I’ve been asked by the local 4-H model railroad club to run a 100+ car train on their layout this year when they set it up. I did it last year. I’ve got 100+ cars, all coal/ore hoppers, to do it with. They have all been inspected for gauge, weight and coupler height.
The question is what motive power to use for it and placement. I’ll use my DCC system. I’m going back and forth between Genesis SD75M/SD75M/SD70MAC/SD70MAC or 3 BLI SD40-2/Kato SD40-2 or Kato SD40-2s and Atlas C30-7s. I used just 3 locos last year, but it was quite a load so I think 4 locos will be needed this year.
Part of me wants to use the BLI SD40-2s for the sound aspect, but I’m not sure of their pulling power. The 4 Genesis engines (2 BNSF warbonnet, 1 BN Cream & Green & 1 BNSF H2) is a nice looking consist and so is a set of BN green/black SD40-2s/C30-7 like they ran in the lates for Powder River coal.
The main question has to do with placement. All four upfront? or split it 2 upfront and 2 mid-train. Should they all be consisted together; upfront yes, but if I go mid-train helpers should I still consist all 4 or 2 and 2 with one person controlling the front 2 and a second throttle controlling the helpers? With 100+ cars the drawbar stress upfront is alot and the mid-train helper might help ease that.
The UP here run two or three up front and one on the rear. The 40-2s with sound would be cool having one of the sound units on the rear . Just a thought.
On the former Atlantic and Pacific (BNSF main across Arizona roughly parallel to I-40) the usual appears to be three units pulling and two shoving.
The sly and cunning trick would be to put three units on the point that can’t - quite - pull the entire train without stalling. Then the pushers will never get pulled and the probability of stringlining is minimized. Ideally, somewhere near the 60th car of a 100 car train there will be one car that is sometimes being pulled from ahead, and sometimes being pushed from behind.
Added up tonnage to be hauled, and compute the horsepower to pull up their encountered grades. That way they put on enough ‘power’ to do the job. Stalling is considered a big no no.
EXCEPTION was hauling empties and Engines being needed elsewhere.
PLAY RR’s haul empties with little-to-no standards. YOUR PROBLEM is matching engine speeds, not pulling power - per se. (DCC or DC).
IT’S TRIAL & ERROR - unless you want to catagorize each car by assigning a rolling friction quotient, classify and regsiter same, and then make up prescribed consists.
Didn’t think so.
I KNOW my ‘Unit trains’ such as passenger, have a certain number of cars (9), pulled by a certain (4-8-4) engine to pull up the clubs mainline grade (2%) + the passenger yard’s restrictions are 10 feet max.
I ALSO KNOW that many cars rolling qualities can be improved by adding better trucks. Over the years I’ve set certain minimum standards.
jktrains, many years ago in British Columbia, Kaiser Resources was a coal mine that had trains running, courtesy of CPR, to the docks in Vancouver daily, around the clock. My recollection was that these were insanely long consists, often near two miles, that used what were called “robots” by the locals, but I’m sure there was a “better” RR term for them. These units were cabless and mid-consist, sometimes in two places separated by nearly 40 cars. I believe the idea was to provide relief for the couplers by having the uphill charging engines shoving the couplers ahead of them to keep the pressure off them, while the engines already on the downgrade side would brake slightly to keep the slack run in a wee bit.
An END-TRAIN helper, consisted (light) with the head-end power. Having independent control of helpers is an invitation to string-lining [#oops].
If you absolutely, positively, have to use mid-train helpers, the head-end power should stall with fewer than the number of cars ahead of the helpers. No locomotive should ever be pulled by or pushed by another locomotive with cars between - unless the cars are the first loco’s tender and canteen.
Chuck (modeling Central Japan in September, 1964 - with pushers when the assigned power can’t handle the 2.5%)
Yes, the CPR had robot trains. I think these were used to experiment with long consists. The robot cars were either recycled FM/CLC CPB16-4 units or rebuilt baggage cars. In one case, a robot was built from the remains of an H16-44. These robots were painted in a sort of dark blue with a red and white multimark. Got some pics too:
Any grades ? In model railroading you can have more problems going downhill (if much of the train is on the grade) and trying to stop the cars and not have them push the cars in the front off the track. In real life I’ve seen many a coal train with 3-4 units up front pulling 100-125 car drags.
Heavy engines could work really good. If you have a BN or BNSF SD60M that would work, there slow but they can pull some cars! The BN SD40-2 and C30-7 would look really nice. BTW i would go with 2 or 3 engines in the front and one in the back thats how BNSF has there coal trains set up in Memphis.
I had 2 SD75M and SD75I running together pulling long of cars before, it was one long track going around the room on 1 by 6 and 1 by 8 as long 10 to 12 ft on wall…
The layout the 4-H’ers setup is basically flat, or as near as is possible considering the unlevel floor.
Crandall & CPRail, while what the CP or Kaiser soes sounds interesting with robot cars etc. I’m purely talking about models here and what will work best, not so much what is most prototypical.
Don - I think its both a problem of matching running characteristics and pulling power. Consider that on average a car weighs approx 4oz, a 100 car train will come it around 400oz or approx 25 pounds, excluding locos. Thats a lot of stress on the couplers of the first 10-15 of cars. My thinking is that the midtrain helper set will ease some of those stresses. I’m hoping to have chance to tweak CVs on the locos to try and get them matched, but I may not have the chance. That’s why I was trying to use engines by the same manufacturer. I know that doesn’t guarantee matching speeds, but it should be better than mix and match. Also consider the amount of real slack in the train. Just 1/10th of inch between cars giveyou around 10 inches of slack to be taken up before the caboose starts to move.
Did I mention this will be a public display so I don’t want to mess things up too bad? I did it last year by slowing adding cars. Starting 40 or 50, running it around the layout and then adding another 10-12 cars until we got to 100. It also required a lot of eyes watching everything
How big are the curves? That will probably be the limiting factor. Do the cars roll good? You said it was mostly level. That helps quite a bit. Kadee couplers are pretty much a must with this many cars. The imitators deflect too much under load.
On our club layout, we have run 150 MDC ore cars successfully with 3 Athearn SD40-2s, or 2 P2K SD60Ms. I have run 141 cars, with 4 Atlas Trainman engines, 2 RS32s and 2 GP38-2s. Our layout is not flat, and some of the curves are a little sharp to be doing this.[:D]
This is the head end. The train does go to the upper part. The long side is 44 feet long.
The short side is 16 feet.
Keeps going.
Sometimes it helps to run something like this on DC. Won’t be any computer glitches of dropped consists, runaway without control, etc. THis train did have a problem like that, went on a level portion of the layout at full tilt without incident.[:O]
For midtrain helpers, cut them in about halfway back. Want them to do more pulling than pushing.
The curve radius is 33", if I recall correctly. All cars have KD couplers, no cheap McHenrys or EZmates. I don’t think they would hold up to the pulling stresses. Some cars, but not all will have metal wheelsets, which should help reduce rolling friction.
WSOR - when you run the trains you described, do you normally run all engines up front or do you run some mid-train?
I have done 120 Intermountain grain cars with 4 units (Kato 4400) up front and 2 (Kato SD40-2) on the rear. It’s best if they are all speed matched and the tractive effort required for 120 - 5.75 oz cars is not 120 x 5.75 oz but 120 x 5.75 x .02 ( 2% ruling grade) + (120 x .12 oz (for wheel drag)) = 28.2 oz. I found that 4 units up front could drag the entire train with lots of wheel slip the 2 on the rear eliminated this substantial. The interesting thing is to walk around alongside the train about 2/3rds the way back and watch the slack run in and out like an accordion, the action transverses through about 25 cars as the grade changes in different parts of the railroad. I have broad radius curves, minimum of 52" radius and the railroad changes elevation from 40" to 92’ and then back to 40" in the reverse direction. Have fun, it is! There is also a 7.5 turn helix 10’ in diameter, no problem either way, up or down on that also. By the way, just like in the real railroad a derailment becomes a big problem with this many cars and you could wind up with cars everywhere real fast, there is lots of mass as opposed to weight there.
If you go with the BN 40-2/30-7 combo, they often ran four up front out of PRB, especially if was going south. If you split the power, BN avoided using GE’s as helpers as they took longer to load than EMD’s. Far better thing to have EMD’s pushing the GE’s until they load then to rip the train apart trying to pull them. And mid train helpers are usually cut in about one third of the train length away from the head end.
BTW, post some video of it if you can after the show.
Putting helper units in a scale model train is a risky proposition. Whether you put them in the body of the train (mid-train, 2/3 back, etc.) or on the rear, you run the risk of derailment from string-lining or jack-knifing. Having the units all consisted together would be a great help, but you will still be at the mercy of any slack action occurring in your train. Since the track layout is basiclly flat with 33" curves, I would put all the power on the head end. Since the power consist you used last time was a little overloaded, add additional locos to the consist until you have balanced control. By that, I mean that acceleration & deceleration occur without exagerrated throttle manipulation (Ooooooo, that sounded really professional, didn’t it?) I know we all like to see our consists look uniform, but don’t be afraid to put a less powerful unit in the consist just because it isn’t the same genre (“old” SD-40’s with newer Hi-tech Toasters) or has a different axle count. A four axle unit won’t be the same as the other “Big Jacks” in the consist, but it might be what you need to allow you to control the train without any undue fuss. Have fun & experiment with different lash ups. If you do it like the prototype, you may be surprised at the combination of units that work the best.
