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Baldwin's "RT-624": Its 'Standard Line' Transfer Model


Last revised: June 23, 2023

By: Adam Burns

The RT624 followed Baldwin's earlier transfer model, the DT-6-6-2000.  It is incredibly surprising the manufacturer elected to catalog a second such variant after the original's dismal sales performance.

The new model was part of Baldwin's new Standard Line that was introduced in 1950.  The then Baldwin-Lima-Hamilton Corporation's (BLH) last transfer switcher was another failure as railroads were not interested in such a specialized design.


BLH was formed in 1951 through Baldwin Locomotive Works' takeover of the Lima-Hamilton Corporation. 

Both companies were under the control of Westinghouse who, unfortunately, had little interest in remaining in the locomotive market.

Sadly, this was not a feeling shared by Baldwin's top management which had a serious interest in revamping the company into a major player in the market.

Alas, without Westinghouse's blessing, BLH was forced to end production.  The industry's most recognized, and longest continually operating manufacturer, shutdown in 1956. 


9326092357235626357368379048.jpgA pair of Pennsylvania RT624 transfer switchers, #8959 and #8960, run light through the yard at Pitcairn, Pennsylvania, circa 1965. American-Rails.com collection.

The RT624 entered production in June, 1951 replacing Baldwin's earlier transfer model, the DT-6-6-2000.

The new system included the number of powered axles and horsepower.  In the case of the RT624:

  • "RT" referred to Road Transfer

  • The first "6" described six powered axles

  • "24" was the abbreviated horsepower rating, 2,400 

Baldwin's reasoning for dropping the previous designation was the discontinuance of steam locomotive production in 1949.

Prior to that time the builder had utilized lettering to differentiate diesel models from steam such as:

  • DS for Diesel Switcher

  • DR for Diesel Road

  • DRS for Diesel Road Switcher

In their place Baldwin used:

  • AS for All Service

  • RS for Road Switcher

  • RF for Road Freight

  • RT for Road Transfer

The RT624 looked very similar to the DT-6-6-2000, featuring a center-cab and C-C truck design.  It's primary difference was the use of two 606A engines in place of the 606SC.

These prime movers could produce 1,200 horsepower each compared against the 606SC's 1,000 horsepower.  The locomotive also featured upgraded variants of the main generator, auxiliary generator, and traction motors.


The Elgin, Joliet & Eastern, Chicago's successful belt line carrier that avoided the city's downtown congestion, was not interested in the follow-up model.

The "J" had purchased a large fleet of the DT-6-6-2000's (26 units in all) but passed on the RT624.

Only the Pennsylvania and Minneapolis, Northfield & Southern (a short line which served the Twin Cities region) bought the RT624.

The PRR purchased 23 of the 24 units sold by the time production had ended in 1954.

One of the Pennsylvania's rare RT624's, #8727 in Philadelphia, circa 1965. American-Rails.com collection.

Once again, one of the model's most marketable features was its incredible tractive effort, which was even higher than the DT-6-6-2000; 106,200 pounds starting and 72,900 continuous (an optional gearing of 15:68 increased the continuous rating to 78,750 pounds).

BLH truly meant for the locomotive to be used in heavy drag service as it had the beef and muscle to do so.

Data Sheet and Specifications

Entered Production8/1/1951 (Pennsylvania #8952)
Years Produced8/1/1951 - 2/10/1954
Baldwin ClassRT624
Engine606A, 6-Cylinder In-Line, Supercharged (2)
Engine BuilderDe La Vergne
TurbochargerModel H-503 (Elliott Company)
Carbody StylingBaldwin
Length (Between Coupler Pulling Faces)74'
Weight354,000 Lbs (Optional ballasting up to 375,000 Lbs.)
Height (Top Of Rail To Top Of Cab)14'
Truck TypeGSC Rigid Bolster
Truck Wheelbase13'
Wheel Size42"
Traction Motors370DEZ (6), Westinghouse
Traction Generator480FZ, Westinghouse
Auxiliary GeneratorYG42B, Westinghouse
Gear Ratio15:63, 15:68
Tractive Effort Rating72,900 Lbs at 9.9 MPH (15:63) or 78,750 Lbs at 9.2 MPH (15:68)
Top Speed60 MPH

Production Roster

Total Built = 24

Owner Road Number Baldwin Serial Number Construction Number Completion Date
Minneapolis, Northfield & Southern2523753937/23/1953


  • 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.

Another issue hurting the locomotive's potential sales was the lack of dynamic braking or multiple unit (MU) capability as a standard option.  

Today, the  RT624 is one of just a few models it produced that is not preserved (although one DT-6-6-2000 does remain at the Illinois Railway Museum).  


Wes Barris's SteamLocomotive.com is simply the best web resource on the study of steam locomotives. 

It is difficult to truly articulate just how much material can be found at this website. 

It is quite staggering and a must visit!