A standby vessel stationed close to a drilling platform, experienced a “black-out” which was caused by water contamination of fuel and occurred shortly after switching from one service tank to another. The water was drained from the tank and fuel system. The main engine was restarted and was running normally. To provide electric current for lighting, steering etc., one of the auxiliary engines had to be started. Upon trying this, it was discovered that the spare starting air bottle was empty although the pressure gauge indicated full pressure.
An emergency arrangement to fill the air bottles from one of the main engine cylinders existed, but the arrangement did not function. It was decided to try to start the engine with high pressure air from a breathing apparatus and a flask was picked up from the dispensary. During the starting operation an explosion followed. Four crew members suffered burn injuries and were evacuated by helicopter. The fire was extinguished and the vessel towed to shore base.
No serious damage was reported in the engine room except for extensive damage to the auxiliary engine concerned. The crew members who suffered burn injuries recovered at the hospital.
The flask brought forward from the ship’s dispensary was coupled up to one of the auxiliary engines’ starting air system by temporary connections using armoured plastic tubes and cleats. The explosion occurred the instant the engine began turning.
The bottle from the ship’s dispensary was later found to be filled with oxygen. The explosion took place when the oxygen mixed with the oil, blowing away the temporary connections and injuring the people occupied in the operation.
The above incident highlights the following:
- Fuel service and settling tanks are to be regularly checked and drained for water.
- The availability and functioning of the arrangement for starting up from “dead ship” should be checked out regularly.
- Standards for colour marking of gas cylinders are not universally recognised and different practices exist; for example, between gas cylinders for medical use and for industrial use. Oxygen flasks from a dispensatory are often white whilst compressed air for breathing apparatus is seen filled on flasks with all sorts of colours, including white.
Consequently, utmost care should be demonstrated by the crew in the use of gas flasks/cylinders on board vessels having world wide deliveries. Information regarding governing safety precautions for the different types of gas under pressure should be a part of the safety drill on board.
Source: DNV
Officer of the Watch 
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