A new system of control for electrically driven winches and cranes

In the first part of the paper the author reviews the conditions which an electric winch or crane should fulfil, and discusses the different ways in which these can be met and the difficulties and disadvantages entailed. An arrangement of contactors, resistances, etc., together with a patent speed-load device, is described as applied to an electric winch, and its method of working and performance under various conditions of hoisting and lowering loads are detailed. A simpler, more compact and less costly system, obtained as the result of experiment, is developed, with curves giving the various speeds obtained at different loads and a description of the safety devices, etc., incorporated.