Wärtsilä Corporation has introduced two new low-speed marine diesel engines each of which will be available in two versions, namely the Wärtsilä RT-flex82C, RTA82C, RT-flex82T and RTA82T.
The two engines are designed for two different markets. The Wärtsilä RT-flex82C and RTA82C are intended to be ideal prime movers for the propulsion of Panamax containerships with capacities up to 4500 TEU at a typical service speed of about 24 knots. With cylinder dimensions of 820 mm bore and 2646 mm stroke, the RT-flex82C and RTA82C will be available with six to twelve cylinders to cover a power range of 21,720 kW to 54,240 kW at 87 to 102 rpm.
The Wärtsilä RT-flex82T and RTA82T are designed to provide the right powers and shaft speeds for the propulsion of large tankers, VLCCs and ULCCs of 200,000 tdw to more than 350,000 tdw. With cylinder dimensions of 820 mm bore and 3375 mm stroke, they will be built with six to nine cylinders to cover a power range of 21,720 kW to 40,680 kW at 68 to 80 rpm.
The first engines of the new types are expected to be completed towards the end of 2007, in cooperation with Hyundai Heavy Industries Co Ltd supporting in engine production design and testing by utilising their existing facilities and manpower.
The separate ‘C’ and ‘T’ versions are designed in parallel using the platform concept. Their parameters are standardised as far as possible, except principally the piston stroke, of 2646 mm for the ‘C’ version and 3375 mm for the ‘T’. As a result, many components can be same for both versions, allowing benefits of rationalisation in the design and manufacturing, lowering manufacturing costs, and rationalising also spare parts stocks.
The layout fields of these engines, as defined by the power/speed ratings R1, R2, R3 and R4, are extended to the rating R1+ at the same power as R1 but with increased shaft speed. The extended fields offer widened flexibility to select the most efficient propeller speed for lowest daily fuel consumption, and the most economic propulsion equipment, namely the propeller, shafting, etc.
The Wärtsilä RT-flex82C and RT-flex82T engines incorporate the latest common-rail technology with full electronic control of fuel injection and exhaust valve operation. The RTA82C and RTA82T have traditional mechanically-driven camshafts with fuel injection pumps, exhaust valve actuator pumps etc. Otherwise the RT-flex and RTA versions have the same principal characteristics and design features.
The engines will meet the market needs for outstanding reliability, high efficiency, compactness, optimised industrialisation, and environmental requirements. As with all new marine engines nowadays, they will be fully compliant with the NOX emission regulation of Annexe VI of the MARPOL 1973/78 convention.
The RT-flex versions have the added benefit of no visible smoke emissions at all operating speeds, together with lower running speeds. The mechanical RTA versions will be available for those shipowners preferring the traditional concept.
Principal characteristics of Wärtsilä RT-flex82C, RTA82C, RT-flex82T and RTA82T marine engines:
|Power/cylinder,R1 & R1+:||4520||4520|| kW
|Speed range, R1+ to R3/R4:||102–87||80–68||rev/min|
|Maximum cylinder pressure:||159||159||bar|
|Mean effective pressure, R1/R1+:||20.0/19.0||20.0/19.0||bar|
|Mean piston speed, R1/R1+:||8.6/9.0||8.6/9.0||m/s|
|Numbers of cylinders:||6 to 12||6 to 9|
|BSFC at full load, R1/R1+:||171/169||167/165||g/kWh|
Mr Clas-Eirik Strand, Vice President, 2-stroke engines
Wärtsilä Switzerland Ltd.
Direct tel: +41 79 331 02 20
Office: +41 52 262 26 66
Direct fax: +41 52 262 07 17