Introduced: 1992 (Kato-made version), 1997 (Atlas Classic version), 2006 (DCC version) and 2008 (GP30 Phase 1)
Atlas's first GP30 model actually came out in the 1970s and was manufactured by Roco (Austria). However, I won't be discussing that one here (as it is ably covered elsewhere in this encyclopedia). But do take note - those old Roco-made Geeps are vastly inferior to all of the subsequent versions (IE, eBay bidders beware).
The first post-Roco Atlas GP30 and GP35 models were manufactured in Japan by Kato (pictured above). And starting with that first Kato-made release, Atlas has always released these two models in tandem (no surprise there since they share the same basic internals). Anyway, the upshot of all that is that I'm going to save myself a bit of time and cover them both here.
Those first Kato-made units were noteworthy insofar as they were the first Atlas diesel models to come with full pilots and shell-mounted couplers. The Micro-Trains friendly coupler-clip system employed in these models was actually first introduced in Kato's SD40 model of the previous year. Additionally, these two Geeps were the very last collaboration between Atlas and Kato. The two venerable firms were destined to go their seperate ways in the mid-1990s (with Atlas subsequently relocating all of their locomotive production to China).
In addition to the shell-mounted couplers, the rest of the mechanism employs all of the other time-honored design features one normally associates with "modern" Atlas diesels - split-frame metal chassis, dual-flywheels, low-friction drive, plastic truck assemblies, plastic gearing, blackened wheels, all-wheel drive, and all-wheel pick-up (no traction tires). The motor is an open-sided 5-poler. Directional lighting is provided by PC boards mounted on either end of the chassis. The couplers are Rapidos (easily swapped out for MT's). Wheels are low-profile and have no problems on Code-55 track.
Performance on these models is perfect in every way - smooth, quiet, flawless pickup and throttle response, exceptional pulling power, etc.
Starting with this very first release, Atlas has made their GP35 model available in two different "phases" (1A and 1B). I'm told that the differences between the two basically boil down to the number (and location) of the various door latches and hinges (seriously, I am not making this up). I guess the 1A has lots of latches and the 1B has fewer. So, if such things concern you... well, now ya know. Additionally, they're available with or without dynamic brakes (presumably based on the prototype in question).
Atlas re-released these models as part of their "Atlas Classic" line in 1997 (manufactured in China). Normally this line consisted of redesigned/retooled remakes of the earlier Kato-made models. However, as far as I can tell, these "new" models are virtually identical to the older ones. About the only difference I can detect is that the PCB's are green instead of white -
Starting with the 2001 production run, these models came with AccuMate couplers -
Revised (DCC-Ready) versions of these models came out in 2006. They also included Atlas's new "slow speed" motor and "white" LED lighting -
A new "Phase 1" version of the GP30 was issued in 2008 -
The cab on the "Phase 1" version is symetrical, whereas the cab on the previous "Phase 2" versions is 10 scale inches shorter on the left side. Also, the Phase 1 version lacks a handrail stanchion on the left side. Despite the minor shell changes, the chassis/mechanism in the 2008 Phase 1 version is the same as the one used in the 2006 Phase 2 version.
Shell removal on these models is pretty simple. Just grab the fuel tank with one hand and the shell with the other. Then just sort of wiggle it up and off.
Grade: A (all versions)
Kato-made GP35 reviewed: 6/92 Model Railroader ("Atlas has again teamed up with Kato of Japan to produce a gorgeous-looking and fine-running locomotive in N scale. The Atlas model closely matches (prototype) dimensions... The models are available in Phase Ia and Ib variations, with or without dynamic brake. Phase Ia has seven sets of latches on the tall engine doors, while Ib has only three sets. For the most part, these locomotives follow previous Atlas/Kato construction methods with a highly detailed styrene body and separate cast slippery plastic handrails to reduce breakage from handling.
"This model's mechanism is a little different than previous four-axle units. The GP35 still uses a pair of cast zinc-alloy frame halves that enclose the motor, flywheels, and worm gears. The truck sideframes are molded in a slippery plastic, and all wheels are used for electrical pickup. However, the trucks have a new wrinkle. They feature needlepoint bearings on the ends of the axles to provide an almost frictionless mechanism. To test the mechanism's rolling qualities, I removed the worm gears so it would roll freely. Then I put it on an inclined track, with a Micro-Trains flatcar on a parallel track, and let them go simultaneously. The engine rolled down the grade faster than the flatcar! Our sample started at 1.5 volts and continued to run smoothly at this low voltage. The locomotive ran quietly until it reached a scale 140 mph, where it began to whine... the model should pull approximately 16 free-rolling cars on straight and level track. The model comes with body-mounted Rapido-style couplers... This well-executed model of a popular locomotive features a fine-running mechanism and crisp detail. N scalers will have to make up some good excuses not to have at least one. Phase Ia: Undec, AT&SF, Conrail, B&O, BN. Phase Ib: Undec, CP, E-L, UP, PRR, N&W. $97.95")
Atlas Classic GP30 Phase 1 reviewed 09/2008 Model Railroader ("Built by General Motors' Electro-Motive Division, the GP30 diesel locomotive was known for its good looks and great performance. This new N scale GP30 lives up to its prototype. Part of the Atlas Classic series, the N scale model is available in a DC or Digital Command Control (DCC) version. The Atlas model's dimensions match drawings of a phase I GP30 in the Model Railroader Cyclopedia vol. 2: Diesel Locomotives (Kalmbach Publishing Co., out of print).
"The Atlas model is built primarily of plastic. All the molded-in detail on the body shell and truck sideframes is sharply defined. Placement of vents, hatches, and other details matches prototype photos. The walkways also feature molded safety tread. The handrails are separately applied and made of Celcon, a flexible engineering plastic. The model's paint is evenly applied with sharp color separation. All lettering is crisp and straight. The Atlas GP30 also has two ownership plates on its frame. Legible under magnification, the plates read "GENERAL MOTORS CORPORATION ELECTRO-MOTIVE DIVISION OWNER."
"The die-cast metal split-frame chassis encases the motor and two brass flywheels. The five-pole skew-wound motor turns two worm gear shafts that transfer power to gearboxes above each truck. The printed-circuit (PC) board is mounted above the split frame. Golden white light-emitting diodes (LEDs) mounted on each end of the PC board illuminate the headlights and number boards. The headlights turn on and off according to the locomotive's direction, which isn't prototypical.
"Our DC-only sample has a low starting speed of 1.5 scale mph at 2.5 volts. The model has a top speed of 116 mph at 12 volts. Depending upon its gear ratio, the prototype's top speed was about 80 mph. Throughout the speed range the Atlas GP30's mechanism was smooth and quiet. I ran the model around 93/4" curves and through no. 4 turnouts without difficulty. The model has a .8 ounce drawbar pull equivalent to 19 average N scale freight cars on straight and level track. With smooth performance and accurate details, the Atlas Classic Series GP30 is a great choice for an N scale diesel roster.")