Helix Help

[Graham70]

Hi guys I am building two helixs and would like to know is it ok to lay the track straight onto the board or should i still use a roadbase ie cork or foam??
Thanks graham.

 

[joed2323]

You can put track down on wood. Why dont you want to use roadbed? Its more forgiving if you ask me. Make sure your joints are perfect to each new arch section.

Whats your diameter of your helix going to be? I would advise you make your width of your arches atleast 5 inches wide, so you have enough room to attach bracing to and to allow enough clearance for your rolling stock.

Also i would advise you make the heights of each track no lower then 3.5 inches to allow room for taller rolling stock.

For my helix im building, clearance between each arch will be set 1x4 blocks cut to approx 5 inches long. Im using the dimension of a 1x4 which equals 3.5 inches to use as verticle spacing for the layers or loops. Im spacing my blocks every 12-15 inches or where i have 2 roadbed (arch) peices that need to be joined.

I neef to gain 4 inches of revolution, so u i will space my blocks at 1" 2" 3" 4" every 90 degrees apart around a circle.

For my first loop i will have it set about 26 inch radius track centerline which will be a 2.45% grade. I will make the inner arch 23.5 and the outside arch 28.5 to get my 5 inch wide arch.

I would also suggest trying to get as big of a arch from one sheet
As possible so you can eliminate alot of joint.

I would like to know your ideas for your helix plan.. good to see other people building a helix. How big is your layout btw?

 

[Rico]

I left the roadbed out of my last helix to keep the minimum clearance I wanted.
If my next one is wood I might use rubber sheeting under it but never had a problem with noise or anything before.
Most likely the next helix will be styrene and the ties will be glued directly onto it.

 

[Graham70]

These helixs are in N gauge with a radius of 280mm, they do two turns each gaining a total of 100mm with a grade of 2.73%. They have 60mm wide boards and suports every 45 deg with a clearance of 50mm between decks.
The theme for this layout is pre ww2 english steam so i will not be running any long wagons or such so shoud not have any dramas i hope.
Should I superelevate my track in the helixs?????? . All the rest of the curves will be.
Here is a plan of my L shaped N gauge layout, the boards are 2.1m x 1.6m x .8m
I will post a pic when the first helix is finished.
http://farm8.staticflickr.com/7213/6895754562_23346ee8f6_m.jpg

 

[D&J RailRoad]

Superelevation in the helix - I don't think I would go to that effort being as it is more for appearance than function in N scale.

 

[Selector]

Do not superelevate the tracks in your helix unless you know what you are doing and can keep it critically consistent throughout. Remember, this is hidden trackage that must be bullet proof, up and down, forwards and backwards, trailing and shoving. The simpler you can keep it, the better it will be in terms of reliability. If your helix sub-roadbed surface (the ramp itself) is smooth and not canted side to side (it is level across itself at 90 degrees), there is neither a practical, defensible, nor aesthetic purpose to superelevating since it won't be seen anyway. Supervelevation is only visually appealing on our models, but serves little or no purpose at the physics level...unlike the prototype where it keeps sensitive items inside the train, babies, women, surprised and annoyed waiters, and fragile freight from shifting outward due to centrifugal forces. Your model won't care about anything except smooth rail joints, gauge around the curves, level rails across any given point, and gauge loading between nearby objects, tracks, and overhead clearances.

You do not need roadbed. Try DAP Alex Plus with Silicone that dries clear. It remains rubbery and is easy to slice through if you decide you don't like the line and want to adjust it later. Being rubbery, it will be very quiet which is what you want when the train is out of sight/inside a mountain.

Finally, about making it bullet proof: File each end of rail with a small needle file to place a slight bevel/champher on the top surface and also on the inside flange surface. This is easy to overlook in one's haste to lay track when it is going well, but especially on curves, and most especially in hidden tracks, those rail ends at each joint, including at turnouts, including the turnouts' rail tips themselves, should be dressed slightly (only slightly) with a needle file to ensure the flanges safely glide across the joints.

One last point...do spend a few days after all the track is laid testing all your locomotives and longer car strings going in both directions and at varying speeds. Passenger trains should be able to fly through your trackage at scale speeds exceeding 80 mph without even a single derailment. Especially in the helix, you won't want to be getting under there even once a month to have to retrieve six or eight passenger cars and a locomotive.

 

[Graham70]

Thanks for all the advice guys.