Reading TrainsBuddy’s post regarding back-up light placement on “B” units made me think of another question that I just took for granted. Apparently “B” units have a front and back end. Connected in an A-B configuration, are the engines oriented with both “front” ends facing in the same direction or are they connected “back to back?” What was general practice?
I can’t speak to what other railroads did, but on the Santa Fe, initially, the units were kept as sets, and usually “front” to “back” with its consist. Later on, this changed as the units were separated and assigned as needed, and the pairings were random, depending solely on which way the B-units were facing at the time.
I just wanted to be the first to say, it all depends on the RR. Usually you see them long hood to long hood, or long hood to short head, but this is also with non-booster locos that have cabs. It was generally thought as safer to put as much distance between cabs for safety reasons, like crashes. Which doesn’t make sense because from what I under stand in MU consists, say one with 3 locos, only the first “lead” loco would have a crew in them, the other locos would be crew less. I personally will run MU trains with the most distance between cabs, in other words the first two engines long hood to long hood, and the middle and end cab would be long hood of end cab to short hood of middle cab. You have a really good question though, I will have to keep my eye on this post. A good example I just realized is the ad >>>> right over there for Standard Hobby Supply. Pair of BNSF (Dash 9’s or AC4400’s?) paired up long hood to long hood.
Thanks, Robert -
My railroad will have a number of A-B sets and I really never considered that B-units had a “front” and “back.”
I am certain every possible combination existed; however, when the units were permanently coupled from the factory the general (default) configuration was “back to back”. I do not know which way the “B” unit was configured when it was in a permanent ABA arrangement.
??? The question isn’t about general MUing but about cabless “B” units. I was not aware that there were any “B” dash-9s or AC4400s. The last modern loco I saw that had a “B” variation was the GP60.
To really see the “front and back” of a “B” unit look at the FT. It was obvious which end of the “B” was the front.
Perhaps I should have mentioned this since your OP was about “B” units. If you are reffering to 2nd gen diesels, like GP40’s for instance, yes they did have a front and back. Most RR considered the cab end, or short hood, to be the front, and even in cabless ‘booster’ locos this was still considered the front. Often times RR’s would have the manufactorer (sticking with EMD here) actually move equipement around, such as moving the dynamic brakes to where the cab used to be. now them are kinda neat lookin. I will be going with newer engines as I’m partially making a fantasy RR, but I think I may turn my existing GP9 into a booster unit. I don’t care if Milwaukee Road never did it, in my MILW world they did.
Perhaps you should have read the thread that the OP referred to in his opening line to understand that he is indeed talking about F7B units, not 2nd generation locomotives. Here is a link to the thread:
http://cs.trains.com/trccs/forums/t/152414.aspx
Don Z.
That’s interesting.
I usually see them coupled in photos as front-back. You can tell because the exhaust fans on the roof sit slightly stearnside of the engine. The exhaust side would be the “rear”
I wonder if they got switched around a lot. I’ve seen a lot of A-A units back to back.
Some people have mentioned FT’s. They are in some respects a special case, since they are asymetrical, theat is the distance from the truck center to the coupler is different on the front than on the back. they came in semi-permanently coupled pairs (back to back) so they pretty much had to always be joined the same way since it was physically impossible to connect them any other way.
Other F units were symeterical so there wasn’t any difference which way they were pointed. While engines were assigned and operated as sequential sets they probably were always back to back since if they came from a set, they went back in the same set so there wasn’t an opportunity to turn them. Once railroads split the sets up and did not try to maintain sequential sets, then it was whatever way the engines were available. Since it made no difference operationally, there is no incentive to try an turn them one way or another. I know that with hooded B units, neither the MP or UP attempted to keep them pointed in any particular direction.
I have plans to couple my A-B and A-A sets with a drawbar, thinking that they’ll look better coupled closer together, and shouldn’t give me any grief operationally. What do ya think?
while we are on the subject of “B” units, didn’t some of the covered wagons have a hostler control station inside so they could be moved about independently?
grizlump
Yes, they did.
Some roads consider the end with the control stand as the front.
Of course railroaders had a hard time telling by looking.
So,some roads place a “F” on the front end of the “B” unit.
By Federal law ALL locomotives in the US have to have a F on the front end.
I would have to think because of MUing, you have to know the “front” from the “rear” to understand direction when connecting up for MUing. Just like our DCC now, you could set up your engines in the wrong direction.
I don’t think that was required on “B” units…
http://www.railpictures.net/viewphoto.php?id=168417&nseq=0
http://www.railpictures.net/viewphoto.php?id=264916&nseq=2
OK, with or without hostler controls, B units of cab type diesels do have a front and back.
In the case of all EMD F or E units, the end with the steam generator (or the space it would be in on F units not so equiped) is the rear. A and B units are layed internally the same starting at the rear. The B units simply don’t have a cab at the other end. The prime mover (diesel engine) is not in the middle, but offset to the rear. So looking a the roof of any F or E unit, the fans are closer to one end than the other. The end they are closer to is the rear. EMD FB units with steam generators used some of the “empty” cab space up front for additional water tanks.
EMD encourged railroads to run them “back to back” for a number of reasons. In an AB set, if you had hostler controls, that did in effect give you control at both ends since the B unit hostler controls are just inside the “front” door.
Also, on E units or if your F units had steam generators, they would be near each other and would work more effiecently and made them easier to operate.
ALCO PA/PB units did not follow this design. Instead the steam generator on the PB was at the front, in place of the cab. So many roads prefered to run the both forward, again because this placed the steam heat equipment together. The steam generators did require some attention by the crew, so having them together was a good idea.
Most of this applies to the earliest use of these locomotives when they where generally thought of as “sets”. As railroads interchanged the pieces of orginal “sets” of locomotives these “rules” may or may not have been followed, subject to a lot of different conditions on each road.
Sheldon
Larry,
The first two pictures you linked to have a “F” on the end to your left, that is the front. And in my experiance many B units where so labeled.
Sheldon