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Why are locos backwards in a unit train consist?

5.8K views 18 replies 15 participants last post by  Scottychaos  
#1 ·
Why do they reverse the second locomotive when they double or triple head locomotives in a unit train? Could they all run facing forward?
 
#3 ·
Railways have limited locations at which locomotives can be turned. ( Loops/Wyes/Turntables ) The easiest way is to have back to back consists allowing you to simply change ends when you reach the turnaround point. The direction they are facing does not effect performance. You can run the lead locomotive long hood forward, though visibility is severely restricted.

Shane
 
#4 ·
There's no mechanical need to run most diesel locomotives back to back..
i think this is merely a convenience factor that began in the late 1940s with the arrival of F-type locomotives which really only had visibility on one end. On the other hand, there are some railroads which are often running engines "elephant style" such as Amtrak.
 
#5 ·
All good points, but you've missed one important factor.

There is no reason to have the engines facing the same way. So, when making up a consist for a train, why bother? It's simply not an issue, except for (usually) the lead unit. I have seen too many consists with two engines pointing the same direction (when they KNOW it will have to be run the other way because of the route) to think the railroads bother trying to have engines turned right on each end. It's mostly random chance that puts the trailing units facing one direction or another.
 
#6 ·
Posted By DKRickman on 30 Apr 2012 07:23 AM
It's mostly random chance that puts the trailing units facing one direction or another.
This must depend on the particular railroad.
I have been watching for this specifically, two locos not back-to-back, and on both CN and CP I have only seen that once in the last 20 years.
 
#7 ·
I know for certain that the St Maries River Railroad, a very small shortline, runs them opposite for the express purpose of return trips, when they get to the end they swap locos and head home. They have no way to turn them around easy on there out and back runs. In plummer with effort they could but when they ran to Clarkia there was no place to turn around. I think this is simply a matter of convienience for them and I would assume for many others. Maybe not UP or BNSF or the likes but for the smaller roads. When it comes to big consists where there is three or more it does seem random. I especially like when there is two back to back in the front and two back to back to back in the rear. If the train is parked it is somewhat difficult to decide which way its going other than the light.
 
#9 ·
Here in the South West I see a big variety of loco combos!

UP does run in a very random order ...But what is most noticed are sets of 2 locos, 1 SD70M & 1 dash-9 running in pairs, more often than any other combo.

N.S. runs elephant style thru here, 2-3 locos mixed with UP, cab forward.

BNSF runs cab forward with UP.

CP & CN run cab forward, mixed with UP.

CSX mostly runs elephant - cab forward also, mixed with UP.

Out watering garden and 3 units went by; a dash-9, SD70ACe, SD70M, all elephant - so go figure!! All UP "lellow...!

Dirk
DMS Ry.
 
#11 ·
Unless the cab has dual control stands, long hood foreward is considered backing up. Another rule of thumb is the engineer rides on the right, the conductor rides on the left(fireman side).
~CLBee, North Carolina Transportation Museum Rail Ops Volunteer
 
#13 ·
Yes, Southern ran long hood forward as did N&W. N&W 620(GP9) has dual control stands, and we sometimes operate it long hood forward. Southern ran RS-3s long hood forward with the "F" on the long hood. To my memory, my Aristo RS-3 has the Front designation on the long hood end.
 
#18 ·
"There is no reason to have the engines facing the same way. So, when making up a consist for a train, why bother? It's simply not an issue, except for (usually) the lead unit. I have seen too many consists with two engines pointing the same direction (when they KNOW it will have to be run the other way because of the route) to think the railroads bother trying to have engines turned right on each end. It's mostly random chance that puts the trailing units facing one direction or another."


I'm afraid this is untrue, at least at CN. Walker yard in Edmonton has a turn table which is used to properly set up most consists. One exception lately involves the new GE engines with trip optimiser. More and more of these consists are being set up front/front, requiring them to be wyed at the other end, thus keeping the optimized unit in the lead. Locomotives can not run backwards in Canada unless equipped with ditch lights and a pilot on the trailing end. There is also language in the engineers collective agreement requiring that single units be operated cab forward from terminals, and if turned on line "all efforts will be made to turn the locomotive enroute."





Shane
 
#19 ·
Posted By Santafe 2343 on 02 May 2012 04:18 PM


Hey JJ,


The N&W for the most part ran the short hood foward, that picture is a rarity. The Southern ran theres th long hood foward. That is why on a N&W had the bell on the short hood, an Southern had the bell on the long hood nose. Rex



I wouldn't say "for the most part" N&W ran short hood forward..thats not really true.
in the early diesel era both Southern and N&W were primarily long hood forward, and high short hoods..
By the 2nd generation diesel era (1960's and 70's) N&W was going more "traditional" (short hood forward and chopped short hoods)
while Southern held on to the old ways longer than did N&W..
but I would guess "for the most part", taking in the entire diesel era for the N&W (up to 1982)
N&W had more long-hood forward, and high hoods, than the other way around..

Scot