Athearn RTR 71753 HO Scale EMD SD40T-2 Rio Grande D&RGW 5407 DC

The SD40T-2 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division having a 16-cylinder EMD 645E3 diesel engine producing 3,000 horsepower (2,240 kW). 312 SD40T-2s were built for North American railroads between April 1974 and July 1980. This locomotive and the SD45T-2 are popularly called tunnel motors, but EMD’s term is SD40-2s with “cooling system modifications” because they were designed for better engine cooling in tunnels. The difference between this locomotive and its non-tunnel motor cousin, the SD40-2, are the radiator intakes and radiator fan grills located at the rear of the locomotive. The radiator air intakes in this model were along the deck to allow more fresh, cooler air to enter and less hot exhaust fumes lingering around the tunnel’s ceiling.

During the late 1960’s and early 1970’s the Southern Pacific was looking for ways to solve the problem of their diesels overheating in their many tunnels and snow sheds. They determined that problem was caused by the locomotive’s taking in their own hot exhaust gases while in the confines of the tunnels. The solution came from EMD’s development team which relocated the radiator cooling intakes to the lower portion of the rear of the car body, creating what railfans dubbed the “Tunnel Motor.” This modification allowed the locomotives to take in cooler air that was nearer to the tunnel floor and thus reducing overheating. The Rio Grande was experiencing the same issues and decided to get some Tunnel Motors of their own, ordering some 73 SD40T-2’s in total in 5 separate orders. The last order, #5398-5413 were built in 1980. Features included a 4000 gal fuel tank, nose gyralights, and extended range dynamic brakes with exhaust silencer. The company wanted to order more of them but EMD convinced them to get their new SD50’s instead.

FEATURES:

88” nose with class lights (non-operational) and gyralight (Effect in DCC)
Standard cab
Small EMD front plow
Extended range dynamic brakes
4,000 gallon fuel tank
Cab-mounted Leslie 3-chime horn
Front small anticlimber
Exhaust silencer
Fine scale handrails
Photo-etched windshield wipers
Separately applied air tanks
LED Lighting
HTC truck sideframes
See-through cab windows
Welded electrical cabinet air filter box
All-wheel electrical pickup
See-through dynamic brake fans
“Mushroom” nose vent on right side
Separately applied wire grab irons
Rubber trainline and MU hoses with silver ends
Late Dash-2 cab, front window arrangement per prototype
See-through radiator grilles with new rear truck gearbox specific for the tunnel motor
Speed recorder attached to appropriate axle per prototype
McHenry® operating scale knuckle couplers
All-wheel drive with precision gears for smooth and quiet operation
5-pole motor with flywheels and multi-link drivetrain for trouble-free operation
Chassis accepts Genesis motor retro fit kit for an even higher performance motor
DCC Ready 21-pin NEM Quick Plug™ technology
Nickel plated, blackened machined wheels
Wheels with RP25 contours operate on all popular brands of track
Highly-detailed, injection molded body
Minimum radius: 18” — Recommended radius: 22”