Equipment
Diving Bell
Submersible chambers used to transport or support divers.
Documents
- 202518 Dec
Dropped object – Bailout cylinder inside diving bell
During saturation diving preparations aboard a vessel, an unsecured bailout set fell approximately 2.5 metres through the bell opening, striking the Transfer Under Pressure door. Nobody was injured; the cylinder was damaged. The flash identifies deficient securing and checks, and records replacement of S-hooks, formal instructions, revised hazard analyses and retraining.
- 202512 Jun
Diving Guidelines - Diving Safety Management Systems and Diving Project Plans
Guidance for preparing diving safety management systems and project-specific diving plans under OPGGS and OEI regulations. It addresses hazard assessment, operational procedures, competence, maintenance, workforce consultation and change management. Emergency provisions include diving bell rescue and evacuation of saturation divers while maintaining pressure, alongside monitoring, investigation and audit requirements.
- 20256 Mar
Diver lifted off seabed
A diver’s umbilical snagged on another bell’s clump weight, lifting the diver approximately 4–5 m above the seabed during adjustment. Services remained intact. The flash describes stopping the operation and clearing the umbilical, and recommends second-diver or ROV monitoring when divers pass close to objects being lifted.
- 202416 Apr
Main bell wire rope damaged
During bell recovery after a saturation dive, a broken outer wire rope strand lifted a proximity switch bracket into the sheave, damaging the main bell wire. Operators stopped recovery and freed the bracket. The flash describes design shortcomings, sensor relocation, cutting back damaged wire, a witnessed load test and an empty-bell trial.
- 20249 Jan
Diver in the bell hit by falling object
A diver sustained minor head and shoulder injuries when a partially frozen water bottle fell into a diving bell transfer lock after its handle broke. Bottles were being used for cooling without a change risk assessment. Actions included updating change management and risk assessment, and starting arrangements for a bell chiller.
- 202327 Nov
Case study: Saturation diver fatality due to hydrogen sulphide
This safety flash summarises a historical saturation-diving fatality during inspection of a leaking sour-crude pipeline in the Bombay High oilfield. Hydrogen sulphide in the bell caused collapse; the diver subsequently drowned. It discusses possible gas-entry routes, absent gas detection, bell-to-bell rescue and the potential use of ROVs for surveys.
- 20223 Oct
Diver Finger Injury – Scrubber Blower Fan
A diver checking a vessel’s diving bell sustained a minor thumb injury from an exposed running scrubber fan with its canister removed. The flash identifies an omitted risk assessment hazard, records a requirement to switch off the fan during canister removal and discusses possible guarding and design changes.
- 202220 Jul
Bailout manifold failure
A diving bell bailout manifold failed under pressure with no divers inside. Forensic testing supported likely lateral loading from inappropriate securing, followed by stress corrosion cracking and internal corrosion. The flash describes suspended diving, bailout inspections, replacement with more robust assemblies and familiarity with planned maintenance tasks.
- 202122 Jul
Failure of dive chamber overhead door centre pin
A diving bell overhead-door hinge pin failed after the dive team left the entry lock. The pin fell into the unoccupied lock, without pressure loss. The door was lowered under control and divers transferred. Investigation remained ongoing; suspected factors included design, corrosion and cyclic fatigue. Similar doors should receive prompt crack checks.
- 20212 Jun
Learning outcomes from a real time diver recovery
A saturation diving team reviews recovery of an incapacitated diver into a bell and transfer arrangements through six-metre trunking. Lessons address loose recovery rope, a pocket-mask seal compressed at depth, ROV observation, realistic weighted-mannequin drills, supervisor exercises and proposed greater medic involvement and CPR refresher training.
- 202025 Aug
Emergency lithium battery failed catastrophically in a diving bell
A diving bell’s emergency lithium battery failed with an explosion and small fire after its pod flooded through an incorrectly fitted replacement check valve. No injuries occurred. The flash highlights interchangeable valve connections, absent management of change and crew uncertainty about immediate battery-fire response.
- 201928 May
Partial pressure of oxygen (PPO₂) getting low in bell
During saturation diving at approximately 147 msw, oxygen partial pressure fell in a bell and the main oxygen bottle was subsequently found empty. The flash describes breathing-mix purging, BIBS use and recovery, followed by changes to oxygen make-up responsibilities, panel positioning, valve configuration and buffer-tank connections.
- 201925 Apr
Hot water fitting failure results in 3m loss of depth in diving bell
A diving bell lost pressure during pre-dive checks following a cracked hot-water fitting. Impact from a diver’s bailout bottle was believed to have caused the failure. The team isolated the leak. The flash highlights effective drills, uncertain fitting replacement history, inspection for impact damage and recording critical components in planned maintenance systems.
- 201920 Mar
Near miss: Diver reports tight gas
A diver switched to bailout and returned to the submersible diving chamber after experiencing restricted gas supply. Internal valves secured during a delay had not been restored following completed checks. The flash highlights checklist timing, recording deviations and repeating valve checks before operations recommence, alongside formal review of habitual procedural changes.
- 20189 Nov
Finger injury: diver caught finger in bell door
A diver sustained a deep finger cut between a bell door and its retaining latch while repositioning an umbilical obstructing closure. The flash identifies incorrect stowage, limited risk awareness and missing hazard markings, and describes pinch-point checks, task risk assessments, toolbox talks and changes to equipment stowage.
- 20183 Aug
Near miss: onboard O₂ bottle leaked into diving bell
A diving bell near miss involved oxygen supply valves left partly open during pre-dive checks, emptying a bottle into the bell. Distraction, delayed topside readings and distrust of an unreliable analyser were identified. The run was aborted; subsequent measures included atmosphere flushing, additional valve checks, analysers and sourcing buffer tanks.
- 20179 Jun
Near-misses during diving operations
Two diving near misses involved a bell approaching subsea lifting gear during vessel relocation and a stud bolt falling from a vessel towards a seabed worksite. A diver stopped the move, and dive control warned the exposed divers. Neither event caused injury or damage; subsequent arrangements included a dedicated tool basket.
- 20173 May
Diving bell TUP O-ring seal damage
A displaced O-ring obstructed diving bell mating on a DSV and was damaged during repeated clamp closures. Trunking pressurisation revealed leakage, prompting inspection and seal replacement. The flash identifies incomplete inspection and difficult access, recommending flange and seal checks between every bell run and describing improved access and inspection recording.
- 201510 Aug
Lost time injury (LTI) and restricted workday case (RWC) following failure of diving bell door system
A diving bell door fell after its hydraulic ram failed, trapping one diver’s feet. A second diver injured his hand during the attempted release using recovery equipment. The flash examines hydraulic pressure, missing maintenance and door securing arrangements, and highlights secondary closure-prevention systems and planned maintenance.
- 201520 Mar
Diver fainted
A tired diver fainted after receiving permission to enter the bell wearing his chemical oversuit. He regained consciousness and the bell was recovered normally. The flash discusses procedural failures, contributory factors identified by the member, and reviews of diving checklists, contamination drills and guidance on precautionary decompression following health issues.
- 201425 Nov
Failure of bell winch clutch coupling during bell recovery
A worn winch clutch disengaged during saturation bell recovery, allowing the partly submerged bell to descend to 10 msw without injury. The flash examines component wear, brake operation and maintenance omissions, and describes coupling visibility improvements, wear measurements, alternating motors and revised inspection and maintenance arrangements.
- 201417 Jul
Bell re-claim failure resulting in minor injury
A saturation-diving incident at 110 msw injured a bellman when a reclaim-line water trap ruptured. An inverted check valve allowed retained exhaust gas to pressurise the trap following a compressor solenoid failure. The flash examines refurbishment errors, filter-change maintenance and inspections that missed the incorrectly fitted component.
- 201421 Jan
Uncontrolled descent of diving bell
A diving bell underwent two uncontrolled descents during lowering into a vessel’s moonpool. Umbilical damage during the second descent caused loss of bell pressure, without injury. Investigation identified operator error, failed programmable safeguards, gaps in risk documentation and supervisory understanding, and insufficiently defined emergency arrangements and safety scrutiny.
- 201329 Nov
Serious DP diving incident
A diving support vessel lost DP control following RBUS communication failure and drifted 240 m. A diver’s snagged umbilical severed, interrupting gas, hot water and communications. The flash describes recovery and medical monitoring, investigation findings without a definitive jamming cause, a firmware remedy and an improvement project for diving and marine operations.
- 201224 Jul
Near-miss: Bell umbilical damage incident
During diving bell recovery, insufficient umbilical tension allowed trapping between the cursor and bell, damaging the sheath and causing a small gas leak. Divers remained unharmed. The flash examines supervisor distraction and a visual-only differential alarm, recording umbilical re-termination, installation of an audible alarm and revised recovery risk assessments.
- 201225 Jun
Near-miss: Saturation diver lost gas supply
A saturation diver conducting pipeline free-span measurements at 100 m lost gas supplies when his umbilical became trapped at the bell interface. He returned unassisted on emergency gas and was unharmed. The flash examines bell movement, restricted access, emergency response, revised procedures and case-by-case assessment of bell positioning for rescue.
- 201123 Dec
Near-miss: Diver loss of gas
A diver’s gas supply became restricted when a bellman lost his footing during bell heave and knocked the supply valve towards closed. The diver used bailout gas and the bellman restored the main supply; no injuries occurred. The flash describes valve-handle repositioning, overlooked ergonomic hazards, team briefing and regular emergency drills.
- 201028 May
Incident during entry to diving bell
A stand-by diver attempted to enter a surfaced diving bell before residual diving gas had been flushed out. Oxygen starvation caused confusion, a fall out of the bell and brief unconsciousness on deck. The flash highlights access control, flushing, atmospheric monitoring and robust confined space entry procedures.
- 2010Jan
Crush incident during work under diving bell on diving support vessel Wellservicer with loss of 1 life
Investigates a fatal crushing accident aboard Wellservicer off Aberdeen during modification of its diving bell recovery system. A faulty hydraulic pilot valve prevented winch brakes applying, allowing the suspended cursor to fall. The report examines commissioning, project oversight, management of change, risk assessment and permit failures, alongside subsequent stakeholder actions.
- 200910 Nov
Tumble dryer fire onboard a vessel
A diving bell bottom hatch jammed during recovery after a detached hydraulic pipe ferrule caused oil loss and disabled its operating system. Manual attempts failed, and divers were recovered successfully through another bell. Corrective actions included valve interlocking, visual alignment indication, revised procedures, training and reviews of failure analysis and maintenance.
- 200923 Oct
Trapped diver umbilical incident resulting in diver fatality
A surface-supplied diver died after his umbilical became fouled on the seabed, with barge movement thought to have interrupted his gas supply. Wet-bell recovery dragged him out twice before the umbilical was freed. Company actions addressed barge movements, in-water tending, emergency briefings, debris surveys and pre-dive communication checks.
- 20092 Oct
Failure of gas supply to diving bell
Checks at a storage depth of 102 metres revealed insufficient breathing-gas flow in both diving bells of a new system. Workshop testing reproduced the problem, and higher-performance regulators restored adequate flow. The flash recommends full functional testing at maximum working depths following significant changes, rather than relying on purging.
- 200919 Jun
Fall from height
A saturation diver fell approximately five feet onto a bell skid while re-entering a chamber using a rotating dogging bar. Removal of the diving bell had reduced edge protection. Recommendations address management of change, correct fixed handholds, personnel awareness and a removable access platform with additional edge protection.
- 20095 Mar
Dive bell gas loss during internal bell checks
A diver’s umbilical accidentally opened a flooding valve during internal pre-dive checks aboard a dive support vessel, releasing gas and reducing bell pressure. The flash describes emergency re-pressurisation, cramped access and ergonomic problems, dual closed valves and securing mechanisms. It stresses correct checklists and recommends more structured, vessel-specific familiarisation.
- 200824 Apr
Partial parting of a bell main lift wire
A diving bell’s main lift wire was found damaged during recovery following partial parting. Internal corrosion had reduced core wire sizes by up to 50%, despite no visible external damage. The flash examines lubricant loss, undetected deterioration and possible sheave and loading effects, urging members to consider reviewing wire-rope maintenance and testing policies.
- 200720 Dec
Bell contamination
A subsea fitting failure exposed divers to a hazardous substance from a pressurised hose. Contamination entered the bell, where a diver felt faint and the analyser did not alarm. The flash examines infrared detection limitations and recommends enhanced diving procedures, decontamination, appropriate atmospheric testing and chemical safety assessments.
- 200529 Jul
Diving bell clamp mating screws
Inspection before saturation diving revealed severely worn bell mating screws and clamp nuts despite apparently acceptable threads. Clamp weight masked the deterioration, making operation appear normal. The member highlighted regular dismantling and thorough component checks with the weight removed from the nuts and screws.
- 20041 Dec
Uncontrolled decompression of diving bell
A diving bell vented to surface from 175 fsw after the last man leaving accidentally kicked open an unsuitable quarter-turn valve. No injuries or equipment damage were reported. The flash discusses prior sealing problems, replacement with a small-bore needle valve, testing before vessel installation, familiarisation drills and cautious movement in confined spaces.
- 20041 Jun
Near-miss: Internal bell door
A corroded hydraulic fitting failed during a dive, allowing the bell’s inner door to fall shut and narrowly miss the bellman’s feet. The flash highlights stainless-steel pipes and fittings, automatic gravity-driven latching rather than manual primary securing, and company instructions to inspect door arrangements and identify rectification programmes.
- 20041 Jan
Diver’s lost gas incident
Two divers lost their main gas supply after replacement bell-panel gauges changed the pressure reference without corresponding procedural updates. Automatic backup gas also lacked sufficient pressure. The bellman restored supply. Lessons address management of change, recording gas pressures during bell checks and communicating departures from normal operating practice.
- 20031 Jan
Near-miss involving winch failure
A saturation diving bell descended uncontrollably during recovery when trapped hydraulic pressure kept the winch brakes and counterbalance valve open. A cross-haul wire checked the descent and the bell was recovered. Investigation identified incorrect control-system plumbing; corrective work included a bleed line, separation of valve and brake, and valve replacement.
- 20022 Jul
Dynamic positioning (DP) vessel blackout
A saturation-diving vessel suffered a complete blackout and moved some 190 m before control was regained. Divers were recovered without injury. Investigation identified degraded power-management electronics and management-system weaknesses. Recommendations address replacement of the ageing system, UPS maintenance and testing, broader redundancy analyses and revised diving emergency arrangements.
- 20011 Aug
Failure of winch brake on air diving bell system
An unmanned wet diving bell fell 6 m through air and a further 15 m through water onto its clump weight, without injury. Investigation identified fatigue fracture following hinge-pin seizure from inadequate lubrication, compounded by hydraulic pressure decay. The company planned winch checks and advised regular brake maintenance.
- 20001 Apr
Emergency communications system incident
Flooding of an external battery pack damaged through-water communications electronics aboard a vessel, allowing smoke into the diving bell and requiring divers to use BIBS and masks. Investigation identified an incorrectly fitted pressure-relief screw after charging. The manufacturer supplied modification information, revised manufacturing procedures and manuals, and issued a field service bulletin.
- 20001 Jan
Commissioning and verification of newly installed modified diving system equipment
A serious near-miss involved unintended diving bell recovery before its door was secured. Modified winch systems had malfunctioning primary and emergency components, with no documented acceptance-test protocol. Recommendations address change assessment, defined responsibilities, subsystem schematics, operating procedures and competent, supervised acceptance testing with retained records.
- Undated
Marathon/Technip - Alvheim/Skandi Arctic - Investigation into diving incident
The PSA investigates uncontrolled diving-bell lowering aboard Skandi Arctic during saturation diving at Kneler. Umbilical separation caused pressure loss before the bell reached the water; divers closed leaking valves and restored pressure using stored gas. The report examines handling-system operation, management deficiencies, competence and emergency arrangements, with no known health consequences.