Abstract: A material hoisting gin has a support beam which pivots atop a mounting bracket which may be releasably attached to an upright pole. A bar for supportably engaging a load is suspended from the beam in a manner which enables the bar to be raised so that it is closely proximate to the base of the beam. This arrangement enables the gin to be mounted with the beam very close to the top of the load (which is to be raised or lowered with respect to the pole). The gin can thus be used in situations where there is minimal operating clearance above the load. In particular, the gin can frequently be used to raise or lower distribution transformers on utility poles without encroaching upon the limits of approach to the overhead power lines.

Abstract: An apparatus and method of automatically threading successive closed framed openings by helicopter towing a line equipped with a separable coupling. The invention utilizes a short cable loop pre-threaded through each closed frame such as the throat of a stringing block which cable loop is provided at its ends with coupling halves releasably supported at the opposite ends of a trough overlying the framed opening to be threaded. A helicopter is manoeuvred to drop the towing line coupling into a trough where its halves are automatically separated and thereafter recoupled to a respective end of the cable loop. Subsequently, the forward coupling can be similarly separated for insertion of a second cable loop in the towing line at the next threading apparatus in the helicopter's path of travel.