The Nautical Institute presents an incident where, a tanker was underway and normal maintenance activities were being accomplished. An engine room crewmember was tasked with opening the steam valve that leads to the deck in order to recirculate excess steam.
This had been common practice on board for the last nine years, ever since one of the heavy fuel oil (HFO) bunker tanks had been modified to Marine Gas Oil (MGO). Since that modification, the excess steam could not be sufficiently cooled by the existing dump/drain cooler when the vessel was running at maximum RPM. The practice of recirculating it through the deck steam piping had been adopted as a solution.
The valve was located in the engine room in an area that required the crew to climb up and into a restricted space. When the crew was in position he began opening the valve, and was suddenly exposed to copious amounts of steam. It was later discovered that the valve gasket had failed, probably due to ‘water hammer’ effect.
The victim suffered from severe skin burns on his face, leg, and arm. He was immediately transferred to the ship’s hospital and first aid treatment was provided. The Master communicated with radiomedics and the victim was transferred ashore for medical care the same day. After 11 days of hospitalisation he was repatriated home for further treatment and recovery.
The company investigation found that the instructions on how to accomplish line draining prior to opening the steam valve were inadequate. The crew completed the task as best they remembered based on their own knowledge. Ultimately, formalised instructions are needed to ensure that the steam supply line is free of water before opening the valve to avoid the water hammer effect.
Lessons learned
- New hazards can emerge when modifications are undertaken. In this case it took nine years for the hazard to be revealed.
- New hazards or old (hidden) ones need careful analysis. Then, a procedure should be written and dutifully practised.
