"Daylia",

One slight correction to one of your early posts in this thread. The Dieppe Raid was in 1942, so maybe it was just a slip when you said a couple of days before D-Day (June 6th, 1944).

Germany's Operation "Sealion" was based on the premise of capturing at least a secondary port intact. The Allies looked into the feasibility of doing the same thing - that was the thinking behind the Dieppe Raid. The result showed that the capture of a port intact was not possible - hence the invention and building of Mulberry 1 & Mulberry 2 - both used off Normandy after the D-Day landings.