The Chicago, Milwaukee, St. Paul and Pacific Railroad

Chicago, Milwaukee, St. Paul and Pacific Railroad

The Milwaukee Road, officially the Chicago, Milwaukee, St. Paul and Pacific Railroad , was a Class I railroad that operated in the Midwest and Northwest of the United States from 1847 until its merger into the Soo Line Railroad on January 1, 1986. The company went through several official names...

 (Milwaukee Road) classes EP-1 and EF-1 comprised 42 boxcab

Boxcab

A boxcab, in railroad terminology, is a locomotive in which the machinery and crew areas are enclosed in a box-like superstructure . It is a term mostly used in North America while in Victoria , such locomotives have been nicknamed "butterboxes"...

 electric locomotives built by the American Locomotive Company

American Locomotive Company

The American Locomotive Company, often shortened to ALCO or Alco , was a builder of railroad locomotives in the United States.-Early history:...

 (ALCO) in 1915

1915 in rail transport

-January events:* January 1 – The Ilford rail crash in England kills 10.* January 15 – The final spike is driven on the transcontinental Canadian Northern Railway at Basque, British Columbia.-March events:...

. Electrical components were from General Electric

General Electric

General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

. The locomotives were composed of two half-units semi-permanently coupled back-to-back, and numbered as one unit with 'A' and 'B' suffixes. As built, 30 locomotives were assigned to freight service, classified as EF-1 and numbered 10200–10229. The remaining twelve locomotives were assigned to passenger service as class EP-1, numbered 10100–10111, with higher-speed passenger gearing. The design was highly successful, replacing a much larger number of steam locomotives, cutting costs and improving schedules.

In 1919, with the arrival of a newer generation of passenger power, the EP-1 locomotives were converted to EF-1 freight locomotives, and renumbered 10230–10241. In this role, they served until the 1950s, when the arrival of the Little Joe

Little Joe (electric locomotive)

The Little Joe is a type of railroad electric locomotive built by General Electric for export to the Soviet Union in 1946. The locomotives had twelve axles, eight of them powered, in a 2-D+D-2 arrangement...

 locomotives began to replace them in freight service.

Technical information

They were fitted with multiple-unit train control

Multiple-unit train control

Multiple-unit train control, sometimes abbreviated to multiple-unit or MU, is a method of simultaneously controlling all the traction equipment in a train from a single location, whether it is a Multiple unit comprising a number of self-powered passenger cars or a set of locomotives.A set of...

 systems, and could thus be joined together into larger sets and operated from a single control station. They were also retrofitted with a special multiple unit control system designed by an electrical engineer of The Milwaukee Road. This enabled the crew of a Boxcab to control trailing diesel electric locomotives. However, the EF-4 "Little Joes", which were also retrofitted, were more often seen leading diesel electrics than Boxcabs, which had by then been largely relegated to the role of helper or bank engine.

The maximum speed of an EF-1 as built was 35 miles per hour (15.6 m/s). Higher speeds led to excessive strain on the traction motor armatures. The rebuilding programme of the 1950s raised this to 45 miles per hour (20.1 m/s) to help maintain faster schedules.

The two powered trucks were connected together with a ball-and-socket joint, and the couplers

Coupling (railway)

A coupling is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the railway gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.The equipment that connects the couplings to the...

 were also attached to the trucks. The bodywork, therefore, did not take the load of the train. Each truck had outside bar frames

Locomotive frame

A locomotive frame is the structure that forms the backbone of the railway locomotive, giving it strength and supporting the superstructure elements such as a cab, boiler or bodywork. The vast majority of locomotives have had a frame structure of some kind...

, allowing more room for the traction motors and equipment. The front powered truck's frames extended forward and carried an outrigger truck and the heavy snowplows the units bore.

EF-2, EF-3, EF-5 and ES-3

In the 1930s, with train tonnage increasing, the Milwaukee began to create three-unit locomotives out of the boxcab units. A simple combination of three was classified EF-2. Twelve EF-2s were assembled, and renumbered 10500–10511ACB. On these, the cab on the center (C) unit was unnecessary and just added weight and length. The center units were therefore shortened by removing the cab, the pilot truck and the frame extension; these were nicknamed "bobtails". These were assembled in between two standard units to create EF-3 sets. These "bobtail" units weighed 52000 lb (23.6 t) lighter than a regular unit. Additional EF-2s were created, but no more were modified into "bobtails".
The locomotives were renumbered in 1939, the EF-3s being numbered E25–E36, and the EF-1s E50–E73.

In 1951, five four-unit locomotives were created; these were classified EF-5 and could have any combination of regular or bobtail units in the center two positions. Their numbers gradually increased until 10 were in service in 1961.

When an odd number of EF-2s were created, a single Boxcab unit became surplus. This unit was classified as a heavy switcher and given class ES-3.

EP-1A

In 1950, two EF-1 locomotives, E22A/B and E23A/B were converted back into passenger service as class EP-1A to help the aging Bi-Polars on the Puget Sound

Puget Sound

Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...

 Extension. E22 received some smoothing of its appearance, including somewhat "streamlined" cab fronts. They were repainted into the Union Pacific Railroad

Union Pacific Railroad

The Union Pacific Railroad , headquartered in Omaha, Nebraska, is the largest railroad network in the United States. James R. Young is president, CEO and Chairman....

 scheme of Armour Yellow with Harbor Mist Gray roofs, and red dividing lines. These two locomotives served until March 1961 in this role; at which time, the E23A and E23B were renumbered E22D and E22C.

Retirements

The fleet stayed intact until 1951, when two EF-1s were retired – E51A+B and E68A+B. Two units of an EF-2 were retired in 1954, and the remaining numbers held steady until the mid-1960s, when old age began to take its toll. Locomotives were patched-up until un-repairable, and units within were swapped between locomotives without being renumbered.

Most were retired by the end of 1973, but one unit, E57B and its "bobtail" companion, were kept in service as the Harlowton, Montana

Harlowton, Montana

Harlowton is a city in and the county seat of Wheatland County, Montana, United States. The population was 1,062 at the 2000 census. The city was once the eastern terminus of electric operations of the Milwaukee Road railroad's "Pacific Extension" route, which went all the way to Avery, Idaho. ...

 switcher until June 1974.

Today

Unit E50A+B, originally 10200A+B, the first locomotive built, still survives and is preserved at the Lake Superior Railroad Museum

Lake Superior Railroad Museum

The Lake Superior Railroad Museum is a railroad museum in Duluth, Minnesota.The museum has seven steam, fourteen diesel and two electric locomotives, and over 40 other pieces of rolling stock...

 in Duluth, Minnesota

Duluth, Minnesota

Duluth is a port city in the U.S. state of Minnesota and is the county seat of Saint Louis County. The fourth largest city in Minnesota, Duluth had a total population of 86,265 in the 2010 census. Duluth is also the second largest city that is located on Lake Superior after Thunder Bay, Ontario,...

. Unit E57B, originally 10211B, is now preserved at Harlowton, Montana.