By the end of the 18th century horse-driven engines, known as gins, were being used in lead and shallow coal mines. The gin was driven by one or more horses harnessed to rotating beams; the horse walked in a circle pulling a wheel geared to a driving shaft. In the early coal pits horse gins replaced the simple windlasses used to wind coal and workers out of the pit. Horse or whim gins continued to be used at some smaller pits until the end of the 19th century.[1]
Early winding engines were of two sorts: a cog and rung gin with the horizontal winding drum located directly above the shaft and where the horse walked around the shaft top. A more practical version was the whim gin with a vertical axle with the whim or winding drum attached a short distance from the shaft, so that the path the horse followed did not obstruct workers at the shaft top.[2]