Introduction to Windlass

Windlass is a mechanical device for throwing, lifting, and winching cables, located at the bow of a ship. The rollers on both sides of the sprocket can be used for twisting and retracting cables. Windlass can be divided into manual windlass, electric windlass, electric hydraulic windlass, and steam windlass according to their different power. At present, the anchor machines on seagoing ships are mainly electric hydraulic anchor machines and electric anchor machines. In the early construction of oil tankers, steam anchors were also used for fire and explosion prevention. In order to control the operation of the windlass, the power windlass is equipped with a master controller, which can perform reverse operation and multi-level variable speed control.
The manual anchor windlass is suitable for ships with an anchor mass not exceeding 250kg, and measures should be taken to prevent the handle from injuring people.
The power source of the electric windlass is the electric motor, which drives the main shaft to rotate after multi-level reduction through the large and small gears in the gearbox. Due to the high requirement for reduction ratio, the reducer structure is relatively large and mainly used for small and medium-sized ships.
Electric hydraulic windlass, also known as hydraulic windlass, is driven by an electric motor to drive a hydraulic pump. The oil pressure generated drives the oil motor, which then passes through a reducer (or without a reducer) to make the windlass operate. It has a compact structure, small power and transmission volume, smooth operation, and good transmission performance, but high manufacturing technology and maintenance requirements, making it widely used in modern large and medium-sized ships.

The steam windlass is driven by the steam engine, and the drum shaft is driven by the gear through the crank shaft. Its characteristics are high power and simple structure. When using a steam anchor, the cylinder should be warmed up in advance, and the residual water vapor in the cylinder should be completely discharged after use. When it's cold, to prevent freezing, run a sports car (keep idling).
Except for the different power parts, the functional parts of various anchor machines are basically the same, including sprockets, cable reels, clutches, and brakes. These functional components are all arranged on the same spindle driven by power. The winch drum (auxiliary drum) at the end of the spindle generally rotates with the spindle, while the sprocket is controlled by an independent clutch and brake. When the clutch is closed, the sprocket and the main shaft are engaged and can rotate together with the main shaft, allowing for the anchor chain to be twisted in or out. When the clutch is disengaged, the sprocket does not rotate with the spindle and can be used for anchoring or cable twisting operations. The brake is used to brake the anchor chain or control the speed of chain release. When the brake is tightened, the sprocket is firmly fastened to the anchor body and cannot rotate. Ships can generally be equipped with a double chain anchor. For large ships or ships with large bulbous bows, due to the large distance between the left and right anchor chains, two separate single chain wheel anchor machines (also known as single side anchor machines) are often installed.
Anchor machines are divided into two types according to their layout: horizontal anchor machines and vertical anchor machines. Modern transportation ships widely use horizontal anchor machines, with their main axes arranged horizontally. For the convenience of mooring and unwinding operations, as well as adjusting the force on the cable, modern ships often use an anchor mooring combination machine, which combines the anchor machine and mooring winch into one. In addition to the auxiliary drum at the end of the main shaft, there is also a mooring winch (main drum) on the anchor machine main shaft, which, like the sprocket, is driven by the main shaft and controlled by an independent clutch and brake. Close the clutch and twist or release the cable. After the cable is tightened, the brake is tightened to maintain the stress state of the cable, without having to move or pull it onto the cable pile.
The chain wheel axis of a vertical windlass is perpendicular to the horizontal plane, which can reduce the deck area occupied by the windlass and is commonly seen on military ships.
In addition, there are automatic anchor machines and remote anchor machines. The former is equipped with an anchor chain length sensor in the automatic hydraulic anchor machine system, which automatically stops the anchor machine when all the required anchor chains are thrown out during anchoring; When the anchor is about to approach the anchor chain tube, it can automatically slow down, and when the anchor shaft enters the anchor chain tube and is collected, it will automatically stop. The latter is a type of anchor machine that can be remotely operated from the driver's cab, and its anchor throwing and lifting operations can be remotely operated from the bridge.