What type of bearing is most generally used as an independent main thrust block on merchant ships?

Correct Answer: Option D — Pivoted-shoe thrust bearing.

Pivoted-shoe thrust bearings, such as the Kingsbury design, are the industry standard for merchant ships. They utilize tilting pads that form a wedge-shaped oil film, allowing the bearing to support extremely high axial loads while maintaining low friction and preventing metal-to-metal contact during operation.