HO scale:I'm looking at running long cars (autoracks, etc) on 2 parallel mainline curves, (also two helix curves) of OuterRadius 31". What is the minimum curve I can use for the InnerRadius, while still having trains pass one another simultanously on these 2 tracks. 1) In other words what is the minimum distance I need to provide between the centerlines of the 2 tracks?
2) What are the two minimum and maximum radius circles I need to provide these 2 tracks such that their 'overhangs' don't interfer with outside/inside, scenery/structure obstacles, etc?
Brian
My Layout Plan
Interesting new Plan Consideration
If you want to see if YOUR cars will work, the only way you'll get an answer is to set up a test track and play around. You'll be able to see all the factors at work, car-length, coupler type, etc. and see what works and doesn't.
Chip
Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.
I guess the first post about autoracks and radius, which involved the well known poster, Anonymous, you know, the one with the 300,865 post count, and Brian trying to revive it, got deleted!
Mike.
EDIT: My reply included things about Dr. Frankendiesel, Space Mouse for president, and such things, Oh well, it's gone.
My You Tube
Mike,
Brian's query was split from the original thread to create a new one and the 11-1/2 year old thread returned to its former place of blissful sleep so it can be resurrected again at some future date.
Sometimes it makes sense to revive an older thread. In this case, however, it was better to start a new one that specifically addressed Brian's questions about track spacing. I just wish the forum software allowed you to move the subsequent responses along with the split thread.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Here is a duplicate answer, same answer I gave in that other forum you asked that question:
Yes, I'd go with a separation of 2 1/2 inches between tracks rather than 2 1/4 inches. A little extra margin helps make sure long rolling stock will pass each other without issues.
BTW, I highly recommend John Armstongs Track Planning for Realistic Operation. He discusses things like separation of tracks on curves and recommendations of centerline distances for straight track and various sharpnesses of curves.
That 1/4 inch sharper inner radius won't make nearly as much difference to trains as the margin of seperation will for ability to run longer cars.
Rio Grande. The Action Road - Focus 1977-1983
Take a look at NMRA Standards 7 and 8, and Recommended Practice 11. You can download then from the NMRA website. And John Armstrong "Track Planning for Realistic Operation" is extremely useful.
David Starr www.newsnorthwoods.blogspot.com
Testing, Started with Long Passenger Cars
Like you I have some long autoracks and passenger cars I want to run on my layout. My plans have evolved from an original concept that had multiple 24" loops, to one that now has its loops and helix all in one 'structure'. I was hoping to make this helix structure as large of a radius as possible, but I have a physical limiting main power pole out back of my train shed that is just 'in-the-way'. I've have looked at options to have it moved, but it is cost restrictive. I have decided I am going to move the shed as far forward under my carport as possible (gaining about 6"). This should allow for me to have a max 32" outer radius for my double track helix and mainline loops. (It might have to be only 31" at worst case). So assuming worst case I believe I can have a second inner radius at 2.5" less,...28.5". Am I correct, is 2.5" centerline track spacing enough at these sort of radiuses? If so that means a distance of about 1.25" from the centerline of the track to an imaginary barrier between the two tracks should be OK? Furthermore a likewise 1.25" clearance outboard of the outer track should be OK?? Brian
Like you I have some long autoracks and passenger cars I want to run on my layout. My plans have evolved from an original concept that had multiple 24" loops, to one that now has its loops and helix all in one 'structure'. I was hoping to make this helix structure as large of a radius as possible, but I have a physical limiting main power pole out back of my train shed that is just 'in-the-way'. I've have looked at options to have it moved, but it is cost restrictive. I have decided I am going to move the shed as far forward under my carport as possible (gaining about 6").
This should allow for me to have a max 32" outer radius for my double track helix and mainline loops. (It might have to be only 31" at worst case). So assuming worst case I believe I can have a second inner radius at 2.5" less,...28.5". Am I correct, is 2.5" centerline track spacing enough at these sort of radiuses?
If so that means a distance of about 1.25" from the centerline of the track to an imaginary barrier between the two tracks should be OK? Furthermore a likewise 1.25" clearance outboard of the outer track should be OK?? Brian
I did some testing out on my 'outdoor test bench' . As I have mentioned before I feel I can easily fit a helix into my plans that will have,... Outer radius 31 inches Inner radius 28.5 inches
I decided to glue some track down on my 'bench' in those 2 dimensions. I chose the 2.5" between tracks dimension after reading a great number of postings indicating that this seems to be adequate for basic curved tracks at these sort of radiuses. So here are my 2 tracks that also have penciled in lines located 1" outboard of them (1" either side of the track's centerline)
That is a newer Walthers 85' heavyweight passenger car on the inner track. It's obivious that its forward end is just shy of that 1" clearance from the C/L.
What is not so obivious is how much does the center of this car project from the C/L of the track. Regretable my camera angle (too close to subject) hides this detail. Let me say that it appears as though the center of this long passenger car requires a FULL 1" clearance on its inboard side on this 28.5 radius curve.
How about two of those passenger cars passing one another on my helix. No problem according to this photo. )and here you can see the center overhang of that upper car barely touches the 1" clearance line at its inboard side)
Since I'm dealing with PRR passenger cars here. I wanted to see if a GG1 could get by, (an IHC one I have).
This photo would appear to have everything OK,...but as it turns out there is considerable 'play' in its trucks that allow it to extend past that 1" clearance line. From these 2 photos we can tell that this loco requires at least 1.25" clearance on its outboard front side.
Its inboard side does NOT seem to present any problems with overhang.
And interestingly, it still has plenty of clearance to negotiate the helix with 2.5" separation of the 2 tracks.
...to be continued
BTW, I moved my shed forward yesterday with some help from a friend with a big pick-up truck, a trailer hitch, and a come-along. Got it moved 8" forward (max possible) !!
I'm putting a 24" radius track on my test board today, as I may well need to utilize this tighter radius in some of my staging area, staging access, and freight yard(s).
I'm also trying to sort out a 'focus problem' I am suddenly having with my once excellent Fuji FinePix S700 camera.
AutoRacks on 26" Radius
So in both cases here its suggested that 2.5 inches between the centerlines of the 2 tracks should work out.
That insinuates that it should only require 1.25" between the centerline of either track to a 'imaginary barrier' between the 2 tracks?
Those autoracks are on the 26" curve, and it appears barely enough for them, although that flatbed has the same footprint as autoracks and it seems it could make the 24".
That photo was from a guy who was experimenting before he decided to go N scale and is not anything like a recommended practice for HO. Note the N scale equipment on an inner circle.
There is a difference between posing trains on lines and trying to drag (or worse, shove) them around curves, especially with grades or in a helix.
Layout Design GalleryLayout Design Special Interest Group
I've seen those monster in action at the Bucyrus club and from that observation I will keep curves to 36" even though they looked more comfortable on the club's 50" and 48" curves.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
I moved my discussions and photo experiments over to this other subject thread that I felt had a more all-encompassing title,What’s the REAL minimum radius of locomotives and rolling stock?
http://cs.trains.com/mrr/f/88/t/267707.aspx