Spread mooring

Spread mooring holds a vessel or floating unit in a fixed heading using several mooring lines led out in a pattern to seabed anchors or piles, so the hull does not weathervane. It contrasts with single point mooring, where the unit swings to the prevailing weather. Spread moorings are used for FPSOs and floating storage on benign or single-direction met-ocean sites, and for ships at multi-buoy berths and dolphin berths where heading must stay constant for a loading arm or shore connection. The lines, chain, wire, or polyester, are pretensioned so the worst environmental load case keeps every line within its safe working tension. A fixed heading suits a directional sea but raises beam loads from a cross sea.