08/21/2026
Ever want see the guts? Last night we were deep into the electrical cabinet of number 12 to diagnose a transition problem! Over the course of 72 years the locomotive went through many rebuilds and changes often not being documented on electrical drawings.
Our problem was finding a relay called TR….. TR allows the locomotive to transition. What is transition? Think of it as shifting gears in your car but done electrically! You start in what’s called series, were the electric from the generator runs to the traction motors in series. It’s like being in first gear in your car. When you reach about 9 mph, the resistance in the motor starts becoming too high and you need to “shift gears”. Locomotive transitions in now powers the traction motors through series parallel to overcome the resistance!
Well, we found the missing relay and are about 95% of the way to solving the problem!
Back at it today for some test runs and trials!
Thanks Doug Crawford for the phone a friend troubleshooting!
The Conrail Historical Society