Wooden Tunnel Portal Design Questions

[NScaler]

I am helping my step-son research a scratch-build of a tunnel portal and retaining walls for his diorama. We have been looking at numerous photos and web sites featuring wooden tunnel portals. I have a lot of bass wood, but I am not sure how all the boards are actually laid out. I don't know where one is local to me to go look at. If I did I would love to do just that.

Does anyone have any really detailed photos or drawings showing how these go together? I realize these things are not standardized. But a lot of the ways I have seen people building these does not seem prototypical, and they are just being built the easy way for modeling purposes.

I have no idea the sizes of the lumber, or how the pieces are arranged to create the structure. I need a blowup drawing really. I know I am just being a bit anal, but I would like for this to be a learning experience for not only the model building, but a bit of engineering. This project is just a stepping stone to greater projects for him such as a 53' Trestle Bridge that will be started next.

Any info you can give me will be much appreciated. I am modeling this up in 3D, and I will be posting the drawing for all to see to be able to create an exact replica of our work.

Thanks!

 

[jdetray]

Hi Kevin -

This thread has a nice diagram and some good photos:
http://www.railroad-line.com/forum/topic.asp?TOPIC_ID=25081

And here is someone's build thread for a wood portal:
http://www.thewhistlepost.com/forums/ho-scale/10858-wood-tunnel-portal.html

And another:
http://www.railroad-line.com/discussion/topic.asp?ARCHIVE=true&TOPIC_ID=8863

Maybe the above will help.

- Jeff

 

[NScaler]

Thanks for the links. I had found the first one, but that second one really helps. So the boards under the bracing are actually stacked beams? I really like that aluminum foil trick. I may see if we can cast a tunnel using foil.

Thanks again!