Caterpillar celebrates anniversary of ship and its engine

Caterpillar has helped celebrate the 75th anniversary of the coastal ferry boat Stadt Keil, which coincided with the 55th anniversary of its propulsion engine, a MaK MAu 423.

The Stadt Kiel was the first of a series of newbuildings of the thirties, built for regular service on the Kiel fjord. After being sunk in World War II and rehabilitated in Denmark the vessel was again deployed by the public transport company Kieler Verkehrs AG (KVAG) on the route between the central railway station and the coastal resort of Strande. On its way, the Stadt Kiel also regularly passed the factory premises of the then MaK Maschinenbau Kiel AG.

In 1954 the original Krupp diesel engine of type S II 6, a six-cylinder four-stroke engine delivering 300 hp, was replaced by the current, more powerful MaK 8 MAu 423 engine. This directly reversible eight-cylinder four-stroke engine delivers a power of 520 hp at a speed of 375 rpm and has been providing reliable propulsion power for 55 years. A feature of this engine is its freely visible, still uncowled valve stems and rocker arms.

With a cylinder diameter of 290 mm and a piston stroke of 420 mm the MaK MAu 423 engine reaches a swept volume of 27.7 l/cylinder. Its fuel consumption amounts to 169 g/hph. In spite of its reliable propulsion system the vessel was put out of service by the KVAG in 1976.

After a longer odyssey, diverse moorings and different private owners, the Stadt Kiel was finally taken over in 1983 by a Society founded shortly before and presented for the first time again to the public at the Kiel Week international sailing event of that year. After a basic overhaul at the Hamburg-based Jöhnk shipyard the museum ship was finally put into service again in 1990. Although since then the Stadt Kiel has only been in service for about 500 hours per year, regular maintenance is required to keep the ship serviceable.

In the 1990s a cooperation between the Society and the then Krupp MaK Maschinenbau GmbH developed in connection with the maintenance of the MaK 8 MAu 423 engine. One of the joint actions was the cylinder liner and cylinder head overhaul in 1991/92.

In 1998 all cylinders were refurbished in the factory complete with liners, pistons and bearings. And also today’s Caterpillar Motoren GmbH & Co. KG is actively supporting the operation of the vessel, e.g. by leasing the “Stadt Kiel” for company events.

Caterpillar says that as a technical monument of Schleswig-Holstein, the Stadt Kiel is at the same time a symbol of the success story of the MaK brand. To date, more than 10,000 MaK engines have been sold which regularly set new standards in terms of innovation, performance, and reliability. After the acquisition of Krupp MaK Maschinenbau GmbH by Caterpillar Inc. and the change in company name to Caterpillar Motoren GmbH & Co. KG all Cat and MaK branded marine engines are today distributed by Caterpillar Marine Power Systems (CMPS) based in Hamburg.

The support of CMPS for the Stadt Kiel is also a commitment to the values of the MaK brand which are nowadays in demand more than ever in the area of passenger navigation. Whether it is a RoPax ferry or a cruise vessel, MaK M 43 C engines are increasingly part of the ship’s equipment. And although current power demand with up to six engines and a total power of 80 MW (107.000 hp) is incomparably higher ? MaK’s combination of innovative technology, high reliability and low operating costs continues to be a guarantee of success.