A gőzösbe is beépítették.

...legalábbis volt olyan, hogy beépítették.

EMD developed and built a diesel MU control box for the cab of 4449, at the request of Doyle McCormack, during the American Freedom Train national tour. Both the air brake and electrical power to control one or more diesel units from the Engineer's side of 4449's cab was the end result.

By plugging in a standard AAR 27 pin MU cable, to pretty much any diesel coupled to 4449's tender, or auxiliary tender, the trailing diesels are controled by the Engineer on 4449. Additional MU control boxes where subsequently made for NKP 765, UP 844 and UP 3985.

All functions of the MU'ed diesels, except for dynamic brake, are controlled from the cab of the steam locomotive,i.e. Forward, neutral, Reverse, Generator Field, throttle positions idle & 1 thru 8, indicator light for wheel slip, a red light to indicate "ALARM", and a toggle switch for emergency train line shut down.