 The plan was berths for offloading five ships simultaneously, providing a capability of 2,500 tons of supplies per day directly onto vehicles.A further 7,500 tons per day could be offloaded using lighters carrying supplies directly to the shore from 30 further ships moored in the pool.This was seen as a very efficient scheme, since the two Mulberry prefabricated ports constructed on the Normandy beaches provided 6,000 tons of supplies a day at a construction cost of 120,000 man-months, whilst Operation Chastity facility would provide 10,000 tons per day (compared to 26,000 tons per day through the Normandy beaches and Cherbourg) but would only need 4,000 man-months to construct the prefabricated facilities.