Most modern yachts utilize a reciprocating diesel engine as their prime power source. Due to their operating simplicity, robustness, and fuel economy. Compared to most other prime mover mechanisms.
The rotating crankshaft can be directly coupled to the propeller with slow speed engines. Or via a reduction gearbox for medium and high-speed engines. Or via an alternator and electric motor in diesel-
A diesel-electric transmission system includes a diesel engine connected to an electrical generator. Creating electricity that powers an electric traction motor.
There are several propulsion systems available. With different specifications:
A fan that transmits power by converting rotational motion into thrust.
Aa pitch propeller mounted on a steerable pod attached to the hull. Linked to the engines through either a direct mechanical link or diesel-
A ducted propellor or pump creates a jet of water. By forcing water through a nozzle.
The are several Marine Engine Manufacturers.
The most common are MTU, Caterpillar, MAN, Yanmar and Rolls Royce Marine.
We created this comparison of yacht / marine diesel engine specifications.
|MTU||2000||22-36 l.||400-1,939||536-2,600||1,800-2,450||IMO II / EPA III||400-500 l/h|
|MTU||4000||51-69 l.||746-4,300||1,000-5,765||1,500-2,100||IMO II / EPA III||800-1,000 l/h|
|MTU||1163||232 l.||3,600-7,400||4,825-9,925||1,200-1,250||IMO I / IMO II||1,496 l/h|
|MTU||8000||347 l.||7,200-10,000||9,655-13,410||1,150||IMO II / EPA III||1,600 – 2,100 l/h|
|CAT||C12||12 l.||492-526||660-705||2,300||IMO II||160 l/h (est.)|
|CAT||C18||18 l.||350-747||469-1,001||1800-2300||IMO II||260 l/h (est.)|
|CAT||C32||32 l.||1193-1417||1,600-1,900||2,300||IMO II / EPA III||300 l/h (est.)|
|CAT||3512C||58||1000-1765||1,640-2,366||1600-1800||IMO II / EPA III||800l/h (est.)|
|CAT||VM32C||37||6000-8000||8,000-11,000||750||IMO II||1200 l/h (est.)|
|MAN||i6-800||12 l||588||800||2,300||EPA III||158 l/h|
|MAN||V8-1200||16 l.||882||1200||1,200-2,100||EPA III||240 l/h|
|MAN||V12-1550||24 l.||1,140||1550||1,200-2,100||EPA III||299 l/h|
|MAN||v12-1900||24 l.||1,397||4900||1,200-2,100||EPA III||373 l/h|
|Rolls Royce||C25:33L6P||2000||2720||1,000||IMO II||182 l/h|
|Rolls Royce||B32:40V12P||6000||8160||750||IMO II||184 l/h|
|Rolls Royce||B33:45V12||7200||9800||750||IMO II||176 l/h|
Marine Engine Manufacturers
Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from certain engines.
In the yacht/marine industry there are two common sets of emission standards: the IMO and the EPA.
IMO Marine Engine Regulations
The International Maritime Organization (IMO) is an agency of the United Nations which has been formed to promote maritime safety.
IMO ship pollution rules are contained in the “International Convention on the Prevention of Pollution from Ships”, known as MARPOL
The NOx emission limits of Regulation 13 of MARPOL Annex VI apply to each marine diesel engine. With a power output of more than 130 kW installed on a vessel.
Tier Date KW2,000
IMO I 2000 17.0 45*(n-
IMO II 2011 14.4 44*(n-
IMO III 2016 3.4 9*(n-
EPA Marine Engine Regulations
The United States Environmental Protection Agency (EPA) has set EPA standards for exhaust and evaporative emission. To reduce the environmental impact from marine spark-
The emission standards require manufacturers to control exhaust emissions from the engines. And evaporative emissions from fuel tanks and fuel lines.
Tier Date KW2,000
EPA I 2004 17.0 45*(n-
EPA II 2011 75% of I 75% of I 75% of I
IPA III 2016 20% of I 20% of I 20% of I