A bridge for my tractor - will it support it?

[brianwelch]

I recall when a professor described a major faux-pas in a high rise design. We were told the designer neglected to consider the weight of the water in the roof-top swimming pool...May be urban legend, but I never forgot it (1976)

[GHR]

There are a lot of wood bridges around.

I think a proper design would provide support where the tires run on the bridge. And a proper design would consider the point loads rather than a distributed load. I think a proper design would use 4x stock rather than 2x stock.

But ...

I don't think it matters. If the bridge fails, you build another.

[meackerman]

any chance that someone have access to the bridge and try to drive something heavier than your kubota over it?

[daddo]

Build it to support twice your needed weight and your good. This will also allow for aging, bouncing, and the extra weight when it rains and so on.

I'd at least use double 2x10's on the edges and the center.

[comfun1]

meackerman said:

---

any chance that someone have access to the bridge and try to drive something heavier than your kubota over it?

---

Better not be, it's in my back yard. I have six acres with a pond and the bridge is going over a small stream that run into it.

[meackerman]

its one of those things...attractive nuisance IIRC. Someone sees the bridge and decides they're driving their big truck (or whatever) over it, next thing they know their truck is in the stream and they're hauling you into court.

Not saying don't build it, but build it with that in mind. A gate or a fence or something (if you don't have one already) to keep them out.

[Bluepine]

I would be cruising Craigslist for a couple I-beams to span that.
Up here $100-$200 for a pair of 12 footers 8-10 inches high.
You don't want to find the breaking point.

[JohnRoscoe]

Would a culvert work better? Might be cheaper, less obtrusive, and longer lasting with less maintenance.

[Lynden]

They built a bridge on Hometime using Pin Foundations and LiteSteel beams. If you can find the episodes to watch, they might give you some ideas.

http://www.pinfoundations.com

http://sweets.construction.com/swts_cont...389421.pdf

[fredhargis]

I went with a culvert some years back at the last house. As it turns out the water in the stream (may be an Ohio thing) belongs to the county, or so I was told. That being the case the county engineer had to spec the culvert as well as the surrounding topography (had to put in a swale along with the culvert. My engineer is a very nice guy with some common sense, something missing in most elected Ohio positions (yep, the engineer is elected) so it worked out very well. The fellow that bought the place wanted another bridge and talked the power company into giving him 2 poles they had replaced...he put them down and decked it with pressured treated 2x stock (this was about a 15' span) and drove his Kubota BX back and forth across it.