I need to construct a couple of timber bridges for some stream crossings. I have researched the various designs and I have settled on a simple 8' wide bridge. the bridge is actually two 4' wide sections make of 2x6 material bolted through every 4' along the length. The bolt needs to be over 4' long, obviously, pointed on one end, threaded on the pointed end for a ways, and have a regualr bolt head on the other. The bolt is driven through pre-drilled holes in the decking, square metal plates are used as fender washers, a lock washer and nut are placed on the pointed end and the point is cut off after tightening.
Does anyone know where I can find bolts like these? I think I am looking for zinc coated bolts.
Has anyone constructed on of these bridges?
I haven't built a bridge like that but I have built dragline mats and used bolts to hold 8x8, and bigger, timbers together. We used solid round rod cut to a length that would expose both ends when in place. We used a jig to drill the timbers so that the holes would be as close as possible in line. We didn't have a 4' drill bit and drilled each individually.
The rod, about 1" in diameter as I remember, was threaded on each end and driven through the timbers. The driven end had a couple of nuts put on it to protect the threads A 6" piece of plate with a hole cut in it was used for a washer on each end. Nuts were drawn tight on each end with the use of a cheater bar and then spot welded to the rod.
One of these rods was installed every 3 feet along the length of the mat.
It sounds like you want to do something similar. We just made our own bolts. I wish I could be more specific but it's been 44 years since I made one. :D
Your on the money, Tom. Do you recall if the rod was zinc coated?
44 years ago I think I was just discovering erector sets :D
Just buy threaded rod and make your own bolts cut to length.
No, they weren't zinc coated, just plain steel. I don't think we were worried about the longivity of the bolt because mats don't live too long anyway. You could probably coat them with roofing tar and they would outlast you. ;D Paint might work too.
Kevin, That's a good idea. that way you don't have to make the threads. They might be a little harder to drive into misaligned holes though.
Use a bigger hammer
OWW. mite try the local power co. some times they bolt two poles together to make deadmen. they are zink plated, Just a thought. Duh---Duane
on the last bridge that I built I coated all the hardwhare with
a zink paint that I got from the steel co. when they made the fish plates, It worked real good but I cant remeber who makes it. ???
On the bolts, see if a local spring shop can fabricate them for you, they make there own U-bolts at the shop near me. Another note, the info I have on bridges like you are making suggests two things. Alternate the 2x material at two different heights for traction and think about some kind of low guadrail on the sides, even just a few inches. Maybe the last two 2x's can be 2x12.
Just a suggestion, when making the bolts from threaded rod, put a die on the rod, cut the angles, then spin the die off. That way you have good threads to start the bolt on once you drive it through the wood.
I built a few of those for a logging crew we where working with in Témiscaminge , helmlock 3 x 8 x14 feet long .I used one inch threaded rods , welded the nut and washer on one end , pointed the other and drove them throught the timbers just like Harold said a bigger hammmer , They where not quite 4 feet wide (the lenght of the threaded rod ) If my memory serve me wright they where bolted every 3 feet...The guys would haul these around with the skidders once they where on sight from one stream to another ....
When I need to cross a stream it is usally just to skid trees. Since I use a D5B Cat I can get just use tree tops that I take out when thru using the crossing. I use a big chain fastened to a tree on each side of the stream and then put the tree tops on it. When I'm thru using the crossing I hook to the chain on one side or the other and just roll the tops out of the stream. This will work with Crawer skidders but with rubber tire skidders will want to kick the tree tops out of place if you are not careful. This practice is used on major streams and you have got to watch the weather in case of a flood. On the very small streams in the woods where no harm can be had later I just put treetops in the stream and don't take them out. These type of crossings let the normal water flow thru the crossings.
If you fellas tried any of the things you are speaking about out here in Oregon, the boys and girls of the Forestry Departments would find the nearest Oak and have you as decorations. ;D Especially if the stream was fish bearing. :'(
To cross any sort of permanent stream and some intermitten streams you need to get a permit, then an engineer structural and hydrology, water resource people, fish and game (state and federal), watershed officials, endangered species officials (whether they exist or not), etc. By that time the trees had died of old age, bettle infestations, fire or a tree hugger living in the DanG thing for toooo loooonnnng, the governments local state or national revolking you cutting permit, the price of logs down so far you would have to refinace everything you own, plust the gold in you teeth (if you could have affored it before the bridge building porposal.
Similar here in Michigan. One had better ask and get a permit if needed from the State DEQ for any stream crossing. Plans need to be reviewed and approved. Also part of the upcoming Forest Certifications by 3rd parties and BMP's.
No way can we leave slash or debri in a water course or run skidders across them without a prior approved crossing method with permit.
QuoteNo way can we leave slash or debri in a water course or run skidders across them without a prior approved crossing method with permit.
Ron,
How often do the beavers have to apply for a permit.:D
I understand the thinking on protecting the streambed, but so often the process gets so involved, that Mother Nature does it worse than the logger would. Wildfires leave slopes denuded, causing erosion and siltation, trees die and drop their tops into the streams or a windstorm fells a bunch of trees into the stream, rains cause streambank erosion, etc.
Minnesota_boy, I worked in the woods for a while back before BMP's and many of the regulations that are in effect now. Some of the things I saw done were a crying shame. Crossing small streams with no thought until the skidders were wallowing in mud past the belly pans and turning the flow of clear water to just a mass of moving ooz. Changing oil by just pushing a hole with the blade , draining it in the hole, throwing in the filtiewr and back blading it over. Most good stewards never did these things but many did. Hundreds and thousands of times.
The way I look at it, these regulations have to be there. They are a good thing.
Jeff,
I agree that the regulations are a good thing, but also look farther into the future and in a blink of an eye (geologically speaking) they will be gone, done in by Mother Nature as she decides that that area needs a new Grand Canyon or Mt. Hood. :o
Jeff, I agree with you too, but it is gettting to the point in some areas of government regulations it is more a taking than anything else, with many regulations. It is like fee increases for a licence to fish or hunt as well as get a licence to drive or a licence on the vehicle to drive the vehicle; taxaction without representation. The system seems to be running away with itself, like the ol' song says; "90 miles an hour down a deadend street". :'(
Minnesota_boy,
Society accepts 'beavers" as part of and belonging in the ecosystem. High impact logging across streams, drainages, and wetlands isn't accepted.
"Beavers' are managed directly by humans when they become too destructive to an ecosystem and loggers by laws, rules, regulations permits, BMP's, fines, etc.
Humans have a brain for proper management and beavers don't. ;)
I am not required to build these bridges but I want to. Here are the reasons:
I wish to keep my streams clear of silt to the extent possible.
A solid bridge prevents soil from dropping off the crawler cleats and trailer into the stream.
A little gas or oil in water goes a long way. The solid bridge will capture and absorb any small leak that may occur.
I think the bridges will add to the esthetics of the woods.
I plan on using a forwarding tailer pulled behind the crawler to increase my productivity and ease the impact on the forest roads. The trailer rolls accross a solid bridge better than it fords streams, with a lot less damage to the stream bank.
I like to build things.
Indiana laws say that no permit is needed to cross streams by loggers or farmers. I however don't like to cross a stream without a bridge or pipe or maybe tree tops to keep the skidder above the water level. They do have a law that anything put into a stream has to be removed when you are done at the site. In flood areas the tree tops have to be moved to high land or secured so they don't float away. They will also allow you to burn the tree tops on site.
Don't forget to check the Federal Clean Water Act should EPA be involved where there is no state law or BMP's regarding water quality. ;)
In Massachusetts the BMP's don't require a bridge in some instances but it really is the best way to go for protecting the streams. I attended a BMP seminar and there was a presentation on skidder bridges that was really good.
http://www.umassextension.org/online_services/vl_nrec/skidder_bridge.pdf
this details the portable bridge construction. Hope you find this useful!! FYI you need adobe acrobat reader, it is in .pdf format.
Craig
Craig,
Thanks for the link. I had not seen that one before. This is the first one I have seen that recommends the use of softwood for the interior. Too bad all I have is hardwood!