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Discussion Starter #1
I am designing my first layout and need some help. I would like to create a track like a figure 8 but I want one loop to pass under the other. How much clearance should I allow and what maximum grade should I use. I did a search and didn't see any answer, but I am not sure what question to ask.
 

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Depends on what scale you are running. 1/20.3 is much taller than 1/32, therefore 1/20.3 needs a lot more elevation than the 1/32. And then there is the LGB FRR trains which are much smaller (read low clearance) than most other large scale trains. The steeper the grade the less cars that can be pulled!!
 

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Brian, one basic rule of gauge one trains is the bigger the better. Try to use the largest radius curves you can fit in and leave the highest clearance. The only place you want to go small is the grades, 1% is "better" than 1 1/2%. Keep those two rules in mind when planning.

An old "rule of thumb" was to have 12 inches from top of rail to top of rail for clearance. This is not good enough for 7/8 inch trains. Would suggest you find the height of the tallest loco and add 1/2 to 1 inch above that. Nowhere near a perfect answer, but it will work for now.
 

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If you give the dimensions of the area you are working with, it will be easier to answer.

In general, when a new person asks this question, the curves are too tight already, and a better method is to make it flat, with a 90 degree crossing in the middle.

Greg
 

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Discussion Starter #5
My layout will be an L shape. 1 leg will be 10 ft x 6 ft, the other will be 14ft by 6 ft. I am using Bachmann track so the radius will be 4 ft. I dont believe I have enough space to make an over/under setup.
 

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Yes, indeed you do not have enough room without really limiting grades, and even if you get over the grades, the increase in geartrain wear will be excessive.

6 foot is very limiting, since you will probably wind up with 5 foot diameter curves (curve is measured from centerline of track, and there is overhang past the outer rail).

No change to push that 6' dimension?

Greg
 

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Discussion Starter #7
Yes, indeed you do not have enough room without really limiting grades, and even if you get over the grades, the increase in geartrain wear will be excessive.

6 foot is very limiting, since you will probably wind up with 5 foot diameter curves (curve is measured from centerline of track, and there is overhang past the outer rail).

No change to push that 6' dimension?

Greg
I might have to rethink my layout and see if I can expand it.
 

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Brian,

I agree with most of what has been advised except vertical clearance. Ironton said tallest loco plus 1/2 to 1 inch top of rail to top of rail. ABSOLUTELY NOT! Yes measure your tallest locomotive, that is correct. The clearance needs to be top of rail to BOTTOM OF OVERHEAD STRUCTURE. His rule will provide zero clearance if you go top of rail to top of rail and add 1/2" clearance. Standard code 332 rail with standard plastic ties is 1/2" thick already removing your 1/2 inch clearance.

Bob C.
 

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I agree with Bob. I actually meant actual clearance with that comment.
 
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