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Maritime Knowledge Base

Browse questions and answers across marine machinery, merchant navy careers, shipboard operations and maritime glossary terms.

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Results for "Thrust bearing"

Marine Machinery

What is a thrust bearing or thrust block and what does it do?

The thrust bearing, or thrust block, absorbs the forward or astern thrust developed by the propeller and transmits it to the ship's hull, so the thrust actually drives the ship.

Marine Machinery

What is a bearing and what types are used in marine engines?

A bearing supports and locates a rotating shaft while allowing it to turn with little friction — marine engines rely on plain white-metal bearings lubricated by an oil film.

Marine Machinery

What is the difference between a controllable-pitch and a fixed-pitch propeller?

A fixed-pitch propeller has blades set at one permanent angle, while a controllable-pitch propeller can rotate its blades to vary thrust and go astern without reversing the engine.

Marine Machinery

What is a reduction gearbox on a ship and why is it used?

A reduction gearbox lowers the high rotational speed of a medium- or high-speed engine to the slower speed that turns an efficient propeller, and can combine several engines onto one shaft.

Marine Machinery

What causes a marine engine turbocharger to surge?

Turbocharger surging is a violent, audible instability of the airflow through the compressor — it signals a mismatch between the turbocharger and the engine's demand.

Marine Machinery

How does a marine diesel engine work?

A marine diesel engine converts the chemical energy of fuel into rotary motion through compression ignition — here is the working principle and the two-stroke and four-stroke cycles.