The mtu Series 4000 Engines for Powerful and Clean Rail Traction

• New Locomotive Building and Repowering Programs under way
• Low Emissions with Common Rail Injection
• Electronic Engine Management

In the rail sector, the mtu 4000 engines were first installed in locomotives in 1997. Up to now, 200 series 4000 rail engines have been delivered and another 550 are on order. Eleven different railway companies have them in their rolling stock. One of the most important customers for the series 4000 is Deutsche Bahn AG. Deutsche Bahn has decided to repower the V290 shunting locomotives with the 1000 kW 8V 4000 and the V218 mainline locomotives with the 16 cylinder version with an output of 2000 kW. Another important client of mtu are the Austrian Federal Railways (ÖBB) who placed an order for 70 engines 16V 4000 to power their new Rh2016 mainline locomotive, called "Hercules".

New Locomotive Building and Repowering Programs under way

Presently, series 4000 engines are being used for both new building and repowering programs. An example for new builds are the Austrian Railways (ÖBB) Rh2016 locomotives currently on order. 70 diesel-electric "Hercules" locomotives, built by Siemens Transportation Systems, are to be equipped with 16V 4000 engines, each delivering 2000 kW. For the drive system of the vehicles mtu delivers complete threephase current units consisting of engine, alternator and monitoring/control unit. The locomotives, the first couple of which just recently entered service, reach a speed of 140 km/h and will be used for transnational passenger and cargo services. There is also an option for more engines to power another set of "Hercules" locomotives. Besides this, series 4000 engines will soon be operating in Hong Kong in the same Rh2016 locomotives like for ÖBB. The first Series 4000 engines are also successfully providing service at a subsidiary of SNCF in France.

More frequent than new building programs are repowering programs of older locomotives, the reason being that it is much less costly to reconstruct an existing locomotive than to build a new one. With the series 4000 it is possible to raise older locomotives onto the technological level of new vehicles. The integration of a new powertrain into an old vehicle requires more than pure engine technology, though. What is needed is systems competence and engineering know how that is usually delivered by the locomotive manufacturer. It requires that all components be integrated into an overall system, including engine, alternator, transmission, cooling system, exhaust system and silencer system. One of mtu's strengths is to deliver precisely this engineering know-how including flexible monitoring and control electronics that allow all components to be integrated into an overall propulsion system. Also, the mtu electronics are flexible enough to allow other peripheral systems of the locomotive to be easily integrated.

Low Emission Levels with Common Rail Injection

A major issue for the future is emission regulations. It goes without saying that all series 4000 engines - and also the new 20 cylinder version - meet all exhaust emission regulations currently in force in the rail sector. Those regulations include, for example, the ERRI 2000 / UIC 1 standard which defines emission limits for nitrogen oxide (NOx) and hydrocarbons (HC). The new 20V 4000 is already within the UIC 2 limits even though they do not come into force until 2003. While meeting the ERRI 2003 / UIC 2 requirements, a large number of series 4000 engines ordered by Deutsche Bahn undercut these values by 20 per cent. mtu is preparing for even stricter legislation and is just about to develop technologies to further optimize the emission levels of their engines at even further reduced fuel consumption.

An important technology to allow for the low emission levels of the series 4000 engines is the Common Rail injection system. This system provides injection pressures up to 1400 bar. The injection is exclusively controlled by electronics, independent from the camshaft. Thus, the common rail system allows all fuel injection parameters that affect fuel combustion to be independently controlled. This includes variables such as the timing, the period and the pattern of injection as well as the injection pressure. This is a decisive advantage when it comes to reducing fuel consumption and exhaust emission levels - and not just at a specific running speed but across the entire engine power curve. The system also has a beneficial effect on the engine's noise and vibration levels which are substantially reduced at idling and mid-range speeds compared to conventional systems.

With its subsidiary L'Orange GmbH, a company located in Southern Germany, mtu has its supplier of injection systems in-house. Together with mtu, they developed the series 4000 common rail system, composed of a high pressure pump, double-walled rails and high pressure injectors. All these components are developed and manufactured by L'Orange.

Electronic Engine Management

Part of all series 4000 engines - and also of the new 20 cylinder version - is the electronic engine management system MDEC (mtu Diesel Engine Control). It enables all engine functions and parameters to be precisely monitored and controlled and also incorporates the basic functions for a trend-analysis and diagnostic system and the facility to monitor the engine by remote diagnosis. All important data about the current status of the engine, like speed, fuel injection volume and a variety of temperature and pressure readings are shown on a display on the driver's control panel and can also be transmitted to service facilities. Transmission is via radio modem and a railway mobile communications network directly to the railway operator's central maintenance facilities. Thus, maintenance work can be planned and tools prepared while the locomotive is still in service. MDEC also contains a safety system that reacts automatically when any part of the engine is out of order. Should a problem occur, the engine electronics reduce the engine output and, if the situation becomes critical, stop the engine altogether. Thus, the engine driver can operate the locomotive without having to pay attention to the engine all the time.