The Bahamas Maritime Authority issued a safety alert, informing about an accident that happened on board a general cargo vessel, aiming to highlight the lessons learnt and to increase awareness, which may help avoid similar incidents occurring in the future. In this particular case, a third engineer was severely injured, after explosion of the vessel’s auxiliary boiler.
The incident
During a voyage from Singapore to Suez, the 3rd Engineer on board a general cargo vessel sustained burn injuries to the face when the vessel’s auxiliary boiler furnace cover shattered by an internal explosion during initial start-up.
The auxiliary boiler fuel valve was dismantled for cleaning in preparation for the vessel’s transit of the Suez Canal. During the overhaul, the fuel nozzle was replaced with another valve held in stock onboard. Prior to installation the replacement valve was not checked, subsequently once installed the valve leaked fuel into the furnace during the purging process prior to initial auxiliary start-up. Installation of the replacement valve was also determined not to have been conducted adequately, compounding the issue. This led to a build-up of fuel, combined with air resulting in a rich combustible atmosphere within the furnace. With the system not adequately purged after pre-set interval, the combustible mixture spontaneously ignited on start-up resulting in an explosion, rupturing the burner sight glass directly in front of the 3rd Engineer.
Probable Causes
- Fuel valve not secured properly, in accordance with manufacturer or ship board procedures.
- Failure to follow correct start-up procedure by purging the furnace prior to ignition.
- Insufficient oversight to ensure the condition of the fuel nozzle prior to ignition.
- Inadequate assessment of operational readiness by Engineers, before the boiler start-up.
Conclusions
- A condition of the replacement fuel nozzle was unknown.
- A fuel nozzle leak test was not conducted after replacement.
- The fuel nozzle leaked fuel during purging whilst the boiler was in manual mode.
- Procedure for purging was not followed.
Recommendations
of a facemask and maintaining a safe distance could be considered appropriate measures.
