Hello all,
I definitely have an affinity for B-units and M/Us.
Realizing that B-units have a forward direction, does anyone know what is the prototypical running of these units?
Elephant; nose to tail, back-to-back or nose-to-nose?
I freelance AT&SF in the late 1970's to early 1980's.
The cow & calf SW1200 M/U I run back-to-back, which puts the cab in the middle.
The 4-unit GP40 M/U is back-to-back, nose-to-nose and back-to-back (cab forward, cab back, cab forward, cab back).
The GP30s are back-to-back in 2-unit M/Us.
Or, does it matter?
Thank you for your thoughts.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
I am not an authority on such matters and if what I tell you is wrong I'm sure someone will correct me. When I think of B units I think of the cabless first generation diesels, such as E and F units although I think a few railroads had B units among their early Geeps. With the F units, it really didn't matter which direction they were turned except of course for the lead unit. Often a rear facing A unit would be the last one in a lash up so it would not have to be turned for the return trip. The trailing unit would simply become the lead. With all the units in between, I don't think it mattered one bit which way they were facing and that was true of both the A and B units.
You're asking about later generation diesels which is way out of my field of knowledge since I am a transition era modeler but it is my understanding B units were only produced for first generation diesels because of bargaining agreements carried over from the steam era which required a full crew for every cab in a lash up. That would of course defeat one of the advantages of MUed diesels in that all the units could be operated from a single cab. I believe all these agreements got renegotiated so later generations of diesels weren't built with cabless units.
Correct me if I am wrong but it sounds like you aren't talking about cabless units when you say B unit. It sounds like you mean the trailing units in an MU lashup. Again, only the lead unit needs to face forward but if the lashup was going to make a return trip together there would probably be a rear facing unit on the end. In between I really don't think it matters. I have seen pictures of MU lashups with all the units facing forward elephant style.
If we're talking about F-units (and we're probably not), if the units were separate (i.e. the B-unit had couplers on each end) it could go either way. The first F-units, the FT, was designed to have an A-B set connected by a drawbar. These sets would be back-to-back, so the open area where the cab would have been if it were an A unit (and where on passenger FTs the water and steam boiler were located) would be nearest the train the set would be coupled to...with, of course the A unit with the cab facing forward.
Sorry for not being more specific.
I am referring to GP7Bs, GP9Bs, GP30Bs, GP60Bs and MLW M420Bs along with calf units.
One of my current projects is a GP40B-T kitbash.
Slugs, I know, need to M/Ued at a specific; end where the traction motor cables are routed.
Again, I apologize for the confusion.
Hope this helps.
UP was the king of "late" B units: They had GP9B's, GP30B's, SD24B's and DD35B's. And more.
I've never noticed UP having a preference for directionality for those units. Except, perhaps, when the GP9B's were first delivered. For awhile, they were ABBA sets. And the sets most likely had an "as delivered" appearance. Which likely didn't last long. All the others were just thrown into the diesel mix from first introduction.
Ed
Maybe at one point they're placed front to front. But later on I have noticed that railroads ran them on both sides. They ran them like another locomotive, which any way they needed.
Amtrak America, 1971-Present.
Remember it was not until the late 50's/early 60's the A-B-B-A/A-B-A set was broken up and the crew could look at each unit as a seperate locomotive.
Geeps were used with F units on some roads.
Railpictures.net is a pretty good source for photos of consists. And they have a very good search engine.
Here's a nice UP one:
http://www.railpictures.net/photo/552900/
and another:
http://www.railpictures.net/photo/130070/
http://www.railpictures.net/photo/27862/
And here's one of the BN SD40-2B's:
http://www.railpictures.net/photo/298946/
If you have a favorite railroad (that had B's of interest), there are also likely photos in books about that railroad.
jjdamnitI am referring to GP7Bs, GP9Bs, GP30Bs, GP60Bs and MLW M420Bs along with calf units.
This I know for certain..The PRR had no preference in which way the Geep B was pointed or where it was placed in the locomotive consist after the lead unit.
The oddest I recall seeing was a RS-11,Geep B,Geep B,RS-11.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
ATSFGuy Geeps were used with F units on some roads.
BN had, for awhile, 4 unit sets of F's. They were usually ABBA. But sometimes you could see a GP-9 in there.
BRAKIEThe oddest I recall seeing was a RS-11,Geep B,Geep B,RS-11.
On my rotary snowplow consist I have a F7-B; steam generator forward, a RS11; long hood forward, and a BL2; short hood forward.
These are interspersed between a steam generator car, a bay window caboose; converted to crew quarters, a flat car with a wheeled loader and a tracked backhoe and finally a rear facing rotary plow. All DCC.
Thanks for all the input!
My knowledge for what it is worth, when railroads build a power consist, they look at a diesel unit as a power source first of all, regardless of body type and for the lead unit which way the cab is facing. Whether it is an F-7B, GP-9B, SD-24B or GP-60B, which direction the "F" end is facing makes no difference at all because unlike a motor vehicle such as a car or truck, a diesel locomotive uses an electrical transmission system which is geared directly to the axles. Current flow through the motors is the only consideration and other than the arbitrary designation of a "front" denoted by an F placed somewhere by the railroad or builder, electrically speaking, these units have no "front". They all run equally well regardless of where the "F" is. Since we are talking about B units, don't forget some roads, ATSF and BN come to mind rebuilt wrecked cab-equipped road switcher units such as SD-45-2 and GP-38-2s as cabless B units. Missouri Pacific ran a U30C for a while with no cab at all. All they did was torch off the offending damaged metal, wall off the rest of the long hood and, put that 3000 horsepower back to work! The electricity does not care where the cab or "front" is facing. So, unless you are dealing with a calf or slug, or a unit with MU connections on one end, do like the prototype and simply "hook 'em up".
Note that, in my second link, the GP30B was the LEAD unit in the consist. I've also seen a photo where a GP9B was the lead on a PC consist.
7j43k Note that, in my second link, the GP30B was the LEAD unit in the consist. I've also seen a photo where a GP9B was the lead on a PC consist. Ed
Could that be a pushing move? It doesn't make sense that they would put a cabless unit on the lead especially with an A unit right behind with long hood forward. The forward visibility would be practically nil.
NYBW-John Could that be a pushing move? It doesn't make sense that they would put a cabless unit on the lead especially with an A unit right behind with long hood forward. The forward visibility would be practically nil.
The photographer says it's not a pushing move. One could ask HOW LONG the run was--a few miles...........?????
As far as forward visibility, consider replacing the front two units with a Challenger, and see how THAT feels, visibility-wise.
The PC one I saw could have been a pusher, but I just didn't have that feeling from the photo. Maybe he just didn't have anywhere to turn the consist and just had to live with it. And/or maybe he wasn't in the mood to re-order the consist.
Pretty rare event, though; I will agree/admit.