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The "DRS-6-6-1500": Baldwin's Six-Motored Road-Switcher

Last revised: June 1, 2023

By: Adam Burns

The DRS-6-6-1500 was the final road switcher to carry Baldwin's early and complicated designation system.  In 1950 it released its new Standard line, a fitting name since it did away with the confusing numbers, dashes, and letters. 

This last model was a six-axle locomotive, C-C version of the DRS-6-4-1500 built during the late 1940s and well suited for branch line operations (although few ultimately sold). 

Overview

The DRS-6-6-1500 found buyers among a scattering of railroads and private companies but in the end could not reach the century mark in sales. 

Today, there are at least two examples known preserved; McCloud River Railroad #29 (preserved as Magma Arizona #10) at the Arizona Railway Museum and Southern Pacific #5208 preserved in its original colors and number at the California Stat Railroad Museum in Sacramento.

Photos

The DRS-6-6-1500 began production in 1948 offering a high, continuous tractive effort of 64,200 pounds thanks to its six powered axles. 

This was a considerable selling point as the locomotive not only provided the highest such rating for any road switcher Baldwin offered up to that time but also any model then in production. 

Nothing then offered by Alco or EMD came close to matching such tractive ability.  During the late 1940s the only manufacturer to have even manufactured a C-C road switcher was Alco's RSD1. 

However, the RSD1 was primarily a specialized model built only for the U.S. Army during World War II and had ended production in 1946.

The DRS-6-6-1500 could produce 1,500 horsepower using Baldwin's supercharged 608SC prime mover, the same as the earlier DRS-6-4-1500 and DRS-4-4-1500.

Reception

While the DRS-6-6-1500 did not sell particularly well several Class I railroads around the country purchased at least a few units such as:

• Bessemer & Lake Erie


• Duluth South Shore & Atlantic


• Union Pacific


• Southern Pacific


• Erie


• Chicago & North Western


• McCloud River Railroad


• Northern Pacific


• Union Railroad


• Minneapolis Northfield & Southern


• Tennessee Coal & Iron


• Chesapeake & Ohio

Additionally, private companies like Kaiser Steel and Tennessee Coal & Iron Railroad also acquired a few examples. 

By the time production had ended in 1950 just 83 units had been sold, which included one B-unit that the Southern Pacific had requested, #5227. 

Buyers of the model found the locomotive useful despite its troublesome prime mover.  The curious lack of dynamic braking also likely hurt sales, a feature then standard on Electro-Motive and Alco products.

The DRS-6-6-1500 saw only a two year run as Baldwin wrapped up production on the unit in September of 1950.

It was soon after replaced by the AS616, which featured an upgraded prime mover and used the company's more straightforward classification system. 

Data Sheet and Specifications

Production Roster

Total Built = 83

Southern Pacific units featured upgraded components including 471B main generator, YG42B auxiliary exciter generator, and 370DL or 370GL traction motors.

* This unit became Duluth, South Shore & Atlantic (Soo Line) #203 on August 23, 1950.

Sources

• Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.

• Kirkland, John F. Diesel Builders, The:  Volume Three, Baldwin Locomotive Works. Pasadena: Interurban Press, 1994.

• Pinkepank, Jerry A. Diesel Spotter's Guide.  Milwaukee: Kalmbach Publishing Company, 1967.

• Solomon, Brian.  Baldwin Locomotives.  Minneapolis:  Voyageur Press, 2009.

The new series sold much better for the builder seeing several hundred examples outshopped amongst the three primary models (AS16, AS416, and the AS616). 

To decipher the meaning of the DRS-6-6-1500's letters and numbers the DRS referred to Diesel Road Switcher unit; the first number, 6, designated its six powered axles; the second 6 meant that it featured six traction motors; and 1500 stood for the horsepower rating.

Once the system is presented it is fairly easy to understand but anyone looking at it for the first time would likely be quite confused at what everything stood for.