As UK MAIB reports in its most recent Safety Digest, a heritage vessel started a short coastal passage to a specialist yard for refit and repair after a lengthy period in port.
The voyage initially passed without incident, but intermittent main engine stoppages and generator problems started to increase in number during the afternoon. As evening approached, the main engine suddenly cut out and the vessel lost all power. The single in-line filter on the fuel system was hanged out and cleaned; however, neither the main engine nor the generator could be restarted. Realising that the vessel was being set towards danger, the skipper called for assistance.
The heritage vessel was later towed to a nearby harbour where the main engine and generator were stripped down and examined. Many of the fuel system’s flexible hoses were found to have degraded, resulting in flaps of rubber detaching from the internal walls and acting like non-return valves. Fuel sludge had also clogged the pipework throughout the engine and generator systems.
Lessons learned
- Check → Thorough tank cleaning and a fuel system check can be invaluable tasks following a lengthy layup. The use of fuels from mixed sources often results in the accumulation of sludge in a fuel tank, leading to blockages and blackouts when this build-up is disturbed by the vessel’s motion.
- Maintain → Flexible hoses are prone to degradation. It is important to make sure there is compatibility between hose types and fuels and frequently check, and where necessary replace, hoses.
- Equipment → The vessel’s single in-line filter arrangement did not allow a continuous supply of clean fuel to the main engine and generator. Switchable fuel filters enable easy filter replacement, an uninterrupted supply of filtered fuel and keeps sludge and debris clear of engines, generators, valves and pumps.
- Action → The skipper’s early call for assistance ensured the tow was arranged in good time and prevented this drama escalating to a crisis.
