Abstract: Air cushion vehicle structure comprises a platform with a grid frame formed of longitudinal girders crossing crosspieces, and an upstanding caisson or compartment formed of transverse frames connected by continuous systems of sheets. The lower segment of each caisson transverse frame is constituted by a portion of the upper beam of a crosspiece of the platform, and the lower longitudinal edges of the caisson are integrated with the upper beams of two girders. The crosspieces and some girders are lattice girders, but the others are ladder girders. Upper and lower beams of the girders and the crosspieces are connected by normal tubes welded to their feet, the oblique tubes of the lattices also being welded to the feet. The structure is especially appropriate for medium tonnage ACV.