Buoy Mooring Spill Risk

Buoy-mooring spill risk is the pollution hazard from oil transfer at single-point moorings, where a tanker loads or discharges through floating hoses connected to an offshore buoy. The common CALM (catenary anchor leg mooring) buoy links subsea pipeline risers to a floating hose-string running to the tanker’s manifold. Failure modes are hose rupture from bending fatigue and wave motion, riser failure, and coupling separation as the vessel weathervanes. Floating hose-strings carry breakaway couplings designed to seal both ends if the string parts, limiting release. The exposed offshore location and large transfer rates make these among the higher-consequence routine transfer operations.