Abstract: Access equipment of the type comprising a turntable on a mobile base and having a lower boom, at least one upper boom and a platform carried by the upper or uppermost boom has the operation of the lower and upper booms interlocked so that the lower boom must be locked in an elevated position before the upper boom or booms can be elevated, and at least one upper boom is extensible.

Abstract: Access equipment comprising an articulated boom arrangement for supporting a cage, in which a lower boom and upper boom are pivotally connected and the lower boom is pivoted to a turntable platform boom relatively to the lower boom and a second ram for moving the lower boom relatively to the platform. With a view of avoiding the need to provide complex control gear, movement of the lower boom under the control of its ram is limited so that, in its rest position, the lower boom is arranged to extend upwardly with respect to the platform at an angle .theta. such that, in operation, the booms are not movable into positions in which the equipment becomes unstable.

Abstract: A load handling vehicle having a chassis with an engine, wheel, and a control cab, a hydraulically extensible and pivotable telescopic boom pivoted to supports mounted on the rear of the chassis, and a load handling carriage mounted on the free end of the boom.The vehicle is provided with strain gauges mounted in connection with one axle of the chassis, and the gauges are electrically connected via a time delay circuit to an alarm, and valves for controlling the hydraulic operation of the boom, in order to signal impending instability, and to prevent dangerous instability from occurring.