SD40T-2 No. 5350

As of December 1991

This left-side oblique view shows a unit from the first group of Rio Grande tunnel motors.  It was about 17 years old at time of the photo, and still carried most original features (with the addition of the positive traction control system).

Rio Grande's SD40T-2s came in several groups, as shown in this table.

Number Range Date Purchased Comments
5341 - 5355 Oct 1974  "Short"  (81-inch) nose.  (All SD40T-2s were delivered in the billboard "Rio Grande" scheme.)
5356 - 5366 July 1975 "Short" nose
5367 - 5373 Aug 1975 "Short" nose
5374 - 5385 Jan 1977 "Long" (88-inch) nose
5386 - 5397 Aug 1978 "Long" nose.  Low-nose light mounted in external box.
5398 - 5413 Mar 1980 "Long" nose.  Leslie horns.

Specific information for individual units may be found on the Rio Grande Modeling & Historical Society's SD40T-2 page.

(1) Wheel-slip sensor cables.

(2)Frame-mounted bell..

(3) 4000-gallon fuel tank.

(4) Electrical cabinet air filter box.

(5) PTC control cabinet.

(6) Rerail frog.

(7) 81" nose.

(8) Ratchet-type hand brake.

(9) Nathan M-3 horn.

  • The positive traction control (PTC) system uses these sensors to detect wheel slippage.  There are sensors on each axle; the rear truck has them on the opposite side.  Some units originally had all sensors installed on the fireman's side, but these were later changed for ease of maintenance.
  • Bell is in the standard D&RGW location.
  • Rio Grande's SD40T-2s had a slightly smaller fuel tank than usual-- 4,000 gallons instead of 4,400 gallons. As a result, they were about 2' 4-1/2" shorter, leaving a noticeable gap behind the front truck.
  • These filters were for the air used to cool the electrical cabinet in the rear wall of the cab, and were standard on the Dash-2 series.
  • PTC was installed on D&RGW tunnel motors beginning in 1985.  The box to house the control system circuitry was installed between the filter box and the blower housing behind the cab on the left side.
  • Rerail frogs were standard D&RGW practice.  This is the later type.
  • Rio Grande's earlier tunnel motors had the 81" nose.  The difference is noticeable when compared to the longer version, even though it is only 7 inches.
  • This series of tunnel motor had the ratchet brake.  Others had a wheel-type brake.
  • This unit still has the as-delivered Nathan horn.



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2004, James R. Griffin.  All rights reserved.