(1) Drop step (front only)
(2) Signal light in external box, on 88" nose.
(3) Toilet vent
(4) Leslie P-3 horn.
(5) Original factory numberboards
(6) Small numbers on rear flank
(7) Wheel-slip sensor cables for PTC system
(8) Engine room drainpipe-- right side only
(9) 4000-gallon fuel tank.
(10) Rerail frog. The emergency fuel cutoff switch is the red dot directly above.
(11) Engine air filter
- This unit was delivered with a Mars light. It's impossible to tell with this graininess whether it is still a Mars, or if a Pyle was installed as of 1991.
- Rio Grande's later tunnel motors had the 88" nose. The difference is noticeable when compared to the shorter version, even though it is only 7 inches. (see this unit for a comparison)
- This small round vent hood (on the engineer's side only) vents the chemical toilet in the nose of the unit. Crewmen gotta go somewhere...
- This unit has had the original Nathan horn replaced with a Leslie.
- These numberboards are as-delivered. After the merger with Southern Pacific, many D&RGW numberboards were replaced with a style that used Railroad Roman numerals (basically matched the numbers on the cab sides). This was in the future, though.
- SD40T-2's, SD50's, and GP60's had the road number on the flank, a practice no doubt originally started because the rear end of the hood on the tunnel motors is square, not angled, and there is no numberboard on the square end. (SP painted a single number centered under the rear headlight on their tunnel motors.)
- 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.
- 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 style. On tunnel motors, the engineer-side frog was hung on brackets just behind the leading truck. The frog on the opposite side was hung next to the trailing truck.