Hi I have an interesting question for you all. Is it possible (hypothetically speaking) for a diesel b-unit to be placed behind the tender of a steam locomotive and be operated without an a-unit? Just picture if you will the Southern Pacific Daylight rounding a curve in the mountains led by a GS-4 and followed by an Alco PB unit what a sight that would be!
Yes it is possible, and I have seen it done. When the CP Royal Hudson went on a tour of CP and Soo Line cities many years ago, around 1979-80 or so, in addition to a train of dark red passenger cars painted to match the dark red on the engine’s tender, two F unit “B” units similarly painted were part of the consist, and all were in a high gloss paint. Presumably the Hudson was retro-fitted with a throttle in the cab that could control the diesel electrics, and there were likely regular MU hoses at the back of the tender. When the train left Waukesha WI rather late at night, as the train was being assembled for departure the locomotive was having a lot of wheel slip issues, until it coupled on to the F units and the MU hoses were attached. Leaving town the 4-6-4 put on a good show of smoke and loud exhausts, but once it was running at track speed north on the Soo Line past Duplainville (now CN trackage ironically) it was obvious that the primary motive power was the diesels - they probably wanted to make it all the way to Stevens Point with that tender full of water and fuel. The steam power was more to power the whistle (although the engine also had a distinctive horn that blew for crossings with the two longs, a short, and a long using the openings musical notes of O Canada!) and keep lubricating lines working. Even with no real steam exhausts to be heard, hearing first generation EMD prime movers working hard as we waiting at a totally dark country crossing at midnight was a chilling sound.
I believe other excursion steam has been fitted with a diesel locomotive control stand in the cab, so in theory any diesel electric, cab unit or B unit, could be coupled to it. In the case of the Royal Hudson train, the goal was to make the F units look inconspicuously like the rest of the train.
Dave Nelson
The UP can MU diesels with its steam. Well not exactly. In any of those set ups there are two separate sets of controls the diesel and the steam and the engineer controls each set of power independently of the other.
Wow I had no idea any actual railroads did that! To actually have a prototype for it, that’s wonderful! Thank you for the information!
Interesting. Thanks!
As far as I know, the ability to control diesels from the steam engine that the others described only appeared much later with preserved steam. Clinchfield may have been the pioneer. If you are modelling the transition era, the diesels required a separate engineer and a control cab.
Well even if the prototype didn’t do it at that time. Was it possible with transition era tech to do it?
This is the kind of thread I like.
Only if you’re being prototypical. That and so much more was possible at that time
Ok thanks!
Your Welcome![:)]
The GS4 and the Alco PB unit is actually somthing I have always wanted to do.
Please check out my other thread about the Old Vicksburg Bridge and the Thebes Bridge!
How can I find photos of tha
Also which roads actually practiced this? Besides the CP of course! In addition which modifications would I need to make to my motive power to make it look right?
Keep in mind that during the actual age of steam I doubt if controlling diesel helpers from the cab of the steam locomotive, by a single engineer, would have been consistent with union agreements. Indeed the railroads were initially fearful that each unit in a multi unit diesel electric consist would be required to have its own crew under those agreements, even though the technology existed to have them all controlled by one engineer.
I cannot seem to find photos or videos of the CP Royal Hudson tour of the US but I suspect I am just not looking in the right place
Dave Nelson
Thanks, is it possible for a seperate crew member to do this either in the cab or maybe in a doghouse on the tender?
This never happened in the actual transition era. The technology didn’t exist, union work agreements likely wouldn’t have allowed it, and there would have been a huge safety concern.
One can put any crazy thing they like on their own layout, of course, since having fun is the prime directive.
Your opinion is appreciated. But I do not agree with that, a few other people here have stated that that was possible with transition era tech! Also as my previous post stated is it possible that an additional crew member to operate the diesel controls from the cab or a doghouse or a station in the booster unit?
Union agreements of the time probably would have required at least a two man crew, and a damp and cramped doghouse probably wouldn’t have worked. Since the operator needed a real cab in which to work, an A unit would make more sense. Sorry to throw a wet blanket on your idea.
I don’t believe that is correct. MU’ing was a challenge for a while even between different diesel manufacturers, let alone between a steam unit and a diesel unit.
Why would any railroad do that when an engineer and fireman could sit comfortably and safely in an A unit? And again, work rules were more important than technology in the transition era as to how things were done.
You should do whatever you like, and I’ll withdraw from this conversation.
The reason is to not to spoil the streamlining of a passenger train!!! And also IT HAS BEEN DONE!!! The CP did it for the royal Hudson Soo/CP tour! Have a little imagination folks!