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Restoration Continues On New Haven RS3 529

Restoration Continues On New Haven RS3 529

Published: March 2, 2026

Thomaston, CT - The Railroad Museum of New England's efforts to completely restore New Haven RS3 529 to operating condition continues as they provide the latest updates on the project. In a Facebook post from March 1, 2026 the group has stated:

"1. Replacement wheelsets have been carefully measured in preparation to being sent out for refinishing.

2. The old water pump has been removed, and the replacement water pump housing is being prepared for installation.

3. Electrical work has been happening...where the older low-voltage wiring has been systematically replaced.

4. The old rotten decking on the long hood as been completed removed. The frame has been needle scaled, old welds ground down, and paint applied to the top of the frame to protect against rust in the future.

5. New deck plate has been cut, and the underside primed.

6. With the MU receptacle cabling temporarily removed, the junction boxes at each end have been scraped and needle scaled."

If you would like to donate towards their cause they have a PayPal link setup for 529's restoration which can be viewed here.

Alco's RS3

The RS3 was American Locomotive's most popular and versatile light road-switcher. The model followed the builder's earlier RS1 and RS2 and was cataloged from 1950-1956. It proved Alco's most successful such design, selling some 1,272 examples and the U.S. with another 146 produced for Canadian roads at its Montreal plant. The New Haven was always a loyal customer and acquired 45 examples between 1950-1952, numbered 517-561. 529 rolled out of Schenectady in August, 1950 with serial number 78176.

Development And Design

The RS3 was an evolutionary improvement of the earlier RS2, itself derived from the groundbreaking RS1—the locomotive type that effectively created the modern road-switcher concept. Externally similar to its predecessor, the RS3 introduced refinements in electrical systems, fuel arrangements, and internal components while boosting output to 1,600 horsepower, an important industry benchmark at the start of the 1950s horsepower race.

Power came from ALCO’s turbocharged Model 244 V-12 four-cycle diesel engine, paired with rugged General Electric electrical equipment including a GT-581 main generator and four GE 752 traction motors. The locomotive rode on B-B (four-axle) trucks, providing an ideal balance between tractive effort and route flexibility. Typical maximum speeds ranged from 65 to 85 mph, allowing the RS3 to transition easily between switching duties and mainline assignments.

Operational Versatility

Versatility was the RS-3’s greatest strength. Railroads quickly discovered the locomotive could handle nearly any assignment:

Local and branch-line freight
Mainline road service
Yard and transfer work
Passenger and commuter operations (when equipped with steam generators)

This adaptability made the RS-3 a true “do-everything” locomotive. Units appeared on dozens of major railroads including the New York Central, Pennsylvania, Reading, Southern, Great Northern, and Norfolk & Western, the latter using RS-3s as some of its first diesel locomotives during the transition away from steam.

Variants And Rebuilds

ALCO also offered the RSC3, a six-axle variant featuring three-axle trucks with only four powered axles. This configuration distributed weight more evenly, allowing operation on lighter branch-line track.

Despite strong performance, the 244 prime mover developed a reputation for maintenance sensitivity compared with EMD competitors. As a result, many RS3s enjoyed second careers through rebuilding programs. Several were repowered with EMD 567 engines during the 1970s, becoming known as RS3m locomotives and extending service lives well into the late twentieth century.

Legacy

Although ALCO ultimately lost the diesel market battle to EMD, the RS3 remains one of the builder’s defining achievements. Many units survived decades beyond their original service lives, working for regional railroads, industrial operators, and tourist lines. Numerous examples remain preserved today, a testament to the locomotive’s durability and universal usefulness.

In railroad history, the model represents the maturity of the early diesel era—a locomotive equally at home switching cars in a yard or hauling freight across a division, embodying the flexibility that reshaped North American railroading in the post-steam transition.