ALCO PA

ALCO PA1/PB1 PA2/PB2
An ALCO/M-K PA-4 of the Delaware and Hudson Railroad in April 1978
Type and origin
Power typeDiesel-electric
BuilderPartnership of American Locomotive Company (ALCO) and General Electric (GE)
ModelPA1, PB1, PA2, PB2
Build dateJune 1946 – December 1953
Total produced297
Specifications
Configuration:
 • AARA1A-A1A
Gauge4 ft 8+12 in (1,435 mm) standard gauge
1,600 mm (5 ft 3 in), Brazil
Length65 ft 8 in (20.02 m)
Loco weight306,000 lb (138,799 kg; 139 t)
Prime moverAlco 244G V16
Engine typeV16 Four-stroke diesel
AspirationTurbocharger
Displacement10,688 cu in (175.14 L)
GeneratorDC
Traction motors4x GE 746 or 752 DC traction motors
Cylinders16
Cylinder size9 in × 10+12 in (229 mm × 267 mm)
TransmissionDiesel-electric
Loco brakeIndependent air.
Optional: Dynamic
Train brakesAir
Performance figures
Maximum speed117 mph (188 km/h)
Power output2,000 hp (1,490 kW) — PA-1/PB-1
2,250 hp (1,680 kW) — PA-2/PB-2
Tractive effort51,000 lbf (226.86 kN)
Career
ClassErie- PA1- PA-20 PA2- PA-22 NH- PA1- DER-3a NYC- PA1- various PB1- various PA2- DPA-4a PRR- PA1- AP20 P&LE- PA1- DPA-2c PA2- DPA-14b WAB- PA1- D20
LocaleNorth America, Brazil
DispositionThree preserved, two under restoration, one converted to steam generator car, remainder scrapped.

The ALCO PA was a family of A1A-A1A diesel locomotives built to haul passenger trains. The locomotives were built in Schenectady, New York, in the United States, by a partnership of the American Locomotive Company (ALCO) and General Electric (GE) between June, 1946 and December, 1953. Designed by General Electric's Ray Patten (along with their ALCO FA cousins), they were of a cab unit design; both cab-equipped lead A unit PA and cabless booster B unit PB models were built. While externally the PB models were slightly shorter than the PA model,[1] they shared many of the same characteristics, both aesthetically and mechanically. However, they were not as reliable as EMD E-units.[2]

ALCO's designation of P indicates that they were geared for higher speeds and passenger use, whereas the F designation marks these locomotives as being geared primarily for freight use. However, beyond this, their design was largely similar - aside from the PA/PB's both being larger A1A-A1A types with an even more striking nose - and many railroads used PA and FA locomotives for both freight and passenger service.

Although the majority of the PAs and PBs have been scrapped, six examples have survived. Five PAs are now preserved in railroad museums, while a converted PB still remains in service as a power car.

  1. ^ Solomon, Brian. (2009). "p.113". Alco Locomotives. Laguna Hills: Quayside Publishing Group. p. 113. ISBN 978-1-61673-136-6. OCLC 1024276965.
  2. ^ Solomon, Brian. Santa Fe Railway. Voyageur Press. ISBN 978-1-61060-672-1.