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The "RS10": MLW's 1600 Horsepower Model

Published: August 15, 2024

By: Adam Burns

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

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

RS10S

Total Built = 70

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.