Wärtsilä RT-flex96C / RTA96C
The world’s most powerful reciprocating engine
For all sizes of large, fast, containerships of from around 3000 to more than 10,000 TEU capacity, at service speeds of around 25 knots, the Wärtsilä RT-flex96C and RTA96C low-speed engines provide a comprehensive engine programme.
Available in 6-cylinder up to 14-cylinder configuration, the Wärtsilä RT-flex96C and RTA96C low-speed engines cover a power range from 24,000 to 80,080 kW at 92 to 102 rpm.
The Wärtsilä RT-flex96C and RTA96C engines are fully compliant with the IMO Tier II exhaust emissions regulations set out in Annex VI of the MARPOL 73/78 convention.
|Wärtsilä RT-flex96C / RTA96C||IMO Tier II|
|Cylinder bore||960 mm|
|Piston stroke||2500 mm|
|Mean effective pressure at R1||18.6 bar|
|Stroke / bore||2.6|
|Rated power, principal dimensions and weights|
|Cyl.||Output in kW at||Lenght A
|127 rpm||102 rpm|
|6||34 320||24 000||30 960||24 000||12 240||1 160|
|7||40 040||28 000||36 120||28 000||13 920||1 290|
|8||45 760||32 000||41 280||32 000||16 510||1 470|
|9||51 480||36 000||46 440||36 000||18 190||1 620|
|10||57 200||40 000||51 600||40 000||19 870||1 760|
|11||62 920||44 000||56 760||44 000||21 550||1 910|
|12||68 640||48 000||61 920||48 000||23 230||2 050|
|13||74 360||52 000||67 080||52 000||24 910||2 160|
|14||80 080||56 000||72 240||56 000||26 590||2 300|
|4 480||1 800||10 925||5 380|
|12 950||*||*||2 594|
|Brake specific fuel consumption (BSFC) in g/kWh|
|Part load, % of R1||85||70||85||70||65|
|RT-flex tuning variant||Standard||Standard||Delta||Delta||Low-Load|
Dimensions and weights
- All dimensions are in millimetres and are not binding.
- F1: Min height for vertical removal
- F2: Min height for vertical removal with double-jib crane
- F3: Min height for tilted removal with double-jib crane
- The engine weight is net in metric tonnes (t), without oil and water, and is not binding.
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).
BSFC figures for Wärtsilä engines are given with a tolerance of +5% across 40–100% and +7% across 25–39% engine load.
For the Wärtsilä engines X62/72/82/92, RT-flex58T-D ER-3, stepwise tolerances have been 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 to provide 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 below75% engine load.
Typical BSFC curves
to illustrate Standard Tuning, Delta Tuning and Low-Load Tuning
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 %
- Cooling water temperature before engine.......... 25 °C
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.
The Pulse Lubricating System with electronic control of lubrication timing has been further developed. The guide feed rate for new engines equipped with the Pulse Jet cylinder lubrication system is 0.6 g/kWh. Engines with different lubricating systems might require a higher feed rate. This allows important savings in engine operating costs.