Having made a start with 8,000-bhp engines for ferries, Krupp MaK subsequently began supplying other important sectors of the North American market. MaK engines are now in service as main propulsion plants on the Great Lakes, in the Atlantic and Pacific fishing industry, in dredging, in tug/barge systems, and also as auxiliary marine engines.
In addition to numerous marine diesel oil engines, more than 20 engines for operation on heavy oil have been sold to North American shipping companies. This reflects the great interest shown by American customers in heavy-oil diesel engines.
G. Kuhl, president of Krupp MaK Diesel Inc., points out that his company has always stood by its product and given its customers efficient after-sales service. In Chicago, close to the world's busiest airport, Krupp MaK set up its sales and service center, including a comprehensive spares depot. Advisory and after-sales service for customers is in the hands of MaK's own specialists, who have many years' experience with MaK engines.
Krupp MaK supplies heavy-oil engines in the output range from 740 kw (990 bhp) to 9,000 kw (12,070 bhp). The M 331/332/282 engines, with configurations of 6, 8, or 12 cylinders, has a bore of 240 mm and output range from 740 kw to 2,200 kw. The M 452/453 model, with 320-mm bore and power output from 880 kw to 4,800 kw, is manufactured with 6, 8, 9, 12, or 16 cylinders. With the same cylinder configuration, the M 551/552 has a bore of 450 mm and output from 3,200 kw to 9,000 kw. The biggest engine in the line, the 580-mm bore M 601, is provided in 6, 8, or 9 cylinder versions with output ranging from 6,000 to 9,000 kw.
MaK diesels work on the 4-stroke principle and are manufactured as in-line and V-type engines. All MaK engines are distinguished by their robustness and low specific load characteristics. The mean pressures of all the engines lie below 18 bar. Except for those with a 240-mm bore, they have multi-section engine blocks with tension-rod assembly and embedded crankshafts. The structural components enclosing the combustion chamber are specially designed for heavy-oil operation. Outstanding features include high resistance to wear and to high- and low-temperature corrosion, and low component temperatures through intensive cooling.
Other features include built-up pistons with steel crowns and hardened annular grooves; specially designed piston rings with chromium-plated working surfaces; bath-nitrided liners with high resistance to wear and corrosion, with wear values below 0.01 mm per 1,000 hours; and intensively cooled exhaust with wear-resistant armoring, manufactured by MaK to the highest possible standards and tested down to the last detail.
MaK engines have proved reliable in all applications. Krupp MaK is devoting particular attention to the following objectives in the field of research and development:
Further reduction of specific fuel consumption combined with reliable combustion of the lowest grade bunker fuels;
Participating in working groups with the aim of obtaining residual heavy oils suitable for marine purpose;
Improvements in bunker fuel operation by retaining the usual load characteristics and by intensive research into materials.