The ALCO S-1 and S-3 were

switcher A switcher, shunter, yard pilot, switch engine, yard goat, or shifter is a small railroad locomotive used for manoeuvring railroad cars inside a rail yard in a process known as ''switching'' (US) or ''shunting'' (UK). Switchers are not inten ...

diesel-electric locomotive A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), prime mover is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conv ...

s produced by

ALCO The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer of locomotives, diesel generators, steel, and tanks that operated from 1901 to 1969. The company was formed by the merger of seven smaller locomo ...

and their Canadian subsidiary

Montreal Locomotive Works Montreal Locomotive Works (MLW) was a Canadian railway locomotive manufacturer which existed under several names from 1883 to 1985, producing both steam and diesel locomotives. For a number of years it was a subsidiary of the American Locomotive ...

(MLW). The two locomotives differed only in

trucks A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...

, with the S-1 using ALCO's own Blunt trucks, and the S-3 using

AAR type A switcher truck AAR Type A trucks were first introduced with EMD locomotives sold in 1935; they were a success, became standard on EMD switchers into the 1970s, and were also used on various other makers' locomotives. Their initial design was a collaboration ...

s. The S-1 was built between April 1940 and June 1950, with a total of 543 completed, while the S-3 was constructed between February 1950 and November 1953 (MLW until 1957) with total sales of 300. A modified version, the S-10, was built by MLW only; 13 were built between January and June 1958.

Identification

The S-1 and S-3 are distinguishable externally from the very similar S-2 and S-4 switchers in that they have a smaller exhaust stack with a round base and a smaller radiator shutter area on the nose sides. The S-1/S-3 radiator shutter area is taller than it is wide, while the S-2/S-4 radiator area is wider. The smaller stack is due to the lack of

turbocharging In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

. The S-10 is not externally distinguishable from later Canadian-built S-3 locomotives; it differed mostly in electrical equipment.

Original owners

The S-1 and S-3 models were sold to an extensive list of railroads and industrial operators, as detailed below. Major owners of the S-1 included the

New York Central Railroad The New York Central Railroad was a railroad primarily operating in the Great Lakes and Mid-Atlantic regions of the United States. The railroad primarily connected greater New York and Boston in the east with Chicago and St. Louis in the Midw ...

(NYC), with 71 locomotives; the

New Haven New Haven is a city in the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound in New Haven County, Connecticut and is part of the New York City metropolitan area. With a population of 134,02 ...

with 65 locomotives; the L&N with 45 locomotives; the

C&NW The Chicago and North Western was a Class I railroad in the Midwestern United States. It was also known as the "North Western". The railroad operated more than of track at the turn of the 20th century, and over of track in seven states befor ...

, with 29 locomotives; and the

Pennsylvania Railroad The Pennsylvania Railroad (reporting mark PRR), legal name The Pennsylvania Railroad Company also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia, Pennsylvania. It was named ...

(PRR) with 27 locomotives. Major customers for the S-3 included the CP, with 101; the CN, with 49; the NYC, with 43 locomotives; the B&M, with 16; and the PRR, with 13. The MLW S-10 was sold only to the CP. The totals below include export orders and MLW-built locomotives.

S-1

ALCO constructed approximately 535 S-1s for the US market between 1940–1950.

S-3

ALCO and the Montreal Locomotive Works constructed approximately 300 S-3s for the North American market between 1950–1957.

S-10

MLW constructed 13 S-10s in 1958, all for the Canadian Pacific Railway, numbered 6601–6613. These units were essentially similar to late-built S3s, though with minor updates to the electrical gear.

S-11

In 1959, MLW built a final order of 660 horsepower switchers for the Canadian Pacific, as model S-11, numbered 6614–6623. The internal machinery of these units was essentially the same as that of the S-10, but the car body was radically redesigned, with the radiator on the front end of the hood instead of on the sides.

Preservation

Numerous S-1 and S-3 locomotives remain in use, and several are preserved: * Ex-U.S. Army S-1 7372 is at the

Western Pacific Railroad Museum The Western Pacific Railroad Museum (WPRM) in Portola, California, known as the Portola Railroad Museum until January 1, 2006, is a heritage railroad and archives that preserves and operates historic American railroad equipment and preserves docu ...

and painted in Western Pacific colors. * Ex-Canadian Pacific MLW S-3 6568 is at the

Saskatchewan Railway Museum The Saskatchewan Railway Museum is a railway museum located west of Saskatoon, Saskatchewan at the intersection of the Pike Lake Highway (Hwy 60) and the Canadian National Railway tracks (on "Hawker" siding). It is operated by the Saskatchewan R ...

. *Two Ex-Steel Company of Wales S-1s are preserved and are being restored to working order at the

Nene Valley Railway The Nene Valley Railway (NVR) is a preserved railway in Cambridgeshire, England, running between Peterborough Nene Valley and Yarwell Junction. The line is in length. There are stations at each terminus, and three stops en route: Orton Mere, ...

in England.

References

External links

Alco/MLW S-1 Roster

Alco/MLW S-3 Roster
{{DEFAULTSORT:Alco S-01 And S-03 B-B locomotives S-01 and S-3 S-03 Railway locomotives introduced in 1950 Railway locomotives introduced in 1940 Diesel-electric locomotives of the United States Standard gauge locomotives of the United States Standard gauge locomotives of Canada Standard gauge locomotives of Great Britain Standard gauge locomotives of Mexico Diesel-electric locomotives of Mexico Diesel-electric locomotives of Great Britain Diesel-electric locomotives of Canada