What is the effect of a "Trailing shaft" condition?

A "Trailing shaft" condition refers to a situation in which one or more shafts on a vessel are rotating but not being powered by the main engine. This typically occurs when there is a failure in the main propulsion system or when the main engine is not engaged, yet the ship continues to move forward due to momentum or water flow, allowing the trailing shaft to turn freely.

In essence, under this condition, the shaft(s) may be driven by the hydrodynamic forces acting on the propeller or by the flow of water as the vessel moves through it. This is significant for navigational control, as the crew must be aware of which shafts are operational and able to provide thrust to manage the ship's movements effectively.

Understanding this condition is important for engineers and operators aboard the ship, as it affects propulsion and maneuverability. Managing a trailing shaft can be crucial during emergencies or when dealing with propulsion system anomalies. Hence, recognizing that the trailing shaft condition involves motion without active propulsion helps in understanding its implications for vessel operations.