Trailer as a bridge

[Todd727]

If you are diligent, you can find semi trailers between $2-3K. You will end up with some stuff that you can sell, such as wheels and tires, axles and scrap steel, so that can offset some of the costs. These trailers are typically rated for 40K. Mine are only used for foot and bicycle traffic.

For your shorter bridge, you can cut that trailer to the correct length. I placed a 48' trailer (black bridge) and an expandable sliding trailer that is stretched out to about 65' (red bridge). I used bar joists for railing. They work fantastically.

The expandable bridge was a lot more work to deck, as I had to raise the profile of the deck in that section to make the deck level.

For the one bridge, I was able to leave the undercarriage on until I had it almost in place. Then that was removed. The other bridge I had to remove everything, turn it on it's side and drag it through the forest. That was quite a bit of work.

I dug a hole for the rear under-ride bumper to sit in, which also serves to secure the bridge.

For your 16' bridge, I would also consider a 25' (not counting any beaver tail) gooseneck trailer. Cut off the beaver tail, if it has one, remove axles and cut off gooseneck.


Pictures may be scrambled, but you get the idea.

 

[51allis]

Is this a dumb idea? Theres a creek that runs through my place and its at the bottom of a big hill. Usually not much flow, but when there is heavy rain, it gets to flowing. Its about a 3-4' drop and maybe 10' wide from trail to trail that leads to it. In the last couple years ive owned it, i tried to make a culvert crossing. First time i put in a 12" culvert, concrete bags on the ends and filled with dirt. That was destroyed in the spring rains. Next attempt i put in two 24" culverts with concrete bags at end and filled with dirt. Washed out again after getting some heavy rains in spring. I dont know if its getting washed away because of all the force on the upcreek side, or if water is coming down enough to wash out the fill, and then the sides collapse. Either way, it isnt working. I was thinking of getting a 16' or so flatbed and spanning it, then remove wheels. My thinking is even in higher water flow, theres not a wall so to speak that the water is pushing against and it should stay put. Mostly it would be for crossing in my SxS so i dont think the weight would be in issue. What about a tractor thats probably 5-6K lbs? The trailer would prob be supported by 3' or so on each end by the earth and/or concrete. Anyone ever done this?

Do you know of anyone who has an old mobile home? such as the ones from the 70's with the 2" walls that would be falling down by now? the frame of that mobile home can be used too as a bridge. That is what I plan to use, we got a mobile home for free, tore down the walls and roof, recycled the material, THEN we salvaged the 2" x 6" floor joists, these were old growth timber where the rings are closer together etc. strong lumber, gonna use that to build a nice shed. At 70 ft, the frame rails can be doubled for each "tire" side and it would be nice and strong. Just an idea for you.

 

[Dr_Zinj]

Semi-trailer twin I-beams make nice small bridges, and generally should last 20 to 50 years, depending on how well you maintain them (rust proofing, especially the support ends, and deck protection.) For comparison, wooden bridges generally only last about 10 years before they fail, unless they have covers like the covered bridges in New England.)

 

[panamaguy]

Is this a dumb idea? Theres a creek that runs through my place and its at the bottom of a big hill. Usually not much flow, but when there is heavy rain, it gets to flowing. Its about a 3-4' drop and maybe 10' wide from trail to trail that leads to it. In the last couple years ive owned it, i tried to make a culvert crossing. First time i put in a 12" culvert, concrete bags on the ends and filled with dirt. That was destroyed in the spring rains. Next attempt i put in two 24" culverts with concrete bags at end and filled with dirt. Washed out again after getting some heavy rains in spring. I dont know if its getting washed away because of all the force on the upcreek side, or if water is coming down enough to wash out the fill, and then the sides collapse. Either way, it isnt working. I was thinking of getting a 16' or so flatbed and spanning it, then remove wheels. My thinking is even in higher water flow, theres not a wall so to speak that the water is pushing against and it should stay put. Mostly it would be for crossing in my SxS so i dont think the weight would be in issue. What about a tractor thats probably 5-6K lbs? The trailer would prob be supported by 3' or so on each end by the earth and/or concrete. Anyone ever done this?

If it were me i would look for a old hiboy 40 foot flatbed. 8 ft wide and also lots of overlap onto the banks. Knock the running gear of and hire a crane to place it. It onlyxosts twice as much to do it right the first time and the life you save may be your own

 

[Lavender Valley]

I have built bridges out of old rail flat-bed carriages, get them for scrap price, and they are built for large loads.

 

[RiversideFarm]

I’d check the FEMA map (FEMA Flood Map Service Center | Welcome!) it will show how high they predict the water to get on a 100 yr flood. That way you have some idea of what could happen in a big storm. Then I’d go from there, if it looks like it could overtop it I’d anchor it to a concrete foundation hopefully that way you won’t have to look for it after the storm.
Our state highways has many bridges that get overtopped in huge storm events, they just go scrape them off, check for damage then open the road if they’re ok. As long as there’s no BIG trees hitting them they last for years.

 

[KennyG]

Semi-trailer twin I-beams make nice small bridges, and generally should last 20 to 50 years, depending on how well you maintain them (rust proofing, especially the support ends, and deck protection.) For comparison, wooden bridges generally only last about 10 years before they fail, unless they have covers like the covered bridges in New England.)

Built correctly, wooden bridges last pretty well. As noted, mine is 13 years old with no deterioration at all. If built to keep the wood from sitting in water, treated lumber should last 30 years or more.

I have a deck that must be close to 40 years old. The decking rotted out because it was installed wrong (tight with no drainage) but I put new decking on the old structure and it's fine.

 

[dodge man]

In a lot of areas FEMA maps are pretty vague.

If you double the size of a culvert it flows roughly 4 times more water, triple the size of a culvert, p times more water. It’s the pi times radius squared thing at work.

 

[Rockbadchild]

That's how I built my bridge, I paid $700 for a retired B train trailer all aluminum deck... its on the narrow side for trucks, trailers and farms equipment's but it dose the tricks.

bridge construction on a budget

good morning TBN members, Id like to share my bridge construction of last summer perhaps it will give ideas to folks with similar project in the future and getting constructive feed back … there is a small creek splitting my property preventing me to access the back end which constitute of...

www.tractorbynet.com

 

[Rockbadchild]

Do you know of anyone who has an old mobile home? such as the ones from the 70's with the 2" walls that would be falling down by now? the frame of that mobile home can be used too as a bridge. That is what I plan to use, we got a mobile home for free, tore down the walls and roof, recycled the material, THEN we salvaged the 2" x 6" floor joists, these were old growth timber where the rings are closer together etc. strong lumber, gonna use that to build a nice shed. At 70 ft, the frame rails can be doubled for each "tire" side and it would be nice and strong. Just an idea for you.

mmm these mobile home frame are not too solid, enough for a side by side but that's pretty much it plus you still have to put a deck on it.