QCDC
This SMS variant is the most complex being both multipath and capable of rapid (emergency) disconnect. With only 3 mooring legs this SMS can be particularly cost efficient. Suitable for both relatively short-term early-production system deployments and for FPSOs and FSOs in tropical cyclone areas vulnerable to hurricanes and typhoons; the vessel propulsion and navigation systems are in commission, there is a marine crew on board, and the SMS is quickly disconnectable. Flow shut-in (via a multipath QCDC) and canister drop can be triggered from the bridge and the dropped canister is designed to float at or below the water surface with the mooring lines and risers suspended from it pending vessel return and pickup. A QCDC SMS can also be used when the vessel itself is used to export oil.
View footage of the model tank tests of the SMS at DHI.
Graphics from the computer simulations of the system.
Animation of the SMS showing how it works.
Video overview of the SMS with commentary.