building a small bridge

[NHbotanut]

I have a job coming up that I have to cross a small stream. I need to build a bridge so I can get across it and do the work.

The stream is 6' wide. I am planning on digging into both banks, dropping in some concrete blocks and then using 3 railroad ties ( 8 feet long ) as my beams. I plan to put 2 x 10 planks across the ties and nail everything down. Total width of the planks will be 60". My tire width is 47"

I'm guessing my tractor weighs about 3,200-3,300 pounds, taking into account the backhoe, loaded tires and 60" 4in1 bucket. The bridge will only be 6-12 inches above the water. I will build a low ramp to approach the bridge.

I will post some pics when I get back out there tomorrow.

 

[Bigfoot62]

Couple of things to consider,
First, if you're planning on using "used" crossties, I would advise against it. If the railroad doesn't want them anymore, there's probably a good reason. They will break at the spike holes. (you might get somebody that you don't like to test it first)
I don't know how much or how fast that stream rises, but down here, you would probably need to build a bridge 6-12 FEET above a 6' wide stream, just to keep it from getting washed away in the first thunderstorm.

 

[2458n]

I would anchor the three New railroad ties in a four foot deep cement column. six holes total with some rebar up and thru the tie ends. Nail or spike on your cross pieces and let the next big rain run over your bridge. Good chance to use your post hole digger.

 

[Kapnfriday]

I have a B7610 too, do you really think it weighs that 3200 - 3300 lbs? I think my manual says just the tractor weighs somewhere around 1500lbs. Add a FEL - what's that 500lbs? I have no idea how much your backhoe weighs. Filled tires probably adds 400lbs? Yeah, I guess you're getting close to 3000.

How deep is the creek? If one of the RR ties snaps how far do you have to fall? I would make sure you set the RR ties with the wider section vertical.

I'm working on a bridge over a small creek with fairly steep banks. My span is about 18'. I've got 5 telephone poles laid across the span and plan to deck the bridge with full dimension 2x6 white oak planks. I still worry that this won't be enough to support the tractor.

 

[bcp]

Dump some rock in it and drive across.

Bruce

 

[Kapnfriday]

Here's a picture of my in-progress bridge after 5" of rain. Creek is probably 3.5' to 4' deep. It's normally about 3 to 4 inches deep.

 

[Tractor Seabee]

I built a bridge 16' long and 9' wide using 3 16' ties for the stringers. They set on a 10' tie in each bank which has 3-4' of 1 1/4 minus rock in trenches 2' wide and 12' long. I had a lot of muck on one side which that overcome as I was able to get down to firm subgrade.

I think you should consider setting back from the banks more as creeks have a way of eroding banks and changing course a little . My set backs are 4' each side.

I take my 1 ton dually truck with 2 yds of aggregate over it and never a creak or movement. My deck is rough cut full 2" clear fir planks. Had to have them milled as lumber yards do not stock rough lumber anymore here.

Ron

 

[bigtiller]

I have a job coming up that I have to cross a small stream. I need to build a bridge so I can get across it and do the work.

The stream is 6' wide. I am planning on digging into both banks, dropping in some concrete blocks and then using 3 railroad ties ( 8 feet long ) as my beams. I plan to put 2 x 10 planks across the ties and nail everything down. Total width of the planks will be 60". My tire width is 47"

I'm guessing my tractor weighs about 3,200-3,300 pounds, taking into account the backhoe, loaded tires and 60" 4in1 bucket. The bridge will only be 6-12 inches above the water. I will build a low ramp to approach the bridge.

I will post some pics when I get back out there tomorrow.

What kind of concrete blocks are you talking about? What are your plans for keeping the bank from washing away where you were digging and dropping the blocks?

 

[NHbotanut]

Thanks for the replies. To give you a little more information, I only need the bridge to do some work this weekend. The stream is an overflow from a fire pond. It is maybe 2-3 feet deep.
For safety reasons, I could bulk up on the RR Ties and use five of them. 2 per tire and 1 in the middle. For this reason, I am not worried about making it a long term bridge. Just have to get across to use the backhoe and post hole digger.
I plan on building the bridge on Saturday, and doing the work on Sunday.

 

[square1]

Thinking out loud within earshot of a friend while facing a similar situation, he suddenly said "Why don't you back the trailer into the creek, drive across it, and when your done pull it back out?". Added a couple temporary dirt ramps, it worked like a charm, TMMV.

 

[dave1949]

Dump some rock in it and drive across.

Bruce

Ditto this. You could make a permanent maintenance-free crossing that way. Since it is an overflow and not a real stream, you could dig out your approach and exit ramps, deepen the bed a bit, and line everything with rocks. In NH you must have all the rocks you could need--free.

 

[EddieWalker]

I hate everything there is about railroad ties. They never last very long and they are of very poor quality for strength. If you have access to them and are dead set on using them, they lay them in the creek and drive over them. Since this is something temporary and a one time use, I wouldn't go to any trouble building a bridge of poor quality. The rock idea is the best one, but putting just about anything in the creek, from those posts, to cut up logs will work also. I like the trailer idea too!!!!

Eddie

 

[NHbotanut]

Can't get the trailer anywhere near the stream. Too far in the woods.
Regarding the stones, they don't want a permanent bridge. They already have a foot bridge. I need to drill 8 holes for posts, and push back some brush and logs for a clearing they want to enlarge.
I am hoping to only make 3-4 trips across. I will not be making trips back & forth bring any material.

An idea I just had is to drop my trailer loading ramps in the stream and then lay the RR Ties on top,,,,,????? For what ever amout they sink in, I can fish them out with the backhoe.

 

[crackerjack222]

A few years ago, I built a cross tie bridge across a ditch. I put two cross ties on each side of the ditch, parallel to the ditch and then decked it with cross ties. It worked fine with any thing I drove across it including my 12,000 lb tractor. Then, during some wet weather, a 30,000 lb fertilizer truck caused one side to sink about a foot. So I replaced it with a 36" tin horn and it has been good to go since.

 

[NHbotanut]

Well, don't have to worry about RR Ties. Customer can't get them.
Looking at going with 8 x 8 x 10 hemlock beam and run my trailer ramps under them.
What do you think?

 

[NHbotanut]

Just an update. Got the bridge finished and it worked out great. I ended up going to a local sawmill and picked up a Hemlock 6x8x10 and a 8x8x10 beam. For planks, we got Hemlock 2x12x12 and cut them in half. When I laid the beams across the stream, I had just about 2 feet of beam on both sides on solid ground.

Since it didn't happen unless accompanied by pics, here they are: The 1st is where I will be crossing,..laying the beams....nailing the planks.....& the finished product

 

[forgeblast]

Nice!! I bet it was fun moving those hemlock beams around

 

[NHbotanut]

Actually, it wasn't as bad as I thought it would be. I was able to bring them down on the clamp on forks. I chained one end and crept over the stream to place the beam down.

 

[zing]

You made a nice little footbridge in what looks like a nice area for walking in the woods. Did the customer ask you to leave the bridge behind when you left? All it needs is a couple of handrails and they would be golden.

 

[NHbotanut]

They already had a footbridge. This was built lust to do some landscaping on the other side. They paid for the materials, so it has been left in place. I may have to go back later this summer for some other projects they may want done.