If I see a train with 9 or more engines, I figure most of them are just a power move, and only a few are needed to pull the train. But what about trains with 5 to 8 engines? Are they A: head-end helpers? B: the train is just plain heavy and fast? C: power moves? Are such consists only found in mountain districts, or anywhere? I would think the latter, because KCS (not known for its grades) often runs 5-7 engines on a train. Incidentally, though I often see trains with large consists in pictures, I've never seen more than five on one train in reality, and that only once. Does CP have less of a tendency than UP, BNSF, or NS to run large consists?
It could be any of the reasons you just wrote. I dont think anyone except the trainmaster and motive power coordinator who ordered the train could tell you for sure. Basically the governing rules for motive power consists just regulate the number of powered axles, number of online/offline units for fuel conservation, speed and placement in train for distributed power and helper service. CT
Union Pacific runs lots of mega-power lashups thru Cheyenne, thanks to a .8% grade out of town. All heavy trains take this routing, while the more well-powered trains take the original 1.5% line out of town. Seeing 5-8 units on a WB is not uncommon.
West out of Denver, a 2% ruling grade puts trains on their knees for 50 miles to Moffat Tunnel. Untold degrees of tortuous curvature and 28 tunnels dot the route, further increasing drag and friction. I have seen westbound empty coal trains with 8 units on the head end. Generally, only 3 are loading,a nd the rest will be used as distributed power in midtrain, and pushing DPU units. Manifests generally get all sorts of power. 7 units westbound out of Tunnel 27: If you count carefully, there are 8 units on this WB coal empty out of Tunnel 2: At Little Ten curve, there are 2 units at the head end of an EB coal load, 2 more midtrain, and 2 more ushing at the tail end. Well, they are all in heavy dynamics, thanks to the grade. At Tolland, a WB empty has to start its long string of coal hoppers up the 2% grade after a meet. 8 units on the point! Hope this helps. The multi-unit lashups are required on the Moffat Route, to get trains up the 2% grade, thru the many tunnels, and down the grade safely with dynamic braking.
Another situation I don't see mentioned, unless I missed it, is that of combining trains. I often see an empty coal drag with anywhere between 150-180 empty coal hoppers and 7 or 8 units on the point. When the train reaches a particular location, 3 units and about half of the cars are set off, the other half of the train goes to another location. Saves time, saves having to pay CSX a per car storage fee after 12 afters at the interchange in Grafton, and one less crew to call out.
UP does that, come to think of it, on its empty potash trains to Green River, WY. Trains of over 175 cars are brought west in a single train. Then split into two, loadaed, and brought back east in two units.
Splitting and combining freight trains... I'd heard of it being done for passengers, but this - this is new. I'm getting some ideas...
Apparently, that doesn't count for power transfers... 11 units westbound at Tunnel 29; Careful eyes will note the trailing engine in the distance, thru the trees:
Actually, except for the Rich Mountain grade south of Heavener, KCS isn't too hilly. The climb over Rich has employed quite a few locomotives, and recently helpers on the rear. Otherwise, it's a power-balancing move, especially if traffic in one direction is more than traffic the other direction. One recent example I've seen was the Katy, which would send more engines north on a train than was needed, but the engines were needed in Parsons and Kansas City for more southbounds.
Fantastic shots It makes me a little envious, though. On our division of the NS, I can see up to 8 units on a train for power moves, but only 4 (max) would be online. I recently saw the specifics of this and it spells out how many axles can be powered on a train, which depends on the types of loco used. Harold
NS specifies no more than 20 conventional powered axles on the head of a train (100 and 300 series trains, as well as non-autorack 200 series trains and solid coal and grain trains, can have 24) or 18 axles in dynamic brake... All Group 2 and 5 units have high adhesion axles, which count as 1.33 axles (1.35 in dynamic) Group 1 and 3 units are conventional Group 6 (the SD80MACs) count as 2. I cannot see any train regardless of grade, having more than four or five modern units online and pulling while in the lead... the resulting TE would break the couplers... (this Chessie, is why NS has the above policy)
Don't forget the concept of less-than-stellar locomotive reliability. I know many old "rails" that would leave a terminal with seven or eight engines, all operating, in the hopes that enough would still be running at the end to get it into the next terminal. There's a great article in TRAINS magazine from the early '90s about the Milwaukee Road that demonstrated this. Amtrak is still widely known to do this, especially with the dubious relability of their "Genesis" series. Many of their one-unit long distance trains (The Texas Eagle is the most noteworthy example.) could be hundreds of miles from an Amtrak terminal and suffer a failure. Many times would a host railroad have to send out power to get the train over the road.
Robbman, Thanks for the specifics about the units... I understood why they were limited, but couldn't remember the specifics of the TE / per unit. Harold
Originally posted by Triplex: Actually Trip you would be surprised. KCS has a few helper (pusher) districts. The very first job of my railroad career was as a conductor on KCS helpers based at Neosho, MO. As a rule all southbound coal and grain trains would have helpers added at Neosho. (rear of train). There were also helpers south of Heavener, OK. I believe to assist trains over Rich Mountain. Man! that was ten years ago already.
