Southern Pacific experienced problems with locomotives overheating in tunnels. This brought about a major design change in the new SP SD45-2s.

The traditional EMD sidemounted radiators and roof fans were replaced with roof-mounted radiators, internal fans and a large opening at the bottom of the rear of the long hood. This allowed for cooler air to be pulled upward through the radiators.

The new locomotive was nicknamed “Tunnel Motor,” both for the problem it addressed and the opening in the long hood. While SP initially bought the SD45T-2, Rio Grande chose the 3000-horsepower SD40T-2. SP also purchased a large numbers of SD40T-2s.

Today, both SP & D&RGW are gone, absorbed by Union Pacific. But the Tunnel Motors remain, many serving on Class II roads and short lines across North America. And just like the SD40-2's these will continue to work the rails for many years to come.

Susquehanna is a short line running northwest from Hoboken, NJ, to Binghamton, NY, where it divides into branches to Syracuse and Utica. The “Susie-Q” has connections with CSX, Canadian Pacific and Norfolk Southern.

General Model Features:

• See-through radiator intake grilles
• See-though exhaust stack
• Snowplow and/or MU catch boxes
• MU hoses
• Coupler cut bars
• Dynamic or non-dynamic brake
• Minimum radius: 18”
• Recommended radius: 22”
• DCC Ready
• Non-operating ditch lights
  
• Different colored cab sunshades per the prototype
  
• Cab-side vent
  
• Break-away stanchion on the end handrails
  
• Double fuel fills
  
• Snowplows
  
• Ground plane radio antennas
• Ex-Southern Pacific
  
• 88” nose with brake wheel and nose headlight
  Anticlimber
  
• Modified L-windshield
  
• Post-1980 extended range
  
• Extended range dynamic brake
  
• 4400-gallon tank with an internal 100-gallon retention tank
  
• Nathan P5 air horn on bracket
  
• Large Susquehanna lettering located close to the upper black stripe on the long hood
  
• Off-white cab roof and diagonal black and yellow sill stripe extends from midway to the end of the long hood