The Milwaukee Road's class F7 comprised six (#100–#105) high-speed, streamlined

Streamliner

A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "bullet trains". Less commonly, the term is applied to fully faired recumbent bicycles...

 4-6-4

4-6-4

Under the Whyte notation for the classification of steam locomotives, 4-6-4 represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification:...

 "Baltic" or "Hudson" type steam locomotive

Steam locomotive

A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...

s built by ALCO

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:...

 in 1937

1937 in rail transport

-January events:* January – Electro-Motive Corporation introduces the EMC E2.* January 18 – The Østfold Line in Norway takes electric traction into use between Ljan and Kolbotn.-March events:...

–38 to haul the Milwaukee's Hiawatha

Hiawatha (passenger train)

The Hiawathas were named passenger trains operated by the Chicago, Milwaukee, St. Paul and Pacific Railroad , and traveled from Chicago to the Twin Cities in Minnesota. The original train takes its name from The Song of Hiawatha by Henry Wadsworth Longfellow...

express passenger trains. Following on from the success of the road's class A

Milwaukee Road class A

The Milwaukee Road class A comprised four high-speed, streamlined 4-4-2 "Atlantic" type steam locomotives built by ALCO in 1935-37 to haul the Milwaukee Road’s Hiawatha express passenger trains. They were among the last Atlantic types built in the United States, and certainly the largest and most...

 4-4-2

4-4-2 (locomotive)

Under the Whyte notation for the classification of steam locomotives, 4-4-2 represents the wheel arrangement of four leading wheels on two axles , four powered and coupled driving wheels on two axles, and two trailing wheels on one axle...

s, the F7s allowed the road to haul longer trains on the popular Chicago–Twin Cities routes.

The F7s are major contenders for the fastest steam locomotives ever built, as they ran at over 100 miles per hour (160.9 km/h) daily. One run in January 1941 recorded by a reporter for Trains

Trains (magazine)

Trains is a monthly magazine dedicated to trains and railroads, and is one of the two flagship publications of Kalmbach Publishing. The magazine is read both by railroad enthusiasts, commonly referred to as railfans, and those within the railroad industry....

magazine saw 110 mph achieved twice—in the midst of a heavy snowstorm. Baron Gérard Vuillet, a French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 railroading expert, once recorded a run between Chicago and Milwaukee where the locomotive reached 125 mph (201.2 km/h) and sustained an average 120 mph (193.1 km/h) for 4.5 miles (7.2 km). However, the British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 locomotive LNER Class A4 4468 Mallard

LNER Class A4 4468 Mallard

Number 4468 Mallard is a London and North Eastern Railway Class A4 4-6-2 Pacific steam locomotive built at Doncaster, England in 1938. While in other respects a relatively typical member of its class, it is historically significant for being the holder of the official world speed record for steam...

 is officially accepted to be the world's fastest, with a run recorded at 125.88 mph (202.6 km/h) in 1938.

The Milwaukee F7s are accepted as the fastest steam locomotives by a different measure—scheduled speed between stations. In 1939, shortly after they were introduced into passenger service, the Twin Cities Hiawatha

Twin Cities Hiawatha

The Twin Cities Hiawatha was a named passenger train operated by the Chicago, Milwaukee, St. Paul and Pacific Railroad , and traveled from Chicago to the Twin Cities in Minnesota. The original train takes its name from the epic poem The Song of Hiawatha by Henry Wadsworth Longfellow...

schedule was modified such that the engines would need to run the 78.3 mi (126 km) between Portage

Portage, Wisconsin

Portage is a city in and the county seat of Columbia County, Wisconsin, United States. The population was 10,662 at the 2010 census making it the largest city in Columbia County...

 and Sparta, Wisconsin

Sparta, Wisconsin

Sparta is a city in and the county seat of Monroe County, Wisconsin, United States, along the La Crosse River. The population was 9,522 at the 2010 census.-Notable people:*William Hawley Atwell, U.S. District Court Judge in Texas*Larry Baumel, NASCAR...

 in 58 minutes—a start-to-stop average of 81 mph (130.4 km/h).

First-built #100 was also the first withdrawn from service, on November 10, 1949; last-built #105 was the final one in service, withdrawn August 10, 1951.

See also

• CNW Class E-4
  CNW Class E-4
  The Chicago and North Western Railway's Class E-4 comprised nine coal-burning streamlined 4-6-4 "Hudson" steam locomotives built in 1937 by ALCO....
  
   - nine very similar 4-6-4 locomotives built for the Milwaukee's Chicago competitor, the Chicago and North Western Railway
  Chicago and North Western Railway
  The Chicago and North Western Transportation Company was a Class I railroad in the Midwest United States. It was also known as the North Western. The railroad operated more than of track as of the turn of the 20th century, and over of track in seven states before retrenchment in the late 1970s...
  
  .