PTC has to be in the lead engine. A diesel behind the steamer won’t cut it. There is no provision in the rules that would allow this. It totally defeats the purpose if the PTC gear is not in the operating locomotive.
The entire main line steam industry is working on this problem. However, the technology is far from being finalized, so the steam guys have taken a wait and see approach to this. Meetings have been held and there is collaboration going on among the main line steam operators, 765, 611, 261, 4449, etc.
Since Union Pacific has a lot of resources the other guys don’t have, they may go their own way and not work with the rest of the industry on this. That would not surprise me at all.
