RS3m

Infobox Locomotive
name = RS3m
powertype = Diesel-electric
gauge = RailGauge|ussg
builddate = 195? – 1978
aarwheels = B-B
primemover = EMD 567
railroad = Penn Central, Conrail, Missouri-Kansas-Texas, Chicago and Northwestern, Amtrak
locale = Eastern and Midwestern United StatesThe RS3m is a road switcher railway diesel locomotive that is a rebuild of the ALCO RS-3. There are many variations with various different spotting features, the common features being the ALCO RS-3 frame, trucks and usually cab and short hood. Railroads started rebuilding their RS-3 fleets early on because of the unreliability of the ALCo 244 [Prime mover (locomotive)|prime movers] .

Perhaps one of the earliest examples of the RS3m is the former Missouri-Kansas-Texas Railroad's RS3m fleet. Built in the early 1950's by ALCo, the Katy had them rebuilt in the late 1950's by ALCo competetor, EMD who rebuilt them with GP9 long hoods to make room for the larger EMD 567 [Prime mover (locomotive)|prime movers] .

The Chicago and Northwestern Railway had a fleet of RS-3m's that were rebuilt using ALCo components. These feature Long hoods from ALCo RS-11 road switchers.

Penn Central started rebuilding RS-3's in 1972, using parts from retired EMD passenger engines. The RS3m rebuild program started in 1972 and continued until 1978 under Conrail. The bankrupt Penn Central needed more reliable local and secondary service locomotives and had a surplus of passenger locomotives. The result is a locomotive that has the frame, body and trucks from an ALCO RS3, but using fan assemblies and EMD 567 prime movers EMD E8 from retired passenger engines in place of the original ALCO 244prime movers.

The principal visible difference on the Penn Central/Conrail rebuilds is the addition of two conical-shaped EMD switcher style exhaust stacks in place of the one rectangular-shaped ALCO stack and a raised hood. Later rebuilds would just have a raised feature on the long hood to accommodate the larger prime mover. The shape would vary from a rectangular shape with fillets on the long sides to a simple box on top of the long hood. These locomotives are often called DeWitt Geeps, so named because Penn Central started rebuilding them in their DeWitt, shops in Syracuse, New York.

RS3u

The Delaware and Hudson Railway had eight RS3u locomotives which are often mistakenly called RS3ms.These locomotives were rebuilt by Morrison-Knudson (also known as M-K TE56s) between December 1975 and March 1976. They received ALCO 12-251C prime movers, boosting horsepower from 1600hp to 2000hp. To facilitate the larger prime mover, M-K raised the long hood six inches and moved the dynamic brake cooling to a box behind the cab. The units also received a cut-down short hood for greater visibility.

=GP12 and GP16=The Missouri Pacific Railroad had a fleet of RS-3's that were rebuilt, receiving the GP12 or GP16 designation after rebuilding. These look like normal ALCo RS-3's with the addition of more exhaust stacks.

Today, you can find rebuilt RS-3's in museums, shortlines and as industrial switchers.

ources

* [http://pc.smellycat.com/pics/equip/diesel-alco.html Penn Central Historical Society]
* [http://www.bridge-line.org/blhs/rs3m.html Bridge Line Historical Society]
* [http://www.midland-ry.org/index.php?page=equipment-roster Midland Railway Historical Association]
* [http://www.rrpicturearchives.net/locoList.aspx?mid=836 rrpicturearchives.net]