Introduction

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 EMDs 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 tunnels ceiling.

During the late 1960s and early 1970s 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 locomotives taking in their own hot exhaust gases while in the confines of the tunnels. The solution came from EMDs 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-2s 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 SD50s 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

SPECIFICATIONS:

• Minimum Radius: 18″ (457 mm)
• Reporting Mark: DRGW
• Full Road Name: Rio Grande
• Scale: HO
• Lighted: LED
• Sub Brand: ATHEARN
• Axles: 6
• Era: 1971-1990
• Prototype Manufacturer: EMD
• DCC: Ready
• Sound: Ready