The Gall Thomson MBC is self-energised and is calibrated to respond to pre-defined loads. The MBC does not reply on human operation and is therefore unrivalled in response time when compared to any alternatives such as Bow Loading Connectors/North Sea Valves (BLS) where human operation and procedures are susceptible to rapidly evolving circumstances
OCIMF has classified MBCs as passive couplings whereas Bow Loading system/North Sea Valve are active couplings requiring human intervention with activation of ESD1 and ESD2. Whereas Bow Loading system/North Sea Valve can take up to two minutes before BLS is disconnected, the MBC is the last resort when all redundancy systems in place fail and when Mooring Masters do not have enough time to disconnect BLS (if applicable).
OCIMF has also identified that passive couplings such as Gall Thomson MBCs have a primary function; which is to activate in cases of tanker breakout or extreme pressure surges caused by sudden failure of BLS systems or failure and slamming shut of butterfly valve during full flow conditions.