The causes of fire in engine room
Fire results from the combining of three factors:
1. A combustible substance.
2. A source of ignition.
3. A supply of air.
These three factors are said to be the three sides of the fire triangle. Removing any one or more of these sides will break the triangle and result in the fire being put out. The complete absence of any one of the three will ensure that a fire never starts.
The first side of the triangle, the substance that can burn, is in abundance in engine room- tanks of oil, pipes full of oil, oily rags, etc. This side can be removed by good housekeeping in the engine room, efficient garbage management, good maintenance of pipes, flanges, gaskets, and machines, etc.
The second side of the triangle, air, is also in abundance as huge engine room blowers pump air into the engine room for ventilation, cooling, and for combustion in the main and auxiliary engines, boilers, and incinerators.
The third side of the fire triangle is the ignition source, which can also be present sometimes due to failure of material or insulation, or due to human error. Lots of hot work is done in the engine room, like gas-cutting and electric arc welding. Hot work done without a valid hot work permit and without the attendance of a senior engineer is inviting trouble. The engineers must make sure that high temperature area like exhaust manifolds are insulated and that the insulation is in good condition. Frequent fires have been caused by fuel spilling from a leaking pipeline on to a hot surface and catching fire. Naked flames like butane lighters and cigarettes should be avoided in the engine room because of the presence of oil vapors. Smoking should only be done in designated areas like the engine control room, which is the certified smoking area. Also ill-maintained machines can cause hot spots and lead to subsequent fires. A badly maintained main engine can have a crankcase explosion and scavenge fire which can lead to a total engine room fire.