Wartsila s Italian Plant Rolls Out Two Stroke

By David Tinsley, technical editor

Given the rigorous commercial and physical environments in which sea commerce is conducted, shipowners are understandably conservative. The requirement for machinery and equipment reliability is all the more intense in a maritime setting, due to the far-reaching safety and shipping service implications of system dependability, while cost sensitivity permeates every aspect of product and system choice, notwithstanding technological level.

Therefore, while the development engineers and technicians were confident from the outset that full electronic control in application to large, twostroke marine diesel engines would yield multiple operating benefits, early hesitance in the uptake of a new generation of camshaftless engines has been entirely characteristic of a prudent, client industry. However, this year's translation of gathering interest into a clutch of orders for electronic low-speed diesel prime movers, suggests that the commercial shipping sector will in time display an equally characteristic trait: a propensity for rapid endorsement of technological advance once plant is at sea, delivering the anticipated benefits.

Leading executives in the marine engineering sector, immersed in the needs and views of fleet operators, believe that the nomination of electronically-controlled, two-stroke propulsion engines for newbuild tonnage will become the norm in perhaps just five years' time.

Indeed, some expect the technology to take off in the same way that fuel injection did in the automotive industry a number of years ago.

Now fully integrated within the Wartsila manufacturing network, the former Grandi Motori Trieste works in northeastern Italy has reached a new milestone by rolling-out its first Sulzer RTflex common-rail engine, only the second to be produced worldwide. The imminent supply of the 7RT-flex60C unit to a combined reefer and container carrier under construction in Portugal underscores what many see as the beginnings of a shift in marine engine selection, in favor of more versatile, electronically- controlled plant. Two such engines of 22,470-bhp (16,520-kW) will be supplied by Wartsila Italia to shipbuilding contractor Estaleiros Navais de Viana do Castelo.

The breakthrough for RT-flex technology was the nomination of a 6RTflex58T- B engine for the 47,000-dwt self-unloader Gypsum Centennial, which was commissioned into North American east coast trade towards the end of 2001. The relatively short gap between the operating debut of the Hyundai Heavy Industries-produced RT- flex58T-B engine and the manufacturer of the 7RT-flex60C in Trieste was nonetheless sufficient to permit early service experience to be reflected in the latest machine.

Although wholly distinct in terms of trade and business interests, the respective ship operators who have made the earliest commitments to RT-flex technology display certain parallels in disposition and management philosophy.

Both USG Corporation-owned Gypsum Transportation, which deploys the Hyundai Mipo-built Gypsum Centennial, and Israeli fruit exporter Agrexco, which will charter two newbuild reefer/container carriers from Munchmeyer Petersen of Hamburg, attach high importance to environmental properties for the long-term, while seeking optimum operating qualities from assets which form the vital link in bringing their materials and produce to key markets.

Endorsement of the RT-flex system through such contracts not only underscores the technology's commercial relevance, but also provides a reference basis, which will help nurture business from other quarters. In the case of the Sulzer RT-flex series, Wartsila's challenger to MAN B&W's ME range of two-stroke diesels, sales have now been confirmed for eight of the engines.

Besides the Gypsum Centennial installation, plus two examples of the 7RTflex60C type for two reefer/container carriers to serve Agrexco's Mediterranean trade, four 7RT-flex60C units have been selected for Chipolbrok multipurpose cargo vessel newbuilds at Shanghai Shipyard, while a 6RTflex58T- B is to be fitted in a Scinicariello aframax tanker entrusted to Sumitomo Heavy Industries.

While the engine for the Scinicariello tanker will be manufactured by Japanese licensee Diesel United, the batch of prime movers for the Chipolbrok series will come from Hyundai's engine works at Ulsan. The South Korean producer's early prominence in RT-flex manufac- ture is indicative of its bid to complement its massive volume output capability with a growing involvement in technological design advances. In the meantime, the pair of 7RT-flex60C units built at Trieste has added a new dimension to the range of two- and four-stroke machinery from a plant that has made considerable strides in productivity and sales since becoming part of the Wartsila network.

Wartsila Italia's president and CEO J u k k a Ylanen said that total output had grown from 274 MW in 1997 to an expected level of around 640 MW for 2002, and that sales had risen from $144.3 million to a forecast of about $253.3 million, against a reduction in employment from 1,634 to 1,149 over the same period. The Wartsila interest in GMT had dated from the formation of Wartsila NSD Corporation in 1997, which had given the Finnish company a 40-percent holding in the Italian maker.

As the first design in the Sulzer twostroke range to have been conceived from the outset as an electronic prime mover, the RT-flex60C type dispenses with the usual camshaft and attendant gear drive, fuel injection pumps, exhaust valve actuator pumps and reversing servomotors.

Instead, it is equipped with a common-rail system for fuel injection and exhaust valve actuation, applying full electronic control to those functions.

Significantly from an economic standpoint, the common-rail solution permits operation with the same grades of heavy fuel oil as are already standard for ingestion by Sulzer RTA-series engines.

The common-rail concept is Wartsila's answer to the challenges set by growing environmental restrictions on engine emissions, and has the parallel virtue of superior combustion performance, bearing upon operating setting flexibility and fuel consumption over the full voy- age pattern and engine load range.

The key feature of the RT-flex system is that it gives complete freedom in the timing and operation of fuel injection and exhaust valve actuation. Engine settings can be matched to varied operating needs, such as slow steaming, or to specific or local air pollution requirements, with the prospect of an overall reduction in fuel oil consumption as well as pollutant release. This flexibility has been employed to provide smokeless operation at all ship speeds, down to just 10- 12 percent of nominal speed. Slow running capability and behavior has therefore been greatly improved compared with the standard two-stroke antecedents.

The precise volumetric control conferred through the RT-flex arrangements is claimed to reduce maintenance costs by extending times between overhauls.

Engine availability is increased by both the integrated monitoring functions and by the redundancy in the system's pumps, piping and electronics.

In addition to its electronic attributes, the RT-flex60C, the latest addition to the Sulzer two-stroke range employs TriboPack technology, focused on pistonrunning behavior.

Circle 63 on Reader Service Card www.maritimereporterinfo.com

Other stories from November 2002 issue


Maritime Reporter

First published in 1881 Maritime Reporter is the world's largest audited circulation publication serving the global maritime industry.