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ALCO S-6 Diesel-Electric Locomotive
The Alco S-6 (specification DL 430) was a diesel-electric locomotive of the switcher type constructed by ALCO of Schenectady, New York; a total of 126 locomotives were built between May 1955 and December 1960. The S-6 was an improved version of the earlier S-5.

Visually indistinguishable from the S-5, the S-6 used an ALCO 251A or 251B prime mover rated at 900 horsepower (670 kW). The locomotive rode on two-axle AAR trucks, giving a B-B wheel arrangement. ALCO produced a cow-calf variant for the Oliver Iron Mining Company designated SB-8/SSB-9.

Original owners

Allied Chemical Company

Quantity: 1
Road numbers: 110


Quantity: 1
Road numbers: 1202

B. Perini & Sons Construction Company

Quantity: 1
Road numbers: 101
Notes: to Upper Merion and Plymouth Railroad 101.

Belt Railway of Chicago

Quantity: 1
Road numbers: 420

Ferrocarril Chihuahua al Pacífico

Quantity: 1
Road numbers: 60
Notes: Renumbered 106.

Cia Fundidora de Hierro y Acero

Quantity: 3
Road numbers: 1–3

Ferrocarril del Pacífico

Quantity: 24
Road numbers: 701–723

Ferrocarriles Nacionales de México (NdeM)

Quantity: 1
Road numbers: 5300

Northern Pacific Railway

Quantity: 1
Road numbers: 750
Notes: to Burlington Northern Railroad 950.

Ohio River Company (ORCo)

Quantity: 1
Road numbers: 56

Republic Steel

Quantity: 3
Road numbers: 153, 317, 318

Secretaria de Comunicaciones de Obras Publicas (SCOP)

Quantity: 3
Road numbers: 7133-1,2,3
Notes: to Ferrocarril del Sureste (same numbers).

Sheffield Steel

Quantity: 2
Road numbers: 15,16

Southern Pacific Railroad

Quantity: 70
Road numbers: 1033–1082,4634–4645
Notes: renumbered 1200–1257, 1270–1281.

South Buffalo Railway

Quantity: 6
Road numbers: 40–45

Tennessee Copper

Quantity: 1
Road numbers: 107

Upper Merion and Plymouth Railroad

Quantity: 1
Road numbers: 61

U.S. Pipe and Foundry

Quantity: 1
Road numbers: 38

Columbia Geneva Steel

Quantity: 1
Road numbers: 1

Western Maryland Railroad

Quantity: 2
Road numbers: 151,152

Ferrocarriles Unidos de Yucatán

Quantity: 1
Road numbers: 301

Total units: 126

ALCO S-6 Overview
Type and origin
Power: type Diesel
Builder: ALCO
Model: S-6
Build date: May 1955–December 1960
Total produced: 126
AAR wheel arrangement: B-B
UIC class: Bo′Bo′
Gauge: 4 ft 8 1⁄2 in (1,435 mm)
Length: 45 ft 5 in (13.84 m)
Width: 10 ft (3.05 m)
Height: 14 ft 8 in (4.47 m)
Locomotive weight: 230,000 lb (104.3 tonnes)
Fuel capacity: 635 gal (2,400 l; 529 imp gal)
Lubricant capacity: 140 gal (530 l; 120 imp gal)
Coolant capacity: 110 gal (420 l; 92 imp gal)
Sandbox capacity: 26 cu ft (0.74 m3)
Prime mover: ALCO 251A or B
RPM range: 375–1000 rpm
Engine type: Four-stroke diesel
Generator: GE GT533
Traction motors: 4 × GE 731
Cylinders: Straight 6
Cylinder size: 9 in × 10 1⁄2 in (229 mm × 267 mm)
Performance figures
Maximum speed: 60 mph (97 km/h)
Power output: 900 hp (670 kW)
Locale: United States, Mexico

The Alco SB-8/SSB-9 (spec. DL 441) was a diesel-electric locomotive of the switcher type constructed as a cow-calf set by ALCO of Schenectady, New York. These were based on the ALCO S-6, and produced exclusively for Oliver Iron Mining, who bought two sets. The 'cow' being the model SB-8, and the 'calf' being the SSB-9.

ALCO SB-8/SSB-9 Overview
Type and origin
Power type: Diesel-electric
Builder: American Locomotive Company
Serial numbers: 81817–81818 (SB-8), 82311–82312 (SSB-9)
Models: SB-8 and SSB-9
Build date: October/November 1956
Total produced: 2 sets
​ • AAR B-B
 • UIC Bo'Bo'
Gauge: 4 ft 8 1⁄2 in (1,435 mm)
Length: 45 ft 5 in (13.84 m)
Width: 10 ft (3.05 m)
Height: 14 ft 8 in (4.47 m)
Locomotive weight: 230,000 lb (104,326 kg)
Fuel capacity: 635 US gal (529 imp gal; 2,404 L)
Prime mover: ALCO 251A,B
Engine type: Four-stroke diesel
Generator: GE GT533
Traction motors: 4 × GE 731
Cylinders: straight 6
Performance figures
Maximum speed: 60 km/h (37 mph)
Power output: 900 hp (670 kW) per unit, 1,800 hp (1,300 kW) per set
Locale: North America

See also:

ALCO Diesel-Electric Locomotives

Diesel-Electric Locomotives


Southern Pacific Alco S-6 No. 1231 at El Centro, California, in 1970.

By Hugh Llewelyn - 1231Uploaded by Oxyman, CC BY-SA 2.0,

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SP Alco S-6 No. 1231 at El Centro, California, in 1970.

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