A coil-operated brake for winches and deck machinery is designed to automatically adjust the braking force in response to changes in the load on the mooring line. This system ensures the correct force is applied between the brake band and the winch drum at all times.

The core principle is that when an additional load is applied to the mooring line, the line stretches, which in turn loosens the tightening mechanism. This loosening action automatically causes the brake to apply the correct force, maintaining constant tension. This has the significant advantage of being a self-adjusting system, meaning that once it's set, there's no need for a crew member to periodically re-apply the recommended torque. The brake is typically released using a hydraulic lever.

When a vessel is riding at anchor, a mechanism is used to lock the anchor chain and relieve the windlass of the strain. This is crucial for preventing damage to the windlass and ensuring the anchor is securely held.

A Cable stopper, often a pawl of a rod, is engaged with a link of the anchor chain. The pawl acts as a stop, preventing the chain from moving. All the weight and force from the anchor and the vessel's movement are then transferred to this locking device and the ship's structure, effectively relieving the windlass of any strain.