![]() The breakout mechanism included dual shutoff valves positioned either side to provide 100% shut off of both of the separated hose lengths. Our engineering and design teams developed specifically for the project an MBC mechanism that did away with the weak bolts concept, using a preloaded coil spring to withstand the external factors and at the same provide a reliable breakout as and if necessary. The Aberdeen based project team turned to MIB for some alternative MBC design to overcome these issues. They were also convinced that the conventional ‘weak bolt’ type MBC mechanism was not the answer under such conditions. Shell were quick to realise that MBCs were needed in each hose to avoid potential damage to the crane jib in case of mooring hawser or export tanker dynamic positioning failures. The lengths needed often meant the lower part of the hose catenaries were in the wave or splash zone and together with the motions of the two vessels would see significant dynamic loading and fatigue under all but the most benign weather and sea conditions. This was overcome by the use of a large crane like jib mounted on the stern of the FSU to support catenary hoses (2 x 12” crude oil plus 1 x 6” bunkering line). Tandem offloading also had its obstacles – the key issue being the safe standoff distances between the FSU and the export tankers. Earlier, much smaller installations (e.g Argyll, Arbroath, etc.) using floating hose-strings from SPMs proved expensive and had issues with downtime due to weather or sea states. The environmental conditions in the North Sea proved a demanding challenge for the offloading system and in particular its export flexible hose-string. ![]() The Fulmar floating storage unit (FSU), was a 210,000 dwt converted tanker with stern tandem offloading to shuttle tankers. Wishing to develop their Fulmar field in the UK North Sea, and with a lack of existing infrastructure at the time, Shell selected to use a floating FSU for the crude oil coming from the Fulmar Production Platform. One such example of these almost unique requests was generated by Shell Exploration & Production in Aberdeen, Scotland. There were of course exceptions to the standard applications where some project demanded more specialised solutions to the conventional ‘weak bolt’ MBC concept. During the late 1960s and early 70s the use of Hose Breakaway Couplings (MBC) at offshore terminals was considered by many operators as a “nice to have” item in their SPM or MBM package, in fact some even thought of an MBC as “another thing to go wrong”! Devoting their R&D time and funding to other more diverse solutions for oil & gas, an MBC was not seen at that time as a target market for MIB.
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