Minimum curves for 85' streamline cars

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Selector

Well-Known Member
#41
My double articulated Rivarossi Allegheny 2-6-6-6 is my most overhung steamer. It's cab roof extension over the tender catches things that no other locomotive I have will catch. I pay especial attention to clearances (properly called "gauge loading") at bridge abutments, tunnel portals, and on passing rock cut faces when all of these are along a curve.

When I am setting a double main along a curve, and wondering whether or not I have left sufficient gauge loading clearances at the beginning of through tusses or through girders, and entering a tunnel of any kind, I always know to go get my Allegheny. I also use it with long passenger cars to check side-swipe along nested curves.
 

Iron Horseman

Well-Known Member
#42
Now how much distance between the track centerline and a trackside post, pole, tunnel edge, etc, do I need to provide for the front 'overhang' of most of those plastic articulated locos?
Wow, tougher and tougher questions. That is going to be very vendor specific and my best advice would be to make a track of given radius, put the loco on it, and measure. Almost anything else is going to be a guess.

As Selector said in the prior post, with the double hinged locomotives one must also check the rear overhang.
 
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beiland

Well-Known Member
#43
My double articulated Rivarossi Allegheny 2-6-6-6 is my most overhung steamer. It's cab roof extension over the tender catches things that no other locomotive I have will catch. I pay especial attention to clearances (properly called "gauge loading") at bridge abutments, tunnel portals, and on passing rock cut faces when all of these are along a curve.

When I am setting a double main along a curve, and wondering whether or not I have left sufficient gauge loading clearances at the beginning of through tusses or through girders, and entering a tunnel of any kind, I always know to go get my Allegheny. I also use it with long passenger cars to check side-swipe along nested curves.
I have at least 3 of those Allegheny's (don't ask why), so can I request from you specifically how much clearance you provide for those cab roofs on,...
1) 28.5" curves (my smaller radius in the helix)
2) 24" curves (might have one of these in a yard or another small scene)
 
#44
Remember, that the prototype railroads used clearance cars, to take measurements, and recorded clearances in clearance books, used for routing. If a locomotive didn't fit, it was prohibited from that territory.

The Horseman, has the solution, take the locomotive in question, and measure it. We have the luxury of building our scenery to conform to our equipment, the real railroads didn't.
 

beiland

Well-Known Member
#45
I would take it out and measure it, but all my trains are still packed away in a transport trailer waiting for me to build a layout....that I am STILL planning
 

Selector

Well-Known Member
#46
I have at least 3 of those Allegheny's (don't ask why), so can I request from you specifically how much clearance you provide for those cab roofs on,...
1) 28.5" curves (my smaller radius in the helix)
2) 24" curves (might have one of these in a yard or another small scene)
I use 2.75", but my curves are 33/36-ish for my inner curves and 42-45" for my outer curves on my folded loop. I would expect to have to add at least 1/8" for the 24" curves you mention, possibly all the way out to 3 inches. But even with the use of a template or a formula, the first thing I do when I get track laid, and before any ballasting or scenery, is to run the problem children I have...those most finicky about quality trackwork and those whose length and overhang might snag something along a curve. Even better is simply to lay experimental curves and test to get empirical data so that you don't have to undo any nice curves.
 
#47
24" curves in a yard, are not really a problem, if the larger locos / cars don't react well, just don't run them there. 6 axel slug sets wouldn't stay on the rail on the receiving yard ladder at Morrisville, for instance, so they were prohibited.
Crandell's 2.75" standard should work for you also, but you really need a test train to be sure. Same with your yard tracks. Sometimes it comes down to individual preference and philosophy.

In a completely different setting, I just reconfigured, the track in an industrial setting. I ran several small switchers through the trackage, to insure electrical connectivity, then I ran a sampling of random freight cars that I plan on using in the complex, just to make sure they track well. next step, will be to place structures to insure clearances are met. Then I secure everything and apply scenery. Each stage requires a test run to insure everything is still as I want it.

Boris
 

beiland

Well-Known Member
#48
Experiment

I'm going to grab some flex track and some long cars and locos from my stowage trailer today, and run some experiments. I'll take some photos.
 

beiland

Well-Known Member
#49
Just to upset the apple cart, then rock the boat a little. I have successfully run Walthers Proto 85' cars on 28" radius curves with no problems. This includes the Capitol Limited cars and the Broadway Limited cars. New layout has minimum radius of 30" for main line curves, with wider when practicable. Bottom line is that you should build your curves to the widest radius possible in relation to the space you have available. One other point, contrary to what Walthers says on the box and in their catalog, they do not take well to 24" radius curves. (Which is one reason I'm building a new railroad). :rolleyes:
Bingo.
And yes those long passenger cars will run on 28" radius curves,...maybe even less.
 

beiland

Well-Known Member
#50
My guess is 28¾ as a bare minimum, and 28½ as a safe radius. I used similar curves on a return loop on my last layout and had no trouble with full length passenger equipment with floor mounted standard shank Kadees. I don't see why a helix would be any different. A centerline of 2¼ to 2½ would be adequate.
That's what I just found out running a few static test. My new helix will be 31" outside radius, 28.5 inside radius
 

beiland

Well-Known Member
#52
My double articulated Rivarossi Allegheny 2-6-6-6 is my most overhung steamer. It's cab roof extension over the tender catches things that no other locomotive I have will catch. I pay especial attention to clearances (properly called "gauge loading") at bridge abutments, tunnel portals, and on passing rock cut faces when all of these are along a curve.

When I am setting a double main along a curve, and wondering whether or not I have left sufficient gauge loading clearances at the beginning of through tusses or through girders, and entering a tunnel of any kind, I always know to go get my Allegheny. I also use it with long passenger cars to check side-swipe along nested curves.
BINGO, that's what i just found
 

beiland

Well-Known Member
#53
Testing Long Passenger Cars & the GG1 loco

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 inche
s

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 obvious 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
 
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beiland

Well-Known Member
#54
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
 

beiland

Well-Known Member
#55
AutoRacks on Curves

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".
 

montanan

Whiskey Merchant
#56
I will bring up one possible problem you may run into with passenger cars on tighter radius curves. At my model railroad club, the have problems with passenger cars with operating diaphragms. They are not sure of the radius of a couple of curves in question, but are guesstimating them to be around 26 inches. One member picked up the entire Walthers Empire Builder and had to change the couplers to ones with longer shanks so they could negotiate the tighter radius curves.

I ran my North Coast Limited on the club layout and did have a couple of occasional derailments caused by the operational diaphragms.
 

beiland

Well-Known Member
#57
problems with passenger cars with operating diaphragms

Yes I do remember that with some older Concor passenger cars I use to have, that had aftermarket diaphragms installed on them. i will have to re-review that situation. And I believe it is further exacerbated by curves that do NOT have any easements
 

montanan

Whiskey Merchant
#58
I can easily run my Walthers cars on my home layout as my minimum radius id 36" in one spot but most are a lot broader than 42 " or even more. I do not plan on changing couplers to run the train at the club because I really like the looks of the close coupling. Using either hand laid track or flex, easements are extremely easy.
 
#59
I can run Walthers cars on 30" and 32" curves, with minimal easements and no super elevation. I also have no problem with Branchline or Rapido passenger equipment on the same curves.

Boris
 
#60
I can run Walthers cars on 30" and 32" curves, with minimal easements and no super elevation. I also have no problem with Branchline or Rapido passenger equipment on the same curves.

Boris
Following the completion of my trackwork/wiring on my new layout i confirm what WJLI26 mentioned. I ran a 13 car Walthers Proto train on 30" curves with some (to none) easements and no super elevation (my prototype did not have super elevation either) and everything is fine. One car derailed at an odd spot but when i swapped one of the wheels all went back to normal.
 



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