For argument's sake, let's say we are using good Kadee couplers and have a layout with modest 2% ups and downs and 40" radius curves. There are other variables I am probably not including, so how many cars as an average do you think an HO train could have before suffering coupler breaks under the weight? Whether the entire train is on the 2% grade or on the flat should make a difference. My tiny layout is too small to conduct an experiment of this magnitude, so, what say you? What would the variables be on a HO scale layout? I am betting someone out there has actually done this test at some point.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Sheldon!!!
Calling all forum members named Sheldon.
Rich
Alton Junction
Sheldon would certainly have a handle on that, or make an educated guess. Wayne as well, Mark Pruitt perhaps, the late Chuck Beckman, Big John would surely have some empirical first-hand knowledge.
Cuda Ken would be another. Those guys push the envelope to see what's what.
I seriously think, Brent, that you'd get stringlining before a Kadee broke, or it would be a defective Kadee. But if we controlled all the variables and relied on good Kadees, no curves, 2% grade, we would have to be into the 150-200 car range, and even then I think the pin wells inside the coupler box would go first.
richhotrain Sheldon!!! Calling all forum members named Sheldon. Rich
My thoughts exactly, but I did want to give you a chance Rich. Buck passer.
selectorI seriously think, Brent, that you'd get stringlining before a Kadee broke
I think you may be right, so a straight piece of track may have to be a constant.
The longest train that I've run on my layout was 71 cars, none of them weighing less that 4 oz.
It was done as a test on my longest grade (about 45' long and on a 2.9% grade), basically to determine how many locos were needed. There were two opposite horseshoe-type curves (34" radii) followed by a couple of "S"-bends of 40"+ radii.
The main wrench-in-the-works was that the grade ended at the point where the planned partial upper level should have been, but it was not yet in-place.
The three photos below show pretty-well the entire grade...
(The train shown in the second photo is not the test train, but simply one loco taking a fairly long train down the hill.)
I also did a test with a heavy train of 48 hopper cars loaded with Black Beauty blasting medium. It was done on the lower track in the first photo.The first attempt was done with one Athearn U-boat, modified with two can motors and a weight of 33oz.It couldn't move the train up the entire grade, but when a second identical loco was added, went up the grade (all of it on an "S"-bend) easily. I would have liked to try a longer train, but had no more Black Beauty on-hand.
Total weight of the loaded hoppers was 24lbs - no derailments, no issue with couplers, either.The three U-Boats later went to a friend in the U.S., and I don't have any other locos with their pulling capabilities. On the 71 car train, I used a variety of locos, usually 6, steam and/or diesels, 3 placed at the front of the train and 3 at the rear, and also pairs at the front, mid-train, and rear. In every case, no derailments, and no issues with couplers.
Wayne
I have pretty much the minimums specified above. Code 83 Shinohara trackwork, visible curves are superelevated. My curves are 32" minimum on the main lines and crossovers are #10.
While not routinely I have run 90 car freights. I presently have a 22 car passenger train made up of mostly BLI PRR P70 coaches but several Walthers Proto B60b and BM70 baggage and RPO cars. Couplers have never been a problem.
Sometimes I let trains like this run "round-n-round" while occupied with other layout chores. still, this isn't the norm and even prototype passenger trains were kept to about 15-18 cars due to passenger platform lengths and steam heat constraints. Most often my freights are in the range of 45-50 cars.
Why would anyone think Sheldon is the only one who likes to run long trains?
Good Luck, Ed
It really is not the coupler to worry about. My old club had a very long grade and I used to haul 70 or more cars up the grade. Until one day, an Athearn hopper decided to shed it's coupler cover and fifty five hoppers and a cabin went screaming down the hill in reverse. Let's just say the crash beams on the cabin did not hold up to the collision with the hill and three hoppers hit the floor. Now all my couplers are secured by a brass or steel fastener.
In the early 1900s the PRR tried out their class CC1. A compound Mallet type of a 0-8-8-0 wheel arrangement. The problem they had was the tractive effort was too much for the rolling stock. If the draft gear didn't tear out, the whole car would be ripped apart. It finished it's life in pusher service.
Pete.
I seam to remember somebody testing the strength and came up with an impessive 11.5 lbs or so.
Shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
It is interesting to note that coupler strength is indeed the limiting factor. This is the reason that the guys from Miniatur Wunderland in their attempt to pull a real locomotive with HO scale locomotives did not rely on couplers, but had harnesses for the model locomotives. Most of this video
https://www.youtube.com/watch?v=vC-dmKHiCnY
is about their first attempt, using 198 Roco HO model locomotives to pull a prototype DB 101 class electric locomotive. Just as an afterthought, they mention that a day later they managed to do the same with just 85 model locomotives. A 101 class loco weighs 83 tons, meaning that each HO locomotive was pulling about a ton. Very impressive!
This is an interesting question. i am an engineer so I'd like to do some calculations. Since Kadee use metals for their coupler, I assume it is steel. For a coupler, we only need to worry about the weakest link, or the place where the coupler has the samllest cross-section area. I assume it is 2mm or 0.08 inch in diameter. Considering the modulus and yield strain (the strain before plastic deformation), you need 250 lb or 4000 oz to yield the weakest link. If the force needing to move a car on a 2% grade is 4 oz (not the weigh of the car), you can move a least 1000 cars..... A huge number...
I seem to recall a club running over 500 coal hoppers in a train. It had mid train and pusher helper'.
Rick Jesionowski
Rule 1: This is my railroad.
Rule 2: I make the rules.
Rule 3: Illuminating discussion of prototype history, equipment and operating practices is always welcome, but in the event of visitor-perceived anacronisms, detail descrepancies or operating errors, consult RULE 1!
The trip pin is a soft steel. The coupler shank and knuckle are pot metal possibly zamack. You can clearly see parting lines and injector pin marks on the number 5 coupler. That is why KD wants you to burnish the shanks for smooth operation. ( How many modelers do that? )
Years ago, I tried the plastic McHenry couplers and quickly switched back to the KD. I never had a failure. But you can clearly see them flex even with a minor load.
gmpullman Most often my freights are in the range of 45-50 cars. Why would anyone think Sheldon is the only one who likes to run long trains? Good Luck, Ed
Most often my freights are in the range of 45-50 cars.
Ed!!!
Calling all forum members named Ed.
On my layout, I ran an 81 car freight train. 4 engines on the lead, 2 Mid-DPU on level grade. Radius varied from 24" - 30" and no issues and a decent speed. All DCC and engines are speed matched for the most part. Cars are weighted and metal wheels on all cars.
If your couplers are properly installed and the train is assembled so you don't have any type of stringlining occurance, you should be able to run very long trains, even up a grade, as long as the motive power adjusts to the grade as well. I have a 2% grade helix and depending on the engines, more than 16 cars on the train requires a helper engine..
Here's the video of my 81 car train...
https://youtu.be/kk2gQTAhqHE
Neal
I have a fairly large basement layout. My steepest uphill grade is 1.5% while the downhill grade is 1.75%. I generally limit my freight cars to 20 cars but early on I tried to see if I could run a 50 car freight. The couplers held up with no problem. The operational problem I had is there is a curve near the bottom of the grade and I superelevated it slightly. I found that all that weight tended to pull the cars over the inside rail.
The other problem is a train that long dwarfs the layout. The locos on the front end would pass through a town while the caboose had yet to reach the town behind it.
I've since reduced the amount of superelevation so the rails are near level on that curve so I might try the experiment again just to see if I get better results, but 20 car freight will continue to be the max. My freelanced layout is loosely based on the NYO&W and 20-30 car freights were not unusual on that line. That's probably why it went belly up.
My former club The Soper Valley RR once ran 120 iron ore hoppers on our portable layout. Five Altlas Engines on the front, no extra power. Wide curves and level track.
I have operated 80 car trains on my home layout, which has Kato 26.375" minimum radius curves, and a 0.4% maximum grade, with no Kadee coupler failures.
Hoppers, especially if empty, are light. My trains include big heavy boxcars and autoracks that weigh more than one typical freight car.
Since the couplers are metal, they are not the weak link. Any of the Intermountain or Accurail style kit coupler boxes that are glued in place via a plastic pin into the floor piece are likely to pull out before couplers will fail.
The other issue is that 80 car trains require careful train handling with the throttle, whether you have superelevated curves or not (I have a mix of both). If you have to do an emergency stop (say the cat jumps on track in front of engines) one can experience a dramatically prototypical train wreck, as I have.
However, couplers have not been an issue. Most of my rolling stock has Kadee couplers, with a few ScaleTrains couplers on their rolling stock, and a few off brand metal shank couplers (Kadee clone). Again, I experienced no coupler failures.
One exception: current BLI Kadee clone couplers just fall right apart even with short trains of less than 10 cars--the ones on the new GP-20's self destruct after only a couple hours of run time and literally fall apart and stop the following cars in the train. Two GP-20's, two coupler failures in the last week. They were replaced with genuine Kadee couplers.
John
I used to belong to a club and remember about 220 cars but only around 200 for long times, this was back in the days of every car being NMRA weighted and on flat and level track on a special track set up for the pull.
Even the big fellows try testing their couplers every once in a while. Sometimes it doesn't go so well:
https://www.youtube.com/watch?v=vFLJvpwm52Q
Thanks, Rich
Cheers, Ed
hjQi Since Kadee use metals for their coupler, I assume it is steel.
Pot Metal.... I am sure it is pot metal.
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
I don't worry about breaking Kadee couplers. The plastic coupler boxes will fail or pull off the car before the coupler breaks. You can improve this somewhat by using panhead head 2-56 machine screws to secure each coupler box in place. Stronger than glue. Longest train I have ever run on my flat, around the walls, 22 inch radius, downstairs bedroom layout was 34 loaded hopper cars behind a single AHC Berkshire. I could fit a few more cars for a show off long train, but not for ordinary running. My passing sidings are only 10 cars long.
David Starr www.newsnorthwoods.blogspot.com
LastspikemikeOnce the initial static friction is overcome, rolling resistance becomes quite low and not meaningfully related to train weight.
Anybody can make a train move. The trick is stopping it.
Couplers on the LION.
Yes, all trains of the LION are six cars long. Six R-21 type subway cars.
No couplers... they make the gaps between the cars too long. LION replaced couplers with drawbars. Push or pull and trains have to do both at the same time singe the power cars are in the middle of the train.
Cars are wired together, all 48 wheels collect power. Very nice. I did not even bother to wire the double crossovers. Trains just glide over them.
LION runs ten trains at once, making all stops correctly. Takes almost 20 minutes for a traiset to run from 242nd Street through South Ferry and back again.
All DC, DCC buys me nothing, you would sitll need operators for those trains.My trains run automatically. One plastic virtual motorman on board each train observing the signals.
LION has a big relay farm do all of this for him.
LION sits in the switch tower at 242nd Street letting trains into and out of the two track terminal. A train departs about every three minutes during rush hours. Only five switch levers are required for normal operations although the GRS frame holds 33 levers.
Much more fun to run the switch tower according to me. and me is the only one I need to please : )
ROAR
I'm not even reading the other replies.
On various layouts, I have been envolved in pulling trains in excess of 100 cars and never had a KADEE coupler, properly installed, fail. That includes Athearn blue box rolling stock with the little snap on metal covers.
My recent layout, and my future one, are designed for trains in the typical range of 40-50 cars. Longer trains will be possible. I expect no difficulties.
My mainline curves will be in the 36" to 60" range, with most being around 40", all with easements.
The previous layout where I have long train experience had similar standards.
I once witnessed a train of 150 Athearn hopper cars on the layout of the York Model Railroad Club in York, PA. The train ran for hours without incident.
Sheldon
gmpullman I have pretty much the minimums specified above. Code 83 Shinohara trackwork, visible curves are superelevated. My curves are 32" minimum on the main lines and crossovers are #10. While not routinely I have run 90 car freights. I presently have a 22 car passenger train made up of mostly BLI PRR P70 coaches but several Walthers Proto B60b and BM70 baggage and RPO cars. Couplers have never been a problem. Sometimes I let trains like this run "round-n-round" while occupied with other layout chores. still, this isn't the norm and even prototype passenger trains were kept to about 15-18 cars due to passenger platform lengths and steam heat constraints. Most often my freights are in the range of 45-50 cars. Why would anyone think Sheldon is the only one who likes to run long trains? Good Luck, Ed
Glad you spoke up, I for one know I'm not the only person interested in this kind of modeling.
The OP specified he was running on 2% grades. As soon as elevation change becomes a factor total train weight does become important to coupler strength.
Please read more carefully.
ATLANTIC CENTRALGlad you spoke up, I for one know I'm not the only person interested in this kind of modeling.
While my home layout will not support train length greater than 12 cars, STRATTON AND GILLETTE equipment has been known to travel to large layouts and be part of very long trains on grades.
I only use Kadee couplers, mostly #5s and 20 series, and to my knowledge, none have ever failed under any operating condition.
-Kevin
Living the dream.
I should ad that several of the layouts where I have 100 car train experiance involved 2% helix grades in and out of lower level staging yards, as many as 8 to 10 turns on the helix. My BLI N&W 2-6-6-4 handled 110 cars up the 2% helix grades with ease.
So the whole 50-60 foot long train would be in the helix at the same time, which was about 150' of track.
ATLANTIC CENTRALMy BLI N&W 2-6-6-4 handled 110 cars up the 2% helix grades with ease.
Mine was a beast, and I miss it.
Lastspikemike Just a note to remind all that a 2% grade doesn't add much weight to the force on the couplers. The maths is fairly easy.
Just a note to remind all that a 2% grade doesn't add much weight to the force on the couplers. The maths is fairly easy.
No, but it reduces pulling capacity by a considerable percentage.