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Building A Bridge  RSS feed

 
Posts: 202
Location: S.E. Michigan - Zone 6a
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Hello,

I have a creek that cuts my property in half and I would like to build a bridge to get a tractor to the back half. Due to various departments of making you sad I need a clear span bridge of 26'-30'. My tractor weighs 3400 lbs and one of the main uses is to get firewood I'm thinking I need the bridge to support at least 5,000 lbs. Any help anyone can provide would be great.

Thanks,
Jerry
 
Posts: 58
Location: Saguenay
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Jerry Ward wrote:Hello,

I have a creek that cuts my property in half and I would like to build a bridge to get a tractor to the back half. Due to various departments of making you sad I need a clear span bridge of 26'-30'. My tractor weighs 3400 lbs and one of the main uses is to get firewood I'm thinking I need the bridge to support at least 5,000 lbs. Any help anyone can provide would be great.

Thanks,
Jerry



Hello Jerry,

See my creek bridge: http://www.usa-gardening.com/bridge/pond-bridge.html

22 feet. Its just an idea... for 5000 lbs... im not sure.. but if this can give idea to you

 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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That is a good looking bridge, but it looks like you only span 8' from post to post. I need to clear at least 24' and more like 28'.
 
Posts: 724
Location: In a rain shadow - Fremont County, Southern CO
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is it possible to buy an old railcar?
i have heard of them being used to span small rivers/streams as they typically can handle most non industrial loads, and are 1 piece.

not sure if it possible, but you may look into it.



more info here:
http://www.pacificrailservices.com/flatcar_railroad_bridges.html
 
Posts: 320
Location: NC (northern piedmont)
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At 28' you're talking steel and lot of it. I'd be looking to salvage an old steel truss bridge the county or state is replacing, if such things still exist near you.

Just my opinion and we all know what that's worth.

Edited to add - I like the railcar idea, might be easier to find.
 
Posts: 3366
Location: Kansas Zone 6a
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Railcar or old semi truck trailer will work.

A shipping container will work, too, if you open both ends. I am assuming your 3400 lb tractor is small enough to fit.

You will want to make sure the bridge itself is well above the water, with a low-pass around one or both sides, so it doesn't wash away with a flood. I wouldn't build it to handle a 500 yr flood, but probably a 50 or 100.
 
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Hi Jerry,

I would, if it must span 26' to 30' either look at a shipping container with end removed and reinforcements added to stabilize (cheapest way to go) or a covered timber frame bridge (expensive if you don't build it yourself.) Note, the seconded is time consuming, but not as hard as it seems if you have standing timber. Many different designs to chose from.

Regards,

j
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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Jay C. White Cloud wrote:Hi Jerry,

... a covered timber frame bridge (expensive if you don't build it yourself.) Note, the seconded is time consuming, but not as hard as it seems if you have standing timber. Many different designs to chose from.

Regards,

j



Is there a resource you could point me to? I have some standing timber, but I don't know the strength of trees species to know if they could handle the weight.
 
Jay C. White Cloud
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Hi Jerry,

No one source per se...for either designs (as those are often specific to the crossing when you build/restore a covered bridge) and for lumber strength...that will depend on grade and species of lumber. It is more challenging (or at least most engineers and building officials try to make it seem that way) as green wood used in timber framing (no matter the species) gets stronger as it drys. So after 10 years you actually have a stronger bridge, as by then all the wood is well dried out (or almost.)

You can build a nice covered bridge in your size range with just white pine, it it is designed correctly. If you add augmentation like 3/8 GAC you can build a bridge that will take a tank-though not a traditional all wood bridge then. If you are considering this, I will be glad to assist as much as I can from a distance.

Regards,

j



 
Posts: 42
Location: Washington State
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If you build a timber bridge, especially if you plan on using timber from your land, here are some resources for you.

http://www.pacoveredbridges.com/historydesign/

http://www.wood-database.com/?s=cotton

http://www.wood-database.com/?s=pine

http://www.wood-database.com/lumber-identification/hardwoods/black-walnut/

You will have to identify which species of pine and cotton wood you have to determine if they are suitable. I know you said you need to thin some walnut, so that may be an option. But I would save as many walnut as I could since they provide nut, and may not be so much stronger than your other timber to justify cutting it.
 
pollinator
Posts: 4339
Location: Anjou ,France
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Do you need to use this bridge every day?
What about an Irish bridge ? Basically its a set of pipes and when it floods you just dont use the bridge . Or a simple ford .
Some ideas here
http://www.transport-links.org/transport_links/filearea/publications/1_471_PA1290_1993.pdf
http://www.transport-links.org/transport_links/filearea/publications/1_471_PA1290_1993.pdf

David
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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What is 3/8 GAC?
 
Joe Braxton
Posts: 320
Location: NC (northern piedmont)
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Jerry Ward wrote:What is 3/8 GAC?



I believe he's referring to 3/8" Galvanized Aircraft Cable.
 
David Livingston
pollinator
Posts: 4339
Location: Anjou ,France
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Any chance a picture of this stream/brooke / river ?
I still think making a bridge is a lot of hard work and cost and maintainance for something with so little use . If you have a tractor it does not mind getting its feet wet why not a combined weir/ ford ? You could then get a pond in the bargin too .
Matbe with fish
Its not like you have to cross the bridge every day or are trying to get something that is perishable back to your house . If the stream is in flood then you dont cross come back another day . You could add stepping stones too make it a feature that adds character and value to your property .

David
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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David Livingston wrote:Any chance a picture of this stream/brooke / river ?
I still think making a bridge is a lot of hard work and cost and maintainance for something with so little use . If you have a tractor it does not mind getting its feet wet why not a combined weir/ ford ?

David



I will post some pictures. The creek is shallow enough that my tractor could drive through it most of the time. However there are several departments of making you sad that frown on that kind of thing.
 
Posts: 551
Location: Central Virginia USA
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https://www.google.com/search?q=rainbow+bridge+china&client=firefox-a&hs=sq2&rls=org.mozilla:en-US

I saw this PBS program a while back about a rainbow bridge-- a very old chinese design using shorter spans of lumber in a tensegrity network to span larger distances--the most important parts of the bridge are the two anchor points on opposite sides of the stream

the link above should get you started if you choose to research it.

i have a ford across my stream for cars, but i've often thought about a bridge like that just for the aesthetics, maybe when the fallen tree i've been walking across finally gives way i'll do the bridge
 
Posts: 226
Location: South central Illinois, USA
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I like the old flatcar in the Kelly Smith photo. Have seen several in my time, but this is the FIRST to have the trucks under it. Well done, I say. Well done!
 
David Livingston
pollinator
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Hi Jerry ,
so building a Ford is illeagal ?
Cost wise I would think it a winner all round plus much easier for the départment of sad to inspect as there are nô weight issues. I am curious to know the argument against one properly planned And built.

David
 
bob day
Posts: 551
Location: Central Virginia USA
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isn't it an environmental issue-- lubricants etc leaking out of vehicles and polluting the creek
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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I think it has to do with stirring up sand and silt in the stream flow. This is what I've been told, but I don't know anyway to find out for sure.
 
David Livingston
pollinator
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I have always found going to the horses mouth works best. A direct question to the planning department .
Like CAN you give we a list of planning régulations for building a ford,

David
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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you must talk to better horses. I can't get a straight answer from anyone about these things other than "I don't think you can do that"
 
Jay C. White Cloud
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Hi Jerry et al.,

I will try to address some of the points that folks have been made thus far, and answer any questions I can accordingly.

As for "wood standards" on the net that have been offered...some are good, some are real good, and some are o.k. Many of these can lead a novice astray because we are talking about "averages" in different grades, and few address "greenwood architecture." There are a few that cover this aspect, but mostly it comes from experience to extrapolate what needs to be understood.

GAC is "galvanized aircraft cable."

I am sorry to counter the suggestion of a steel for any bridge, yet I must. They are "perceived" as "stronger and more enduring," yet are anything but that. Yes, steel can be more commonly engineered by more folks, and the math applied can be more simplistic, done by more folks, and will be better understood and supported by the "masses" today...that is when the steel is new.

Steel "rots" (oxidizes) just like wood does, just in a different way, and unfortunately in very surreptitious manner that is not often easily observable, as the critical location is quite often hidden from view. As far as "endurance" goes for bridges (assuming a proper Bridgewright was involved in some capacity) it goes stone, arch, wood arch (then spans of different types) then you get steel.

Steel must be monitored way more closely than a wooden (covered) bridge...and painting often only hides the issues on many steel bridges. The famous ones have full time PE and maintenance folks that monitor and repair them all the time.


The Chinese "moon" bridge that was reference was partly facilitated by a friend and mentor. (I was suppose to go but alas could not.) They are very beautiful but manly for foot traffic not machines line tractors. A Chinese "cantilever span" bridge could work if one had the skill sets to tackle them...that is a plausible design concept for you.

Fording for small occasional vehicles are o.k., or foot traffic, yet they do have a very big impact on stream ecology...that is why they are either illegal or frowned upon as folks tend to abuse the practice. There are a few types that use "gabions" that you might be able to get past the "department of being sad."

Regards,

j


 
bob day
Posts: 551
Location: Central Virginia USA
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wow, i'm impressed that you were in line to work on that project-- i remembered when the bridge was finished they had two oxen that walked across the bridge and thought that might be pretty close to the weight of the tractor.

but it does seem that the whole thing is overkill for an occasional crossing with a tractor
 
David Livingston
pollinator
Posts: 4339
Location: Anjou ,France
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Hi Jerry
How to get the horse to speak to you ?
Well all I can tell you is how I do it .
Firstly dont bother phoning . They can and will deny what they said if it suits them . They are busy folks and will try to brush you off.
Secondly be professional, consice , assertive and direct .
Thirdly play the game .

I would write a letter to the planning officer something like

Dear Sir

I wish to built ( x) at (y) I enclose full details of my proposal .

In order to prevent future possible litigation wasting both my time and your time could you advise me what changes I should make to this proposal in order to conform with the national and local planning guidlines .

Your etc etc

There are three possible outcomes

1 You get a nice reply telling you what changes to your plan you need to make , if you do write a thank you note. It means you will be remembered and get better service next time

2 You get a poor reply so you write again asking for more details , thus creating more work for them and in future they will write you a full reply to save themselves time .

3 You get no reply after one month . Then you write to the boss of the first person saying obviously the first person must be ill could this work be passed on to who ever is now doing the work .

Then if still no reply find out if there is a complaints section or proceedure use them to complain you have had no reply after two letters . Still no reply then complain to your elected representative whom I am sure would be glad to help ( even if you think him or her is an idiot ) its a gimmee for them and they are always trying to get voters indebited to them.

I have used these techniques with sucess in two countries .There is a lot of talk about being different on this site and I wonder how many people would find it easy to get things done via the man if we just used our pens more effectively.

David
 
David Livingston
pollinator
Posts: 4339
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Jay C Whitecloud
I accept that a ford can have an impact which is why I asked for a pic of the site . If the OP fancies building a pond too this could all be taken into account into one deal . Impacts can be positive and negative depending on the area concerned

David
 
Jay C. White Cloud
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Hi David L.

I agree with much of what you are sharing about trying to get one of these "fordings" approved, and also about their potential both ways for impact on a stream. From a construction ease viewpoint...if done well and properly, they can almost be as demanding as building a small covered bridge (almost.) I have seen, been part of, and built countless fordings in my life from the more complicated ones that employ heavy stone work and/or gabion, to the less complex sandbag and hardening methods. Again, in small streams and rivers with the correct underlying soils and/or bed rock, these can be effective... I have seen just as many that are complete fails as well, so I (subjectively) look at them with a very "fuzzy eyeball" when they are offered as an option.

Regards,

j
 
Jerry Ward
Posts: 202
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Here is a picture of my kids and a friend chilling in the creek. You can see the little foot bridge I built has come off the one shore.
 
Jay C. White Cloud
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Hi Jerry,

Looks like very silty soils and an area that sees flooding in sections? You maybe able to come at this side ways with local authorities and ask about using gabion to reinforce the banks for erosion control. I have seen/done this for trout stream reconditioning projects and if you just happen to reinforce section of the stream bed with gabion and/or stone all the better. Many of these "harden" methods for erosion control will also allow a tractor to "occasionally" meander over to the other side for a bit of work.

Regards,

j
 
David Livingston
pollinator
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I'am with you on this one Jay C Looks like very silty soil . How often does it flood I wonder ? Spending money building a bridge that could easy be washed away in a flood does not appear a sound investment to me

David
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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I do get floods a few times a year where if just barely overflows the bank. However I did get a flood last year that came up a foot or so above the bank, so I would need to build a bridge at least 2 feet above the bank.

Jay C I'm not following the gabion idea. All the gabions I know of are wire boxes you fill with rocks. I don't see how a tractor could traverse one.
 
Posts: 48
Location: twin tiers of WNY zone 5A
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I have heard of people using the trailer part of old mobile homes. Call a trailer park and ask where they send all the old run down homes, to die. I know my
mates parents live in a 14 X 28 footer and our place is something like 40 or 42 feet long. Concidering it's designed to hold a house and all its belongings, I would
think a tractor would be no problem.
 
Jay C. White Cloud
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Hi Jerry,

The "gabion" is based on technology that is almost 5000 (or more) years old. They can be (mostly are) fully structural (when don well and not just thrown together) and can more than take a tractors load. Google them and take a gander...I think you will see the potential really quick, and that is a key feature..."quick." I have used them for a number of projects including house foundations. Also google "koti bannal" as this is an acient form of the "gabion" concept, but traditional, with the wood forming the "basket" matrix.


Regards,

j
 
Jerry Ward
Posts: 202
Location: S.E. Michigan - Zone 6a
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What about using utility poles? Of course I have no idea where to buy some but do you think 4 poles (two under each tire) would work?
 
Posts: 69
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@Jerry:
Your bridge is far too long for any inexpensive solution.
For 28 feet with 5000 pound load you would need some massive steel joists or a very sophisticated timberwork. I do not think you can do this for a reasonable price for occasional use.
I would suggest to reinforce the banks with concrete or stone fundaments.
I estimate the distance of the banks in your picture is 4 – 5 meters?
This distance that could be bridged with massive wooden beams ore steel joists of an affordable size.
I think of a draw-bridge or something you can put in place and remove with your tractor´s hydraulic system.
 
Jay C. White Cloud
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Hello All,

I agree at this point that hardening the banks and some from of gabion structuring will probably be the quickest and most cost effective of the suggestions thus far. Post or Pylon structures are viable as long as the EPA types can approve the chemicals in them...seldom now do they, as they are very toxic.

Hello Manfred,

Timber framed truss bridges can seem daunting to the novice, but that is why folks come here for assistance. A timber framed covered bridge of this size and span is rather simple to design and facilitate. With guidance, patience and simple hand tools anyone could more than complete the task...as it has been done for millenia. In this case, once timber/logs are gathered, you would be looking at somewhere in the area of 350 to 400 joints or about 100 plus 8 hour days (~ 800 man hours) for a novice Timberwright. Myself and 1 other could build in approximately a month and a half with little effort, in a dry location with hard ground. It is very doable...

Regards,

j
 
Manfred Eidelloth
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@Jay:
I have no doubt it can be done. But as you write: You have to know what you are doing to get the statics right. Und it takes quite some time and material.
Here a qualified timberman charges about 40 Euros per hour. The assistant might cost you 10 – 20 Euro per hour (including insurance) if you do not have the time yourself or some fried helping out.
Even if you have the timer required at hand, you could sell it if you do not use it for the bridge. So you have to take this money into account, too.
Than the fundaments and perhaps some machine to put the bridge in place.
At my guess such a wooden bridge would cost me at least 15.000 – 20.000 Euros around here. A lot of money for driving over it 5 times a year.
Even if you can do it for half the price, it is still some investment.
On the other and: Such a wooden bridge is a beautiful thing to have. It can last for decades. And as soon as it is installed you might find more and more reasons and occasions to use it.
 
Just put the cards in their christmas stocking and PRESTO! They get it now! It's like you're the harry potter of permaculture. richsoil.com/cards
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