A stern tube with bearings radially supports the propeller shaft from the main engine. The stern tube is a hollow tube which accommodates the bearings, the seal boxes and the propeller shaft.
The stern tube is filled with oil, grease or water and forms a barrier between the water outside and the engine room inside the vessel. The stern tube mainly consists of the following parts:
- the tube itself
- connection flanges (forward and aft)
- bearings (forward and aft)
- smaller pipes for temperature sensors
- lubrication of the aft seal (or drain pipes for air-type seals)
- forward seal (engine room side)
- aft seal (water side)
More information about stern tube seals
