MLW "RS10" Locomotives: Specs, Roster, History

Published: August 15, 2024

The Montreal Locomotive Works (MLW), a significant player in the railway manufacturing industry, created the RS10 (specification DL-700), as part of its broader efforts to expand its Canadian catalog during the 1950s.

Known for its adaptability and robust performance, the RS10 was produced only by MLW, one of many similar Alco models which were never offered in the States such as the RS13, RS18, RS23, and RS24 among others.

This article provides a detailed exploration of the RS10, covering its historical context, technical specifications, operational history, and legacy.

CP Rail (Canadian Pacific) RS10 #8564 has the "Cornwall Swing" heading west at Brucy, Quebec in September, 1979. Roger Puta photo.

Historical Context

Originally stablished in 1883 as Locomotive & Machine Company of Montreal, the Montreal Locomotive Works became a subsidiary of the American Locomotive Company (Alco) in 1904 and was subsequently renamed as MLW in 1908.

The company produced numerous wheel arrangements in the steam era and offered Alco's diesel-electric catalog beginning in the 1940s.

The RS-10 was introduced in late 1954. As John Kirkland notes in his book, "The Diesel Builders Volume Two: American Locomotive Company and Montreal Locomotive Works," the model followed up MLW's RS3, which had enjoyed modest sales of 146 units throughout Canada.

The RS10 carbody closely resembled Alco's RSD7 sold in the U.S. It featured a high hood carbody that nearly reached the top of the cab roof but lacked the trademark corner notches designed to provide access to the sandbox fillers.

Specifications

The RS-10 is characterized by several distinct technical features that contributed to its performance and adaptability:

- **Powerplant:** At the heart of the locomotive was a late-era variant of Alco's 244 prime mover, the 244G. The 12-cylinder diesel engine delivered 1,600 horsepower. This engine was known for its robustness and ability to handle heavy loads.

- **Configuration:** The RS10 sported Alco/MLW's standard drop side equalizer rigid bolster trucks (AAR Type B) typically found on its road-switchers during that time. It featured a gear ratio of 65:18 and top speed of 65 mph.

- **Dimensions:** The locomotive measured 56 feet, 11 ¾ inches in length and was available in weights between 235,000 - 260,000 Lbs (depending on ballasting).

- **Tractive Effort:** With a starting tractive effort of 60,000 pounds and continuous rating of 44,000 pounds, the model offered a good blend of sure-footedness and pulling ability.

- **Improvements:** During the course of production, MLW changed the model from a conventional to static generator excitation. Canadian Pacific #8568 was the last produced with conventional excitation while Canadian Pacific #8569 was the first built with static excitation. Both were completed in April, 1956.

Static models were subsequently reclassed as the RS10S and a total of 70 units produced while 58 RS10s were built for a production total of 128 units.

Data Sheet

Attribute	Specification
Engine Builder	Dominion Engineering Works
Engine	4-cycle 244G (V12)
Bore & Stroke	9" X 10.5"
RPM (Maximum / Minimum)	1000 / 400
Main Generator	GE GT581
Horsepower	1600
Gear Ratio	65:18
Speed	65 mph
Trucks	4-Wheel
Configuration	B-B
Weight	235,000-260,000 lbs
Traction Motors	GE 752 (4)
Tractive Effort (Starting)	60,000 lbs at 25%
Tractive Effort (Continuous)	44,000 lbs at 10 mph
Multiple Unit Capability	Yes
Dynamic Braking	Yes
Auxilary Generator	GE GMG139
Air Brake	Westinghouse (24L)
Compressor	Westinghouse (3CDC)
Exterior Dimensions	RS10
Total Length	56' 11 ¾"
Pilot to Pilot	47' 9"
Wheel Diameter	40"
Truck Wheel Base	9' 4"
Height to Top Cab Hood	14' 9 ½"
Cab Width	10'-00"
Top Walkway Width	9' 2"
Walkway Width	5' 0"
Engine Hood Width	5' 5"
Center Bolster	30' 0"
Center Front Truck to Front Pilot	10' 6"
Center Rear Truck to Rear Pilot	11' 0"
Distance between Truck Centers	39' 10"
Minimum Turning Radius	21 degrees
-
Fuel Oil	1200 Gallons
Lubricating Oil	166 Gallons
Engine Cooling Water	200 Gallons
Sand Capacity	28 Cubic Feet

Operational History

The RS10 saw widespread use primarily in Canada, with the Canadian Pacific and Canadian National comprising the bulk of orders.

- **Freight Service:** In its freight capacity, the RS10 excelled at hauling a variety of goods including agricultural products, minerals, and manufactured goods. Its powerful engine and reliable performance made it a staple on many of CP's and CN's lines.

- **Passenger Service:** Adapted for passenger service, some RS10 units were equipped with steam generators for heating passenger cars, offering a comfortable travel experience. These locomotives were instrumental in maintaining efficient passenger services across Canada’s diverse landscape.

Legacy

The RS10 holds a special place in the legacy of Canadian railroading and locomotive manufacturing. Despite the challenges faced by the diesel locomotive market in the subsequent decades, the RS10's impact remains significant for several reasons:

- **Durability:** Many served well beyond their expected operational life spans, a testament to their robust engineering and MLW's commitment to quality.

- **Preservation:** A few RS-10 units have been preserved in railway museums and heritage railways, allowing future generations to appreciate the technological advancements and historical significance of these locomotives.

These units include Ontario Northland #1400 at Exporail (Saint-Constant, Quebec) and Pacific Great Eastern/BC Rail #586 at Central BC Railway and Forestry Museum (Prince George, BC). Unfortunately, the latter unit is in very poor condition.

Production Roster

RS10

Total built = 58

Serial Number	Completion Date	Owner	Road Number
81051-81054	12/1954	Canadian Pacific	8462-8465
81055-81061	1/1955	Canadian Pacific	8466-8472
81062-81065	2/1955	Canadian Pacific	8473-8476
81066-81069	3/1955	Canadian Pacific	8477-8480
81070-81071	4/1955	Canadian Pacific	8481-8482
81175-81178	7/1955	Canadian National	1878-1881
81179-81182	8/1955	Canadian National	1882-1885
81183-81184	9/1955	Canadian National	1863-1864
81207-81210	9/1955	Canadian National	1865-1868
81211-81216	10/1955	Canadian National	1869-1874
81478	11/1955	Canadian National	1875
81479-81480	12/1955	Canadian National	1876-1877
81481-81482	12/1955	Ontario Northland	1400-1401
81483-81484	2/1956	Canadian Pacific	8557-8558
81485-81490	3/1956	Canadian Pacific	8559-8564
81491-81494	4/1956	Canadian Pacific	8565-8568

RS10S

Total Built = 70

Serial Number	Completion Date	Owner	Road Number
81495-81496	4/1956	Canadian Pacific	8569-8570
81497-814502	5/1956	Canadian Pacific	8571-8576
81503-81504	6/1956	Canadian Pacific	8577-8578
81515-81520	6/1956	Canadian Pacific	8579-8584
81521-81527	7/1956	Canadian Pacific	8585-8591
81528-81535	8/1956	Canadian Pacific	8592-8599
81536	9/1956	Canadian Pacific	8600
81537-81539	5/1956	Pacific Great Eastern	579-581
81540-81544	6/1956	Pacific Great Eastern	582-586
81559-81566	10/1956	Canadian National	3066-3073
81567-81568	11/1956	Canadian National	3074-3075
81583-81588	11/1956	Canadian National	3076-3081
81589-81594	12/1956	Canadian National	3082-3087
81595-81560	1/1957	Canadian National	3088-3093
81601-81602	2/1957	Ontario Northland	1402-1403

Conclusion

The RS10 represents a pivotal chapter in the evolution of railway technology. Introduced to meet the demands of the mid-20th century rail industry, the model demonstrated versatility, reliability, and robust performance across various operational scenarios.

Its role in freight and passenger services, coupled with its enduring presence in railway heritage, highlights the enduring influence of the locomotive.