Reply to "Big Boy #4014 moves under power for the first time in over 50 years • The UP is bringing out the 4014, see schedule 🚂"

Chuck Sartor posted:

What is the green box with the push button?

Cab signal acknowledgement button? I recall Steve Lee in some video somewhere talking about how the 844 had a little lever in its cab that he had to flip whenever the signals changed otherwise an audible warning sound would continue to go off.