hjQigmpullman It is really interesting to know there is such a book! But probably not surprise as real operation of a railroad does need lots of planning, even for running the trains...
It is really interesting to know there is such a book! But probably not surprise as real operation of a railroad does need lots of planning, even for running the trains...
There is a lot more than one such book.
The company I work for uses all this sort of information to build the train simulators used by the railroads to train and certify engineers. We also simulate and optimize both hump and flat yards according to the math. Our latest product called PrecisionTrain Builder uses all the math and artificial intellilgence to determine the cause of accidents and more importantly predict what will happen if a certain train goes down a certain track. It therefore can indicate how to organize that certain train's cars and where to put the power to make it the safest and most efficient run. "Efficient" can be determine by the client whether it be most efficient for fuel cost, crew cost, run time, loads moved, etc.
doctorwaynebecause I preferred painting and lettering them to suit whatever prototype or free-lanced road I might be creating.
Thanks, Wayne! There are so many masters like you, Ed, Alyth Yard, Gregc I admire so much... You guys are just amazing...
I honestly can't recall when I bought them, Jerry, but I'd guess that it would have been sometime in the late '80s or early '90s, as I didn't have a layout until after I built my house in 1988.I'm fairly certain that those diesels were available some years prior to that, though.They're pretty much standard Athearn, not a lot of fine detail, but sturdily-built. I always bought locomotives as undecorated kits, when possible, partly because I was freelancing but also because I preferred painting and lettering them to suit whatever prototype or free-lanced road I might be creating. I did a fair amount of commercial model-painting, too, but never had a clue of what those painters earned...in comparison, I was making peanuts, but, for the most part, I was enjoying the work. Nowadays, I still paint for a small circle of friends, but I'm scaling back on that, in order to finish a lot of my own stuff that's been put-off for far too long.
Wayne
doctorwayneeach of them weighed just over 33 oz. If I had kept them, I would have cast more weights for them, as I'm pretty sure that I could have got them somewhere north of 40 oz.
Wow.... that is amazing, Wayne! 33oz is really heavy. So you were actually carrying more than 6 lb of load to your club. When were these Atheran diesels made? I have some Athern diesels I bought more than 10 years ago...
Jerry
Putting longer cars at the tail end of the train will help reduce the stringlining.
So will lowering the center of gravity of the cars.
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
Here's one of them...
...and the power source...
...and the reason they pulled so well...
...as mentioned, each of them weighed just over 33 oz. If I had kept them, I would have cast more weights for them, as I'm pretty sure that I could have got them somewhere north of 40 oz. each. The old-style sintered wheels on those Athearn diesels did seem to also contribute to their pulling ability.
For model steamers, weight can also contribute to pulling capabilities, but balancing the distribution of the weight is crucial. Ideally, the weight should be balanced at the mid-point of the drivers' wheelbase.
This is interesting, Wayne. Thanks for sharing. I tried to ake a viode of pulling 60 cars by three locos on my small layout that has continuous curves and 2-3% grade It failed some many times. One time it was some well cars fell and the other time was several tank cars, causing some damages. I finially was able to take a video without any issues but would probably dare not try again soon. I was able to glue the broken parts this weekend though.
doctorwayneThe three of them together had a tested pulling force of 24.9oz.
This seems to be a lot of pulling power, 8.3oz per loco. I watched youtube video by jlwii. He measured the ET44AC by intermountain and Scalestrain. Intermountain's is about 4.9oz and scaletrain is about 4.6oz. The U-boats are amazing!
trainlivebobbut any ideas how to make sure they are in sync? Apart of running a long electrical line. These are Lionel PW locos.
I do speed match for my locos by using DecoderPro and AccuTrack Speedometer to adjust speed tables. I remember someone said MTH locos cannot be adjusted by using DecorderPro. I don't have any Lionel locos so don't know if this method works for Lionel.
LastspikemikePutting a second locomotive mid train will reduce the tendency to stringline.
That's true, as I've used them often for that reason.
The worst case of stringlining that I've witnessed was at an open house on a club layout. I brought along three re-worked Athearn U-boats, hoping to get a chance to see them pulling a long train, as the club often did.Once I got the okay, I put the three on the track, then the operator backed them to a fairly long train...I never counted it, but I'd guess it to be at least 60 cars. The train started to move and was doing very well until it came to a curve entering a long diagonal to the other side of the layout, which was probably 25' or 30'. With a good-sized crowd watching, something near the rear of the train caught on an obstruction (perhaps a drooping coupler catching on a turnout or other obstruction.
Within seconds the middle of the train, 20 or 30 cars were headed for the floor. My diesels, however, carried on with several derailed cars and a couple still connected, but lying on their sides.
The three diesels, each weighing just slightly over 33oz., carried on until the operator was alerted to the derailment, which wasn't visible from his location.I felt sympathy for the club members, but was excused, as my locos were not at fault. The three of them together had a tested pulling force of 24.9oz. On my own layout, two of them had easily moved a loaded 22lb. coal train up a multiple curve 2.5% grade, roughly 17' long.
I sometimes miss having them around (they went to a friend), as they were great pullers, but way too modern for a late '30s-era layout.
I was planning to double head a train, running one diesel as the lead and the other as a slave. The slave would be operated by the lead's e Unit. so that they are in sync through a wire cable.
I understand the math of placing it in the middle, but any ideas how to make sure they are in sync? Apart of running a long electrical line. These are Lionel PW locos.
Bayway Terminali will plan on a 36" radius for the grade level loop
This is good to know. If there is no grade, you should be ok.... Have fun!
Thanks for the response Jerry, i will plan on a 36" radius for the grade level loop, much appreciated. Bayway Terminal NJ
Bayway TerminalMy goal is to be able to run either 12-33,000 gal tank cars, 12-53' well cars, 12-4 bay hoppers through the loop for continus operation without any probelms, so based on this thread i assume the loop track will need to be a much wider radius of maybe 48"/54", even though it will be installed on flat grade.
If there is no grade, I feel that a radius of around 32" should be ok. The long train (60 cars) I tried has 6 53" well cars and 10 40" well cars (each with two containers), two Atlas articulated auto carrier cars, 6 4-bay hoppers, and many box cars and tank cars. My track is kind of an octagon spiral with a continuous 2-3% grade. The adius at each corner is about 32-36". I used three modern diesels pulling at the front. Initially, I also had 4 89" bi-level auto carrier cars and I put them at the front. They fell of at some of my curves. They might be ok if I put then near the end of my train but I didn't try.
Since your loop will not have a grade, the operation will be relatively easy as you would not have a large hauling force. So I think you don't need that large radius (48"/54").
gregcpresumably you know the weight of the car and the lateral forces on the coupler the height of the coupler above the track and center of mass between the rails and can calculate the torque required to rotate the car to the side you could compare the coupler force needed for difference car lengths and weights vs track radii
This is a quite good suggestion! I will try in a few days... Hopefully would not bother folks who don't like math
Good thing i'm still in the panning stage for the elevated radius, and good thing to have all of this expert advisement. I do have room to go out to a 36'' curve at same 2% incline, but i don't have enough track space within in the existing switching yard to assemble long intermodal unit like trains leading out to the subject radius. This being i will most likely be limiting out-bound trains to 5-6 cars each through the 24'' inch curve to a planned main staging yard / ladder system. I have several 6 axel ATH Genesis 2 and scale trains engines to handel the coefficient load.
In addition i am planning a grade level loop track around the staging yard ladder with a single main leading back to the original point of origin. My goal is to be able to run either 12-33,000 gal tank cars, 12-53' well cars, 12-4 bay hoppers through the loop for continus operation without any probelms, so based on this thread i assume the loop track will need to be a much wider radius of maybe 48"/54", even though it will be installed on flat grade. Bayway Terminal NJ
hjQi gregc this was referring to stringlining I see. Yes, longer cars are hard to deal with...
gregc this was referring to stringlining
I see. Yes, longer cars are hard to deal with...
presumably you know the weight of the car and the lateral forces on the coupler
the height of the coupler above the track and center of mass between the rails
and can calculate the torque required to rotate the car to the side
you could compare the coupler force needed for difference car lengths and weights vs track radii
greg - Philadelphia & Reading / Reading
doctorwayneI would normally run such trains only as tests, not for regular operations, as there are a lot of places where a derailment could put locos and/or rolling stock airborne on a 48" to 59" drop straight to the concrete floor.
Agreed. It was quite scary when I tried to run 60 cars on my track that has 2-3% grade with several 28-32" curves. The long train looks amazing but I probably would not run it again for a while...
gregcthis was referring to stringlining
gmpullmanMore than you wanted to know...
It is really interesting to know there is such a book! But probably not surprise as real operation of a railroad does need lots of planning, even for running the trains... Thanks!
hjQi gregc hjQi Try not to pull long cars, you might be ok. not sure how your accounting for this shouldn't longer cars be heavier and won't that help offset tipping? Long cars have more side force because the angle between them is large. On his 24" curve, the angle between two 8" car is t=19 degree, the force transfer coefficient is A=cos(t)=0.94. If the cars are 10" long, the angle is t=23.8, A=0.91; for 12" long car, t=28.6, and A=0.88. Also, I feel if the car is long, you would have more side force, thus the effective friction coefficient might also be higher.
gregc hjQi Try not to pull long cars, you might be ok. not sure how your accounting for this shouldn't longer cars be heavier and won't that help offset tipping?
hjQi Try not to pull long cars, you might be ok.
shouldn't longer cars be heavier and won't that help offset tipping?
Track fiddler .... "If radius re-versus, it cancels itself out". With either Ed or Wayne saying that, I will take that one to the bank. I think it was Wayne with a long train wrapping all the way continuously through both reversed curves and he found reversed radius canceled itself out I don't do any math when I see it's unnecessary. TF
.... "If radius re-versus, it cancels itself out".
With either Ed or Wayne saying that, I will take that one to the bank.
I think it was Wayne with a long train wrapping all the way continuously through both reversed curves and he found reversed radius canceled itself out
I don't do any math when I see it's unnecessary.
TF
Resistance is always cumulative, so whomever made that claim is sadly mistaken. If a single curve, u pick the direction, offers resistance X to Train A, why would one following immediately, same train, same curvature, no other variables changed, reduce the effect of the first to 'zero'? You must add the second curve to the first to get what is in reality twice the resistance as either of the curves by themselves.
gmpullman Track fiddler I think I remember it was either Ed or Wayne that said. "If radius re-versus, it cancels itself out". Must have been Wayne, TF, I don't recall saying that. I cant imagine that two reverse curves "cancel" each other out.
It definitely wasn't me. If I'm running a long train on my longest grade (45'@2.9%), there are two 34"radius horseshoe-type curves , the first one curving to the right, the second to the left, followed by a series of three S-curves with radii of around 45" each.
None of the curves, even those generous ones, nor the relentless 2.9% grade will cancel-out anything, unless it's a loco that's not quite up the the task. A train of that length would likely have a minimum of five or six steamers...a couple at the front, another couple mid-train, and one or two shoving on the caboose.I would normally run such trains only as tests, not for regular operations, as there are a lot of places where a derailment could put locos and/or rolling stock airborne on a 48" to 59" drop straight to the concrete floor.
It would likely take a little over 80 cars, plus the locos, to occupy the grade completely, and many of those cars are well-over the NMRA recommended weights.
Track fiddlerI think I remember it was either Ed or Wayne that said. "If radius re-versus, it cancels itself out".
Must have been Wayne, TF, I don't recall saying that. I cant imagine that two reverse curves "cancel" each other out.
Still, I like to run long trains and I do have lots of curves. It is a necessary evil in our layout designs.
One thing I'll mention about long cars is a design technique some manufacturers adopt and that is to place the truck bolster pivot closer to the center of the car. This has the effect of "shifting" the car centerline outward which helps prevent binding and excessive overhang of the center of the car under the inside rail. It may aid in reducing the "stringlining" effect as well.
Train resistance:
Alco_data_hilite by Edmund, on Flickr
Alco_data_0001 by Edmund, on Flickr
Alco_data_0002 by Edmund, on Flickr
Alco_data_0003 by Edmund, on Flickr
More than you wanted to know...
Cheers, Ed
Track fiddlerI don't do any math when I see it's unnecessary.
I feel once the track is built, no more math is needed. And all I have is some of kind regret. I wish I could have done more math when I planed my track
gregc Try not to pull long cars, you might be ok. not sure how your accounting for this
not sure how your accounting for this
Long cars have more side force because the angle between them is large. On his 24" curve, the angle between two 8" car is t=19 degree, the force transfer coefficient is A=cos(t)=0.94. If the cars are 10" long, the angle is t=23.8, A=0.91; for 12" long car, t=28.6, and A=0.88. Also, I feel if the car is long, you would have more side force, thus the effective friction coefficient might also be higher.
There's a really good-looking almost naked lady on their advertisement here slightly dressed in red.
After I looked at her a little bit
I think I remember it was either Ed or Wayne that said. "If radius re-versus, it cancels itself out".
hjQiTry not to pull long cars, you might be ok.
Sometimes a pusher can unbind the slack!
If you just so happen to be that lucky with your push-a-me-pull-you calculations
Yes! I really felt that....
Track fiddlerThat string line effect always sucks doesn't it eh?