Krauss-Maffei ML 4000 C'C'
The ML 4000 C'C ' was built by Krauss -Maffei diesel locomotive, which was acquired in 1961 by the U.S. railroad companies Denver and Rio Grande Western Railroad (D & RGW ) and Southern Pacific Railroad (SP). Manufactured were 21 locomotives in two series. Furthermore, 16 locomotives were built for the Brazilian Railway Company Estrada de Ferro Vitória a Minas on meter gauge.
- 4.1 Motor
- 4.2 Transmission
- 4.3 cooling
- 4.4 Control
- 4.5 Structure and Suspension
- 4.6 brake
Development
Due to the ever -growing trailer loads of freight trains studied the two railway companies in the early 1960s new ways to get more powerful locomotives. The requirements in the operation were enormous: It was gross combination weights of up to 12,000 t over the ramps of the Sierra Nevada or the Rocky Mountains to convey. It had to be overcome on the route through the nearly 10 -kilometer-long Moffat Tunnel altitude of 2,800 meters in the route network of the D & RGW. These were dealt with to date with seven to twelve diesel-electric locomotives of type F9 EMD and EMD GP9 1750 hp EMD SD24 or with a maximum of 2400 hp.
Although American railway companies of EMD demanded the development of more powerful locomotives, EMD did not these wishes (for now) after. With the construction of diesel-hydraulic Krauss -Maffei ML 3000 the companies were, however, aware of a 3000 horsepower locomotive of the German manufacturer. The hydraulic transmission also made a commitment to the power required by other advantages provided by a lower power to weight ratio and better utilization of the wheel-rail friction, with the diesel-electric locomotives from American manufacturers than was possible in the early 1960s. You could design and build a stronger and zugkräftigere locomotive so at a given maximum possible weight.
With this perspective, initially joined the D & RGW approached Krauss- Maffei. The manufacturer needed but for economic reasons, yet another order, which is why the Southern Pacific took part in the procurement. Both railways first bought three locomotives. The vehicles possessed a rated output of 4000 hp and were the world's most powerful diesel locomotives framing their time. Also, the fact that an American railway company in Germany is purchasing locomotives, in America and in Europe at the time was a sensation in the art.
Testing in Europe
Krauss -Maffei tested the first locomotive on the route Münster -Emden as well as on the Semmering Railway in Austria, which has gradients of 2.5%. The locomotive went there in such a slope a train with 867 t from the state and accelerated it to 26.5 km / h The sea trials were successfully concluded in July 1961. In 1961 were exported to the United States every six locomotives.
Operation
USA
Denver & Rio Grande Western
The locomotives were classified under numbers 4001-4003 and usually for two or three freight trains with 4000 tonnes and 7000 tonnes towing capacity on the routes across the Rocky Mountains used. In continuous operation, however, the machine proved to be susceptible to interference. A major problem was the relatively high proportion of full- load operating hours. The D & RGW, it amounted to up to 45 % of operating hours, while Krauss -Maffei was assumed based on the development of ML 4000 on the experience in the operation of Deutsche Bahn only a proportion of up to 10%. Therefore, the lead locomotives with only a small amount of cooling water. This amount was not enough during the full load - mountain rides through the Moffat Tunnel, so that the engines overheated. Problems also arose because of poor compatibility of the installed compressors Gardner Denver, which were designed for slow-running U.S. diesel with about 800 revolutions / minute, while the Maybach engines of ML 4000 ran at up to 1600 revolutions / minute. There were also problems with the lubrication of the exhaust turbine.
Reached on the demanding route network of the D & RGW, which on the route from Denver to Salt Lake City heights of 2800 meters ( Moffat Tunnel ) or 2270 meters ( Soldier Summit ) and numerous tunnels included, the ML 4000 were impacted on their performance limits, so rapidly accumulated machine failures. The staff of D & RGW locomotives called the pejorative " Damned Krauts" ( " damn German ").
The three machines were therefore sold to the Southern Pacific in February 1964. The locomotives were delivered in yellow / silver / black color scheme of the D & RGW and they retained this color scheme even after the sale.
Southern Pacific
The Southern Pacific also received in 1961 their first three locomotives, which were provided with the usual red and dark gray color scheme of this company. Initially, the locomotives, left a lasting impression. It was possible to make the operation of trains with the more powerful engines more efficient. Therefore, he was ordered in 1963 by Krauss -Maffei 15 locomotives of the second series and took over in 1964, the three machines of the D & RGW, who retained their original color dress, but got the Southern Pacific lettering.
The SP stationed all its diesel-hydraulic locomotives together in Roseville ( California). At first they drove to the Sierra Nevada and Oregon mountain ranges, but because of the increasing difficulties with the air intake in the numerous galleries and tunnels, the locomotives were used from 1965 to the lowland stretches of the San Joaquin Valley. Usually a freight train of a Krauss -Maffei and an EMD GP9 EMD F7 or was performed.
After all, dealt after the commissioning of German locomotives and American manufacturers with the construction of diesel-hydraulic locomotives were equipped with transmissions from Voith. For example, purchased the SP in 1964, three ALCO locomotives DH -643 for comparison with the ML 4000 C'C '.
The Southern Pacific took from 1967 to 1968 all the Krauss-Maffei locomotives from service as an extensive overhaul decency. While it certified that the diesel-hydraulic drive that he was reliable and competitive from the maintenance cost itself, but the engines of locomotives were the American mechanics too complicated and difficult to access.
Whereabouts after operation
1969, KM, the No. 9113, formerly the 9010 to a camera dolly (camera car) was rebuilt. The SP wanted to film their routes for a computer-based driving simulator. It provided the locomotive at the cab end with a stable structure for the film camera. A drive unit has been removed. In their place was a generator that powered the film with current equipment installed. The fuel for this was taken from the original locomotive tank. The second motor at the rear end has been shut down, but remained installed in the locomotive. The interior of the cab survived because they wanted to control the pusher locomotive from the camera car from. In 1984, one of the camera cars out of service in 1986 and handed it over to the California State Railroad Museum. In 2008, the locomotive was purchased by the Pacific Locomotive Association and started the restoration. This makes it the only diesel-hydraulic locomotive, which has been preserved in the United States.
Brazil
The railway company Estrada de Ferro Vitória a Minas ( EFVM ) procured 1966-1969 sixteen locomotives of the type ML 4000 C'C ' with a track width of 1 meter, the 701 wore the # numbers to 716. These were approved for a maximum speed of 78 km / h and were on the purchase date, the most powerful diesel locomotives on meter gauge. The locomotives remained until the 1980 years in the service.
Technology
Motor
The locomotive received two 16-cylinder Maybach -870 diesel engines. Their performance was increased with high charge on each 1470 kW at 1585/min. For American conditions, the speed of this motor was uncharacteristically high, we worked mostly with speeds up to 1000 rpm. The motors are operated, two drive units, each of which had three axes of a bogie. Each cylinder bank had its own turbocharger.
Transmission
Each drive unit was equipped with a three -stage Voith Turbo Transmission. These were provided with a hydrodynamic brake and the gearbox.
Cooling
The heat was removed via hydrostatically driven fan who sat under the roof of the engine room. The cooling water circuit shut the engine blocks, the heat exchanger for the hydraulic oil flow of the gear unit and the heat exchanger for the engine oil with. When driving through tunnels, cooling could be enhanced by a water spray when hot exhaust gases rendered this necessary. By means of suction sucked the cooler soil air in tunnels.
Control
The locomotives originally had a pneumatic multiple unit control. Later, you replaced it with an electro-pneumatic, so that the locomotives could be operated in conjunction with other locomotive types of the railway company. However, the control caused some problems, which contributed to the early decommissioning in 1968.
Body and frame
Here, a distinction the first and second series of each other. The first series had a self-supporting structure with machine room and a Endführerstand. The second series was carried out with smaller, removable Stems and a two-sided circulation. The locomotives of the first series were Cab- units, which is also called the second series Hood units. The locomotives of the second series was used instead of the Krauss -Maffei - bogies an adapted version of the ALCO.
Brake
The air brake was prescribed by the purchaser. So you set up the Type 26 L Westinghouse Airbrake Company. Each locomotive had two brake compressors, which were driven by the auxiliary gear. In the first series with V-belt driven, in the second series using an intermediate circuit with a hydraulic control clutch. Each bogie had four brake cylinders, each had 3 brake pads. The two pads in the outer wheel and a brake pad of the middle axle were actuated by a cylinder. Thus were on each truck side two cylinders available.
The hand wheel of the handbrake was on the rear cab wall and assigned as a spindle handbrake on a chain his force on the two pads on each wheel, the middle axis. She was weak dimensioned and designed primarily as a parking brake (save the stationary locomotive ), and not to stop the locomotive.
In addition to the pneumatic brake a hydrodynamic brake was still installed, which was used as inertia brake on slopes. This was connected to a hydraulic dual-clutch gearbox with each flow. The primary blade wheels sit on the extended shaft of the hydraulic turbine gearbox, while the secondary blades are built into the housing.