Marine capstans can be divided into four categories according to the drive mode: hand ,electric, pneumatic and hydraulic .
The most usual ones is electric.
Hydraulic capstans can be categorized by pressure: middle-lower pressure(for bulkers with the pressure of 50-70kg),middle pressure(for over 70kg of pressure) and high pressure( for over 150kg of pressure). The advantage for the hydraulic capstans are more powerful and steady.
Marine capstans can also fall into three categories by installation: horizontal ,vertical and inverted.
The capstans are warping drums which can be vertically installed. They are power-driven machines which can wind but can't store ropes . They also refer to winches with the rotating axis perpendicular to the deck, and are self-protective and traction equipments for the ship.