MLW "S-13" Locomotives: Specs, Roster, History

Published: August 19, 2024

The S-13 was a Montreal Locomotive Works (MLW)-only switcher cataloged between 1958 and 1967. A distinguished member of the Alco S-series, which was adapted for the Canadian market, the S-13 was designed primarily for switching and light road service.

Under its robust exterior, the S-13 was the first to utlize a 251C prime mover, capable of generating 1,000 horsepower. This output, coupled with its B-B trucks, made the S-13 a versatile workhorse ideal for the rigorous demands of yard duties.

Throughout its production run, MLW built a total of 56 units, many of which were purchased by Canadian National. The S-13 is remembered for its role in transitioning the rail industry from steam to diesel power, serving as a testament to mid-20th-century locomotive engineering and MLW's contribution to the first-generation era.

Canadian National S-13 #8512 switches the coach yards at Spadina Street on Toronto on September 1, 1984. Doug Kroll photo.

In 1959, MLW introduced the S-13 model, a switcher that marked a pivotal shift from the 539 engine to the more advanced six-cylinder inline 251C power plant.

The S-series had been one of Alco's most successful; in the U.S. the company sold some 3,177 examples within seven cataloged models (S-1 through S-6, and the T-6 transfer variant) according to John Kirkland's book, "The Diesel Builder's Volume Two: American Locomotive Company and Montreal Locomotive Works."

In addition, MLW saw 468 sales which included the S-2, S-3, S-4, S-7, S-10, S-11, S-12, and S-13. The latter was Montreal's only variant to feature the 251 engine.

This upgrade provided the S-13 with a robust 1,000 horsepower, ideal for more demanding tasks and railroads generally favored switchers with greater power.

Retaining the carbody and trucks of its predecessor, the S-12, the S-13 offered two locomotive weights and two types of electric transmissions, each identified by specific configuration numbers.

The DL-411 units, weighing approximately 233,000 pounds, featured a sophisticated electric transmission system composed of a GT740 generator and four GE731 traction motors with 75:16 gearing.

Meanwhile, the DL-411A variant, heavier at 246,000 pounds, utilized the same generator but replaced the traction motors with more powerful GE752 models and 74:18 gearing, optimizing it for heavy-duty switching, particularly hump yard operations. Both configurations could be equipped with multiple-unit (MU) control and specialized hump control options.

The inaugural S-13 units, built to the DL-411 specification, comprised a trio of locomotives for the Pacific Great Eastern Railway, numbered 1001-1003 and completed in January 1959.

Soon after, the Canadian National placed orders for 23 DL-411 units and 26 DL-411A units, delivered between February and December 1959. This extensive order saw CN’s locomotives numbered 8500-8522 and 8600-8625, respectively, with several equipped for transition control and hump yard operations.

Specifications

Data Sheet
Engine Builder	Dominion Engineering Works
Engine	4-cycle Model 251C 6L
Bore & Stroke	9" X 10 ½"
RPM (Maximum / Minimum)	1000 / 375
Main Generator	GE - GT740PA
Horsepower	1000
Gear Ratio	75:16
Speed	60 mph
Trucks	4-Wheel
Configuration	B-B
Weight	246,000 lbs
Traction Motors	GE 731 (4) or GE 752 (4)
Tractive Effort (Starting)	57,000 lbs at 25%
Tractive Effort (Continuous)	36,000 lbs at 8 mph
Auxiliary Generator	GE GMG490 GY24A
Air Brake	Westinghouse (26L)
Compressor	Westinghouse (3CD)
Exterior Dimensions (S-13)
Total Length	46' 3"
Pilot to Pilot	37' 3"
Wheel Diameter	40"
Truck Wheel Base	8' 0"
Height to Top Engine Hood	12' 8"
Height to Top Cab Hood	15' 2"
Cab Width	10' 1"
Top Walkway Width	7' 9"
Walkway Width	5' 1"
Engine Hood Width	9' 11"
Center Bolster	22' 3"
Distance between Truck Centers	30' 3"
Minimum Turning Radius	50 degrees
Capacities
Fuel Oil	1050 Gallons
Lubricating Oil	200 Gallons
Engine Cooling Water	67 Gallons
Sand Capacity	27 cubic feet

Production Roster

Serial Number	Completion Date	Owner	Road Number
82548-82550	1/1959	Pacific Great Eastern (1)	1001-1003
82551	2/1959	Canadian National (2)	8500
82552	1/1959	Canadian National (2)	8501
82553-82557	2/1959	Canadian National (2)	8502-8506
82594-82596	3/1959	Canadian National (2)	8507-8509
82597-82601	4/1959	Canadian National (2)	8510-8514
82602-82606	5/1959	Canadian National (2)	8515-8519
82607	6/1959	Canadian National (2)	8520
83139-83140	6/1959	Canadian National (2)	8521-8522
83141-83144	10/1959	Canadian National (3)	8600-8603
83172-83177	10/1959	Canadian National (3)	8604-8609
83178-83181	11/1959	Canadian National (3)	8610-8613
83202-83205	11/1959	Canadian National (3)	8614-8617
83206-83213	12/1959	Canadian National (3)	8618-8625
83214	9/1962	Asbestos & Danville (2)	50
83215	2/1963	Canadian Internat. Paper (2)	24-065
83216*	2/1966	Marathon Corporation (2)	28-120
M3483-01	7/1967	Spruce Falls Paper & Pulp (3)	108

Specification 411 Modified: Equipped with traction motor transition.
Specification 411: Featured GE 731 traction motors.
Specification 411A: Featured GE 732 traction motors.

* Was instead built on serial/construction number M3435-01 before the locomotive was completed.

BC Rail S-13 #1001 (ex-Pacific Great Eastern) is seen here at the North Vancouver Yard on May 25, 1984. Doug Kroll photo.

Production continued sporadically over the next few years, eventually culminating in a total of 56 S-13 units: 29 built to the DL-411 specifications and 27 to the DL-411A. These versatile and powerful switchers demonstrate MLW’s commitment to innovation and the railroad industry's transition to more efficient diesel-electric locomotives.

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