Do you bank any curves?

[Fawlty Logic]

I have a code 83 Atlas Flex track curve about 22 or 24 inch radius on a 2 1/2 degree descent that tends to throw long frame locos and rigid steamers off the track.  I can't quite see what is happening, but I believe the front trucks are just climbing off the rails.

Do you think banking this curve will be beneficial?  Or perhaps the gauge is a little tight.  I am going to pull the track nails and shim it on the outside.

This is annoying because 95% of the locos take it well.

 

[selector]

My answer to all you ask, and what you are thinking of doing is...probably...yes.  I think banking is going to work better on a large radius because a tighter curve requires the into and out-of of the banking to happen over a shorter arc, and if the track going into either end of the curve segment is iffy, you should expect derailments on larger framed engines of all types...diesel or steam.

Let's assume your wheel gauges are all good and you have the engineered sideplay in your axles so that your engines can legitimately take the curves they are purported to take by the manufacturer; If your curve is on the tighter end of the minimums stated, it leaves that much less room for manufacturing errors and variances in assembly, etc.  Less buffer or fudge room, IOW.  So you have to make your trackwork that much better to compensate.  If your track gauge has tightened up quite a bit, now you are eroding that buffer you wanted.

In my experience, whenever I introduced a (always bigger) steamer to my track system, I learned I had work to do within half a lap.  Almost always, it was not so much the turnout or the curve that ended up being the problem, but what led into it....or out of it.  It is most often the previous joint or segment that was misaligned or uneven, or the gap was just that much too large....whatever...and that made all the difference.  Note, also, that I learned from Chuck (tomikawaTT) that every single rail end, whether in a turnout or on a section of track, must have its top tire face and inner flange face champhered, or beveled, even if slightly, using a metal file.  This is very important, again, as curves tighten because now you are forcing the flanges tight against their working faces, and when they come to a slightly wider gap (wood expanding in humidity below the joint), the flange is more apt to snag on a sharp angled end than on one beveled.

Run your engine slowly through 24", eyes right at track level, and good light behind the engine.  Watch for wheels lifting.  Keep an eye on the far side of the engine, too.  Also, you can use the light and eye-level look using a stiff straightedge placed over several spots to see if you can spot uneven rail tops.

[jeffrey-wimberly]

I do bank my curves slightly. This allows a train to negotiate a turn better at high speed if I should have the inclination to do so. There's a speed demon in all of us after all. It also allows me to get the curve into a slightly tighter space.

[Texas Zepher]

Do you think banking this curve will be beneficial?

In railroading it is called super elevation.  Real railroads do it all the time.

Or perhaps the gauge is a little tight.

That would be a good thing to test first.  In fact the gauge going through the curves should be slightly wide.  I would also check the gauge of the wheels climbing off  the rails.  

 

[Geared Steam]

There's a speed demon in all of us after all. 

Not me, nothing looks sillier and screams "toy" than a model tearing around a circle at 300 mph, but thats just me.

 

 

[Fawlty Logic]

Do you think banking this curve will be beneficial?

In railroading it is called super elevation.  Real railroads do it all the time.

Or perhaps the gauge is a little tight.

That would be a good thing to test first.  In fact the gauge going through the curves should be slightly wide.  I would also check the gauge of the wheels climbing off  the rails.  

 

Thanks to you all.  Yes, if anything my curves are less forgiving in gauge than the straights.  Maybe that is the way Atlas Flex track works.  I know now not to put the track nails in too tightly.

Did I read somewhere to spread the rails by putting in track nails against them at an angle or pushing outward on them?

If I make any big additions in the future, I am upgrading to better rail and turnouts.  Live and learn.

I will also go around with the file on the rail ends.  I read that before and then forgot it.

Real railroads sure do put in that super elevating.  There is a fairly tight curve just outside my house here in town, so the speed limit is in effect, but the rail bed is still built to lean that train waaaay over and use its mass to force it down in the swing around the curve.  Don't want anything coming off the tracks near all these houses.

[JulesB]

Track nails too tight will foul up your track, been there, done that, it's all part of growing up I'm told. Be 74 in Febuary, still growing up!!!

I super elevated a few 24" curves. I found one can over do it. Some thin strips of plastic, .020" with a 0.10 leading in works fine. It looks good and it's all you need. It's all 1.87/1.

 

Jules

 

[E-L man tom]

I superelevate my turns all the time (24-30" radius turns); I use small pieces of 1/16" thick cork (used for automotive gaskets; I use it for branchline or major siding track bed). This works fine except you can still get wheels riding over the track either going into -or coming out of the turn, even with some under weight rolling stock. What I have found is that if you play with the shims that are on these turn exits/approaches, by moving then either further into or further out of the turn you can eliminate that. Yes. some filing of rail ends helps as well but it is usually the manner in which the turn is superelevated, at least that's what I have found. 

[CSXDixieLine]

Superelevating track does wonders in making a model look more like the real thing. I will be superelevating all of my mainline curves once I start laying track in the next month or so, although my goal is better visual realism as opposed to operational improvements. I am in N-scale and plan on shimming under the "outside" ends of the ties with very thin strip styrene or cardboard--in fact I have recently viewed photos from another N-scaler that used small rectangles cut out from a Cheez-It box to do the superelevation. Jamie

[corsair7]

Superelevating track does wonders in making a model look more like the real thing. I will be superelevating all of my mainline curves once I start laying track in the next month or so, although my goal is better visual realism as opposed to operational improvements. I am in N-scale and plan on shimming under the "outside" ends of the ties with very thin strip styrene or cardboard--in fact I have recently viewed photos from another N-scaler that used small rectangles cut out from a Cheez-It box to do the superelevation. Jamie

I have never superelevated my curves. I'm in N-Scale also but I'll look into doing this on my new layout. Are there any tips or other advice you could give me?

Irv

[selector]

A very simple way to super-elevate your curves is to use split strips of masking tape laid atop one another, but with the layers staggered a bit at either extreme of the curve to permit a transition into the banking.  Start with one long curved layer of 1/2" tape, but slit lengthwise (or not, your choice) and when that is in place, a shorter piece laid on top of it, but with its ends about 1" inwards from the previous layer's, and so on.

I wouldn't be surprised to find that only three layers makes quite an impression when you see how the trains lean in the curve.

[CSXDixieLine]

Superelevating track does wonders in making a model look more like the real thing. I will be superelevating all of my mainline curves once I start laying track in the next month or so, although my goal is better visual realism as opposed to operational improvements. I am in N-scale and plan on shimming under the "outside" ends of the ties with very thin strip styrene or cardboard--in fact I have recently viewed photos from another N-scaler that used small rectangles cut out from a Cheez-It box to do the superelevation. Jamie

I have never superelevated my curves. I'm in N-Scale also but I'll look into doing this on my new layout. Are there any tips or other advice you could give me?

Irv

Irv, I still have not got to tracklaying yet (gotta get that helix built first!), but here are a couple of N-scale layouts that I know use superelevation and they have info posted about it on their website/blog:

Southern Pacific Coast Line in N-Scale
http://www.sp-coastline.com/

SPSF Owens valley Subdivision in N-Scale
http://www.owensvalleysub.com/
http://www.owensvalleysub.com/august2008.html (superelevated track shown on this page)

Jamie

[tomikawaTT]

I superelevate my curves.  I also use proper spiral easements on ALL trackage, even hidden track destined to be buried under a mountain.

Since all of my single track (including the parallel tracks of multi-track main lines) is laid on cookie-cut plywood, my preferred technique is to impart a twist to the plywood subgrade and lay everything above that in the conventional manner.  From having the rails level at the actual point of tangency (measured at a right angle to the rails - there isn't much level track on my layout outside of yard limits) I gradually increase the tilt to about 1mm between rails at the actual point of curvature.  Thus the superelevation is proportional to the tightening radius through the transition.  The equivalent tilt is about 1/16 inch between tie ends.

Selector already mentioned my rail end bevel trick, so I won't beat it to death.

One thing to check is the possibility of a small but significant kink.  The Mark I mod 0 eyeball might not spot it, but a stiff, long-wheelbase loco will find it every time.

Chuck (modeling Central Japan in September, 1964)

[Loco]

When super elevating curves, would there be any problems if using the WS foam roadbed?  I'm going to be running U.P. motive power and that means Big Boys, Turbines and the like so I need to think about what I'll need to use while still in the planing stages.

[tstage]

I super elevated a few 24" curves. I found one can over do it. Some thin strips of plastic, .020" with a 0.10 leading in works fine.

Fawlty,

This is exactly what I did to the R18" and R22" curves on my mainline recently.   I used 1 x 8 and 2 x 8 dimenional styrene for the superelevation.  The styrene strips were glued to the bottom side of the rail ties with liquid adhesive, directly underneath and parallel to the outside rail of the curve:

Quick and easy.  It probably took me 2-3 minutes to complete a curved section of track.  Although practically invisible, the styrene will disappear completey once the track is ballasted.

Tom

[Loco]

Tstage, is that cork your using for the subroad?

[dehusman]

In the model world, superelevation is purely cosmetic because unless you are operating at toy train speeds, the the effect is neglible.  I won't do much superelevation on my layout because the railroad is such a slow speed line that the amount wouldn't be that noticeable.

Dave H.

[CSXDixieLine]

When super elevating curves, would there be any problems if using the WS foam roadbed?  I'm going to be running U.P. motive power and that means Big Boys, Turbines and the like so I need to think about what I'll need to use while still in the planing stages.

I have used the WS foam roadbed in N-scale. I would be concerned that the track may just push whatever you are using to superelevate it down into the foam. I could be wrong but I could see this happening.

In the model world, superelevation is purely cosmetic...

Dave H.

Absolutely....and it is BEAU-TI-FUL:

Photo from Joe Fugate's Siskiyou Line

Jamie

[mobilman44]

Hi!

Super-elevating mainline curves is great, but I have a hunch that you have a basic "curve too tight for the loco" problem.  "Assuming" your loco can take 22" curves - and that is something to be checked upon - I would check the curves in question using a piece of 22 inch radius sectional track and just moving it over the flex track.  This will tell you if a part of the curve is tighter than the sectional 22 inch.  Also, you may have some kinks in the track, especially if your joints for each rail are at the same place.  And, like was mentioned, you may have pulled the track out of gauge by pushing the track nail(s) in too deeply. 

Oh, it is also possible that the lead/tail truck is binding and just will not negotiate the curve.  With all due respect, all of the above needs to be checked out before you super elevate.

Been there, done that.......

Mobilman44

[tstage]

Tstage, is that cork your using for the subroad?

Loco,

Yes, it's cork roadbed.

Tom

[larak]

When super elevating curves, would there be any problems if using the WS foam roadbed? 

Nope. At least not on 30" and 33" radius. The trains look better too. Just don't over do the thickness. I used 1/16" cardstock sliced into bands. Shaved the ends in a taper to nothing.

Karl