Single Point Mooring Buoy System (CALM)

Catenary Anchor Leg Mooring (CALM) single point mooring (SPM) buoy system designed for the loading and offloading of VLCC tankers up to 300,000 DWT in offshore locations without port infrastructure. The 13-metre diameter steel buoy provides a stable mooring point via a 4-leg catenary anchor chain system, each leg comprising 120-metre sections of 132mm Grade R4S studless chain.

The buoy houses a hydraulic swivel stack allowing the tanker to weathervane freely while maintaining continuous crude oil flow at 12,000 m³/hour through a 20-inch swivel and submarine hose system (flexible risers to 60 bar). The hose string is 230 metres long with an integrated emergency release coupling (ERC) for safe disconnection under emergency conditions. Telemetry and SCADA monitoring of buoy position, mooring tensions, and oil flow are transmitted via satellite to the onshore terminal. Full installation, commissioning, and marine warranty survey support included in the rental package.