AN IMPROVED LOAD SUPPORT SYSTEM

The invention provides a preload device which includes a pressure vessel body which Includes, an outer dished component which comprises an outer base wall and an outer sidewall circumscribing the outer base wall, an inner dished component; with en inner base wall and an inner sidewall circumscribing the inner base wail and which inner dished component is received in the outer dished component to provide a socket, bordered by the inner cylindrical sidewall, in which an end portion of a prop Is received, with the inner sidewall contiguous with the outer sidewall along a sealed Join line to seal an Interior of the body, a pressure releasing intet valve extending through a wall of the body through which a hydraulic fluid is passed to inflate the body, wherein the outer base wall is profiled to define a first plane against which a hanging wall abuts, wherein the inner base wall, within the socket, is profiled to define a second plane on which an end of the prop finds support, and wherein the first plane is spaced from the second plane in an axial direction of the prop.