What is a stern tube bearing?

Stern tube bearings are of the slide bearing type (also referred to as journal bearings or plain bearings). The bearings are located inside the stern tube of the vessel, therefore the name stern tube bearings. The amount of bearings used in a stern tube varies, but a set-up of one aft bearing and a forward bearing is a common solution.

A stern tube is a precisely machined weldment consisting of several tubes, the bearings are press-fitted into the stern tube. To be able to transfer the bearing forces to the vessel, stern tubes are installed in the ship’s structure. This can be done by a combination of resin casting and a bolted connection, or by welding.