Abstract: The invention provides a tracked air cushion vehicle comprising a vehicle body, a lift platform from which the vehicle body is suspended, end bogies provided at each end of the lift platform, the lift platform and the end bogies being adapted to run within an inverted channel section track so as to define a chamber which can be maintained at subatmospheric pressure, apparatus connected to the chamber for providing the sub-atmospheric pressure, and biasing apparatus coupled between the vehicle body and the end bogies for biasing the end bogies towards the roof of the track, the biasing apparatus exerting a force equal to at least a substantial portion of the weight of the end bogies.

Abstract: A tracked air cushioned vehicle system comprising an inverted channel section track and a vehicle body suspended from a lift platform guided by end bogies. The platform and bogies define a chamber with the track, which chamber is maintained at subatmospheric pressure. The chamber is divided longitudinally into two separate subchambers, the dividing member including sealing members cooperating with the track and a gravitationally displaceable member is provided which is responsive to any lateral force exerted on the body except those due to centrifugal action, to cause a differential pressure between the subchambers for causing a rolling moment to be applied to the platform to counteract the lateral force. The dividing member may include a longitudinal flange depending from the roof of the track or a beam extending between the bogies and a flexible member extending longitudinally of the platform between the beam and the platform.