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Built Review
HO scale
RSD-4/5 Locomotive
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by: Frederick Boucher [ JPTRR ]

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RSD-4/5 Locomotive from Atlas is part of their Atlas Classic™ Lines range of models. The Classic Line features two ranges: Gold and Silver. Gold features DCC and sound. The Silver series is analog yet includes an 8-pin socket for DCC. According to Atlas;
    The Atlas Classic™ Lines – Atlas’ original high-end locomotives, many of which were ahead of their time and have now been upgraded to meet today’s detail and operating standards.

    This line consists of older tooling that has been upgraded with features such as separate grab irons and other minor retooled pieces. These are generally only offered without sound and usually have an 8 pin DCC plug, space permitting.

This Chesapeake & Ohio RSD-4/5 is an Atlas Classic Lines Silver model.
    Well over 1,300 RS-3 road-switcher locomotives were built by ALCO between 1950 and 1956. It can be considered one of the most successful four-axle diesel road-switchers ever produced by the builder. ALCO’s Canadian subsidiary, MLW, produced an additional 146 RS-3s in Canada. These 1,600hp locomotives were powered by an ALCO 244 V-12 engine which was complemented by rugged GE electrical components. The RS-3 was truly a versatile locomotive. It could be found in virtually every type of service from passenger and commuter runs to heavy-haul and local freight assignments. Original owners of the RS-3 tended to be in the eastern and central regions of the US (with heavier concentrations in the northeast and southeast).

    During this same time-period, ALCO offered a six-axle road-switcher which was more commonly found in the west. The RSD-4/5 was externally very similar to the RS-3, having six-axle trucks as an obvious spotting feature. They produced the same 1,600hp as an RS-3, but offered increased tractive effort due to the use of a larger generator. Many RSD-4/5s were assigned to operate in mountainous territory (with varying degrees of success) on the Southern Pacific, Santa Fe and the Utah Railway.
    - Atlas

Come and inspect this model with me.

Engine house
Atlas' Classic Lines RSD-4/5 were first released in the 1980s in partnership with Kato. This Classic Lines RSD-4/5 is different in that it now uses an Atlas drive instead of Kato's, as well as separate grab irons and the couplers are mounted on the frame instead of the pilot, as they were on the Atlas/Kato models. (Before Kato, Atlas partnered with Roco, using Roco's gloriously growling "coffee grinder" drive.) I don't have an previous release to compare this model to so I can not say whether Atlas enhanced the tooling.

Today Atlas securely packs the model with a seven-piece custom cradle consisting of a hard base with vacuformed detachable sides, held within a flexible clear plastic sleeve. Two screws secure the loco to the hard base and foam blocks on the cab and rear body stabilize the model. All of that is held in a sturdy top/bottom box with a cellophane window. Atlas includes a parts diagram and advertisement in the box.

The Classic Lines RSD-4/5 is produced with a metal frame and injection body. Styrene and metal parts detail the unit. Molding is of good quality with no sink marks, flash, visible ejector marks nor obvious seam lines. Surface detail consists of both raised and recessed detail.

Atlas invested in two bodies - one for the air cooled stack and one for the water cooled stack.

Atlas lists particular features as;
    Analog version includes an 8-pin socket for DCC

    Metal grab irons

    New! Improved tooling on turbo exhaust stack. Also includes option of water cooled or air cooled turbo exhaust stack

    Separately-applied handrails and stanchions, including separate drop step detail

    Factory installed AccuMate® couplers

    Dual flywheel-equipped five-pole skewed armature motor for optimum performance at all speeds

What else did I find? As mentioned, Atlas makes a different body shell for the water cooled stack or the air cooled stack. Being an older model, most of the surface detail is molded on and basic. Except for the grab irons, handrails and stanchions, cut bars, exhaust stack(s), headlight lenses, and traditionally separately-applied items like the horns and hand brake wheel, everything else is molded on. This includes pilot air and signal hose fittings (the hoses are not represented), what I presume are the body lift rings, air filters, radiators and cooling screens, air reservoirs and piping, fuel filler neck, and truck sideframe brake cylinders.

While those qualities detract a bit from the visual appeal of the model, they are well molded and look good. They are also not as obvious considering the separately-applied handrails, stanchions and grab irons which capture the eye and enhance the overall look of the model.

AAR C-trucks carry the loco. Those types are not as visually "busy" as other locomotive truck sideframes so the most obvious details are the brake cylinders and coils. Atlas upgraded the electrical pickups. Another improved feature is that now the brass conductors are no longer visible behind the springs. They have routed the power pickups out of sight - another great improvement that shows how much value Atlas puts into their models.

Paint and Markings
Atlas did not skimp on the paint and markings on this Classic Lines Silver RSD. The paint is opaque yet does not obscure detail. Edges between colors are sharp. The road name, numbers and other data are crisply printed. Even the faux Alco builders plate is legible.

Atlas offers this RSD-4/5 release in three road names (plus two undecorated engines), with two road numbers for each railroad;
    Chesapeake & Ohio (Blue/Yellow "Simplified")
    Milwaukee Road (Black/Orange)
    Santa Fe (Black/Silver "Zebra Stripe")
    Undecorated (water-cooled exhaust)
    Undecorated (air-cooled exhaust)

More road names are available with the RSD-3 version.

-- (Release brakes, proceed)
Atlas' Classic Lines Silver RSD-4/5 Locomotive is a good looking model out of the box. It captures the look of the RS-3/RSD-4/5 family well. While it may not have all the new-tooling bells and whistles of Atlas' Master Line series, the upgrades have kept it competitive and desirable. Those upgrades - hidden pickups, metal grabs, individual handrails and stanchions, attached cut levers, repositioned coupler mounts, two new stacks and bodies to go with them, plus DCC or an 8-pin DCC plug - puts the model several steps closer to the later generations of model locomotives.

Classic Lines boasts the same exceptional paint and lettering as Atlas' Master Lines.

Atlas has put a good deal of improvement into this model. That is apparent. And it will look good whether or not a modeler will want to add some air hoses or other external details. Alco lovers should be satisfied by this model. Recommended.

The Alco RSD4
The Alco RSD4 was the builder's fourth installment of its six-axle Road Switcher (RS) series built at the same time as the RS3. Essentially, the design was a C-C version of that model (Alco had also produced an A1A-A1A RSC3). Unfortunately, it was one of the least successful with fewer than 50 produced by the time production had ended during its two year production run. Perhaps most notable was the incredible tractive effort it offered, by far the most of any RS model produced up until that time. Unfortunately, railroads still had yet to embrace the six-axle concept, another reason for the design's poor sales (not even EMD could sell many six-axle units at the time). Amazingly, today at least one RSD4 remains preserved, and operational, Kennecott Copper Corporation #201 (the only RSD4 the company ever owned).

The Alco RSD4 line was built for two years, between 1951 and 1952 at the same time as the RS3. The locomotive featured Alco's standard, but troublesome, 244 model prime mover allowing for 1,600 horsepower. As with the original six-axle model (RSD1) the RSD4 was meant to provide a sizable increase in tractive effort. The model had a slight design flaw as there was insufficient space for the unit's main generator, which was corrected with the RSD5 featuring a longer hood and carbody. As a result of this change the RSD5 sold much better than the RSD4 with nearly six times more units produced during the time Alco cataloged the locomotive, from 1952 through 1956.
Alco's Other Six-Axle Road-Switchers

The Army's Six-Axle RSD-1

The A1A-A1A, RSC-2 Variant

The More Successful Six-Axle, The RSD-5

Another Failed Six-Axle Design, The RSD-7

A Late-Era Six-Axle, The RSD-12

The RSD-15 "Alligator"

One important historical note about the RSD4. From a technical standpoint, the model was the very first C-C design (meaning all six axles were powered) that Alco offered standard in its catalog. The RSD1 was merely a specialty order for the US Army and the RSC2 and RSC3 locomotive were A1A-A1A designs whereby the center axle was not powered (i.e., lacking traction motors). With the RSD4's six motors the model could produce a starting tractive effort rating of 89,000 pounds and 78,750 continuous. This was nearly a 33% increase over the RSC3 which could produce 60,100 pounds starting tractive effort and 52,500 continuous.

Internally, the RSD4 was supplied with parts from General Electric (its model 752 traction motor) and Westinghouse (air brakes and compressors). It kept the same frame as the RS3, remaining at a length of 55 feet, 11 inches. However, the one striking difference aside from its six axles was the weight; at 180 tons the RSD4 weighed nearly 70 tons more than the RS3 (of course, this weight also added to its increased tractive effort). The five railroads that ultimately did purchase the model used them as intended, in heavy freight service. This include the Atchison, Topeka & Santa Fe, Utah Railway, Central Railroad of New Jersey, Kennecott Copper Corporation, and the Chicago & North Western.

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.


* American-Rails.com. The Alco RSD4. [Web.] n.d.

** American-Rails.com. The Alco RSD5. [Web.] n.d.

Click here for additional images for this review.

Highs: Fine detailed molding. Metal grabs and railings, and fantastic paint and lettering.
Lows: Incomplete molded-on pilot signal and air brake hoses.
Verdict: It is obvious that Atlas has upgraded the model. This Classic Line RSD-4/5 should be popular with modelers of the RSD era.
  Scale: HO Scale
  Mfg. ID: 10 001 946
  Suggested Retail: $149.95
  Related Link: Atlas Products
  PUBLISHED: Dec 09, 2016
  NATIONALITY: United States

Our Thanks to Atlas Model Railroad!
This item was provided by them for the purpose of having it reviewed on this KitMaker Network site. If you would like your kit, book, or product reviewed, please contact us.

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About Frederick Boucher (JPTRR)

I'm a professional pilot with a degree in art. My first model was an AMT semi dump truck. Then Monogram's Lunar Lander right after the lunar landing. Next, Revell's 1/32 Bf-109G...cried havoc and released the dogs of modeling! My interests--if built before 1900, or after 1955, then I proba...

Copyright ©2020 text by Frederick Boucher [ JPTRR ]. Images also by copyright holder unless otherwise noted. Opinions expressed are those of the author(s) and not necessarily those of ModelGeek. All rights reserved.


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