Bridge beams?

[9shooter]

I've been working to get a bridge over a small stream. The span is about 28' so I figure I'll need some beams in the neighborhood of 36-40'.  I looked into the idea of putting in some piers in the stream bed so I could use shorter poles but after hearing about the drain commissioner and the DEQ and the fines I am looking to do a clear span instead. What my question is; would bitternut hickory poles work and are they rot resistant enough if I install them on proper footings? There are plenty of them in the woods and they are straight and long enough.

[Mad Professor]

I don't think hickory species are rot resistant.

[thecfarm]

What are you going to be driving over the bridge with? Just a car,cement truck in the future,big tractor?

[Jim_Rogers]

Yes it is important to understand the intended load first before you decide on types of wood and sizes......

[routestep]

Over in the foresrty and logging section of this website July 5 2008 a fellow had the same question on building a bridge. Lots of solutions given. Take a look.

[tyb525]

I think we concluded that I-beams or treated ties/lumber last the longest.

[pineywoods]

Here was my solution...

https://forestryforum.com/board/index.php/topic,27763.msg397484.html#msg397484

Center span is about 18 ft. It's used most every weekend.

[scgargoyle]

For a foot bridge (I think up to 2000 lbs) check out pacifi.ca. They have free span designs up to 50'. I built a 15' one over our garden pond. Interesting project, and very graceful, attractive bridges.

[moonhill]

I like Don P's solution at the end of pineywood's link.  King or queen post trusses.  28' is quite a distance to carry any load, dead load alone would be bouncy.   The next question would be how to connect the king or queens?      Tim