>>1487424A special MU system was designed for the Little Joes back in the 1950s, the rear cab of each Joe housed the equipment for this that's why one cab end of every Joe is blacked out. The mechanism was called a Wylie throttle (pic related).
>The engineer could choose how much electric power and how much diesel power he wanted (and same with how much regenerative braking and how much dynamic braking he wanted).>There were instances when only the trailing diesels were working power on a train led by a Joe, such as on a detour movement over the NP. 