Using a bail-out bottle to power hull cleaning equipment is a bad idea, in this case it resulted in tragedy. According to a safety alert issued by the International Association of Oil and Gas Producers a diver died when his main air supply failed while he was powering a ‘brush cart’ with his bailout bottle.
Says OGP: “A routine surface supplied diving operation was undertaken to clean marine growth from a vessel hull. This involved using a hull cleaning device with rotating brushes, termed a brush cart, and this also required a diver to guide and operate it.
“The brush cart contained diver operated tooling that was actuated by an air driven piston. Standard company practice was to use the suit inflation take off from the diving mask for this purpose.
Prior to this dive the diving mask was changed to a model that did not contain a suit inflation take off capability.
A decision was made to connect the diver’s emergency gas supply line (Bailout) directly to the brush cart tooling. This resulted in the diver having no personal emergency gas supply.
During the dive the diver’s gas supply line (umbilical) was caught in the wheels of the brushcart and the diver experienced a reduction in breathing gas. The diver, having no emergency gas supply, removed his mask, immediately losing communication to the surface team and was observed in distress at the surface.
The surface team was composed of a radio operator (a diver) and a tender for the diver (non diver) and a diving supervisor who was not on the site at this time.
An attempt was made to pull the diver back using the diver’s umbilical, this was ineffective. The radio operator, who was also the standby diver, jumped into the water without diving equipment and attempted to rescue the diver. The brush cart was negatively buoyant and the rescue diver was unable to prevent it sinking with the diver attached.
The standby diver returned to the vessel and dressed into the standby diver’s equipment (SCUBA) and recovered the body of the diver from the seabed.
What Went Wrong?:
- Risks with the work equipment were not identified and addressed
- Critical Safety equipment was misused to achieve the work task
- Personnel levels were inadequate
- No onsite supervision
- Inadequate Emergency recovery equipment
Corrective Actions and Recommendations:
Utilise the OGP report 411, Diving Recommended Practice (direct download here) as the baseline standard for diving.
Verify contractors are in compliance.
Establish that adequate risk assessments have been carried out
Ensure minimum personnel levels for diving are 5. One supervisor who cannot leave the dive site, a diver, a diver’s tender, a standby diver and standby diver’s tender. All personnel should be diver qualified and competent.
Verify emergency breathing supply equipment is of suitable volume and immediately available.
Confirm that any use of the divers breathing gas supply for tooling power is unacceptable
Ensure the standby diver’s equipment is the same as the divers
Verify that while any diver is in the water, the standby diver is dressed and in immediate readiness to carry out a rescue.
Ensure emergency recovery equipment and procedures are adequate to achieve recovery.