Height Clearance

[Pher]

Hello all,

I went to my first NMRA meeting last night for the area, and they are doing a bridge building contest at the next show in march. I have an Idea for a Bridge I want to use/make for my layout when it comes time to build it. However what is the Height Clearance you guys use for Tunnels and pass unders. I looked at the NMRA page and it says 3 Inches, but on another page on the NMRA it says 3" isn't enough. so what do you say I should use?

Chris

[BoxcabE50]

Chris-

As you've mentioned that this will be for your layout, one thing that can be done, is to decide what would be the tallest car you'll have for the era modeled. For example- If modern times, that would likely be double stacks, auto racks, or an odd sized specialty load. Then add what you feel would give a comfortable clearance to that height.

:D

Boxcab E50

[Doug F]

The clearance needed on your bridge will depend on the era that you are modeling.

If you are modeling the transition era then the 3" NMRA clearance is more than enough.

If you are modeling the modern era the 3" clearance is not large enough to clear modern double stacks, triple deck auto carriers, etc. I will have to leave it up to the modern modelers to tell you the clearance that you need. The Walthers double track truss bridge (948-899) will not clear double stacks.

Doug

[slimjim]

3 1/4" may or may not get it done. I would go with 3 1/2".

[Pher]

Yes I do want todo modern/semi old. I can't make up my mind, tho I can make some exceptions. so I will do what I can. thanks for the Info, I will probly make the openings on the bridge about 3.5" just for safety.

Chris