The Alco RSD5
The Alco RSD5 was essentially an extension of the RSD4 model
as it meant to replace a flaw in the earlier design. After fixing the
issue, which had to do with inadequate spacing the RSD5 sold nearly six
times as many units as its predecessor. The model was meant to compete
with the Electro-Motive Division's SD7 design, the six-axle cousin of
the GP7. Interestingly, despite railroads' disinterest in C-C
locomotives at the time, Alco actually outsold its competitor by a few
units. The RSD5 was, of course, nearly identical to the RSD4 although
Alco did bump its horsepower rating just slightly, which actually made
it a touch more powerful than the SD7. Today, at least two of these
units have been preserved, former Utah Railway #306 (as Nickel Plate #324) and Chicago & North Western #1689.
The Alco RSD5 was rushed into production as a replacement for the
earlier RSD4, whose frame was not long enough to support the main
generator. As such, at nearly 56 feet, 7 inches the later RSD5 was
nearly eight inches longer than its predecessor. Internally, the model
was identical to the RSD4 and both were essentially the same as the
four-axle RS3. From a strength standpoint, the RSD5 was slightly
better; it offered 1,000 pounds more starting tractive effort (90,000
pounds) and an additional 100 horsepower (1,600 hp). Interestingly,
despite the RSD4's issues most railroads that purchased it returned to
buy the RSD5.
The Alco RSD5 entered production in 1952 directly after the unsuccessful RSD4 and remained in the company's catalog until 1955. The new model used the same Alco 244 prime mover. As with all other "D" designated models, the Alco RSD5 used a C-C truck arrangement with all six axles powered. The six axle models were meant to provide a sizable increase in traction and be used on light branch/secondary lines allowing the locomotive's weight to be distributed more evenly over additional axles.
In an attempt to probably ease railroads fears over the
problematic RSD4, Alco even built an RSD5 demonstrator to prove that the
model no longer suffered from its previous issues. Apparently, the
Atchison, Topeke & Santa Railway was quite impressed as they
purchased more than 50 units of the design after only picking up ten
examples of the RSD4. Additionally, lines like the Chesapeake &
Ohio and Southern Pacific, both of which had not even purchased the RSD4
bought nearly 90 of RSD5s between them. For information related to the RSD5 line please click here.
Production Roster Of Alco RSD5s
|Chesapeake & Ohio||5570-5595||26||1952|
|Central Railroad Of New Jersey||1615||1||1953|
|Chicago & North Western||1665-1667, 1684-1690||10||1953-1954|
|Southern Pacific||5294-5339, 5345-5448, 5494-5507||64||1953-1956|
|St. Louis Southwestern (Cotton Belt)||270-272||3||1953|
|Texas & New Orleans (SP)||155-186||32||1953|
Many of the railroads that purchased the RSD5 employed them in heavy
such as the Utah Railway, Milwaukee Road, Chicago & North Western,
Southern Pacific. The latter three roads particularly loved six axle
diesels, practically since they were first manufactured by Alco and EMD.
In any event, for a six-axle model the Alco RSD5 sold relatively well
at 204 units for a number of Class I railroads such as the Milwaukee
Road, Southern Pacific, Chesapeake & Ohio, and Santa Fe (this also
includes the 37 purchased by Mexican lines, Ferrocarril del Pacífico and
Ferrocarriles Nacionales de México). To read more about other Alco Road-Switcher (RS) models please visit the Diesel Locomotives section of the site, which can be reached from the top of this page.
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