Investigation Report
Over-pressurisation of a cargo tank on oil tanker Mobil Petrel
Over-pressurisation of a cargo tank on oil tanker Mobil Petrel
- MAIB
- Investigation Report
- Unknown
- Pressure SystemsProcess Safety
- CorrosionHydrocarbon releasePressure systemsStructural and asset integrityVessel flooding and foundering
- Cargo transferFluid transferInspection and maintenance
- Process pipework and pipelinesPumpsStorage tanksValve
- Emergency responseFlood containment and watertight integrityPressure reliefPreventive maintenance
- Marine industry
- Port and quaysideVessel
Summary
Investigation of Mobil Petrel’s cargo-tank failure during ballasting at Fawley. A closed inert-gas branch valve prevented adequate venting, causing over-pressurisation and structural damage. The report examines valve condition, pressure-relief capacity, flooding through connected spaces and emergency response, with recommendations addressing maintenance, watertight closures and individual tank pressure monitoring.
Classifications: Corrosion; corrosion damage.
Classifications: Hydrocarbon release; hydrocarbon leak; oil and gas release.
Classifications: Pressure systems; stored pressure; pressurised systems; pressurized systems.
Classifications: Structural and asset integrity; asset integrity; structural integrity.
Classifications: Vessel flooding and foundering; water ingress.
Classifications: Cargo transfer; cargo handling.
Classifications: Fluid transfer; fluid loading; fluid offloading.
Classifications: Inspection and maintenance; asset inspection; equipment maintenance.
Classifications: Process pipework and pipelines; process piping.
Classifications: Pumps.
Classifications: Storage tanks; atmospheric tanks.
Classifications: Valve; valves.
Classifications: Emergency response; emergency preparedness.
Classifications: Flood containment and watertight integrity.
Classifications: Pressure relief; overpressure protection.
Classifications: Preventive maintenance; preventative maintenance; planned maintenance.
Classifications: Marine industry; shipping industry; maritime sector.
Classifications: Port and quayside; quayside; harbour; harbor.
Classifications: Vessel; aboard ship; onboard vessel.
Themes: pressure systems, process safety.