ALCO Century 636

The ALCo Century 636 was the most powerful single-engine diesel-electric locomotive constructed by the American Locomotive Company (ALCo). It used their 251 prime mover. The locomotive had a C-C wheel arrangement and 3,600 horsepower (2,700 kW). The locomotive rode on a pair of trucks of all-new design, known as the Hi-Ad, standing for 'high adhesion'. Visually, it is similar to the Century 630, but can be distinguished by the intercooler box. The C630 has two grilles here, one above the other. The C636 only has the upper grille.

ALCo Century 636
RPRX 78, now NYSW 3660 is on the point of SU-100 at Ridgefield Park, New Jersey, September 2005.
Type and origin
Power typeDiesel-electric
BuilderALCo, AE Goodwin (licensee)
ModelCentury 636
Build dateDecember 1967 – September 1970
Total produced63
Gauge4 ft 8 12 in (1,435 mm) standard gauge
Prime moverALCo 16-251F
Engine typeV16 diesel engine
Performance figures
Power output3,600 hp (2.7 MW)
DispositionMost scrapped, some rebuilt, 1 preserved


The production of only 1000 units, built in 1969 and 1970, reflected ALCo's dwindling locomotive market share. Despite many new and innovative features, the C636 could not hold its own. Three demonstrators were built costing Alco about $5.5 million. 636-2, the only former demonstrator operating, was a factor in dissuading potential customers from purchasing these locomotives. During an evaluation on the Santa Fe Railway, the same traction motor blower on 636-2 failed (which causes engine shutdown) and was replaced on three of four runs, and had other unsatisfactory results while being tested on the Southern Pacific Railroad.

AE Goodwin in Australia built 29 C636s between May 1968 and September 1970 for the Pilbara iron ore railroads. Hamersley Iron purchased 12 units in 5 separate orders. Bechtel purchased 5 C636s for use in the construction of the Mount Newman Mining facilities. The latter company ordered 12 C636s a year later and bought Bechtel's locomotives. Hamersley Iron had their fleet rebuilt in the 1980s by Comeng, Bassendean with the Australian designed Pilbara cab.[1]

Montreal Locomotive Works produced a M636 variant of the C636 on Dofasco trucks for Canadian Pacific Railway and Canadian National Railway. This was also built in Australia for Hamersley Iron, Mount Newman Mining and Robe River Mining.[1]

Original ownersEdit

Railroad Quantity Road numbers Notes
Alco Products (demonstrators)
To Québec Cartier Mining Company 77-79[2]
Illinois Central Railroad
Penn Central
Ordered by PRR before PC merger; to Conrail as 6780-6794[3]
Spokane, Portland and Seattle Railway
330–335, 340–343
To Burlington Northern 4360-4369
Hamersley Iron
Built by AE Goodwin, Australia
Mount Newman Mining
Built by AE Goodwin, Australia
Total 63

Current usageEdit

As of March 2020, the only C636 in existence is in operation on the Delaware-Lackawanna Railroad of Scranton, PA. The two former Cartier, ex-Alco demonstrator units stored on the Bath and Hammondsport Railroad for many years have been scrapped by a local contractor. The NYS&W is currently an all-EMD powered railroad. The WNY&P still operates M630 and M636 MLW locomotives, but these units will be removed from service in Summer 2019 and replaced by GE AC6000CWs that formerly served on CSX. The WNYP M-630s and M-636s are reportedly going to the Delaware-Lackawanna in the future.

See alsoEdit


  1. ^ a b Clark, Peter (2012). An Australian Locomotive Guide. Kenthurst: Rosenberg Publishing. pp. 109–119. ISBN 9781921719554.
  2. ^ Komanesky, John. "Quebec Cartier Mining Railway Past & Present Power". The Diesel Shop. Retrieved 24 February 2013.
  3. ^ Waller, Robert S. "Loco Rosters: April 1, 1976". Conrail Cyclopedia. Archived from the original on 10 August 2011. Retrieved 24 February 2013.

External linksEdit