A gin pole is a simple lifting device consisting of a single pole supported by guy wires and operated via pulleys mounted at the top and bottom of the pole. Also known as a guyed-mast or poled derrick, the gin pole is commonly used to erect a variety of structures, from radio towers to log cabins. A gin pole can also be used in a variety of applications to lift machinery, hoist concrete blocks and stones, and can also be used to drag objects horizontally toward the base of the pole. The device is limited, of course, by the location of the pole and the desired movement of the object to be dragged.
The parts involved in a basic gin pole are simple: a pole of sufficient size for the task at hand, a quantity of rope and a set of pulleys. The pole is set into a hole and secured with anchorage stakes to prevent movement. Guy lines attached to the top of the pole are strung out and attached to anchoring points some distance away; four guy lines are typically used to provide adequate support.
Lifting the gin pole into place can be done by a few people for smaller poles, but poles longer than 40 feet (about 12 meters) in length may require mechanical assistance via supplemental rigging and power equipment. With a helper monitoring each guy line, four or more helpers lift the pole until the angle is sufficient for the rear guy line to take over lifting duties. At this point, as much pulling power as needed is applied to the lifting line, while helpers maintain tension on the supplemental lines to prevent the pole from drifting off its position. Once the pole reaches its final position, commonly just off-vertical to enable clear lifting of loads, the guy lines are lashed to their respective anchorages.
In the simplest configuration, a single pulley at the top and a single pulley or hand-cranked winch at the bottom of the pole will suffice for lifting relatively lightweight items. The user will be limited, however, to only those items they can lift under their own muscle power; a simple block and tackle or multiple-pulley configuration can increase the mechanical advantage, enabling the lifting of much heavier items by the hand power of a single person. For very heavy items, an electric winch in conjunction with a multiple-pulley arrangement would be in order, but the sizing of the pole and the hardware used must be scaled up to handle the increased weight; the pole is subjected to tremendous compressive stress during lifting and might buckle if its carrying capacity is exceeded.