banking wide radius curves

[RailMark]

 

Hey all you 3 rail folks who have built large layouts, Do any of you bank the curves on your layouts.? like with curves of 4 2" or larger. Looking for advice.

 

Thanks,

 

Railmak

[Konga Man]

I don't generally bank large-radius curves, but I have been known to bank O-31.

This may not be the easiest way to do it, but this is what I do:

- Start with a 1x3 (actual size: 3/4" x 2½").

- Rip it on a bandsaw at ~ 6º.   This gives you two pieces that are ¼" at one end, ½" at the other.  I then cut this board into pieces ½" wide.  Each of these pieces will fit inside a tie, leaving one end flush with the ground and the other elevated ¼".  A screw on the inside hole holds it down.

There was no science to this; the angle was determined by the size of the board and the cut needed to come up with identical pieces from both halves of the cut.

If you do this on 0-54 or 0-72, you'll need a lot more blocks than you will on 031. ;)

[lionelsoni]

The problem with superelevation is that the drawbar force tending to pull toy trains off the track to the inside of the curve is often greater than the centrifugal force tending to pull the train off the track to the outside of the curve.  I have been tempted to use negative superelevation (subelevation?) for just this reason, but have always settled for level track after imagining how unrealistice the tilt to the outside would look.

[Buckeye Riveter]

lionelsoni

The problem with superelevation is that the drawbar force tending to pull toy trains off the track to the inside of the curve is often greater than the centrifugal force tending to pull the train off the track to the outside of the curve.  I have been tempted to use negative superelevation (subelevation?) for just this reason, but have always settled for level track after imagining how unrealistice the tilt to the outside would look.

It is great to read a post that has it right.  I talked with a gentleman years ago when I was in HO scale who was building a spiral to change levels and he found that the small negative superelevation prevented many derailments as his trains went up grade.  Now if you stop suddenly going downgrade, I suppose you could have a problem.  Remember, there is a difference in performance between models and the prototypes.  My individual O gauge train cars don't have brakes to ease them down grade.  (With some of the new nano technologies, we just might have car breaks in the future.)

[Konga Man]

I don't know there's a "one size fits all" answer to the question of "to bank or not to bank".  If I'm running a solo loco, I could almost certainly go faster on banked turns.  If I'm running a long consist, perhaps that same banking would effectively amplify the drawbar force.

I run short consists: 1 loco, 5-6 (usually) short cars, often with a "junior engineer" at the throttle.  Flying off the outside of a curve is much more common than clotheslining off the inside.  OTOH, there are those who live at the other end of the spectrum: quasi-realistic coal trains and other consists that are several times longer than mine (and at much lower speeds).  For these folks, it's a different problem.

So where's the tipping point in the debate? I dunno -- but it seems that what helps one may hurt another.