A Simple Force Analysis for the Raising and Lowering of a Small Wind Turbine and Tower

Abstract

This paper considers the tension in the cable used to raise or lower a small wind turbine and tower without a crane. The tower is hinged at its base and has a gin pole. It is assumed that the movement is slow enough to ignore inertial effects. Most results are obtained for the situation where the gin pole is very close to the tower hinge. Two cases are analysed. In the first, a fixed-length cable from the far end of the gin pole is attached directly to a vehicle. In the second, either a pulley anchored to the ground passes the cable horizontally to the vehicle, or a winch is fixed at the same location. Equations are derived for the maximum tension in the cable in both cases, the maximum vertical force in the first case, and the total length of cable used with second, which may well determine the efficacy of using a winch.