Marine Engineering
Terms from Auxiliary Engine to Waste Heat Recovery, each linked to related terms and to the desks that work with them.
Entries updated May 2026
Related desks
Terms in Marine Engineering
15 termsAuxiliary Engine
A secondary diesel engine on board a vessel used primarily to drive electrical generators that supply power for the ship's hotel load, cargo-handling equipment, navigation systems, and other onboard services.
Ballast Water Treatment
Systems installed on vessels to treat ballast water before it is discharged overboard, removing or neutralising harmful aquatic organisms and pathogens.
Bow Thruster
A transverse propulsion device installed in a tunnel through the bow of a vessel, used to improve manoeuvrability at low speeds during berthing and unberthing operations.
CII
Carbon Intensity Indicator, an operational measure introduced by the IMO that rates a ship's annual carbon emissions relative to the cargo carried and distance sailed.
Dual Fuel
An engine technology that allows a marine engine to operate on two different types of fuel, typically LNG and conventional marine diesel or heavy fuel oil.
EEXI
Energy Efficiency Existing Ship Index, a measure introduced by the IMO to reduce the carbon intensity of existing ships by requiring them to meet a minimum energy efficiency standard.
Four-Stroke Engine
A type of internal combustion engine that completes a power cycle in four strokes of the piston (two revolutions of the crankshaft).
LNG Fuel
Liquefied natural gas used as a marine fuel to power ship engines, offering significant reductions in sulphur oxides, nitrogen oxides, and particulate matter emissions compared to conventional heavy fuel oil.
Main Engine
The primary propulsion machinery of a vessel, responsible for driving the propeller.
Scrubber
An exhaust gas cleaning system (EGCS) installed on ships to remove sulphur oxides (SOx) and particulate matter from engine exhaust gases, enabling the use of high-sulphur fuel oil while meeting MARPOL Annex VI emission limits.
Shaft
The rotating mechanical component that transmits power from the main engine to the propeller.
Shaft Generator
An electrical generator driven by the main engine through the propeller shaft, used to produce electrical power while the vessel is at sea.
Stern Tube
A watertight tube through which the propeller shaft exits the hull at the stern of the vessel.
Two-Stroke Engine
A type of internal combustion engine that completes a power cycle in two strokes of the piston (one revolution of the crankshaft).
Waste Heat Recovery
A system that captures thermal energy from the main engine's exhaust gases and cooling water to generate additional electrical power or steam.