mtu Series 8000 Background Information

Posted on April 06, 2004

The Austal fast ferry “Spirit of Ontario” is equipped with four mtu 20 cylinder engines of the Series 8000.

Most modern engines of their kind

The Austal fast ferry “Spirit of Ontario” is equipped with four mtu 20 cylinder engines of the Series 8000. The engines deliver a total propulsive power of 44,000 HP (32,800 kW) and speed the fully loaded ship up to a maximum of 45 knots (52 mph/83 kph). This speed was measured at test rides and is above the expectation of ferry operator C.A.T.S. (Canadian American Transport System). The 8000 engines are very successful on the market. 40 units have been sold so far for commercial and naval vessels as well as for large yachts.

Power output: 8,200 kW, max. 9,000 kW
Output per cyl.: 410 kW
Cylinder displacement: 17.37 liters
Bore: 265 mm
Stroke: 315 mm
Rated speed: 1,150 rpm
Dimensions: LxWxH approx. 7,400 x 1,900 x 3,300 mm
Weight: 44 t (dry, coupling and mountings included)
Weight-to-power ratio: 5,3 kg/kW
Specific fuel consumption: 189 g/kWh (at full load and IMO)
Mean eff. pressure: 24.6 bar
Mean piston speed: 12.1 m/s
Fuel-injection: Common-rail injection system
Aspiration: Quadruple mtu ZR 265 turbo chargers
Maintenance intervals: TBO 24,000 hours with standard load profile

With their maximum power of 9,000 kW (12,000 HP), the 20V 8000 engines are the strongest units the company has on offer and are by far the most modern high speed diesels of that power in the market. The engines of the Series 8000 are based on a completely new and individual concept which includes various of the tried-and-true technical solutions mtu engines are renowned for - common rail fuel injection, modern electronics and a very effectice turbocharging system.

One of the most important innovations to be seen in an engine of the 8 to 10 MW power category is the common-rail injection. This technology, which has developed into the standard of modern automobile diesels, allows to independently determine all injection parameters. Thus, the fuel consumption can be considerably reduced – as are the exhaust emissions in the entire performance range. The level of structure-borne noise of the engine when idling or at partial load range has been clearly decreased in comparison to that of engines with conventional injection systems.

Another characteristic of the Series 8000 is the sequential turbocharging, an optional feature. This technology considerably helps supercharged engines to achieve a wide performance map and thus good acceleration while keeping fuel consumption and smoke levels low. With sequential turbocharging, individual exhaust turbochargers can be switched in and off during operation, depending on the engine’s power demand. mtu first introduced this technology into series production in 1982. In the mean time, it has proven its mettle in far over ten million hours of operation.

The engines of the Series 8000 are controlled and monitored by the electronic engine management system MDEC (mtu Diesel Engine Control). Using this system, an optimal control of all engine functions is possible, and the basis for a trending and diagnosis system is provided. Furthermore, the engine can be included in an overall controlling and monitoring concept of the entire propulsion system and of other areas of the ship. MDEC can be easily connected to the mtu remote control system RCS and the monitoring and control system MCS using the interfaces provided.

High performance engines with potential for the future

In mounting the 20V 8000 in fast commercial ships, the continuous output of the engine is 8,200 kW (11,000 bhp). However, the concept and the technology of the new series include the possibility of clearly augmenting the output – an option mtu realizes on demand. With its Series 8000, mtu not only expects to strengthen its already strong position in this field, but to considerably enhance it, especially in ships of over 50 meters length. mtu provides the most modern propulsion system and a system that has the potential to meet future demands, too.

For navy vessels and yachts, the 20V 8000 offers a top rating of 9000 kW. However, what is at least as important as the maximum power of navy vessel engine is its accelerating power and smooth running in partial load operation. Due to its modern technology, the Series 8000 is a leader in both respects. For navy ships – which have increasingly been subjected to economic and environmental criteria – the low fuel consumption, low exhaust emissions, and low noise levels of the Series 8000 counts as much as its high performance.

Economically attractive and low emissions

One of the objectives defining the development of the 8000 series was to minimize the life cycle costs of the propulsion plant. mtu therefore placed great emphasis on keeping fuel consumption as well as the maintenance and service costs of the new engines low.

When deployed in fast commercial ships, the fuel consumed by the 20V 8000 lies, over a wide operating range, below 195 g/kWh. At its best performance, it remains below 190 g/kWh - always in keeping with the IMO (International Maritime Organization) limit values for nitrogen oxide (NOx). On the basis of these values, the new engine attains the best fuel economy in its performance class. The common-rail injection system and sequential turbocharging have especially contributed to making this possible.

Lube oil consumption is another factor influencing life cycle costs. The so-called power units of the 8000 series allow to constantly keep the wear and tear of the piston rings – and thus oil consumption – low. The life cycle costs are also influenced favorably by the fact that the 8000 series is easy to maintain and service. The intervals between the engine main overhauls (TBOs) are set at 24,000 hours for fast commercial vessels and are backed by test runs with extensive changing load programs and endurance runs at full load and overload speed. The scope of the maintenance work as well and thus, the down time required, is clearly lower than in comparable engines. One reason is that in the series 8000, all components subject to maintenance routines have been placed into a so-called service block at the free end of the engine. This block comprises all accessories required for operation.