Idea for a Bridge deck?

[jcmaurice6]

Any idea of which material to use for building a durable bridge deck?

The stream is about 20 feets wide, and the two crossing beam are made of steel latice 4 inch wide, probally around 5 feet of each other. It will be mainly for my tractor with a trailer full of wood.

 

[Industrial Toys]

5 feet is quite a span. Although the tractor and trailer would place the load not far off the support structure. How about galvanized decking?

 

[PILOON]

Pruche, (Hemlock) makes good decking and is relatively cheap as not wanted for construction.
It also is quite rot resistant and strong,

Having done some renovation work in your area I know that some local lumber mills can supply it in rough cut to order, call around.

In that it is simply for decking you also can buy it in random widths which again will favor U as the sawmill will have minimal wastage.
I'd look to obtain it in 3" thick for longevity ans load bearing.

With 8 ft being a standard lumber length I'd consider decking with that and simply nail a 'railing' on the decking edges which would also act to keep the planking tied together. (maybe in 2 x 4)
I see it as a large like platform simply sitting on your steel main rails with only perhaps a few fasteners here and there simply to keep the deck in position.

Bonne chance!

 

[Industrial Toys]

A friend of mine builds the occasional bridge, some as long as 50 feet but not for vehicle traffic. He usually gets rough cut 2" (I believe) cedar.

 

[Mendonsy]

I have seen a few bridges that were made from old flatbed trailers. They just towed them into place and removed the running gear from under them.

 

[jaxs]

Wood bridges around here are White Oak.

 

[jcmaurice6]

Thanks for idea, here (hand made) a view of the section of the bridge I have in mind. What do you think?

Piloon can you send me the contact info of the mills you have in mind?

 

[jcmaurice6]

Oups, forget one important structural detail!

 

[/pine]

White oak...4" full...JMO...! (if the steel does not rust away it will still be there when you die)

 

[bcp]

How is the deck fastened to the frame?

Bruce

 

[jcmaurice6]

My idea was just deposit the deck on the frame, but each side of the frame you have the 2”x6” on the side that is fastened to the deck itself.

 

[bcp]

I would be worried that something heavy might wander to the far edge and flip the deck over.

Bruce

 

[BoylermanCT]

How much wood can your trailer hold? A cord of fresh oak can weigh 4,000 lbs. How much does the tractor and trailer weight? The steel beams are holding all the weight, any idea what they are rated for at 20 foot span?

 

[jcmaurice6]

The weight of the tractor with the backhoe and the front loader is probably srounf 4000 lbs. He should be ok for the bean but you are right, it should be calculated.

 

[lpigott]

I built the bridge on my driveway 20 years ago and it has held up great with only periodic replacement of some top decking. Main beans are 6x12 creosote repurposed from old county road bridges. Main cross members were new 3x8 creosote with 2x12 pressure treated runners on top. The runners are double wide. The runners are the only thing that has needed replacement. Bridge spans just over 20'.

 

[LD1]

The weight of the tractor with the backhoe and the front loader is probably srounf 4000 lbs. He should be ok for the bean but you are right, it should be calculated.

This reply has me confused.

You are asking about a bridge so YOU can drive a tractor and trailer of wood over it.

Then someone questions weight and calculations and you say "HE" should be okay????????????????

Are you building this bridge for someone else? Cause if you are......you might have a bigtime liability case against you if something fails. And
I wouldnt touch anything without an engineers stamp of approval and do EXACTLY what they require and then the liability is on them.

And I-beam shape....pound for pound.....is gonna be stronger than channel sections.

 

[jcmaurice6]

No it’s for my personnal use, I want to use this steel channel section because I have it in hand.

 

[LD1]

No it’s for my personnal use, I want to use this steel channel section because I have it in hand.

Well what are you thinking? and whats the budget?

Basically I would look at how trailers are supported and decked. either wood or steel. Copy a HD trailer design for supports and webbing. Because thats basically what you are building....a trailer deck minus the axles and tongue.

 

[crazyal]

I've built bridge decks with pressure treated 2x4s stood up on end and sandwiched together with threaded rod. However anything you put down will add to the weight. I don't know what your beams are so it's hard to say if it can handle the weight.

 

[LD1]

I don't know what your beams are so it's hard to say if it can handle the weight.

Was wondering the same thing.

Everyone always list dimensions. And channel iron and i-beams are typically sized by depth x weight per foot.

Standard Structural C-channel in the 9" variety dont have 3" webs. And MC (ship and Car) channel has 3.5" flanges.

So just what he has I dont know