Diving Incident: Umbilical Snag

• A diver was lifted off the seabed because their umbilical got caught during a diving bell clump weight adjustment during bell recovery.

What Happened?

• While moving from the bell to the worksite, a bight of Starboard Diver 2’s umbilical fouled on the port bell clump weight.
• When the port bell was raised to a short mark (about 10m from its deployed position) by the Diving Supervisor, Starboard Diver 2 was lifted about 4-5m due to the umbilical issue.
• The Diving Supervisor called an ALL STOP and the port bell clump weight was lowered when they realized the diver had been lifted.
• Starboard Diver 2’s umbilical was then cleared.
• The diver had an assessment in the bell after returning, with equipment.
• The diver did not lose any services.
• Diver 2 was then cleared to continue work, now using Diver 3’s equipment.
• The bell could have 3 divers out of the bell and the bellman).

What Went Wrong?

• The route from the Starboard bell to the worksite caused the umbilical to be close to the port bell and its clump weight
• The risk of the umbilical snagging on the clump weight had not been recognised

Lessons Learned

• When the diver needed to go past the port bell from the starboard bell, the observation ROV should have been focused on the diver's umbilical.
• Divers who need to be near objects being lifted or moved from one place to another must be watched by a second diver or an ROV.
• A Time Out For Safety (TOFS) was held in Dive Control, for all divers on shift to recognise, discuss, and communicate the near miss
• Offshore Managers and supervisors had further discussions.

Matters to Discuss

• Behaviours - Line of Fire
• Tidal effects and current on umbilical slack
• The diver path and proximity to objects being lifted
• Umbilical drifting
• Personal Factors – Inattention: Potential umbilical snagging should have previously been recognised before lifting
• Use of the observation ROV to focus on the diver while en route to the worksite or between worksites.