Abstract: A jack block and stop for a trailer includes an internal relatively lightweight support structure, a bottom surface having a relatively flat aspect to provide stable support when weight is applied on said jack block and stop, an upper surface having relatively flat aspect and a central open surface entirely extending through from said upper surface to said bottom surface which is large enough to at least part of a trailer part to retain said jack block thereabout in a stored mode.

Abstract: A dump vehicle, such as for agricultural use, includes a movable support member and a slide structure for supporting and guiding the support member, a container pivotally mounted to the support member, a hydraulic actuator mechanism actuable to lift the container from an original lowered position to a predetermined raised position and to tilt the container at the support member when in the predetermined raised position to a preselected tilted position to permit discharge of the contents of the container. The dump vehicle further includes a hydraulic lock mechanism actuable in response to tilting of the container towards the tilted position to lock the support member in the predetermined raised position to prevent over centering and downward movement of the container from the predetermined raised position during tilting and discharging of the container.