Abstract: An aerial lift apparatus unit includes at least a lower boom pivotally interconnected to a transport unit for raising and lowering of the lower boom. An upper boom is pivotally connected to the outer end of the lower boom for raising and lowering of the upper boom with respect to the lower boom. A single integrated lifting and compensating cylinder unit includes an elongated cylinder with a piston and piston rod journaled in the one end and operable to extend outwardly therefrom. The cylinder defines a dual operating cylinder with a base end from which the piston rod extends and an inner base end extending from the base end and defining an upper boom/compensating unit. A hydraulic control system includes a first hydraulic gated control system for raising and positioning of the upper boom relative to the lower boom.

Abstract: An aerial lift apparatus unit includes at least a lower boom pivotally interconnected to a transport unit for raising and lowering of the lower boom. An upper boom is pivotally connected to the outer end of the lower boom for raising and lowering of the upper boom with respect to the lower boom. A single integrated lifting and compensating cylinder unit includes an elongated cylinder with a piston and piston rod journaled in the one end and operable to extend outwardly therefrom. The cylinder defines a dual operating cylinder with a base end from which the piston rod extends and an inner base end extending from the base end and defining an upper boom/compensating unit. A hydraulic control system includes a first hydraulic gated control system for raising and positioning of the upper boom relative to the lower boom.

Abstract: A buried cable laying apparatus to lay a cable in an open trench in the ground in a relaxed or tension-free state. The apparatus progressively forms a trench and then buries detensioning line and a cable in the trench. The detensioning line is in tension and the cable is in a relaxed state. The detensioning line and the cable are both unreeled from drums moving at the same rotational speed. The drum of the detensioning line is of a smaller diameter than the drum of the cable whereby the detensioning line drum will feed more cable than is required but slip relative to the cable until the cable gets tight.