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

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Results for "Two-stroke engine"

Marine Machinery

What is scavenging in a two-stroke marine engine?

Scavenging is the process of pushing the burnt exhaust gases out of a two-stroke engine cylinder and replacing them with fresh air, ready for the next combustion cycle.

Marine Machinery

What causes a scavenge fire in a two-stroke marine engine?

A scavenge fire is the ignition of accumulated oil and carbon in the scavenge spaces of a two-stroke engine — here is why it happens and how to respond.

Marine Machinery

What is cylinder lubrication in a two-stroke marine engine?

Cylinder lubrication is the separate oil supply fed onto the liner of large two-stroke engines to lubricate, neutralise fuel acids and keep the surfaces clean.

Marine Machinery

What is the difference between a two-stroke and a four-stroke marine engine?

Two-stroke and four-stroke marine engines differ in how many strokes complete a cycle, their speed and size, and the roles they play aboard ship.

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.

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 an indicator diagram and what does it tell the engineer?

An indicator diagram plots the pressure inside an engine cylinder against volume or crank angle, letting the engineer assess the power, condition and faults of each cylinder.

Marine Machinery

How does a marine engine turbocharger work?

A turbocharger uses the energy of the engine's exhaust gas to drive a compressor that forces more air into the cylinders, greatly increasing power and efficiency.

Marine Machinery

Why is my main engine jacket cooling water temperature high?

Working through high jacket-water temperature — flow, the cooler, the sea and central-cooling side, thermostats, air locks and load.

Marine Machinery

Why won't the main engine start on air?

A main engine that turns on air but will not fire, or will not turn at all, points to a short list of common causes across the starting-air, fuel and control systems.

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.