Q Why do modern locomotive throttles still use notches?
— Ben Redl, Williams Lake, B.C.
— Ben Redl, Williams Lake, B.C.
A The primary reason is to help the locomotive’s engineer direct a specific response from the locomotive. Engine RPM speed must be increased gradually during normal operation. As the engineer demands more power from the locomotive by moving a notch at a time, the power throttle sends a signal to the computer to increase engine RPMs by only that defined amount.
— Ray Weart, Canadian National locomotive engineer
