The velocity at which a winding engine lifts a cage or skip in a shaft. Winding speeds reach up to 6,000 ft/min (1.8 km/min) for deep mines. The normal maximum speed for deep shafts is 3,500 to 4,000 ft/min (1.1 to 1.2 km/min) and for geared winders, 1,500 to 3,000 ft/min (0.46 to 0.91 km/min).