Marine Accident Investigation Branch Safety Digest 2/2005 Case 8

In Hot Water

Narrative
Two motormen were issued with a ‘Permit to Work’ covering routine maintenance of the main engine on board a ro-ro passenger ferry that was berthed alongside.

The work included changing the circlips and “O” rings on the main engine rockers. Without gaining prior approval, the two men decided to remove an adjacent thermometer pocket in the engine’s cooling water system in order to ease access to the rockers.

As the pocket securing union was being removed from the pipe, the pressure in the system ejected the thermometer pocket, and hot water in excess of 75o C sprayed onto the men, badly scalding their legs.

The task that the men were given did not require the pocket to be removed; had they followed their instructions the accident would not have occurred. However, having made the decision to remove the component, neither of the motormen made any attempt to check the system conditions, or make the necessary isolations to ensure that the thermometer pocket was safe to remove.

Engineering staff are, of course, encouraged to use their initiative and to suggest improvements to procedures. Unfortunately, in this case little thought was given to the consequences of the motormen’s actions. Neither of them considered the risks involved in removing the thermometer pocket. Fortunately both men escaped serious injury.

The Lessons
1. Before carrying out maintenance, those involved should ensure that they are fully conversant with the requirement and should know the extent of the work.
2. Work should be allocated according to crew members’ competence and skill levels.
3. Where a “Permit to Work” has been issued, the work undertaken should remain within the bounds of the permit. If this is not possible, revised instructions should be issued.
4. Maintenance instructions should always be referred to. Where additional components need to be removed to facilitate access, prior approval should be sought and systems and equipment correctly isolated.