Marine Link
Sunday, August 1, 2021

Finnish Power Ploy

Wartsila Diesel's reputation as a high quality propulsion supplier is not new to anyone experienced in the maritime industry. The engine maker has been one of the more active propulsion players in recent years, aggressively introducing new, market-driven products, and increasing its overall market share. About two months ago, Wartsila added a new 320-mm bore engine to its stable. The Wartsila 32 brings higher unit power, enhanced fuel consumption, significantly reduced componentry and integral computer control to a fiercely competitive sector of the engine business. This new type has been engineered to deliver 460 kW per cylinder at 750 rpm in marine applications, compared with the maximum 420 kW attained with the Vasa 32 at the same crankshaft speed. The fact that the Vasa 32 has achieved such a prominent market standing and has set new standards in key performance areas has prompted Wartsila Diesel to set rather high technical attainment levels for itself, in regards to the new generation of machinery.

Although the Wartsila 32 is viewed as the long-term replacement for the Vasa 32, sales of the latter show no sign of diminishing. Wartsila 46: A study in reliability More than a decade has passed since the design of the Wartsila 46 was started. Since then, the market requirements have changed in many respects, and the Wartsila 46 has been successfully adapted to these needs, with advantages including high thermal efficiency at NOx emission levels which meet the proposed IMO limits, reduced operating costs and increased reliability by introduction of the antipolishing ring concept.

The engine has perhaps made its biggest mark in the large cruise vessel segment, where safety, noise, vibration and environmental issues are all prime concerns.

Other key markets for the engine include RoRos and tankers.

In the early 90s, Wartsila began development of a new combustion process, called Low NOx combustion. The target with the development program was to reduce the NOx level by up to 50 percent without any reduction in thermal efficiency. In 1995, Low NOx combustion technology was included in the production engines of the Wartsila 46 as a standard feature.

Since production started in 1998, more than 250 engines, equaling 2,600 cylinders, have been delivered. In addition, there are 65 engines of this type on order. Some of the engines have logged more than 40,000 operating hours in the most demanding operating conditions.

For example, the first production engine of the Wartsila 46 wasinstalled as a single main propulsion engine in the RoRo vessel Polaris. As of September 1996, the engine had logged 43,200 operating hours.

Experience gained during the first years of operation provided the basis for further development. For example, the piston was one of the key components where the design was altered because of hard skirt contact against the liner. The problem was solved by introducing a piston with increased compression height, slightly increased skirt length and optimized skirt form. The piston ring set, comprising two compression rings and one oil scraper ring was first introduced on the 46 to reduce friction losses and to achieve a better dynamic behavior of the rings, resulting in less blow-by, cleaner ring grooves and lower wear rate. Operating experience with the three-ring pack has been so positive that all new engine designs by Wartsila Diesel have this concept as standard.

A significant cruise vessel installation is Silja Serenade, which cruises the demanding Helsinki-Stockholm route. The 666-ft. (203-m) vessel is equipped with four Wartsila 9L46 engines, coupled in pairs to two CP propellers. The main engines produce 32,580 kW, helping the vessel maintain a speed of 21 knots in all weather conditions.

Safety concerns were accounted for in engine room design, with the main and auxiliary engine rooms divided into two compartments. The propulsion machinery is equipped with engine-driven lubricating oil pumps and cooling water pumps.

Sea water pumps and diesel oil pumps get their power supply from the emergency network, and a pneumatically driven diesel oil pump is installed for use in the event of a blackout.

Silja has played an important role in the further development of the 46, allowing Wartsila to test new solutions and alternative component suppliers.

For example, the SPEX supercharging system was successfully tested and introduced on Silja Serenade. SPEX lowered the thermal load, and improved the critical load response needed for safe maneuvering in the narrow archipelago passages.

Expanding In Indonesia Wartsila Diesel announced plans to built a factory for genset packaging and engine assembly in Indonesia, close to Jakarta. The $10 million investment is in accordance with the company's strategy to strengthen its local presence in the growing Asian markets. The company has operated in Indonesia since 1978, in cooperation with PT Stowindo Power.

For more information from a six-cylinder, in-line version

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