Activity
Dynamic Positioning
Maintaining vessel position and heading with automatically controlled propulsion.
Documents
- 20254 Dec
BSEE Safety Alert - 510 - Blackout and Weather-Driven EDS Incidents Underscore the Need for Stronger Operational Discipline
This alert examines two emergency disconnects on a dynamically positioned drillship: a blackout during damper maintenance involving the wrong control panel, and loss of position during severe weather. Both resulted in pollution. Recommendations invite operators to consider clearer controls, competence verification, closed-loop communication and proactive weather-related operational adjustments.
- 202517 Sep
Handling alarms on the bridge – a DP incident
During scrap-metal recovery, a DPO inadvertently selected an adjacent command while trying to silence an alarm, leaving the vessel in manual mode with 10 metres of uncontrolled movement. The flash examines alarm overload, a frozen panel and inconsistent silencing arrangements, emphasising interface design, procedural reinforcement and openness within a no-blame culture.
- 202516 Apr
UK HSE: Risk of collision with offshore installations from attendant vessels
This safety flash summarises five vessel collisions with offshore installations and wind turbines reported in an HSE notice. Cases examine distracted watchkeeping, restricted visibility, dynamic positioning limitations and bridge communication. Recommendations address watchkeeping procedures, bridge resource management, alarm operation, attendant-vessel monitoring and consideration of sailing audits.
- 20257 Mar
BSEE Safety Alert 497 - Weather Creates Sudden and Unpredictable Risks
BSEE describes a wave-related femur injury on a deepwater drilling rig and further adverse-weather incidents involving personnel transfers, vessel collision and lost dynamic positioning capability. Recommendations address weather-dependent access restrictions, communication of unusual hazards, suspension of non-critical work and assessment of medical evacuation capabilities during adverse conditions.
- 2025Mar
Risk of collision with offshore installations from attendant vessels
HSE safety notice examines five vessel collisions involving offshore installations and wind turbines. Cases highlight distracted watchkeeping, lost situational awareness, environmental conditions and poor bridge communication. Recommended reviews cover watchkeeping instructions, bridge resource management, navigational alarms and vessel monitoring, with consideration of sailing audits to identify operational bad practice.
- 20243 Sep
Near miss: lift bag released unintentionally from crane hook
A lift bag detached from a crane hook at the splash-zone during a saturation dive and floated near a vessel operating in DP mode. Incorrect folding and attachment allowed buoyancy to defeat the self-locking latch. No harm occurred. The flash recommends risk assessment, rigging checks and a tool basket.
- 202418 Jun
Swinging load after loss of position
During backloading of an empty refrigerated container, a Pipe Supply Vessel lost position and the load swung uncontrollably. Wind gusts, thruster wash and loss of a thruster DP signal contributed. Nobody was harmed and equipment was undamaged. Lessons address vessel-to-vessel operational limits, cargo-lifting procedures and adherence to ASOGs.
- 20243 Jun
Vessel collided with platform
A vessel waiting on weather collided with an unmanned, unlit platform while using joystick auto heading mode. Nobody was injured and damage was minor. The flash examines distracted watchkeeping, position monitoring and unset navigation alarms, and describes revised DP checklists, watchkeeping analysis and restrictions on non-watchkeeping duties.
- 2024
CHIRP Maritime FEEDBACK 76 (Autumn 2024)
This maritime digest examines unauthorised enclosed-space entry, tug propulsion failure during LNG berthing, suspected officer fatigue, rotating-shaft hazards, inadequate provisions, deficient dynamic-positioning capability and departure in strong winds. Case commentary contrasts effective teamwork and stop-work intervention with commercial pressure and weak safety culture, highlighting entry permits, towing configuration and position-reference requirements.
- 202113 Jun
Report - Error tolerance in dynamic positioning systems - November 2018
NOPSEMA examines inadvertent deactivation of dynamic positioning controls through incident database review, manufacturer consultation and a survey covering 28 Australian facilities. The report assesses double-press vulnerabilities, confirmation dialogues, alarms, protective covers and interface layouts, finding widespread additional safeguards while identifying gaps requiring further risk reduction.
- 201912 Nov
Near miss: Emergency stop pressed accidentally
A vessel’s port azimuth thruster stopped during dynamic positioning when a passing crew member accidentally struck its emergency stop with his elbow. The vessel safely withdrew from the 500m zone. The flash identifies ineffective switch guarding and calls for similar emergency stop buttons across vessels to be identified and replaced.
- 201923 Aug
Accidental activation of emergency stop during saturation diving operations
Accidental operation of unprotected emergency-stop buttons stopped both lubricating-oil pumps and tripped a vessel’s starboard Voith Schneider propulsion during saturation diving. The vessel maintained position and divers were safely recovered without injury. Lessons address button covers, situational awareness, shipboard familiarisation, and more thorough job safety analysis and toolbox talks for routine engine-space maintenance.
- 2019Feb
Considerations for Walk to Work and Multi Operation Vessels – Regulatory Guidance
UK regulatory guidance for offshore oil and gas walk-to-work safety cases addresses vessel selection, installation collision resistance, station keeping and task-specific procedures. It examines gangway evacuation availability, contractor competence and combined rescue-vessel arrangements, requiring rescue and recovery capability to remain available throughout operations.
- 201820 Jul
Vessel collision with fixed structure on wind farm
A vessel struck a wind turbine transition-piece platform twice after changing from dynamic positioning to independent joystick control in worsening weather. Thrusters returned to zero pitch during changeover. The flash examines handover awareness and judgement, subsequent system testing, and revisions to procedures, familiarisation and passage planning.
- 201721 Sep
Property damage: Platform supply vessel collided with legs of jack-up rig
A platform supply vessel struck a jack-up rig leg after its starboard engine and thrusters tripped following water transfer, while the hose remained connected. The flash identifies fuel-oil pump seal failure and weather-side working contrary to procedures, and highlights simultaneous-operations risk assessment and planned maintenance.
- 201619 Dec
Some Ergonomic Issues of DP Vessel Controls
This safety alert examines accidental disengagement of dynamic positioning on a semisubmersible drilling rig and delayed recognition of manual control. It identifies inadequate button protection and unclear mode displays, and calls for operators to review control ergonomics, alert crews to weaknesses and make appropriate improvements.
- 201627 Jun
Vessel loss of position while diving in close proximity to a hydrocarbon facility
A diving vessel drifted over 40 metres after inadvertent deselection of its surge control disabled automatic positioning. A diver noticed his umbilical becoming taut. The alert examines vulnerable console layout, absent confirmation and ineffective excursion feedback, highlighting interface design and safeguards against unintended deactivation.
- 201627 Jan
Crew transfer vessel (CTV) personnel transfers
Two offshore wind crew-transfer incidents illustrate hazards from fall-arrest attachment during vessel movement and thruster wash near a dynamically positioned construction vessel. The flash describes a rogue wave during a dark winter transfer, suspension of transfers pending improved conditions, and revised vessel separation and work sequencing arrangements.
- 201524 Feb
Safety Alert 315 - Dynamic Positioning System Failures on Offshore Supply Vessels Engaged in Oil and Gas Operations
Joint Coast Guard and BSEE alert examines an offshore supply vessel losing position during wireline plug removal, shearing a wellhead tree through connected high-pressure lines and releasing lubricant. It discusses ignored DP failures, emergency disconnect capability, DP equipment classes, activity-specific guidance, personnel competence and leaseholder oversight of contracted vessels.
- 201420 May
Safety Alert 312 - Dynamic Positioning System Failures On Vessels Other Than Mobile Offshore Drilling Units (Vessels)
Joint Coast Guard and BSEE alert examines loss of vessel position during critical well operations. Overdue circuit-breaker maintenance, protection-circuit faults and unsynchronised bus reconnection culminated in total loss of thrust; crew disconnected safely. Recommendations address failure-mode analysis, critical operating modes, maintenance planning, contractor safeguards and demonstrated DP personnel competence.
- 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.
- 201326 Jun
USCG Homeport Marine Safety Alert: Recent failures of dynamic positioning (DP) systems on MODUs
This safety flash clarifies US Coast Guard recommendations following dynamic positioning failures on mobile offshore drilling units. It discusses conditional live short-circuit and ground-fault testing of ride-through capability, planned onboard testing to validate analytical models, and regular thermal imaging within preventive maintenance, with appropriate planning and risk mitigation.
- 201323 Jan
Warning to offshore industry on blocking of data communications in dynamic positioning systems
This alert examines shared-network vulnerabilities in dynamic positioning systems after a diving support vessel drifted off position with divers subsea. A single fault was identified as a probable cause of blocked communications. Duty holders and suppliers should investigate communications architecture and ensure appropriate protection where functions depend on shared media.
- 2012
MAIB Safety Digest 1/2012
A marine accident digest presenting separate merchant vessel, fishing and small craft cases. Lessons examine navigation, propulsion-control trials, fires, maintenance hazards and overboard recovery. Emergency drills, competence, revised risk assessments and equipment securing recur, alongside detailed discussion of lifejacket fitting, lifting loops and tether limitations.
- 201125 Nov
Near-miss: Dropped taut wire clump weight
During diving operations, a recovered port taut wire parted while being slewed inboard, dropping its 315 kg clump weight clear of divers and subsea assets. A worn, sharp-edged wire guide had damaged the wire. The flash discusses dropped-object cones, ROV checks of landing locations, repairs and review of inspection routines.
- 20111 Nov
Dynamic positioning (DP) system failure
This safety flash reports an incident involving a vessel’s dynamic positioning system. The company identified an inherent possibility of failure and a need for software modifications across several vessels in its fleet. The system manufacturer issued a technical bulletin addressing the matter.
- 2011Aug
Contact made by platform supply vessel SBS Typhoon with standby safety vessel Vos Scout and platform supply vessel Ocean Searcher
SBS Typhoon struck two vessels during harbour trials of a replacement dynamic positioning system in Aberdeen. Incorrect propeller command configuration escaped factory and commissioning checks. The investigation examines testing, contractor coordination, mooring arrangements and impaired recovery through an emergency-stop defect and control-mode selection, recording subsequent corrective actions.
- 2011Jul
Review and Assessment of Underwater Sound Produced from Oil and Gas Activities and Potential Reporting Requirements under the Marine Strategy Framework Directive, July 2011
This research review catalogues underwater sound from oil and gas operations and assesses potential reporting under the Marine Strategy Framework Directive. It compares acoustic measurements and marine-animal impact criteria across seismic surveying, piling, explosive decommissioning and continuous sources, highlighting data gaps, conversion uncertainties and differences between proposed reporting thresholds and biological effects.
- 200821 May
Loss of DP position caused by incorrect gyro heading
A DP Class 2 shuttle tanker lost position during an offtake operation when erroneous GPS signals affected all gyros, corrupting offset calculations and position references. The flash records stricter acceptance criteria for position reference systems and a forthcoming manufacturer software upgrade to reject erroneous latitude and speed compensation data.
- 200612 Dec
DP run-off incident – Class 2 DP vessel
A Class 2 DP vessel alongside a platform experienced a run-off following loss of reference systems and was recovered safely under manual control. The flash examines linked reference failures, incorrect VRS voting configuration, omitted sensor offsets and pitch-compensation wiring errors, highlighting limitations of FMEA trials and the need for current configuration records.
- 200612 Dec
Near-miss: Divers nearly hit by weight on taut wire
A taut-wire weight swung towards two divers and a subsea structure during recovery from a DP vessel, narrowly missing them. An unrelated acknowledgement was mistaken for permission to lift. The flash identifies communication failures and gaps in operational experience, recommending repeat-back protocols and review of personnel familiarisation.
- 20069 Oct
Wire break in wind sensor caused DP drive-off
A vessel suffered a DP drive-off during open-water valve monitoring after water ingress through a failed junction-box seal led to a wind-sensor wire break. Erroneous wind readings affected positioning; the vessel stabilised 17 m from its set-point. Actions included wiring changes, a discrepancy alarm and fleet-wide wire-break tests.
- 20066 Sep
Safety Alert 243 - Unplanned Riser Disconnect Results in Spill
A dynamically positioned semi-submersible lost station during worsening currents and storm conditions, prompting a riser disconnect and release of 710 barrels of synthetic mud into the Gulf of Mexico. The alert identifies unsuitable rig selection and inadequate procedures, recommending site-specific disconnect planning and review of storm-related criteria and T-time estimates.
- 200628 Feb
Recent DP incident onboard a DSV
A diving support vessel lost position during open-water diving when exceptional wave action triggered rejection of all five DP position references. Investigation identified tighter prediction-error limits following a software upgrade and gaps in crew briefing and guidance. Recommendations address settings, reference reselection, operator familiarisation and fleet communication.
- 200531 May
Safety Alert 231 - Human Engineering Factors Result in Increasing Number of Riser Disconnects
This alert reviews accidental and emergency riser disconnects in deepwater operations, highlighting human error, hydraulic connection mistakes and station-keeping failures. It recommends reviewing existing requirements for deliberate sequential disconnection, protected controls and documented subsea function testing. An accompanying table summarises eleven events involving drilling and production risers.
- 20041 Dec
Loss of position of DP DSV
A DP diving support vessel moved some 107 metres off its worksite, leaving a diver unable to return unaided to the bell. He suffered carbon dioxide toxicity from overbreathing. The investigation attributed the movement to a soliton; recommendations address seasonal scheduling, vessel heading, radar watch, quick-release arrangements and diver communication.
- 20023 Jul
Power management system dynamic positioning (DP) incident
A power management fault interrupted stern thruster operation during saturation diving, causing a DP vessel to leave its intended position. Divers returned to the bell and were recovered. The flash examines inadequate control-card segregation and an unidentified single-point failure, recommending reconfiguration, electrical protection, independent review and FMEA validation trials.
- 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.
- 20001 Jan
Thruster feedback incident
A vessel operating in Class 2 alongside a platform experienced a drive-off after severe gear wear in a thruster’s azimuth feedback unit. Incorrect thrust direction appeared normal to the operator, and the mismatch alarm did not activate. No damage or injury occurred; the company advised assessment and preventative measures for affected arrangements.
- 19991 May
Eureka wire locks
During vessel DP trials in open water, a taut wire pulled through a Eureka wire lock and dropped to the seabed, without injury, damage or loss of position. The flash contrasts conflicting termination guidance and records the member’s instructions to fit two locks, retain specified bolts and apply correct torque using appropriate tools.
- Undated
Emergency Disconnect During Completion Operations Releases Zinc Bromide
BSEE investigates a weather-related emergency disconnect during completion operations aboard Noble Stanley Lafosse in the Gulf of Mexico. A misaligned thruster compromised station keeping, while the well suspension procedure remained incomplete. Zinc bromide discharge was revised to approximately 420 barrels. The report examines failed barrier tests and subsequent thruster correction.
- Undated
Drillship Excursion During Drilling Prompts Emergency Disconnection and Mud Release
BSEE investigates a weather-driven excursion of the Deepwater Poseidon drillship during drilling in Mississippi Canyon Block 391. The report describes emergency disconnection, synthetic-based mud release and ROV verification of well security. It also documents a falling drill-pipe and bearing assembly, recovery operations and failures to disclose the resulting damage.
- Undated
Emergency Riser Disconnect and Drilling Mud Release During Drilling
Investigation of an emergency riser disconnect during drilling on Diamond Ocean Confidence. High winds, currents and engine unavailability increased dynamic-positioning power demand. Approximately 218 barrels of synthetic-based mud entered the Gulf of Mexico. Subsequent engine trips caused blackout and drifting; manual restarts restored station keeping. No injuries or fatalities occurred.
- Undated
Casing Lost Overboard Following Running-Tool Mandrel Fracture During Drilling
BSEE investigates the loss of approximately 3,107 feet of casing from Noble Jim Day during drilling at Walker Ridge 508. Strong loop currents complicated dynamic positioning before a running-tool mandrel fractured. Testing found no material anomalies; the report attributes failure to casing weight and current loading. ROV checks found no infrastructure damage.
- Undated
Blackout and Drift-Off During Accommodation Fire Damper Testing
BSEE investigates a blackout and drift-off aboard Noble Stanley Lafosse during accommodation fire-damper testing. Inadvertent operation of emergency fuel shut-off valves preceded loss of station keeping, emergency disconnection and brine discharge. Findings address missing task risk assessment, unused stop-work authority, inadequate assistance and unprotected valve controls.
- Undated
Electrical Failure Disabled Thrusters and Caused Vessel Drift
Investigation of an electrical failure aboard Discoverer Clear Leader that disabled thrusters and allowed a five-foot drift off station. Power returned to five thrusters after approximately 50 seconds. The crew closed middle pipe rams following a yellow alert. A circuit card was suspected, with investigation still pending; no agency recommendations were made.
- Undated
Drillship Drift and Emergency Disconnection Released Calcium Bromide
An investigation examines the Discoverer Inspiration drillship’s drift during well abandonment in strong frontal weather. Emergency disconnection released a reported 513 barrels of calcium bromide from the riser. Reduced thruster output remained unexplained; the disconnect system performed as intended, with no injuries or equipment damage. BSEE made no recommendations.
- Undated
Vessel Collided with Platform While Preparing to Offload
Investigation of the Triple Play’s collision with Matterhorn Platform while preparing to offload. Both GPS systems failed, resulting in loss of dynamic positioning before the captain regained control. Two caissons were damaged; no injuries, spills or vessel damage were reported. The probable cause was loss of dynamic positioning system power.
- Undated
Emergency Disconnect and Calcium Chloride Release Following Loss of Station Keeping
BSEE investigates weather-driven loss of station keeping aboard the Noble Stanley Lafosse drillship during preparations for cementing. The crew initiated an emergency disconnect, closing blind shear rams and releasing an estimated 417 barrels of calcium chloride to sea. The report examines forecast limitations, vessel excursions and the decision to disconnect; no injuries were reported.
- Undated
Transformer Failure Causes Total Power Loss During Well Completion
Investigation of a transformer failure aboard Deepwater Pontus during well completion operations. Total power loss led to vessel drift, emergency disconnection and seabed damage to the lower marine riser package. The well remained secure, with no injuries or pollution. Findings identify unmonitored breaker position and planned monitoring improvements.
- Undated
Electrical Fire in Dynamic Positioning Controls Disabled Thrusters
An investigation documents an electrical fire in the Discoverer Clear Leader’s dynamic positioning controls. Cooling-system cracks allowed water into electrical cabinets, disabling six thrusters and causing the rig to drift 15½ ft off location. Personnel mustered, power and position were restored, and control logic was subsequently modified to respond better to power demands.
- Undated
Vessel Lost Station Keeping and Severed Production Tree During Wireline Operations
Investigation of Endurance’s loss of station keeping during wireline operations at Eugene Island 355A. Vessel movement severed the production tree through connected rigid pipework, causing an oil spill and deck damage without reported injuries. Suspected communications-tower interference and absent emergency disconnection are examined, alongside equipment-separation measures and proposed vessel evaluation procedures.
- Undated
Electrical Failure During Drilling Leads to Drift and Emergency Disconnection
BSEE investigated an electrical failure aboard Ensco 8502 during drilling in Green Canyon 237. Loss of four thrusters led to vessel drift and emergency disconnection. The disconnect system operated as designed, but approximately 150 barrels of SBM escaped from drill pipe and hoses. No injuries occurred; the well remained secure and undamaged.
- Undated
Emergency Buoy Disconnect Failed Following Loss of Station
BSEE investigates a failed emergency buoy disconnect on Helix Producer 1 following weather-related loss of station. Subsea production shut in successfully, but a hydraulic piston failed to open. The report details disconnect-system testing, piston replacement and subsequent maintenance measures; teardown inspection found no cylinder failure, and no injuries or infrastructure damage were reported.
- Undated
Dynamic Positioning Malfunction with Riser Disconnection and Brine Release During Well Completion
Investigation of a dynamic positioning malfunction during well completion and console maintenance. Corrupted control data and subsequent troubleshooting caused the rig to leave its watch circle, triggering riser disconnection and releasing approximately 550 barrels of sodium bromide brine. Planned changes address alarms, command timing, console verification and simulator training.
- Undated
Equinor – Statfjord A – investigation of collision by vessel
The PSA investigates Sjoborg’s collision with Statfjord A during cargo discharge. Reduced thruster power led to loss of position, damage to lifeboat arrangements and personnel evacuation. The report examines technical faults, alarm interpretation, compliance with activity-specific operating guidelines and bulk hose handling, using interviews, inspections and supplied documentation rather than independent technical testing.
- Undated
Equinor/Floatel International - Floatel Endurance - investigation of unintentional gangway disconnection
Investigates Floatel Endurance’s loss of position and automatic gangway lift at Martin Linge on 29 February 2020. One person returned safely without physical injury. The report examines wave loading, dynamic positioning limitations, deficient operating limits, conflicting safety instructions and delayed personnel accounting, alongside helicopter transfers following disconnection.
- Undated
Floatel International - Floatel Superior - Investigation of stability incident
Investigation of anchor-induced hull damage and flooding aboard Floatel Superior on the Njord field. It examines bolster strength, fatigue, anchor restraint, winch behaviour, alarm failures and damaged-stability calculations. Physical damage reconstruction, biological dating and causal analyses support findings, alongside assessment of watertight protection and helicopter evacuation.
- Undated
Loss of Stability and Positioning
Inspection guidance examines maritime integrity management on floating installations, including stability calculations, ballast operation, watertight boundaries, mooring integrity and dynamic positioning. It addresses competence, emergency arrangements, failure analysis and FPSO cargo operations. Illustrative inspection questions contrast good and poor practice, supporting assessment of dutyholder arrangements and risk ranking.
- Undated
Parting of mooring line between shuttle tanker Randgrid and monobuoy resulting in discharge of 12 tonnes of crude oil
Investigation of Randgrid’s mooring release at the Tetney monobuoy during cargo discharge. Accidental operation of chain stopper controls released the chafing chain; the pickup-rope lashing subsequently failed and discharge hoses broke away. An estimated spill of about 12 tonnes occurred without injury. Recommendations address control design, alarms and bridge procedures.
- Undated
Seadrill – West Mira – investigation of unintentional disconnection of LMRP
Investigation of West Mira’s unintended LMRP disconnection during drilling on the Maria field. Weather-related loss of position triggered automatic string cutting and well shut-in, with drilling fluid discharged to sea. The report examines thruster-assisted mooring, power-sharing constraints, draught changes, procedural deficiencies, alarm limits and inadequate assessment of operating assumptions.