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Review by David Otte

GP-35 Diesel Locomotive
MSRP 3-rail:  $399.95; 2-rail:  $379.95
2-rail:  with TMCC $399.95
3-rail & 2-rail Unpowered:  $199.95


Atlas O, LLC
378 Florence Ave
Hillside, NJ  07205
908-687-9590 – FAX:  908-851-2550


If you are a fan of second-generation diesel locomotives and model in O scale, then you are probably aware of all the great prototypes to come your way over the last several years. MTH produced the Alco RS27, Weaver released the GE U25B, and Lionel has offered the EMD GP30, all 1:48-sized replicas of the locomotives that replaced the Fs, FAs, GP7s, C-Liners, and other cab and hood units that had worked the rails since the 1940s.While the U25B embodied the basic design characteristics that all future high horsepower 4-axle locomotives would display, these advancements in locomotive technology were refined and instilled into perhaps the ultimate of second-generation power, EMD’s GP35.

Although the GP35 had been ignored by O scale manufacturers in the past, a scale model of this historically important road switcher is now being manufactured by Atlas O. The O scale GP35 is being offered set up for 3-rail track with Trainmaster Command Control and RailSounds as well as for 2-rail track either with TMCC/RailSounds of DCC ready. Probably the biggest news of all, however, is that for the first time Atlas O will be selling unpowered models of one of their locomotives. Now you can double or triple head GP35s without having the expense of all the Geeps being powered.

Following EMD’s lead, the O scale GP35s will be produced with both high and low short hoods depending on the prototype. Roadnames released to date include:  Chesapeake & Ohio; Gulf, Mobile & Ohio; New York Central; Santa Fe; Western Pacific; Norfolk & Western; Southern; Burlington Northern; Reading; Southern Pacific; Savannah & Atlanta; Western Maryland; Nickel Plate Road; and undecorated models for both hood arrangements. In turn, each roadname is available with two different roadnumbers. Additionally, a limited edition GP35 has been produced in the colors of EMD’s demonstrator locomotive.

EMD’s GP35

When GE debuted its’ 2500 horsepower U25B in 1960, the locomotive building industry was turned upside down. A 4-axle high horsepower diesel with such cutting edge technologies as a sealed carbody, a filtered, centralized air intake system, and an equipment layout designed for ease of maintenance. Two U25Bs could do the job of three first generation diesel-electrics. Although not fully up to the new standards set by the U-boat, Alco had also entered the high horsepower market with the release of their 2400 horsepower RS-27 the year before. EMD was forced to scramble their design department as this new horsepower locomotive race unfolded. The result was EMD’s GP30 delivered in 1962. However, EMD had come to the racetrack with only 2,250 horsepower under the hood of their Geep. As this three-way competition for the second-generation diesel market unfolded, GE moved up to the second spot behind EMD in production of locomotives leaving Alco behind, never to recover.

Fearing GE’s further advancement into their dominated market place, EMD went back to the drawing board. They unveiled their new GP35 at the American Railway Progress Exposition in October 1963. Generally a makeover of their GP30, the new model offered a horsepower of 2500 meeting the competition face to face. Responsible for the newfound power was a redesign of EMD’s faithful 567 prime mover. Designated the 567D3A, the engineers at LaGrange made changes in the 567’s pistons, cylinder head, and turbo charger while also improving the air filtration and electrical system. External changes as compared to the GP30 included a simplified carbody with a squared off and angular cab, which had been used by EMD in one form or another up until the emergence of the safety cab design.

EMD’s timing of the introduction of the GP35 seemed to be just right as a massive retirement of first generation locomotives was underway, and just like a new car dealership, railroads began trading in their worn out cab units for GP35s. In all, EMD would produce 1,333 units between 1963 and 1965, putting the company far out in the lead over their competitor’s measly 478 U25B sales. Some 41 different railroads purchased the GP35 new, including Canadian and Mexican customers. Many GP35s are still in service today through second hand owners, but as of February 2004, the BNSF was still rostering 150 rebuilt ex-Santa Fe GP35s.

Generally, the GP35 is easily identifiable from other later EMD angled cab units by the unique cooling fan arrangement on the rear of the long hood – two 48’inch diameter fans with a 36-inch fan in between. For additional referencing GP35 production, railfans have determined the locomotive was built in two different Phases. Phase I GP35s have a thick fame like the GP30 and previous models representing 77 percent of the total GP35 production. The minority Phase II units have a thin frame as on the GP40 and production 4-axle units that followed. So, to a degree, the GP35 stands as a true EMD transitional design locomotive representing what has been and what was to come down the road in the category of 4-axle high horsepower units.

Atlas O GP35

This brings us to the Atlas O GP35. It is a fine representation of a Phase Ia model, to be specific. Not only does it have the thick frame, but it also exhibits the multi-latch engine compartment doors, triple louver sets on the battery boxes, and eggcrate style radiator grilles that warrant this subclass of the early production GP35s. At 13 inches long over the pilots, the Atlas O Geep is a correctly proportioned 1:48 scale model of the 52-foot long locomotive. Its’ 8-inch wheelebase, 2.5-inch overall width, and 3.875-inch height match the prototype’s dimensions almost perfectly.

Details, details, details – Atlas O models are known for plenty of accurate details and the GP35 does not let O gaugers down here, either. First of all, the correct compartment doors, latches, hinges, vents, and grilles are crisply represented in the carbody tooling. Parts such as air horns, lift rings, sand fill hatches, metal grabirons, safety chains, coupler cut bars, MU hoses, bell, drop steps, windshield wipers, cab window glazing, and sun shades have been separately applied to the superstructure with the addition of brake cylinders, sand lines, and a speed recorder appropriately added to the well-modeled Blomberg style trucks. Of special note are the proper 48-inch and 36-inch rooftop cooling fan housings with free-turning fan blades visible beneath the grilles, and the positionable windscreens located on the cab side windows.

Secondly, Atlas O has taken great care in representing some of the major optional details on their GP35s as appropriate for the roadname. For the Southern and Norfolk & Western units, that means high short hoods, while for the Nickel Plate Road units it means no dynamic brake blister. Then there is the issue of the trucks. As mentioned earlier many railroads began trading in their worn out first generation diesels in on new GP35s. Some of the first locomotives to be retired were Alcos with their AAR Type B road trucks. These trucks, as well as other components of the trade-ins, were reused in building that particular railroad’s GP35s as a cost saving measure. Therefore, Atlas O will be equipping some of their GP35s such as the GM&O and S&A models with proper ARR Type B trucks. Snowplows are also provided with appropriate models.

The O scale Geep’s weight at over 5 pounds alludes to the type of construction used by Atlas O when manufacturing this model. The plastic carbody rides atop a thick die-cast metal frame supplied with metal stanchions and wire handrails. An early style EMD fuel tank is slung underneath, which also doubles as the sound system’s speaker grille. The truck assembly, side frames, couplers, and pilots are also made of die-cast metal.

Besides the good tractive qualities provided for by this weight, the Atlas O GP35 is further enhanced with the power of two can motors with brass flywheels providing all wheel drive. Traction tires on the inner wheelsets add to this awesome pulling power too, which I experienced while pulling a mixed train of 28 cars on level track You really need a large layout to take advantage of the true hauling capabilities of this Geep! On the other hand, the GP35 will operate on O36 diameter curves so folks with small layouts can still operate this diesel despite its size and vigor.

Also to be enjoyed by both 2-rail and 3-rail hobbyists, are TMCC and RailSounds. If you already have Lionel’s Trainmaster system installed on your pike, then you can take full advantage of the remote control abilities of this locomotive including the operating sound system.  For conventional transformer owners, the GP35 will still operate on your layout, but without the ability of controlling all the sounds or the ElectroCouplers. Sound volume can be manipulated manually though, by way of an adjustment screw located beneath the front pilot. Furthermore, in conventional mode, the modeler will need to install the included 9-volt alkaline battery in order for the sound system to work correctly. This requires the removal of the carbody, which is kind of a pain, as six mounting screws need to be unfastened and the handrails at the cab pulled out.


Our 3-rail sample was a blast to operate on the test layout. The sounds of a 2-cycle 567 prime mover filled the air with a multi-chimed air horn blaring on command. Crew communications, a mechanical bell, squealing brakes and air release sounds could be heard as well. When I engaged the couplers from the CAB-1 remote of the TMCC system, the clanking of a coupler knuckle was also audible as the coupler opened.

Running qualities of the Atlas O model were found to be on par with their past offerings, which is a good thing as all their models have been terrific performers. I tested our sample with a MTH Z4000 transformer as well as under TMMC. The start voltage of our sample fresh from the box without load was 6.6 volts, which also provided the lowest speed of 11.9 smph while drawing 1.0 amp. Advancing the throttle to 9 volts, the locomotive required 1.1 amps to reach a speed of 31.1 smph. Finally, at 12 volts, the model was traveling at 62.2 smph while still drawing less than 1.5 amps. This is a pretty good range and the maximum speed at which I tested the model was within the prototype’s ability. Enhancing operation is the GP35’s directional lighting system. Numberboards, marker lights, and bright headlights are all illuminated and functioned as advertised on our sample.


The largest purchaser of GP35s was Santa Fe with 161 unites, for which our model is decorated. Number 1302 was one of the first 50 (1300-1349) GP35s produced and delivered to the ATSF between January and June 1964. Like the prototype, the Phase Ia model wears the early blue and yellow freight scheme with the large billboard “Santa Fe” on the sides of the long hood, which appears to correctly follow Santa Fe paint and lettering practices. The paint application and quality of graphics on our sample was well done as usual, right down to the small EMD builder’s plate applied to the sill beneath the cab. Of course, no Atlas O locomotive would be complete without their usual hand painted crew figures in the cab adding just the right touch of detail to this animated locomotive.

Final Thoughts

As O scale modelers, collectors, and operators alike, we all have come to expect the very best in models produced by Atlas O. I have to admit, I can’t find anything really negative to say about the GP35 and there were certainly no disappointments experienced in my observations of this scale model. With the potential for numerous roadnames, I can’t imagine a diesel enthusiast not having one of these Geeps on their roster. As it stands now, we have an excellent O scale rendering of the champion racehorse in the 1960s second-generation diesel competition.



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