Injury: Failure of subsea HP water jetting gun

Following publication in IMCA Safety Flash 05/11 (Diver safety – high pressure water jetting), whch reported an incident where an injury sustained by a diver after the subsea failure of a high pressure (HP) water jetting gun, a member would like to draw attention to a similar earlier incident. Whilst using an HP water jetting gun underwater, the rear barrel of the gun became unscrewed and fell causing minor injury to the diver’s left arm. There was no injury or damage caused by the HP water jet. Upon closer inspection, it was noticed that the threads on the barrel were worn.

Our member noted the following:

• The rear barrel of the gun is a protective cover designed to be screwed onto the gun, to protect the diver from the (equalising) HP water jet at the rear during work;
• It is possible that due to constant handling, the barrel may have become loose at the screw end;
• Failure of pre-use inspection to check the tightness of the barrel may also have contributed to the barrel falling off.

Subsequently, modifications were made to this and all similar HP water jetting guns, in order to prevent recurrence of the incident.