Accident: Engine failure on the flyover - where the fault is often found
Johannes Erdmann
· 12.10.2023
Yesterday, the Danish newspaper "Nordjyske" reported the rescue of a yacht off Sæby. A German crew had just bought the boat in Sweden near Gothenburg and were on their way to their new home port in Germany when the engine suddenly stopped working ten miles off Asaa. With wind forces of seven and waves up to two metres high, it was too dangerous for the crew to set sail. They therefore alerted a Danish rescue cruiser via Lyngby Radio. A sea rescuer jumped on board the sailing yacht to establish a line connection, after which the yacht was towed into the harbour of Asaa.
Engine failure on a new sailing boat: a classic case. A look at the logbook of the Danish sea rescuers shows "engine stop" or "engine problem" before almost every second rescue operation. Time and again, the engines of sailing boats that are now 20, 30 or even over 40 years old cause problems on the Baltic Sea.
More dramatic maritime emergencies:
Contamination in the tank: these are the possible consequences
Without knowing the exact background to the case in the Kattegat, it is relatively common for impurities in the tank to be stirred up by waves and find their way into the suction pipe of the tank. There they then block the flow of fuel. Either immediately by blocking the pipe - or by accumulating in front of the diesel filter until hardly any diesel can get through.
The tricky thing is that even a test run in the harbour or longer test drives in light swell usually do not indicate possible problems. This is because the impurities lie at the bottom of the tank, usually a few centimetres below the suction pipe. Only in rough seas are the small floating particles and thick "clumps" whirled up, drift around and sooner or later are sucked in.
The possible consequences are manifold: small suspended particles gradually accumulate in front of the filter until nothing can pass through, thick pieces often block the hose completely. In some cases, medium-sized pieces also get stuck in the intake manifold and allow enough diesel to pass through at low engine speeds. At higher engine speeds, however, too little diesel passes through, so that the engine no longer accepts gas or stutters.
This is how often you should check your tank for contamination or diesel pest
Boats do not have such a high throughput of fuel as cars. A full tank of fuel for a sailing boat often lasts a whole season. This means that the fuel sits in the tank all year round, algae forms in the summer heat and condensation in the winter. A pre-filter, for example from Separ or Racor, separates water and filters dirt on the way to the engine's fine filter. But once "the plague" is in the tank, even pre-filters quickly become clogged.
With older boats in particular, it is therefore a good idea to check the tank for contamination or diesel pest every few years. Of course, this is only possible if there is also an inspection hatch. And even then, contamination often remains undetected, for example if it has accumulated behind baffles. To make sure that the tank is really clean, it can't hurt to completely clean the entire fuel system, i.e. the tank including the pre-filter holder and hoses. In the past, it was even common practice to have a day tank (around 30 to 40 litres) on board, into which the diesel for daily use was pumped and cleaned through a filter. With larger tanks, the crew could then be sure that the diesel sloshing around in the day tank was really clean.
Prevent engine failure: How to act correctly when transferring an unknown boat?
If you want to transfer an unfamiliar boat and don't know what the inside of the tank looks like, you can also run the engine directly from a new tank if in doubt. An outboard motor tank (12 to 25 litres) is sufficient for the transfer or alternatively a 10-litre or better 20-litre canister. In the accessories shop for oil heaters, there is even a prefabricated cap that can be screwed onto standard canisters to operate a heater from the canister. Alternatively, it is also sufficient to hang the fuel hose into the canister. However, the lid should be modified with holes so that the hose sits tightly in it. Otherwise there is a risk of the diesel sloshing out in rough seas.
When operating the diesel engine from the extra tank or canister, always ensure that the return flow from the engine is also fed into the canister. This is because the fuel pump always delivers more diesel than the engine requires at low speed. Unused diesel is fed back into the tank via the return line. And if the return line remains connected to the main tank, the canister is empty in no time - and a large proportion of the clean diesel is in the contaminated tank.
