What is the purpose of main thrust bearings on a ship?

Main thrust bearings are crucial components in a ship's propulsion system. Their primary purpose is to absorb axial thrust, which is the force acting along the axis of the shaft. This axial thrust is generated primarily by the propulsion system, particularly when the propeller operates in water.

When the propeller spins, it creates a force that pushes the shaft forward, and without adequate support from the thrust bearings, this movement could result in excessive wear or damage to the shaft and the connected equipment. By effectively absorbing this axial thrust, the thrust bearings help maintain the integrity and functionality of the propulsion system, ensuring that the ship can operate efficiently and reliably.

The other options may describe functions of different components or characteristics of the propulsion system, but they do not capture the specific role of the main thrust bearings as well as the absorption of axial thrust does.