Abstract: A platform for attachment to an aerial boom, said platform being constructed of lightweight dielectric material and mounting collapsible guard rails. The platform includes braces which stabilize and position it on the aerial boom.

Abstract: A hydraulic control system which is of an open center parallel circuit arrangement for aerial boom devices with two return lines, said system having control valves for upper and lower boom arms, wherein the lower boom control valve overrides the upper boom control valve. The system includes a valve connected to a pump actuating engine and responsive to hydraulic pressure to increase the speed of the fluid pump when the flow or pressure in one return line is reduced due to diversion of fluid within the system into the second return line. The system also includes a normally open relief valve carried by the boom supporting turntable adjacent its pivotal connection to the lower boom and operable to control a winch actuator and to deactivate said winch actuator when the boom is in an unstable position.

Abstract: A portable boom support adapted to be mounted on a vehicle which can be adjusted to the contour of the ground and provides the total support for an aerial boom or similar device during its operation. The boom support includes a frame which is attached to the transport vehicle frame and a turntable support pivotally attached to the frame. The turntable support is shiftable about its pivot point by a brace which is adjustable in length and connected at one end to the turntable support and at its other end to the frame. Lateral stability is provided by adjustable outriggers connected to the frame at its ends.