MAN field test engine in the Lake Constance catamaran

MAN Engines for Commercial Shipping

MAN field trial engines in Lake Constance catamaran provide first results regarding consumption and reliability

catamaran Constanze

Katamaran-Reederei at Lake Constance again chooses MAN engines. The subsidiary of Stadtwerke Konstanz and Technische Werke Friedrichshafen relies on the six-cylinder, 412 kW (560 horsepower) MAN D2676 LE432 due to its state-of-the-art technologies. The inline six-cylinder engine specifically designed for workboats delivers top results during a field trial in public ferry service with the catamaran Constanze: Significant diesel savings and especially reliability are the key reasons for the use of the MAN engines in local public transport, which is served by the catamarans on Lake Constance.

For one year, two MAN D2676 engines have been working hard as the heart of the Constanze on Lake Constance.

At the end of 2015, MAN Engines presented the D2676 as an innovation for workboats in the USA. Since May 2015, two field trial engines have already been running on Lake Constance in the catamaran Constanze and are providing excellent results after one year. In spite of their significantly reduced displacement compared to the predecessor, the performance and dynamics have remained consistently positive. Significant fuel savings are the consequence of the modern engine concept and the smaller number of cylinders, among other factors. Through a technological leap in consumption optimisation and higher average pressures thanks to common rail injection, the engineers at the MAN Engine Competence Centre in Nuremberg were able to optimise consumption: at the best point it is now a mere 188 g/kWh. The catamaran Constanze needs eleven percent less diesel with the D2676 than with the previous drive unit. “In addition to the new engine, we have carried out other projects with a view to saving on fuel. In spite of the reduction in the ship’s resistance, the structure of the off-flow and the overhaul of the rudder, we can assume that the majority of the savings are linked to the engine”, says Christoph Witte, Managing Director of Katamaran-Reederei. More than 15 percent was already saved last year due to an altered route. It enabled lower maximum speeds on the lake with the same timetable. “As is well known, the shortest path connecting two points is a straight line, which we have come slightly closer to achieving with the new route”, says Witte. Now a speed of 17.3 knots (32 km/h) is sufficient for the catamarans, instead of 21.6 knots (40 km/h), in order to cross the lake at 60-minute intervals. Due to the lower speed, the catamarans again use less diesel.

The Managing Director is not worried about missing time reserves either: “We may and can still travel at 21.6 nautical miles per hour with the new engines. Therefore, it is possible to make up for a delay of eight minutes, which means that the craft always reach their destination on time”, says Witte.

Reliability is top priority

Christoph Witte, Managing Director of Katamaran-Reederei, is pleased with the eleven percent fuel saving on the catamaran Constanze. The new MAN engines are the most important factor in this. © Katamaran-Reederei Bodensee GmbH & Co. KG.

As Katamaran-Reederei's craft are increasingly being used for local public transport on Lake Constance, the reliability of the engines is very important. “We cannot take the risk of the engines' breaking down. Many commuters travel with the catamarans, and they need to reach their place of work on time”, explains Witte. “High technical availability of the craft is the crucial precondition for this. The high reliability of the MAN units significantly assists us in this. In this way, we achieve a rating that is excellent for local public transport operations”, says the Managing Director, smiling. He added that in order to maintain this reputation, the reliability of the MAN engines is the most important factor, other significant advantages of the engine being its compact installation dimensions and its agility, which very much suit the catamarans. The developers of the MAN engines are also aware of this: “Through the state-of-the-art common rail injection technology, the D2676 registers a touch on the throttle very quickly and reacts immediately”, according to Stefan Löser, Project Manager for the D2676 marine engine. Furthermore, the engine is economically efficient. Christoph Witte quickly recognised the advantages during the course of the field trials: “As Managing Director, economic efficiency and reliability are naturally extremely important to me. Our customers, who rely on the punctuality of the catamarans, should not be disappointed. MAN has simply launched a good product on the market for us”, says the Managing Director.

Serial number one to be used on Lake Constance

The series engine which will soon be used in the Constanze is not just any engine. Following the end of the second field trial, Katamaran-Reederei on Lake Constance will receive the very first series-produced D2676 for marine applications in this performance class to roll off the production line in Nuremberg. The engine that will be used on Lake Constance is thus not just something singular in terms of its specialist configuration for workboat applications. “The D2676 is a modern, future-proof engine, which has been specifically modified for workboats. Its reliability and sophistication are based on basic engine components which have proven themselves in many millions of kilometres in HGV applications”, says Project Manager Löser.

Competent partner

Due to the positive cooperation, the business partners extended the field trial, which started in May 2015, by a further year. Now that the first target of 3,000 running hours has been attained, the engine is to be tested for a total of 10,000 hours. “It is a partnership that both parties benefit from”, says Witte. That is why the Managing Director is looking forward to good cooperation in future too.

Specific fuel consumption of the D2676 LE432 (full-load curve & propeller curve).
Consumption development of the Constanze: After the start-up with the new D2676 engines, average annual consumption fell by eleven percent. © Katamaran-Reederei Bodensee GmbH & Co.