Dimensions and weights
All dimensions are in millimetres and are not binding. The engine weight is net in metric tonnes (t), without oil and water, and is not binding.
Fuel consumption
All brake specific fuel consumptions (BSFC) are quoted for fuel of lower calorific value 42.7 MJ/kg (10 200 kcal/kg), and for ISO standard reference conditions (ISO 15550 and 3046).
The BSFC figures for Wärtsilä engines are given with a tolerance of +5%.
Wärtsilä RT-flex engines have a lower part-load fuel consumption than the corresponding Wärtsilä RTA engines. Wärtsilä RT-flex engines are also available with Delta Tuning for even lower part-load fuel consumptions.
The values of power in kilowatts and fuel consumption in g/kWh are the standard figures, and discrepancies occur between these and the corresponding brake horsepower (bhp) values owing to the rounding of numbers. For definitive values, please contact our local offices.
ISO standard reference conditions
Total barometric pressure at R1 ............................................ 1.0 bar
Suction air temperature ............................................ 25 °C
Relative humidity ............................................ 30%
Scavenge air cooling water temperature:
- with sea water .................... 25 °C
- with fresh water .................. 29 °C
IMO NOx emissions
All Wärtsilä low-speed engines found on this site comply with the NOx limit specified in Annex VI of the MARPOL 73/78 convention.
Wärtsilä is adapting its low-speed engines to comply fully with both the IMO Tier II and IMO Tier III NOx emission limits. It is expected that Tier II will involve a slight increase in fuel consumption. Wärtsilä RT-flex electronically controlled common-rail low-speed engines are expected to comply with Tier II NOx emissions limits with a smaller increase in fuel consumption than Wärtsilä RTA low-speed engines.
Provisions for compliance with IMO Tier III NOx emissions limits will be announced at a later date but in ample time for the implementation date.
Find more information about IMO Tier II and IMO Tier III here.
Raiting points for Wärtsilä low-speed engines
The engine layout fields for Wärtsilä lowspeed engines are defined by the power/speed rating points R1, R2, R3 and R4 (see diagram left - click the picture to enlarge it). In certain engines, the layout field is extended to the points R1+ and R2+. R1, or R1+ instead if applicable, is the nominal maximum continuous rating (MCR). Any power and speed within the respective engine layout field may be selected as the Contract-MCR (CMCR) point for an engine.
Cylinder lubrication
The load-dependent accumulator cylinder lubricating system has proven reliable operation since its introduction in the 1970s. It is employed as standard on Wärtsilä RTA low-speed engines of smaller bore.
To enable lubricating oil feed rates to be reduced the accumulator system has been further developed in recent years. The new Pulse Lubricating System with electronic control of lubrication timing has been developed. It is available for all Wärtsilä RT-flex low-speed engines and for selected RTA engines. The guide lubricating oil feed rate with the Pulse Lubricating System is 0.7–0.8 g/kWh. This allows important savings in engine operating costs.
For further information on this subject, please consult your nearest Wärtsilä company.
