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This review is from Railroad Model Craftsman, April 2001. Reprinted with permission of Carstens Publications.

EMD SD35 and SDP35:  O Scale

by Larry Kline

The Atlas O scale SD35 is an outstanding model that is highly detailed and runs well.  The SD35 was an early EMD entry in the mid-60’s diesel locomotive horsepower race, with 360 produced from June 1964, until January 1966. It used a turbocharged version of the EMD 567 engine and was rated at 2,500 horsepower. The SD35 was followed in 1966 by the 3,000 h.p. SD40, which used the then-new EMD 645 engine. Half of the SD35’s were produced with high short hoods. These units went to the Southern (110) and the Norfolk & Western (80). Low-nose SD35’s went to Atlantic Coast Line (24), Baltimore & Ohio (20), Chesapeake & Ohio (14, including two replacements), Central R.R. of New Jersey (12), Louisville & Nashville (26), Pennsylvania (40), Southern Pacific (29) and Western Maryland (5). The SDP35 passenger version (these had a steam generator at the rear of the long hood) went to the Seaboard (20), Louisville & Nashville (4), Union Pacific (10), and Atlantic Coast Line (1).

Atlas is producing both high-nose and low-nose SD35’s and an SDP35, all with prototypical-accurate paint schemes. The model reviewed here is a two-rail, low-nose unit lettered for the PRR; the locomotives also come in a three-rail version with the pilots and couplers adapted for that use, along with tinplate type wheel sets.

The model’s dimensions match the plans by Al Kamm, Jr., in the December 1964 issue of RMC. Plans were published in the 1966 Car and Locomoitve Cyclopedia. The various access doors, grilles, stack, lights, etc. all match prototype plans and photos. The Brunswick Green paint on the hood looks good compared with published photos of new PRR diesels, and the lettering is an accurate rendition of the PRR “austerity scheme” in use when the SD35’s were delivered. This paint scheme has no road name, just a road number and PRR heralds. The lettering also includes a nicely done EMD builders plate and small lettering on various access doors and elsewhere.

The detail on this model is outstanding. The see-through fan grilles show off the rotating fan blades inside, a nice touch. The cab windows look good and there are windshield wipers. The cab is populated by an engineer and a fireman. Other details include lift-rings, horns, accurate handrails, wire hand grabs that match the prototype, fuel fillers, sight glasses, a fuel filter, a bell, drop steps, m.u. stands, coupler lift bars, m.u. cables, and brake piping on the trucks. The model is truly ready-to-run.

Additional details that could be added include air hoses, ditch lights to represent units currently in service, fuel gauges on the tanks, and a partial cab interior. (The motor position does not allow a full cab interior.)  There are no brake shoes on the outboard ends of the trucks. These were apparently omitted to allow the model to negotiate short radius curves. Since the ends of the trucks are hidden behind the steps, the lack of brake shoes is not noticeable on typical O scale curves.

The overall effect of the well-done paint and lettering, the many details, and the finely-executed tooling is a model that really captures the feel of the prototype.

The SD35 ran well right out of the box. However, one sample shorted out when negotiating turnouts. I traced this to the cut-offs from the casting sprues at the inboard bottom ends of two sideframes. When these were trimmed, no further problems were encountered. If you run into the same thing, this should take care of it. The back-to-back distance for the wheelsets is slightly narrow (less than 0.01”) compared to the NMRA specs. However, this did not cause any operating problems, and the model ran well through a mix of Roco, Peco, Eschelman, and scratchbuilt turnouts, as well as a scratch built curved crossing.

Electrical pickup is from one rail only on each truck and is reliable. There is plenty of space in the two-rail version for a DCC decoder and a sound system, should you wish to add one. The three-rail version comes with Lionel Trainmaster control and sound.

With the loco running light, I measured the following scale speeds: 3v at 9; 6v at 28; and 12v at 72 s.m.p.h. The speed at 12 volts is very prototypical. With 62:15 gearing, the prototype had a top speed of 71 m.p.h. The minimum speed is about 6 s.m.p.h. at 2.5 volts. The model is powered by two motors, one on each truck. All axles are powered with spur gears transmitting the power to the two end axles first. The power trucks are self-contained, and the trucks swivel freely. The three-rail version minimum radius is specified as 18 inches. This probably also applies to the two-rail version, although only for the unit running by itself. The model runs fine around a 36” radius curve coupled to an Atlas 52’ gondola.

Weighing in at 6 pounds, 1 ounce, the SD35 has plenty of pulling power. I coupled the locomotive to a string of Weaver hoppers, each weighted to 14 ounces and rolling on Athearn plastic trucks. The locomotive easily pulled this train up a curving 2.5 percent grade. With this 25 car train, the current draw when running up the grade was 1.75 amps, The current at full slip is 1.5 amps. The stall current at 12 volts is 7 amps.

The model comes with Atlas magnetic knuckle couplers; they are compatible with Kadee couplers. The coupler boxes are mounted on a cleverly-designed, removable piece that fits between the steps and the front platform and fills the large opening needed for the Atlas three-rail coupler. I removed the Atlas coupler box by taking off the cover plate and then removing the screw that holds the coupler box in place. To mount a Kadee No. 804 coupler, I made a 0.60” spacer to get the correct coupler height. I attached the back of the Kadee coupler box using the mounting hole for the Atlas coupler box and ran a 2-56 screw through the spacer and the front hole in the Kadee box.

In summary, Atlas has set a new standard for O scale diesel locomotives at an affordable price. The following road names are listed in the Atlas O catalog and the Atlas O web site ( For the low nose SD35: undecorated, Chessie, Conrail, Jersey Central, Pennsylvania, Southern Pacific, and Western Maryland. For the high-nose SD35: undecorated, Norfolk & Western, and Southern. For the SDP35: undecorated, Seaboard, and Union Pacific. The two-rail model lists for $349.95, and the three-rail for $399.95. 


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