Functioning of the Air Cushion

The system of bearing and stabilization on the seabed during the submersion phase uses an elastic "skirt" whose internal chamber lets on to an air cushion situated within the series of steel casings which are themselves interconnected. The chamber inside the "skirt" is divided into three sections; a laod-bearing central section and two lateral parts whose job is to maintain lengthwise horizontal trim.

When the "gate-ships" have been lowered into their submersed, closed position their upper surface remains at three metres above sea-level, therefore the maximum height for a depth of 15 m would be 18 m. They have a constant width (thickness) of 15 m although varying in length and height.