Landing craft, freeboard, and carrying tanks ashore

Operation Sea Lion becomes a naval-engineering problem: a converted barge had to carry a heavy vehicle, survive an open-water crossing, approach a shallow beach, and unload without a port. Reinforced frames, longitudinal girders, concrete laid over the bottom, and an internal trackway distributed the tanks' weight but increased draft. The bow opening and its temporary timber closure offered far less subdivision and watertight protection than purpose-built landing craft. The external ramp was especially vulnerable because roughly twenty men might need four minutes to assemble it while exposed on the beach. More elaborate portal ramps proved too complex and could fail if the barge developed a list, illustrating how improvised equipment magnified the assault force's tactical risk.