Bell re-claim failure resulting in minor injury

The incident occurred during saturation diving operations at 110 msw. The bellman was assisting diver 1 and diver 2 to prepare for diving activities. On opening the reclaim return line hull valve the internal in line water trap was immediately pressurised and ruptured. Perspex fragments of the water trap dispersed inside the bell causing superficial lacerations to the bellman’s left ear and face. The force of the blast caused a small rupture to the tympanic membrane in his left ear. Diving activities were aborted and divers were returned to the living chamber. The injured person was further assessed/treated by the diving medical technician in consultation with a physician ashore and with assistance of the on board medic.

• In 2013 the diving bell underwent refurbishment and total re-build and as part of this process the external check valve was removed and then re-installed.
• The diving bell had made 23 successful bell runs since being refurbished.
• The reclaim compressor solenoid had failed resulting in non-operation of the cross feed actuator, in turn causing pressure to be retained in the exhaust line.
• The bell return line external check valve had been previously incorrectly installed (inverted) during the refurbishment, allowing stored gas in the exhaust line to pressurise the internal in line water trap once the reclaim return line hull valve was opened by the bellman.

The root cause of the incident was determined to be that the check valve was incorrectly installed (inverted). A contributing factor was that the planned maintenance regime did not include increased frequency of filter change since the refurbishment; the reclaim compressor was started remotely.