Building a footbridge

[MikeD74T]

Motorseven, If you're really interested in a suspension bridge send me a PM. Our snowmobile club built a 100' span suspension bridge. we limit traffic to 3 sleds spaced out but would probably hold much more. It's not as tough as it looks once you understand a few simple design criteria. I wouldn't recommend it for riding a horse but we have seen moose crossing ours and persons walking horses. The next club up the trail built a 120' span after ours. We used 1-1/4" cable for the main span. 3/8 for vertical cables. 4x6 PT stringers. & 3x6 rough hemlock planking. Used 6" well casing for the towers & poured concrete anchors.

 

[radair]

</font><font color="blue" class="small">( Just out of curiosity, why did you pre-cast the abutments in your garage?)</font>

It was much easier to precast them in the garage than to haul all the tools & materials out to the site. It was no problem to level and compact the ground for them. It also enabled us to:
1. get them done ahead of time,
2. be productive on rainy weekends prior to the erection day,
3. leave the existing bridge in place until the last minute,
4. make minor final adjustments in alignment and position.

 

[MikeD74T]

TNhobbyfarmer, I stumbled across this wooden bridge plan & thought you'd like it. Wouldn't be as cheap to build as steel & planks but it sure would be a handsome bridge. There seems to be enough detail for someone with your woodworking experience. Oddly enough it comes from your state DOT website.
http://www.tdot.state.tn.us/bridges/king_post_truss.pdf

 

[tom30519]

Radair,

Just one word: wow!

I have to replace a rotting wood bridge that crosses a creek that divides two fields. I've been putting this off for several years, but a moose fell through it last fall (no damage to the moose!) so now I have to do something!

I'd been pondering how I might use steel bar joists, how to anchor them, etc. Then I joined TBN, browsed around a bit and there was your project, beautifully documented with clear photos! You've done a fine job! I hope mine turns out nearly as well.

Thanks for posting the results of all your work!

Tom.