EMD F7

The EMD F7 is a series of diesel-electric locomotives of the U.S. locomotive manufacturer General Motors Electro-Motive Division (EMD ). Make the most numerous sub- series of the EMD F- series.

Originally designed as a freight locomotives, some specimens were also used in passenger train service. Among other things, they moved the legendary El Capitan train of the Santa Fe and the Empire Builder of the Great Northern Railway.

A total of 2,366 aircraft were built with cab (A- units) and 1,483 führerstand loose B units. Until the construction of the EMD SD40- 2 from 1972, the F7 diesel locomotive class, the most numerous in North America dar.

Construction

Technically, based on the previous series, the F7 F3. Changes primarily related to the electrical equipment. So the last F3 structure are hardly to be distinguished from the first F7.

The EMD F7 had a self-supporting locomotive body. The A units at the front, a cab was arranged. Behind the engine room was with the traction generator which supplied the DC power to the traction motors and the diesel engine EMD 567B. The type designation EMD 567 means that the engine had a displacement of 567 cubic inches (about 9.3 liters ) per cylinder. The vehicles of the F- series had engines with 16 cylinders, while in the locomotives of EMD E - series two engines were installed, each with 12 cylinders. The exhaust gases from each of eight cylinders were taken via an exhaust pipe to the outside.

The battery box and fuel tank were located between the bogies. He took 4,542 liters of diesel fuel.

Equipment

On request, the machines were supplied with additional equipment. Many models come with a brake resistor (Dynamic Brake). Here, the driving motors are switched into the generator mode. Thus, the kinetic energy of the locomotive is first converted into electrical energy and then via braking resistors heat. This additional braking effect of the wear of the mechanical brake has been reduced. To dissipate the heat to the environment, the so -equipped locomotives had an additional roof vent. This initially had a diameter of 36 "( 914 mm) and was later extended to 48" is increased ( 1.219 mm).

The F7 locomotives were equipped with a small boiler for train heating. This one use on passenger trains was possible. By EMD but the F- series advertised as a freight locomotive. For passenger trains the same built -axle EMD FP7 or the six-axle E-Series was intended. They had steam boiler with significantly greater capacity.

Variants

During the construction period, some improvements have been implemented on the machines by EMD. On the basis of these differences was of railroad enthusiasts a classification made ​​in the production phases, this representation has been but never confirmed by EMD.

The first units of F7 had at the upper horizontal strip fan openings. In the center of the vehicle four more vents with horizontal grill were arranged.

Between March 1951 and October 1951, the top fan openings got a vertical grill. The cab doors were rounded in the corners and increases the side window.

Since February 1952, the interior ventilation grids were supplied in the vehicle center with vertical openings. In the last machine also accounted for the overhang at the rear of the vehicle.

List of first-time customers

Built In Electro-Motive Division, USA units

Built at General Motors Diesel Canada units

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