Wärtsilä 46F; the new medium-speed standard for the future

Wärtsilä Corporation, Trade press release 29 September 2004 at 14:00 UTC+2

The Wärtsilä 46F is the latest in the highly successful marine engine series launched in 1987 with the Vasa 46, as it was then called. Though visually similar to the original Wärtsilä 46, with similar bore and stroke, the Wärtsilä 46F is a new engine with the latest technology applied to all major components. It is packed with new features including common rail injection and scaleable embedded control, for high performance and record-low exhaust emissions, regardless of fuel quality. It is ideally suited to applications which place a premium on optimum space layout, savings in operating and maintenance costs, superior environmental performance and fuel adaptability.

The Wärtsilä 46F is our proud and most recent achievement in medium-speed marine engines. It marks a synthesis of Wärtsilä’s long experience and world-class engineering to create a concept that matches today’s demands while adapting to the forecast needs of tomorrow. It is a concept we call ‘Innovation and Tradition’ and is rooted in the requirements for reliability, economy and environmental efficiency keenly felt by shipowners and operators today.

High power-to-weight ratio
The new engine initially covers the output range from 7500 to 11,250 kW at 600 rpm in 6-, 7-, 8- and 9-cylinder in-line configurations. The 1250 kW cylinder output results in a high and therefore attractive power-to-weight ratio that has been realized with efficient use of materials but without compromising on reliability, user comfort or maintenance friendliness.

The higher output of the Wärtsilä 46F compared to the original Vasa 46 has been achieved by increasing engine speed instead of mean effective pressure, allowing full exploitation of the latest developments in turbocharger technology for efficiency and environmental optimisation. In full-load operation, early closure of the inlet valves makes it possible to use a low effective compression ratio, resulting in a workcycle characterized by low combustion air temperature, which keeps the rate of NOx formation low.

The high output also contributes directly to operational and maintenance savings. For example, many typical single main engine applications, such as general cargo vessels and container feeder vessels, could use a Wärtsilä 46F main engine with one or two fewer cylinders compared to current ship designs (e.g. a 7-cylinder main engine compared to a 9-cylinder main engine), yielding maintenance savings in the region of 20%.

Optimum use of space
Similar to all newer Wärtsilä engines, the Wärtsilä 46F has modular built-on systems and features such as lubricating oil module with oil cooler and filter, crankshaft driven lubricating oil pump and cooling water pumps, and thermostatic valves. Besides minimizing installation cost, built-on modules are the key to the engine’s compact design; the new Wärtsilä 46F has the same outer dimensions as the highly successful Vasa 46 regardless of its considerably higher power output.

Compactness offers shipbuilding advantages through optimum use of space in the vessel layout. A compact machinery can in many ship types yield more cargo capacity or, in the case of passenger and cruise ships, a higher degree of billable capacity. Alternatively, the vessel’s material costs can be reduced for a fixed cargo capacity.

Condition Based Maintenance (CBM)
The Wärtsilä 46F enters the market as the first engine to have continuous temperature monitoring of the big end bearings as standard. This patented feature, in addition to main bearing temperature monitoring and exhaust gas temperature monitoring, now standard for many years, provides a complete set of reliable real-time data to monitor the engine performance in all its crucial areas – a prerequisite for Condition Based Maintenance that is becoming the standard in maintenance practice today.

The monitoring system on the Wärtsilä 46F is configured for easy hook-up to Wärtsilä’s CBM system, a data analysis and condition evaluation service that Wärtsilä provides for its customers. The CBM service advises operators on how to perform engine fine-tuning in varying operational conditions and allows owners to get the maximum service lifetime between overhauls. This approach balances extended service times with maintaining reliable operation. The benefit to owners is minimum operational costs with traceable reliability. Wärtsilä offers all Wärtsilä 46F customers the CBM service for a free trial period during the warranty period of the engine.

Advanced emissions control
Many shipping segments expect to see volume growth in the near future, e.g. container feeders, general cargo vessels and RoPax vessels operate in heavily populated areas where the environmental debate already has a loud voice. Some shipping segments are under greater pressure from the charterers or the cargo owners than from the regulatory bodies. This is accelerating the growing need for lower emission levels and, in certain sensitive areas, even smokeless operation at all loads.

Common rail (CR) technology, standard on the Wärtsilä 46F, offers almost unlimited possibilities to adjust the fuel injection process to prevailing engine operating conditions, fuel characteristics and local emission requirements. The Wärtsilä 46F is also available with more conventional fuel injection equipment. In this case the injection equipment is based on injection pumps of the double plunger type that have been used with good experience on Wärtsilä 64 engines.

Fuel flexibility
Another unique benefit of the CR system is the engine’s ability to adapt to changes in fuel quality. Political initiatives to regulate marine fuel qualities regionally seem to be growing. Operating ships economically in the near and distant future will call for an ability to adapt to different fuel qualities, maybe even during the same voyage.

The Wärtsilä common rail system brings the flexibility needed to maintain optimum combustion and minimum emissions with various fuel qualities. The system can be set up with multiple sets of parameters to achieve optimum performance using different fuels, e.g. high ash fuel, low sulphur fuel or regular commercial bunker.

Scaleable engine control
The Wärtsilä 46F engine is equipped with a scaleable embedded control system capable of covering a wide range of engine applications. Reliability and serviceability were the main cornerstones of this system’s design.

The automation system is based on five hardware modules that control the engine safety functions, instrumentation, speed control and overall engine functionality, engine instrumentation measurements, and the electronic fuel injection. The architecture is based on CAN (controller area network) communication between the modules, and Ethernet communication to external automation systems. The system also internally implements redundancy on selected systems and components.

As the engine is also available with conventional diesel injection equipment on request, the system can even be scaled to match systems where only the fundamental engine safety is handled by the engine safety module and the speed/load control by the main control module. Other measurements are taken out to external automation systems. On request, an engine with conventional diesel injection can also be supplied with a fully embedded control system.

Tomorrow’s technology today
The Wärtsilä 46F represents Wärtsilä’s innovation and tradition at their best. The engine is built on a platform of long experience and a track record of ground-breaking functionality. It is enhanced with the latest innovations to support environmentally friendly and economical ship operation. It is optimized for today’s shipping and shipbuilding needs with built-in adaptability to the needs of tomorrow.

Marit Holmlund-Sund
Public Relations Manager, Ship Power
Wärtsilä Corporation
Direct tel: +358 10 709 1439
Direct fax: +358 10 709 1425
e-mail: marit.holmlund-sund@wartsila.com
Internet: www.wartsila.com