From engine to propeller
- The gearbox or clutch, the shafting and bearings, the stern tube and its seal, and the propeller.
- Controllable-pitch propellers and thrusters where fitted, and their control systems.
- The steering gear: the hydraulic power units, the rams or the mechanical linkage, and the emergency steering arrangement.
- Alignment, vibration and the checks and maintenance these systems need to run reliably.
The drive train carries the engine's power to the propeller through the gearbox, shaft and bearings, with the stern tube seal keeping the sea out where the shaft passes through the hull. The steering gear turns the rudder, usually hydraulically, and the engineer must be able to change to and operate the emergency steering. Vibration, a hot bearing or a leaking stern seal are warnings the watchkeeper acts on, because a failure in the drive train or steering at sea is serious.
NOTE — Know the emergency steering Every watchkeeper must be able to change to emergency steering quickly, operate it, and coordinate the changeover with the bridge. A steering failure gives no time to learn the arrangement.
WARNING — A hot bearing or leaking stern seal is a warning Vibration, a bearing running hot, or seawater at the stern seal are early signs of trouble in the drive train. The watchkeeper investigates and reports them before they become a breakdown or a flood.