Quick Bridge
- Thread starter deepNdirt
- Start date
- Views: 4054
Pete Judd
Veteran Member
- Joined
- Aug 18, 2010
- Messages
- 1,013
- Location
- The Thin Gravy Ranch in The wet PNW
- Tractor
- Yanmar 186d, JD 314
If you have a local truck wrecking yard (semi) you might be able to get some frame rails out of a semi tractor or a wrecked trailer for the price of the metal by the pound. These rails are hardend steel, and can take one heck of a load. If it's a trailer frame, might have usable decking as well.
dmccarty
Super Star Member
There is an Army/Navy Surplus store a hour or so west of us.
A REAL Army/Navy Surplus store. :thumbsup:
I have never stopped, which is likely a very good thing, but we have driven by a couple of times. I would have stopped but we were always on a schedule.
This guy has a quite a few things I would like to look at for our place. One of his items is a quite a few bridge sections. I cannot tell if they are the bridge sections that are laid down by an engineering tank to cross smaller obstacles or part of a larger system.
We have a wet area that it would be nice to span at some point. One or two sections would work nicely.
Depending on price.
I figure if they can handle a M1 they can handle my truck and tractor. :laughing:
Maybe I will drive out there over XMAS vacation....
Later,
Dan
A REAL Army/Navy Surplus store. :thumbsup:
I have never stopped, which is likely a very good thing, but we have driven by a couple of times. I would have stopped but we were always on a schedule.
This guy has a quite a few things I would like to look at for our place. One of his items is a quite a few bridge sections. I cannot tell if they are the bridge sections that are laid down by an engineering tank to cross smaller obstacles or part of a larger system.
We have a wet area that it would be nice to span at some point. One or two sections would work nicely.
Depending on price.
I figure if they can handle a M1 they can handle my truck and tractor. :laughing:
Maybe I will drive out there over XMAS vacation....
Later,
Dan
Tractor Seabee
Elite Member
- Joined
- Oct 5, 2011
- Messages
- 3,896
- Tractor
- Kubota BX25
That 4" channel is pretty light for the span. Not an engineer but have worked construction all my life and that is based on what I have seen. Here is food for thought:
I built a bridge this summer over my creek. 16' long 9' wide. Two 8' RR ties for the sills on each side (they are 8' from center creek each way). Dug out each side 2' wide, 4' deep, 10' long with BH. Filled with crushed gravel so sills were one RR tie deep from surface. Set 3 16' RR ties across and anchored with 3/4" form stakes to the sills. Decked with full 2" rough cut fir. It will still be there when I die. I ran my pickup with a yard of gravel on it with no deflection. Total cost of material about $600. I was supposed to get a hydraulic permit, have it approved by fisheries, the indians, and who knows who else as it is classified as a migratory fish stream. I have never seen even a minnow in it. Did it any way as it would have taken at least 3 mo and had the possibility to be denied. Longer it sets there the older it looks to argue grandfathering with the fish police.
Ron
I built a bridge this summer over my creek. 16' long 9' wide. Two 8' RR ties for the sills on each side (they are 8' from center creek each way). Dug out each side 2' wide, 4' deep, 10' long with BH. Filled with crushed gravel so sills were one RR tie deep from surface. Set 3 16' RR ties across and anchored with 3/4" form stakes to the sills. Decked with full 2" rough cut fir. It will still be there when I die. I ran my pickup with a yard of gravel on it with no deflection. Total cost of material about $600. I was supposed to get a hydraulic permit, have it approved by fisheries, the indians, and who knows who else as it is classified as a migratory fish stream. I have never seen even a minnow in it. Did it any way as it would have taken at least 3 mo and had the possibility to be denied. Longer it sets there the older it looks to argue grandfathering with the fish police.
Ron
LD1
Epic Contributor
There are two different sizes of 4" channel iron. 1 has 3/16 thick web and 1.5" wide flanges, the other is 5/16 web and 1.75" flanges.
If it is the lighter of the two, with a 13' span, you are only looking @ 650lbs MAX per beam, point load in the middle.
If it is the heavier channel, you could up that to about 800lb per beam.
Neither of which I would want to drive a 3300lb tractor across a 13' span.
Since you want 3300lb max load, that is going to be 1650lb per beam. For a margin of safety, if you use something that can handle ALL the weight at the mid-point, it should be fine since your tractor will distribute the load over the 2 axles.
But for 13' and 3300lbs, even 5" channel Iron falls short. But anything 6" and up is good.
If it is the lighter of the two, with a 13' span, you are only looking @ 650lbs MAX per beam, point load in the middle.
If it is the heavier channel, you could up that to about 800lb per beam.
Neither of which I would want to drive a 3300lb tractor across a 13' span.
Since you want 3300lb max load, that is going to be 1650lb per beam. For a margin of safety, if you use something that can handle ALL the weight at the mid-point, it should be fine since your tractor will distribute the load over the 2 axles.
But for 13' and 3300lbs, even 5" channel Iron falls short. But anything 6" and up is good.
slowzuki
Elite Member
- Joined
- Sep 19, 2003
- Messages
- 4,100
- Location
- New Brunswick, Canada
- Tractor
- Kubota L5030 HSTC, MF 5455, Kubota M120, Allis Chalmers 7010
And don't forget the weight of the deck material, wet. My 2.5" thick deck on my 27 ft flat deck weighs almost as much as the frame when it is wet.
