Wärtsilä RT-flex48T / RTA48T

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, and for ISO standard reference conditions(ISO 15550 and 3046).
• All given BSFC figures for Wärtsilä engines are given with a tolerance of +5% across 40–100% of engine load.

For engines Wärtsilä X62/72/92 & RT-flex82T-B, RT-flex58T-D ER-3, stepwise tolerances are now introduced for the brake specific fuel consumption (BSFC):

• 5% tolerance for 100% to 85% engine load
• 6% tolerance for 84% to 65% engine load
• 7% tolerance for 64% to 25% engine load

Standard Tuning, Delta Tuning, Low Load Tuning are available for the electronically-controlled common- rail engines providing optimum fuel consumption and flexibility for different engine loads.Delta Tuning focuses on reducing fuel consumption in the operating range below 90% engine load. Low Load Tuning reduces fuel consumption below 75% engine load.

Rating points for Wärtsilä low-speed engines

The engine layout fields for Wärtsilä low-speed engines are defined by the power/ speed rating points R1, R2, R3 and R4 (see diagram). 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.

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: 29 °C

Emissions

All Wärtsilä low-speed engines are fully compliant with IMO Tier II NOX limits specified in Annex VI of the MARPOL 73/78. They can also be equipped with a SCR catalyst to meet IMO Tier III NOX emission levels and a scrubber to reduce SOX emissions to 0.1% – even with high sulphur fuels.

Cylinder Lubrication

The Pulse Lubricating System with electronic control of lubrication timing has been further developed. It is available for all Wärtsilä Generation X, Wärtsilä RT-flex and for selected Wärtsilä RTA engines. The guide feed rate for new engines equipped with Pulse Jet cylinder lubrication system is 0.6g/kWh. Engines with different Lubricating Systems might require a higher feed rate. This allows important savings in engine operating costs.

Wärtsilä common-rail system

With the common-rail system, fuel oil, servo oil and control oil are delivered at regulated pressures to rail pipes arranged along the side of the cylinders. Electronic control units then regulate delivery from these rail pipes for fuel injection and exhaust valve operation.
In this way, the Wärtsilä low-speed engines have complete flexibility in fuel injection timing, rate, pressure and volume, as well as in exhaust valve operation. This provides engine operational benefits that cannot be obtained with mechanically-controlled systems.