Diving Bell Bailout Manifold Failure

Bailout Manifold Failure

• A diving bell bailout manifold failed due to pressure while no divers were in the bell.
• The bell was being prepared for diving, with the bell trunk isolated at 31msw and the system at 32msw.
• A dive supervisor heard a gas rush, and a camera check revealed misting from a gas leak.
• Four pieces of a failed nut were discovered from the bailout manifold assembly
• Diving operations were suspended, and all bailouts were removed for inspection.
• Uneven rubber boots on each cylinder likely caused stress on one side when moved.
• The securing strap holding the bottles was loose.
• The design of the bailout manifold was less robust compared to others.
• Lateral force from inappropriate securing mechanisms likely caused stress corrosion cracking.
• This led to material ingress and internal corrosion over time.
• Existing bailout manifold assemblies were replaced with a robust version, and a reminder to ensure awareness maintenance tasks related to bailout alignment, integrity and boots, occurred
• The nuts were made from copper alloy CW614N, susceptible to stress corrosion cracking and dezincification and are widely used in the industry.

Master Links Came Free from Lifeboat Release Hooks

• A vessel was waiting on weather and was completing annual checks, including a lifeboat launch.
• The unmanned launch led to the fore and aft master links disconnecting in an uncontrolled way while in the water.
• There were no injuries, but the lifeboat was slightly damaged.
• The lifeboat was lowered, the weight was taken, and the falls slacked.
• The forward master link disconnected.
• The crew in the rescue boat monitored the lifeboat.
• As the rescue boat approached, the aft master link disconnected.
• The lifeboat was tethered by forward and aft painters.
• The forward painter disconnected after the forward master link hit the painter release system.
• The lifeboat swung 180 degrees, the aft painter connected to the bitt released and the lifeboat drifted away.
• The rescue boat and quayside crew recovered the lifeboat.
• Incorrectly oriented master link handles faced inboard towards the hook latch and lifeboat.
• Movement of the handles impacted and released the hook safety latch, releasing the hooks.
• Action includes to replace master links with handles orientated to the sides.

Three Bolts Sheared on a Lifting Trunnion

• After installing an offshore renewables Transition Piece (TP), the cover plate of the lifting trunnion was found fallen off on the hatch cover of the TP.
• The three securing screws had sheared.
• The cover plate weighed 44kg and fell approximately 0.5m.
• Damage occurred to a survey beam and a GNSS positioning equipment antenna.
• The antenna was fixed onboard; the survey lifting beam was replaced.
• The method of verifying the suitability of the screws was incorrect.
• It was assumed that sideway forces were introduced in the center of the lug cover, resulting in an inadequate securing method.
• A permit to work was used, a toolbox talk was held, a Job hazard analysis was referenced, a Last-minute risk assessment was used, and the task plan was followed throughout installation.
• Side forces exceeded the screw's capacity, likely due to human error, and the cover plates are to be welded to the lifting trunnions.

Hose Management and Chemicals

• While filling a bucket from a hose, someone was adversely affected by the contents.
• Two engineers were flushing non-potable water through a hose before filling a cooling water system.
• One engineer started coughing and was escorted to the bridge, after which they recovered with rest and fresh air with no long-term effects sustained
• The engineers noticed yellow/brown liquid, but it was assumed to be water.
• The affected person was not wearing gloves.
• The hose contained stagnant water and cooling medium liquid, having been coiled in a cupboard for nearly two years, which had previously been used to fill system with Antifrogen in Jul 2019 and was not properly flushed.
• Old Hose was disposed of and two new hoses were prepared, one for cooling agent, one for non-potable water, and to avoid touching unknown substances.

Chemical Reaction

• Post grouting operation for an offshore wind farm transition piece, a sub-contract grouting team cleaned equipment with high pressure water jets, resulting in of the team member receiving first degree burns to his knees and left calf in three places
• Burns were healable and cured in the span of three weeks
• A person with grouting dust on coveralls started working with a water jet, soaking their skin, causing a corrosive solution
• The Safety Data Sheet lacked information on the hazard of grout dust mixing with water and becoming corrosive, leading to no risk mitigation.