On a small ship, the skipper had been in the engine room to make checks and saw no faults. An hour later the fire alarm went off in the engine room. It turned out that the main engines had lost their coolant when the hoses from the engine block to the electrical engine heater had burst. The water vapour that formed had triggered the fire detector. A likely cause of the accident is that cold water was sucked into the seawater inlet filter, froze into ice, blocked the inlet and thus limited the cooling of the engines. This led to overheating of the hoses, which contributed to their failure. Another factor may have been that the coolant had been replaced with a more corrosive type. The problem has arisen a number of times before at the shipping company. If the coolant or type of hose is replaced, there is good reason to contact the supplier.
SFu 06.05.02 TSS 2012-3947