GP9 is a classic
Product review from the October 2005 issue
Here’s a great-looking model of the classic Electro-Motive
Division GP9 road switcher that includes a powerful mechanism
and provisions for easy conversion to Digital Command Control (DCC).
Atlas O offers it in two versions for two-rail layouts that
operate with either DC or Lionel’s TrainMaster Command Control
and RailSounds 4.0 system.
Division introduced the prototype GP9 in 1954 as the 1,750-hp
successor to its popular 1,500-hp GP7. This general-purpose unit
continued the clean utilitarian design of its predecessor.
However, GP9s can be identified by their single sets of louvers
in the battery box doors just ahead of the cab and in the last
side door on each side of the long hood. During their
production, from January 1954 until December 1959 (Canadian
production continued until August 1963), 3,436 GP9s were built
for U.S. customers, while 646 were sold in Canada and 10 to
As general-purpose locomotives, the GP9s handled all sorts of
jobs from yard and local switching to fast freights and
passenger service. Most rode on EMD GP-type trucks, although a
few were fitted with Association of American Railroads type A
The Atlas O GP9 closely matches the dimensions shown in a
prototype drawing published in the Model Railroader Cyclopedia:
Vol. 2, Diesel Locomotives (Kalmbach).
Our sample represents a fairly typical GP9 painted as an
Atchison, Topeka & Santa Fe prototype built in 1956. In railfan
terminology, it’s a phase II locomotive because of its three
rows of tall louvers in the long hood and cap-top cooling fans
(four 36" radiator fans and one 48" dynamic brake fan). It has a
well-detailed plastic body with some individually applied
details and wire grab irons. Separate sunshades, m.u. hoses, and
air brake hoses are provided.
A heavy die-cast metal chassis, including the pilots and fuel
tank, provides most of this Geep’s 4-pound, 2-ounce weight. All
four sets of corner steps and the footboards have fine
see-through openings, and the running boards and platforms
include a nice-looking safety tread texture.
The rigid-frame GP trucks have well-detailed die-cast metal
sideframes with individually applied brake cylinders, piping,
and swing hangers. The blackened nickel silver RP-25 contour
wheels match the National Model Railroad Association standards
Small tabs along the outer edges of the lower printed circuit
board provide connections for the Digital Command Control plug
and wiring harness that's provided.
the chassis follows the same pattern Atlas used on its previous
GP35 andP60 models. Each truck is driven by a powerful can motor
mounted vertically above the kingpin. A couple of black masks
within the cab hide the inner workings, while a crewman on each
side of the cab adds realism.
Both motors have gimbal mountings so the trucks can move
freely.The vertical motor shaft drives a worm and gear inside
each truck that transmits power to a set of five spur gears that
drive both axles. A smoke unit, controlled by a switch under the
sill on the engineer’s (right) side of the cab, simulates diesel
exhaust from both stacks.
A removable secondary printed-circuit (PC) board is provided so
the model can be converted to Digital Command Control (DCC). Two
plugs are provided with color-coded wires matching the NMRA
Recommended Practice 9.1.1. Atlas includes separate DCC
instructions covering how to connect these plugs to the main PC
board and install a heavy-duty (6-amp) decoder.
The GP9 has constant-intensity, reversing lights so the
headlight is illuminated only in the direction of travel. Its
classification lights display a red indication to the rear to
serve as marker lights for lightengine or pusher movements.
I’ve reviewed the DC model here, but Atlas also makes a two-rail
version that includes the Lionel TrainMaster command control and
RailSounds digital sound system, which operates only under
GP9 started moving on only 2.5 volts at just under 10 mph, but
I’d expect the slow speed to drop somewhat after the model is
run for a while. It ran smoothly and quietly throughout its
speed range, but the scale 163 mph top speed is excessive as
prototype Geeps were geared for maximum speeds between 55 and 89
The dual motors produce a 20-ounce drawbar pull that’s
equivalent to 60 free-rolling cars on straight and level track.
However, they draw more than 4 amperes.
Magnetic knuckle couplers are mounted in boxes at the proper
height on each pilot.
Model Railroader’s sample GP9 is neatly and evenly painted in
Santa Fe’s "Zebra-stripe" scheme with sharp edges on the
stripes. The lettering was clear and opaque with colorful EMD
builder’s plates on both side sills.
Overall, Atlas O has done a fine job of capturing a classic
first- generation diesel locomotive with this nice-running
model. – Jim Hediger, senior editor
O scale EMD GP9
Price: Two-rail (with Lionel electronic system) $439.95
2-rail DC, $379.95
Dummy units, $199.95
Atlas O, LLC
378 Florence Ave.
Hillside, NJ 07205-1102
Plastic and metal locomotive
Atchison, Topeka & Santa Fe (nos. 707, 715); Baltimore & Ohio
(nos. 676, 681); Erie (nos. 1261, 1264); Milwaukee Road (nos.
2436, 2439); Southern Pacific (nos. 412, 416); and Western
Maryland (nos. 30, 34)
EMD GP9 features:
Blackened nickel-silver RP-25 wheelsets (in gauge)
Digital Command Control receptacles and wiring
Directional headlights and marker lights
Drawbar pull: 20 ounces
Eight-wheel drive and electrical pickup
Kadee-compatible scale magnetic couplers, mounted about .05" low
Metal grab irons and handrail stanchions
Minimum radius: 36"
Separate add-on details
Twin motors with flywheels
Weight: 4 pounds, 2 ounces