[Tom_C]

How do you guys bend flex track on a grade? Meaning, if I'm going to shape track up a grade, flatten out for a turnout and then continue up, is there a preferred method for that?

This will be HO track.

ADDED: this is not for curves, but up and down.

 

[CTValleyRR]

Let the natural spring of the flex track define the curve. Make sure it returns to level before it gets to the turnout's location. Fasten it down and cut it off., install your turnout, and again use the "spring" to define your curve.

 

[Tom_C]

Thanks. So, I shouldn't try to bend it much more (or at all) beyond the natural spring of the track?

 

[65446]

You can bend flex and install it to any radii and shape it can tolerate..Far as laying it on a grade it's no diff than anywhere else (other than the question do you want to super elevate (bank it) or not..No need if its short 7 car trains.
BUT, if there is a switch (T.O.) enroute it must be exactly on the plane with the rest of the climb, not kinked in any way with the surrounding track.. The diverging route from it must also continue on that very same plane until you can level it without affecting the switch in any way whatsoever (about 1-2 engine lengths). If you want the switch to lay plumb level within the curve you too must have the approach tracks not affect the switch's parts and rails in any way at all..Then of course you can run a diverging track at level from it all the way out....
In other words model train switches can not be bent, kinked, nudged at all away from their factory shape or you're looking at a lot of derails and stall outs.
Also, if you are employing two or more 3' flex sections, even if switch is within that, first solder 2 or 3 sections together (with rail joiners) while they are lying dead straight. This insures no kinks in the curve when you do bend them...M

 

[Tom_C]

Thanks Telltale. I will keep the turnout "on the level" or at least it will not be bent.

This will likely be very contained... 4 feet at the most, with only a car or 2 behind a little loco. It's an experiment, for now. I'm going to do another kit-bash with an azatrax switchback controller and a DCC shuttle controller. (see my history for another kitbash I did)

I will take your comments to heart though. I appreciate it.

 

[Chaostrain]

You want to be sure to have your grade change a few inches from track joints so you get smooth transitions.

 

[Tom_C]

Got it. Thanks.

 

[cv_acr]

if I'm going to shape track up a grade, flatten out for a turnout and then continue up, is there a preferred method for that?

FWIW a turnout doesn't have to be "level" - it can be on a grade. Just make sure the grade is even through the turnout; don't introduce vertical bends or side-to-side angles.

Keep the grade going evenly through the turnout instead of leveling out and restarting. That might actually cause more problems...

 

[Tom_C]

OK, thanks. That seems like it makes the next step of the grade harder though, doesn't it? It solves a potential problem coming into the turnout, but going up the next step of the grade means you have to bend it more sharply?

I suppose I will figure this all out when I start, but I'd rather not end up with a stack of useless flex track when I'm done.

 

[Shdwdrgn]

From what I'm reading here, there should not be any 'step' along the grade. Your grade should be a smooth level climb including the spot where the turnout lays. Basically treat both legs of the turnout as if they were continuing at exactly the same slope, and don't change the slope until you have moved a distance from the turnout. Another way of describing it would be to visualize laying a straightedge along the track of your grade. All of the track, including the turnout itself, should be flush to the straightedge. Hope that helps?

 

[DonR]

The reason for using the 'natural bend' in an inclined
track, as some have posted, is to ensure that the
front coupler of the loco doesn't 'dig into' the grade
at the bottom, or have loco trucks leave the rails
at the top. You allow a natural grade of the flex and
then build your support under it.

Don

 

[mesenteria]

All railroads are on grades. There's really very little that is 'level' anywhere. Even bridges and turnouts are on grades.

The difference between them and our scale models is the real distance we have to work with. A prototype turnout might be a whopping 60 feet long when the crane lifts it off the flatbed and into place. Even on vertical curves at the base of a grade, the distances involved are enormous, something like eight or ten miles in HO scaled trackage. We have to fashion the same thing inside of 12-18 inches. That's where we run into trouble with wheels lifting or pilots/snowplows snagging and rubbing on vertical curves that are too sharp.

You can let your flex track sag naturally and ballast under it to fill and to support it. If you have to insert a turnout there, you'll have to pause the grade or gently force the turnout into a couple of degrees of accommodation. That can cause problems, but if you keep it minor, you should be okay. The turnouts are NOT designed to sag, but you can impart a minor 1/16" sag near the frog if you are careful. I'd advise against it. It won't be the through route that will cause the problem; it will be the diversion at the depressed frog that will cause you derailments at least 40% of the time, if not double that, and it gets worse the longer the frames of the leading head end power.

And yes, the longer your vertical curves to get into a progressively steeper grade, and they are necessarily longer, the shorter the grade between the two vertical curves. You can't have your shallow grade cake and still get the rise you need in a short distance. Or, you can't have your steep grade cake and not have longer curves at either end...meaning you still have less rise when you're done.

 

[AmFlyer]

To provide some specifics I have a professionally built S gauge layout with track that allows operation of either scale or highrail equipment. All yard turnouts and most mainline turnouts are level. The few that are on a constant grade are minimum #6 turnouts and the grade through the turnout is not more than 2%. There are no operational issues. For vertical easements the rate of transition is about 8" per degree of grade. So a transition from level to 2% takes 16". Multiply by 64/87 for HO distances. Some of these vertical easements are on curves with superelevation. The superelevation is also transitioned in over about a 6" distance. Complicated to build accurately but operates flawlessly with scale wheels as well as highrail.
The maximum grade is 2.5% and the total vertical distance from lowest track to highest is 16"

 

[Tom_C]

Thanks all, I appreciate the input.

Another question. If I want to keep the vertical up/down as 'narrow' as possible (limit the total footprint of the hill) would it be better to use wye turnouts or regular left/right turnouts, or would it make much difference?

 

[Homeless by Choice]

...

For vertical easements the rate of transition is about 8" per degree of grade. So a transition from level to 2% takes 16". Multiply by 64/87 for HO distances. ...

Tom, for HO scale, that equates to near 12". Please clarify for me that means 6" on each side of the theoretical intersection point of the horizontal and 2% grade as shown on the attachment.

Thank you,
LeRoy

 

[AmFlyer]

Your sketch is correct, that is the design standard we used. During construction the layout builder had 15 of my engines on site for testing. As a result we found we could cut the design easement length at the top of the grade in half, unless there was a turnout at the end of the easement. Remember my layout has to work with scale wheels as well as high rail, if we tested with just highrail engines we could cut the easement length almost in half.
In almost all cases we were able to get to a 2.2 to 2.4% grade without extending the easement length. But each location was tested before final track installation. as an example typical grade length from level to level is 240", including the easements, to climb 5". I am able to run long trains with these track standards. It all depends on how you want to operate your own layout. In 3 years of operation I have never had a track caused derailment, just a few operator errors throwing turnouts while the train was still on them.