damage before being extinguished by CO2; in the other case the fire was extinguished in less than a minute using a hi-fog system and the damage was limited to one $500 component..

 

Fire No 1

 

Cylinder covers after the fire. The two hot box covers at the end have been blown off

Melted floor pates between main engine

 After initially trying to fight the fire using hand held extinguishers, the engine room was evacuated and CO2 was injected 11 minutes after the start of the fire. Initial assessment of damage showed:

  • The port main engine ‘hot-box’ covers had been blown-off Nos 1,2,3 and 9 units.

  • Affects of severe heat on covers and entablature of both main engines

  • Melted aluminium walkways between the engines.

  • Heat damage to both main engine turbochargers

  • Heat damage to deckhead insulation above the main engines.

  • Heavy smoke damage (black) to entire main engine room.

  • All electrical wiring in the vicinity of the main engines burnt.

  • Light smoke damage in engine control room.

The photograph shows a new fuel pump in position after the incident, with the erosion plugs secured with locking wire.

 

Information of this event was taken from the Isle of Man Accident Investigation website website. The full report can be downloaded here in pdf format

Fire No 2

 

The second fire was caused by the same problem, but what made the difference was the lack of damage because of the swift actions of the engineer in dealing with the situation. A previous fire on another of the companies vessels had led to an awareness program and the fitting of CCTV and hi- fog systems.

 

This photograph is taken at the start of the incident. The fire occurs on the engine closest to the camera. A man is working on the next engine (circled)

A haze is starting to rise from the engine closest to the camera.

The man smells burning and turns to face the camera. (He was not injured in the incident).

Within 5 seconds the fire is ablaze from the fuel spraying from the tapping in the pump where the erosion plug has come out.

Within 23 seconds the fuel has been isolated from the engine and the hi fog actuated.

The fire isn't immediately extinguished, but flashes back up as the hi fog injection continues.

After one minute the fire is out, and after five minutes a fire party enters the engine room with BA to confirm it is extinguished.

 

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