Near-misses during diving operations

Incident 1: diving bell nearly carried into subsea lifting equipment

During a bell run at 90msw a task was completed and the diving support vessel (DSV) needed to relocate to a pipeline end. The move was started with the diver on the bell clump. He called an ‘all stop‘ when he saw the wire rope and four-part lifting bridle approaching the bell.

The vessel move was stopped and a new path to the next job was plotted. The DSV was relocated safely and work continued. There were no injuries and there was no damage to equipment.

Our member noted the following:

• There was no information available as to the depth of the buoys;
• There was added risk of umbilical entanglement when the divers passed unknowingly through the wire lifting slings;
• An ROV was deployed to the worksite and found buoys at 13m above seabed. The bell was being held at 90 msw (10m above seabed).

Incident 2: subsea dropped object – stud bolt dropped to seabed

A stud bolt 3½” x 1015mm was dropped to the seabed from the vessel side whilst attempts were being made to secure it to a device being prepared for subsea use. Dive control immediately alerted divers on the seabed, who were working on a pipeline flange 16m away from the drop point. The divers cleared out from the job and the bolt landed without harming anyone or anything.

Subsequently a safety stand-down was held at the next bell turnaround. It was arranged for further items to be deployed in a dedicated tool basket.

DROPS online have published a handy two-page reference on subsea dropped objects which can be found on the Drops online website.

Members may wish to refer to the following incidents:

Near-miss: Divers nearly hit by weight on taut wire [“In undertaking its work, the DP vessel had moved, resulting in the taut wire running above the divers and the subsea structure.”]

Near-miss: ROV shackle (potential dropped object)