Author Topic: Super elevation?  (Read 2782 times)

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soo

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Super elevation?
« on: December 15, 2014, 09:19:35 AM »
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Sup,

Since recent actions, I am thinking about going a different path when it comes to my helix.

I decided that a single track helix reduced my ability to run trains, so I am thinking about using the double track curve pieces in Kato's Unitrack. In the concrete line they make a 18 7/8" 17 5/8" radius piece. That would be perfect for running trains side by side with long equipment such as auto parts box cars, racks,, and the F89J's.  My thought was that the super elevation would cause a string line.

Yes, no, maybe so?

Adios Wyatt

Denver Road Doug

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Re: Super elevation?
« Reply #1 on: December 15, 2014, 09:30:26 AM »
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I've been wanting to buy some to test that theory but haven't yet.  I've seen at least two guys try it on forums and swear no problems.
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bman

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Re: Super elevation?
« Reply #2 on: December 15, 2014, 11:44:56 AM »
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While I've no experience with Kato's super elevated track, I did super elevate the curves on my layout that uses Atlas code 55.  I have 13.75" radius and have had no issues with string lining trains.  I run around a 20-25 car train usually.  I even run the longer equipment, 89' flats,  86' boxes as well.  While they don't look as good on the sharper curve I know, I just had to have some.

eric220

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Re: Super elevation?
« Reply #3 on: December 15, 2014, 01:38:41 PM »
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I was debating this same question when I built my helix a few months ago. The general conclusion that I came to was that although superelevation might encourage stringlining, the added reliability of Unitrack probably cancels it out. Despite that, I chose to go the route of sectional C55, since it gave me more options and greater clearance between levels.
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Rossford Yard

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Re: Super elevation?
« Reply #4 on: December 15, 2014, 04:08:14 PM »
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I am presuming that you feel the old helix is not worth/beyond repairing?  Honestly, given you say you may never have an op session, I can't really imagine the helix being your limiting factor.  Might be nice if your under layout storage yards are configured as a loop, so you can bomb proof run two trains while you switch the yards, etc.

In general, SE shouldn't hurt and the bullet proof nature of the Kato track would help (not that yours needs it)  It might depend on the degree of super elevation.  Seems like the Kato Unitrack has a bit more than you would get putting shims of - 0.10-0.20 styrene under flex track. 

To be honest, the tighter radius would probably give you more problems than anything, as it adds to grade.  As you might recall, I considered Kato track and wondered about it's 19" radius.  At 20", I wish we would have used the extra few inches to get to 22-24" to reduce grades and crapumates pulling apart mid to upper helix.

On the other hand, I don't really know and am just musing out loud.


Mike C

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Re: Super elevation?
« Reply #5 on: December 15, 2014, 07:19:06 PM »
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   I use the 16 3/8 " 15"  superelevated curves and don't have any problem with them .  Their only half circles on either end of the layout , and I don't run really long trains , but I've never seen any string lining .

daniel_leavitt2000

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Re: Super elevation?
« Reply #6 on: December 15, 2014, 08:09:29 PM »
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17 inch radius and you need to clear the train, track, and benchwork? That's going to be a tough incline.
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CodyO

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Re: Super elevation?
« Reply #7 on: December 15, 2014, 10:04:45 PM »
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I`ve built a helix with the kato super elevation
Never had a train stringline on me  60 55 ton hopper trains handled it and I used the smaller unitrack super elevation
Also add the way it was built its possible to remove and reinstall in a few hours post no track to expand or solder joints to do







It dumps into a staging yard that has a few reverse loops and a few stubs in the middle 



We have a second one built for the 3rd deck

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soo

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Re: Super elevation?
« Reply #8 on: December 16, 2014, 10:31:15 AM »
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Thank you for all the replies guys!!!

I did the math on the expense required to build one helix,, just in track alone I am looking at 321.70$ for the sections and one each of the easement curves.  So you can see why I am asking questions. I do not want to drop all that green on something that will not work or make me happy.

If you follow any of the other forums,, you know what happens when I am not happy, HULK SMASH.

Jeff,, I removed the old helix all together. ( he removed the old helix) shameless "Airplane" plug. You and I are thinking alike,, run the trains in the continuous run option and switch where I want.

Nothing is set in stone yet,, I am just planning. After seeing CodyO's pictures,, the double cross over makes complete sense,,, hmm.

Adios, Wyatt

CodyO

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Re: Super elevation?
« Reply #9 on: December 16, 2014, 11:51:02 PM »
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What other sections do you need?
Only cost me $200 for unitrack super elevated from MBK
And I think 40-50 for the double cross
It's nice having it at the bottom but really only use It for getting the trains in and out of the stubs
Everything goes up the outside and down the inside

Just don't hulk smash this one!
Modeling the Pennsylvania Middle Division in late 1954
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Dksw

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Re: Super elevation?
« Reply #10 on: December 17, 2014, 09:35:04 PM »
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CodyO,

I am planning a very similar helix and staging layout.  To help me visualize what can be achieved along the wall I am planning, can you tell me how many feet your staging wall is? How deep is your yard?
Thank you!
David

nickelplate759

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Re: Super elevation?
« Reply #11 on: December 17, 2014, 10:28:33 PM »
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Umm - the effect is small, but superelevation actually increases the effective radius of the curve.  The only way it should make stringlining more likely is if your cars are top-heavy.

George
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I'm sorry Dave, I'm afraid I can't do that.

CodyO

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Re: Super elevation?
« Reply #12 on: December 18, 2014, 12:10:40 AM »
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David
That yard is 16' long And 18" wide
Built using 2 HCDs and a bit of ply for the reverse loop
4 tracks have a loop and 4 tracks stub
But we try to leave the outside loop open to reverse trains
Modeling the Pennsylvania Middle Division in late 1954
             Nothing Will Stop The US Air Force

Rossford Yard

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Re: Super elevation?
« Reply #13 on: December 18, 2014, 10:41:14 AM »
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I recall that super elevation should make it easier to climb a grade, due to physics of some kind.

Agree that string lining probably due to high ride and maybe excessive weight. My old layout had a Wyatt built 16" radius helix, with no SE and my overly weighted coal hoppers tended to string line. Those fishing tackle weights were somewhat vertical, on an angle along one of the bays and maybe not even perfectly centered, those bethgons tended to fall over like a Saturday night drunk on that helix.  I haven't even tried them on my new Wyatt Built Helix, as I haven't had time to convert to low pro wheels, remove the weights, etc.

I would recommend all weights be no more than NMRA standard, checked for centering and set as low as possible, based on that experience.


peteski

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Re: Super elevation?
« Reply #14 on: December 18, 2014, 12:16:06 PM »
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I recall that super elevation should make it easier to climb a grade, due to physics of some kind.


It is done to shift the center of the gravity towards the inside of the curve. That way when a high speed train travels through the curve it will not fly off the track towards the outside of the curve. Kind of like what happens when you turn while riding a bike (the bike tilts towards the center of the curve).  I don't think it has anything with making the climb easier.
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