ATV/Riding Mower bridge using materials laying around...request thoughts

[ovrszd]

how many bridges do you have?View attachment 783195View attachment 783196View attachment 783197

If you are asking me that question, I have two.

 

[cpy911]

I like doorman63's suggestion of utility poles. They'll support a lot of weight, and will likely outlast you before they rot, unlike the fir.
As far as center support (should you go that route), how big is the stream at its highest? A strong current or high level is going to put a lot of stress on those supports unless they're well anchored.

For the center of the stream and possible supports, the water will not go much higher than the picture. I picked this spot because the water will rarely even get close to the bridge itself and usually will be halfway or less up to the bridge itself.

 

[Doorman63]

If you are asking me that question, I have two.


View attachment 783214



View attachment 783215

My comment is when people say it’s too bouncy

 

[cpy911]

Any thoughts on painting roof coating (asphalt based) on the fir beams to help them last longer?

 

[bcp]

An inverted king post bridge design will add strength, even if the post is 1 foot. More is better if you can keep it out of the water.

How Inverted King Post Trusses Allow for Large, Elegant Open Spaces

Inverted king post trusses are made of steel bars and cables, these last used to reduce bending and deformation and truss’ height

www.archdaily.com

Bruce

 

[Doorman63]

An inverted king post bridge design will add strength, even if the post is 1 foot. More is better if you can keep it out of the water.

View attachment 783249

How Inverted King Post Trusses Allow for Large, Elegant Open Spaces

Inverted king post trusses are made of steel bars and cables, these last used to reduce bending and deformation and truss’ height

www.archdaily.com

Bruce

I’ve considered doing something similar with 1/4 or 3/8 aircraft cable and 2 short pieces of tube steel if the bounce is too much. I have most of the materials on hand.
I know you can buy everything at Rural King/Farm and Fleet/etc

 

[jjeff]

Used an old tank as a culvert over a seasonal creek bridging a ravine on my up north property. I found tank in the woods cut both ends off it left a few inches around the ends of plates to add rigidity I think I posted a picture of it when I towed it up north, anyways worked great driving ATVs snowmobiles and a sxs over until my stubborn confidence took over and I partially crushed in the side when I attempted to drive my 10k lb skid steer over it.

 

[bcp]

A good design feature is to have weak bridges narrow enough to keep heavy vehicles off them.

Bruce

 

[ovrszd]

A good design feature is to have weak bridges narrow enough to keep heavy vehicles off them.

Bruce

Yep. That was my thoughts with my "ATV" bridge. A Jeep or tractor won't fit on it. Same with Doorman's design.

 

[Doorman63]

Yep. That was my thoughts with my "ATV" bridge. A Jeep or tractor won't fit on it. Same with Doorman's design.

My next one is gonna be for vehicles…..I have all of the steel tubes/angle iron. Most of the 3x4 decking. May not run the Kubota over it…….