The operating characteristics of the windlass

The operating characteristics of the windlass
Stage one - retract the anchor chain lying underwater. At this point, the anchor motor runs at full speed, and the load torque on the motor shaft remains unchanged. The ship slowly approaches the anchor point under the pulling force of the anchor winch to retract the chain. The shape of the suspended part of the anchor chain remains unchanged.
Phase 2- Tighten the anchor chain. At this point, the anchor machine tightens the anchor chain, gradually increasing the load torque on the motor shaft, decreasing the speed, and changing the shape of the hanging part of the anchor chain until it is straightened. The ship continued to move forward.

Three stages - anchor extraction and excavation. After the anchor chain is tightened, the anchor is pulled out and excavated due to the inertia of the ship's progress. If it cannot be pulled out, the motor will experience a "locked rotor" phenomenon, which means it will stop rotating under a large locked rotor current. To prevent the motor from being burnt out due to blockage, it is required that the motor has a "soft" mechanical characteristic, and the locked-rotor torque is twice the rated torque. To avoid prolonged lockup time (set at 1 minute), drivers can drive slowly and use the force of the thruster to pull out the anchor and excavate the soil.
Four stages - retracting the anchor and anchor chain suspended in the water. After the anchor was unearthed, the load torque of the motor suddenly decreased, and the motor speed also increased. As the anchor chain shortens, its load torque also gradually decreases.
Five stages - pull the anchor into the anchor chain hole, and the motor runs at low speed. When anchoring into the hole, the load torque of the motor increases due to the friction between the anchor and the steel plate of the anchor chain hole.