# Need Help! Building an Elevated & Banked ladder bridge



## R_Armstrong (Jul 23, 2014)

Hey all,
I am working with a young man who is doing his Eagle Scout Project in our Bike Park. We have some low spots that hold water for long periods at a time, and rains have crushed numerous days of riding due to the trail being underwater (long story but the area given to us is not a very desirable plot of land). We are going to build a ladder bridge over this section - which is a 90 degree angle turn, so we'd like to bank the turn as well. Any advice on how to go about making a "blue print" for this project, other than finding a licensed carpenter?

Attached is an example of what we'd like to do, however we'd make the flat portion much wider for younger, inexperienced riders.

Thanks.


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## Flamingtaco (Mar 12, 2012)

That project would never see the light of day in our council, unless it included providing access to disabled persons. Although the requirements of service to others doesn't include the words "in need", most councils require the project be of benefit to all community members, so specialized projects benefitting certain groups of the community are off limits.

Do you have experience building bridges? If not, you will want to consult someone that does. If you don't have someone experienced with load bearing surfaces, it won't last long, will be damaged easily, someone could get hurt...

Luckily, you have a scout running the project. He should be able to either raise the money, or better yet, find an engineer that is willing to donate their time to help design what is needed.

Good luck! sounds like a fun project.


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## aero901 (Apr 11, 2012)

Search for the "On the Edge" trail in the Copper Harbor trail system to see the joinery and post/beam layout for the bridges in that photo. I have seen it in person and it is quite advanced work. I'm hesitant to say too advanced for an eagle scout project, but it would definitly require some expert guidance to get a quality finished product.

I created a couple of models of this style of bridge in 3D CAD a few years ago for a trail project proposal (drawings here). Hopefully they will be helpful to show how everything fits together. The bank angles need to be adjusted to suit your conditions. Faster entry speeds and tighter turn radii require steeper bank angles and vice versa.

Another topic was posted recently about building banked bridges (with lots of construction photos): Curvy Bridge Build

If the riders' entry speeds are low and the turn not too tight, you can probably get away with a bridge as shown in the curvy bridge build post and greatly simplify the construction.


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## cglasford (Sep 26, 2011)

How high is this bridge going to be?


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## R_Armstrong (Jul 23, 2014)

Aero901 - FANTASTIC resource!!! WOW, that 3D CAD is amazing!! The support beam diagram in itself is very helpful! The trail is for beginner mtbrs so the speed they will be entering is considerably low. The turn radius is going to be a 90 degree turn however...

We are definitely going to "hire" a carpenter to oversee the project. It's well out of my scope, and the Eagle Scout.

Can't thank you enough for the resources! This is a great start.


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## R_Armstrong (Jul 23, 2014)

cglasford - It will be 1 to 2 feet off the ground. The trail system is for beginners, so we're going to keep it low, but I also want to design obstacles for riders that become more advanced as well.


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## cglasford (Sep 26, 2011)

cool... being so low you have a lot more options for bracing and building out of the actual bridge


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