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Bridge Decking


jeeper61
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10 minutes ago, m.c.farmerboy said:

you still live in a part of the country where they have common sense, 240,000 lb. logging truck run over wood deck bridges in northern Maine but in southern we need a 12-million-dollar concrete bridge to drive a 2200 pound electric car over

The stuff I see go on is insane 

About two miles east the black top road goes over the same stream

They built a new bridge over it then two year later they ripped it down and built a new one because it was 6 inches too narrow for big trucks

There is an old bridge farther down the road that is even narrower than the new one they ripped down

One would think the efforts would have been better spent replacing the old narrow one   

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6 minutes ago, Art From Coleman said:

How does one avoid "incidental contact" with water, when building/using a dock?

I think in this case it's an allowable use under the legal definition of incidental - I. E.  Incidental to means occurring in, or associated with, the normal, typical, or customary operations of the particular trade or business under consideration. In other words you can't build a dock or bridge without contact therefore it's OK.

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32 minutes ago, New Englander said:

I think in this case it's an allowable use under the legal definition of incidental - I. E.  Incidental to means occurring in, or associated with, the normal, typical, or customary operations of the particular trade or business under consideration. In other words you can't build a dock or bridge without contact therefore it's OK.

Does that apply to cigars?

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40 minutes ago, jeeper61 said:

I am pretty sure that bridge was designed for the loads M.C. Farmerboy stated it was originally put in by a logging company.

They waited years for that one tract where they were allowed to cross the stream to come up for sale 

The rest of the area along that stream is what they call "Meadow" in Maine which is a boggy area   

When it did they put that bridge in they harvested this tract in the early 90s

That road is the only access for 4-5K acres along one of the rivers  

not referring to the structure

the cedar decking does not meet the standards [too soft]

thats why talking to an structural engineer is important

Mike

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14 minutes ago, m.c.farmerboy said:

you still live in a part of the country where they have common sense,

Maybe a little better but we still have over regulation here too. 

Too many chiefs, not enough indians. 

Too many people trying to justify their jobs by having to have their name on a project before it can be passed on to the next desk. 

If I kept going, it would get this thread poofed and I don't want to do that.

We all know what the problem is and where it comes from. 

I try to retain an optimism for a return to an America that puts high value on common sense and strong work ethic. 

Sorry bout the sidetrack jeeper, good luck with your bridge!

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47 minutes ago, Mike H said:

not referring to the structure

the cedar decking does not meet the standards [too soft]

thats why talking to an structural engineer is important

Mike

Good point 

If the cross timbers were made of hemlock there is a considerable difference to cedar 

If they were white pine as I suspect they are there is not that much of a difference

IRC the steel I beams are directly under the vehicle tread width so all the wood is in compression if used by a normal tread width truck 

I have seen a large skidder drive over that bridge and its so wide it bears on the rub rails they have some nads to do that

But they're just doing what the boss told them  

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3 hours ago, New Englander said:

I wonder if it was the old PT that had arsenic (CCA) or all PT that you can't use? I do remember there was a push to get the arsenic treated stuff out of playgrounds. 

A guy in town installs docks, which he manufactures out of PT, so I looked up NH guidelines which say no CCA, not in production anyway, but today's stuff is ok although it sounds like they'd rather you use stainless steel for the direct water contact. Here's a paragraph I cut:

EPA, along with the U.S. Department of Human Services recommends that “treated wood should not be used where it may come in direct or indirect contact with public drinking water, except for uses involving incidental contact such as docks and bridges.”

That doesn't mention salmon of course. Maybe it's time to dig further and see if your buddy can use today's PT?

CCA is still in use in fence posts. But only for agriculture use.

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It appears as if all modification of existing structures requires special approval 

This stream is a tributary of the Machias River   

They likely dictate what is used 

 

"Any activity involving work in waterways designated as Essential Fish Habitat for Atlantic salmon including all aquatic habitats in the watersheds of the following rivers and streams, including all tributaries to the extent that they are currently or were historically accessible for salmon migration: St. Croix, Boyden, Dennys, Hobart Stream, Aroostook, East Machias, Machias, Pleasant, Narraguagus, Tunk Stream, Patten Stream, Orland, Penobscot, Passagassawaukeag, Union, Ducktrap, Sheepscot, Kennebec, Androscoggin, Presumpscot, and Saco River requires review by Department of Inland Fisheries and Wildlife and Department of Sea Run Fisheries and Habitat"  

2.3 Bridge Timber and Lumber Material Standard.

Which stipulates timber species, timber grading requirements, acceptable treatment options

 Effort should be made to minimize the exposure of treated wood to sunlight (reduces viscosity of oilbornes) and rainfall in the design of the timber structure to prevent runoff into aquatic environments.

This caveat is a foot note in the regulations which I think the above agency is applying 

 “Wetted Perimeter” is the area of stream channel extending to the normal high water marks, which is evident in the field as the boundary on the stream bank between the scoured channel and the edge of rooted vegetation.

So use of PT is prohibited in the Wetted Perimeter which they maybe applying to bridge decks because they are in the "river channel" 

Above it but still in the channel in their view 

 

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7 hours ago, m.c.farmerboy said:

up here on the logging roads they use tamarack or hemlock some cedar 4  24or36-inch I-beams under 6x8 deck trucks gross 240 thousand lbs. 

What kind of rig are they running that grosses 240,000. We run 11 axles here and depending on the configuration the maximum legal gross for us is 164,00.

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There is a whole private road system in the North Woods of Maine that is owned by the timber industry they run over height over weight 

The North Woods is 3.5 million acres owned by the timber industry

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I see reference to hemlock a few times in the preceding posts, there must be two types of hemlock, the stuff in PA grows big, but is one of the quickest things to rot when water gets on it.

Most of the hemlock on the east coast has been infested with a little woolly bug, it sucks the life from them.

 if they are not already dead, they will be soon.

I wonder if enough black locust is available? that stuff lasts. My father made some posts from black locust in the 70's, they still hold up.

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12 hours ago, TractormanMike.mb said:

What kind of rig are they running that grosses 240,000. We run 11 axles here and depending on the configuration the maximum legal gross for us is 164,00.

as jeeper said these are offroad trucks 3 axle truck 4 axle trailer, trailer is 14' wide 53 long they load 20 feet high 

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18 hours ago, jeeper61 said:

Good point 

If the cross timbers were made of hemlock there is a considerable difference to cedar 

If they were white pine as I suspect they are there is not that much of a difference

IRC the steel I beams are directly under the vehicle tread width so all the wood is in compression if used by a normal tread width truck 

I have seen a large skidder drive over that bridge and its so wide it bears on the rub rails they have some nads to do that

But they're just doing what the boss told them  

most of them bridges last 20-25 years if there used daily the one going to my place is almost 30 and will be re-decked this year it is 125 feet long and they will have it done in two days that is the difference between privet owned and state owned it would take the state all summer with six engineers and 12 men leaning on shovels 

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7 hours ago, supermechanic said:

I see reference to hemlock a few times in the preceding posts, there must be two types of hemlock, the stuff in PA grows big, but is one of the quickest things to rot when water gets on it.

We use it for fencing rails it has lasted real well for untreated lumber 20 years no rot we used some spruce it didn't make it 10 years 

It is a hard wood softwood has a very high strength compared to other softwoods 

 

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5 hours ago, mike newman said:

plenty of idiots though.

No shortage of them anywhere 

I was reading through those regulations and any excavation to control water erosion like putting Rip Rap on the bank requires the whole area to covered with blasting matts to get the machine near the shore.

or were historically accessible for salmon migration

 This the part that gets me 

The population could be gone but we still need to protect like it is there 

This river never had a salmon migration there is a 30 foot falls before it dumps into the bay 

There was a land locked population of salmon but I think they may be gone 

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what makes them last is they stay wet, and that stops the dry rot, tamerac is much like hemlock but has some oil in it witch helps it last  the way they are built  helps also the runners are only as wide as the tires so mud and water go through

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4 hours ago, m.c.farmerboy said:

what makes them last is they stay wet, and that stops the dry rot, tamerac is much like hemlock but has some oil in it witch helps it last  the way they are built  helps also the runners are only as wide as the tires so mud and water go through

We had some tamarack fence posts that grandpa put in probably 40 years before they finally rotted off right at ground level. After years though they got so hard it was almost impossible to drive an 1 3/4” staple all the way in

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14 hours ago, m.c.farmerboy said:

as jeeper said these are offroad trucks 3 axle truck 4 axle trailer, trailer is 14' wide 53 long they load 20 feet high 

Wow that's a lot of weight on 7 axles. I seem to recall seeing trucks like that on the show American loggers.

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1 hour ago, TractormanMike.mb said:

Wow that's a lot of weight on 7 axles. I seem to recall seeing trucks like that on the show American loggers.

There is a song about running the North Woods 

 

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Wooden bridges don't last long down here. Too many termites.

Woods resistant to rot:

Cedar

Redwood 

Cypress (old growth)

White oak

I think white oak would wear very well but might be expensive. Cedar is quite rot resistant but brittle. Old growth cypress might be hard to find. Redwood comes from California so it might not be available anymore.

Imported woods like teak and mahogany are probably too expensive.

How about that wood substitute made from recycled plastic and saw dust? I see alot of it on docks.

Thx-Ace 

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6 hours ago, midnightman said:

We had some tamarack fence posts that grandpa put in probably 40 years before they finally rotted off right at ground level. After years though they got so hard it was almost impossible to drive an 1 3/4” staple all the way in

Sounds like hedge posts. Have to attach barb wire to posts with tie wire cuz you can't get a staple in em.

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14 hours ago, TractormanMike.mb said:

Wow that's a lot of weight on 7 axles. I seem to recall seeing trucks like that on the show American loggers.

Those are the ones, sometimes they pull a second trailer with a dolly and the truck has planetary drives, half a million pounds at 45 mph. I think Jeeper had some pic's on another thread

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