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Ratings are based on ISO 15550 conditions of: 

  • Barometric pressure 100 kPa (29.612 in Hg)
  • Inlet air temperature 25°C (77°F)
  • 30% relative humidity

Propeller shaft power represents the net power available after typical gear losses and is 97% of rated power.

Fuel consumption has a tolerance of +/-5% and is based on fuel of 35° API gravity at 16 °C (60 °F) having an LHV of 42,780 KJ/KG (18,390 BTU/lb) when used at 29 °C (85 °F) and weighing 838.9 g/liter (7.001 lb/US gal).
  Propulsion 

Continuous Duty (CON)
Intended for continuous use in applications requiring uninterrupted service at full power. This rating is an ISO 15550 standard power rating.

Typical vessel applications include: ocean-going displacement hulls such as fishing trawlers, freighters, tugboats, bottom drag trawlers and towboats.

Heavy Duty (HD)
Intended for continuous use in variable load applications where full power is limited to eight (8) hours out of every ten (10) hours of operation. Also, reduced power operations must be at or below 200 rpm of the maximum rated rpm. This is an ISO 15550 fuel stop power rating and is for applications that operate 5,000 hours per year or less.

Typical vessel applications include: displacement hull vessels such as mid-water trawlers, purse seiners, and towboats where frequent slowing is common and engine speed and load is stable. Also used in high speed vessels such as ferries and crewboats.

Typical auxiliary applications include: cargo pumps and thrusters in dynamic positioning modes.

Medium Continuous Duty (MCD)
Intended for continuous use in variable load applications where full power is limited to six hours out of every twelve hours of operation. Also, reduced power operations must be at or below 200 rpm of the maximum rated rpm. This rating is an ISO 15550 fuel stop power rating and is for applications that operate less than 3,000 hours per year.

Typical vessel applications include: planing hull ferries, fishing boats designed for high speeds to and from fishing grounds, and (non-cargo) displacement hull yachts and short trip coastal freighters where engine load and speed are cyclical.

Typical auxiliary applications include: powerpacks and some cargo pumps.

Intermittent Duty (INT)
Intended for intermittent use in variable load applications where full power is limited to two hours out of every eight hours of operation. Also, reduced power operations must be at or below 200 rpm of the maximum rated rpm. This rating is an ISO 15550 fuel stop power rating and is for applications that operate less than 1,500 hours per year.

Typical vessel applications include: planing hulls such as customs, military and police vessels, charter and some fishing vessel applications.

Typical auxiliary applications include: hydraulic powerpacks and thrusters for maneuvering, and emergency fire pumps.
  Auxiliary and Generator Set

Prime Power
Engines with this rating are available for an unlimited number of hours per year in variable load applications. Variable load is not to exceed a 70 percent average of the rated power during any operating period of 250 hours. Total operating time at 100 percent Prime Power shall not exceed 500 hours per year. A 10 percent overload capability is available for a period of one hour within a twelve hour period of operation. Total operating time at the 10 percent overload power shall not exceed 25 hours per year. This power rating conforms to ISO 8528 guidelines.


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