Building a bridge

[mwb]

In a way, this thread points up the reason why I don't post much on internet BBs that much anymore..

If the poster was a friend, and he asked us all to come over and see the new bridge he had constructed, I doubt that many would show up with their engineering library, sliderule, calculator and tape measure to measure it up, calculate the loads, pick it apart and deem it to be safe or unsafe.. We'd just take a look, give a pat on the back and tell our friend how good it looks and what a great job he did!
One the internet however, it seems that folks think it is their God given right to pick things apart and criticize, but maybe it's just a mirror of life in general... It seems that there is always someone to show up at the party with the intention of urinating in the punchbowl..

I wonder why life has not spawned as many experts on any subject as the internet has!

I agree. Forums like this are supposed to be a community, allowing us to share ideas and discuss them. I think it is healthy for this community for everyone to share their point of view but there is no point in turning it into an argument or flaming.

Most of the heated discussions here seem to originate from poor communication; topics raised by the OP get distorted into intangible arguments that in the end add little value and end up discouraging everyone from participating.

Buggyman, nice project. Thanks for going out on a limb and sharing.

Mike

 

[Erik_in_Hoyt]

bridge looks good!
congrats!

 

[JohnDeere4300]

I agree. Forums like this are supposed to be a community, allowing us to share ideas and discuss them. I think it is healthy for this community for everyone to share their point of view but there is no point in turning it into an argument or flaming.

Most of the heated discussions here seem to originate from poor communication; topics raised by the OP get distorted into intangible arguments that in the end add little value and end up discouraging everyone from participating.

Buggyman, nice project. Thanks for going out on a limb and sharing.

Mike

Very well said...This happens all the time with just about everyone that builds something or hauls equipment and other things, and a person that's interested in the thread can't enjoy reading it.

And when this happens, it will get the thread closed.

 

[powerstroke444e]

In a way, this thread points up the reason why I don't post much on internet BBs that much anymore..

If the poster was a friend, and he asked us all to come over and see the new bridge he had constructed, I doubt that many would show up with their engineering library, sliderule, calculator and tape measure to measure it up, calculate the loads, pick it apart and deem it to be safe or unsafe.. We'd just take a look, give a pat on the back and tell our friend how good it looks and what a great job he did!
One the internet however, it seems that folks think it is their God given right to pick things apart and criticize, but maybe it's just a mirror of life in general... It seems that there is always someone to show up at the party with the intention of urinating in the punchbowl..

I wonder why life has not spawned as many experts on any subject as the internet has!

I really enjoy reading and seeing what people build but I am always leary of putting what I have done on here as some just like tell everyone that there is a flaw or something that could have be done better. I know I am not perfect but this bridge looks better and more thought out than 90% of the poster could have ever done. GREAT JOB and let see the photo's of the second one.

FYI my idea of a homeade bridge is the biggest piece of pipe I move covered in dirt.

 

[Transit]

Johndeere4300, you missed my point about the Hindenburg fire. A seemingly innocent mixture in pant brought the Hindenburg down. Not that Termite Welding was unknown at the time. Would you paint your house with what amounts to be rocket fuel? If you were on trial for your life would you be your own lawyer? Have you ever seen Termite Welding in action? Try this link YouTube - Thermite weld and the next few vedios
I have formal training in Civil Engineering and I know enough about bridges to know I'ed be biting off more then I can chew. Some things are best left to the pros. One small error, a point overlooked and your dead.

 

[J_J]

buggyman1 ,

Nice job, would you come over and build a bridge across my creek? Just kidding, it would never stand up to the flood I get after 3 days of rain. My creek , normally about 12 to 15 ft, grows to about 400 ft wide, and cleans out everything in it's path. I am guessing that water from about 800 to a 1000 acres drain through my creek, and sometimes, the church by the creek gets flooded if it rains for about a week. I have some pictures somewhere that shows the water level at 400 ft wide. The bottom 4 acres is almost unusable because of that .

 

[Ford850]

Nice looking bridge. I think it is strong as it sits today. My concern is as it starts to weather and the hardware rusts. Everyone seems focused on the 6x6 beams or joists. I'd be concerned with how most of the bridge weight is supported by the 2 cross beams made of 2x6 or 2x8. 4 bolts hold all the weight on that double span. When the bolts rust out, and they will in half the time with our new treated lumber, they could shear with no warning. Those cross beam pieces should be notched into the upright posts to hold the weight rather than all of it on the bolts. You could add a set of vertical 2' long 2x6 cleats under the cross beams to support them. That would be a quick and cheap way to add some strength to it for years to come.
But like I said, it's a nice looking bridge. I wish I had one.

 

[workinallthetime]

anyone ever seen one of those old bridges the trains used made out of timber? I bet they dont work on paper either!!

great lookin bridge man, dont let hours of your sweat get beat down on here. The ones I have built to drive my b3030 tlb over are alot less complex than yours and continue to perform everyday. I used some railroad ties, bridge timmbers, and 2 x 6's for tread. Mine have no rails on them since pulling brush across the bridge might damage the rails.

GREAT JOB MAN!!!!!!!

 

[Transit]

Nice looking bridge. I think it is strong as it sits today. My concern is as it starts to weather and the hardware rusts. Everyone seems focused on the 6x6 beams or joists. I'd be concerned with how most of the bridge weight is supported by the 2 cross beams made of 2x6 or 2x8. 4 bolts hold all the weight on that double span. When the bolts rust out, and they will in half the time with our new treated lumber, they could shear with no warning. Those cross beam pieces should be notched into the upright posts to hold the weight rather than all of it on the bolts. You could add a set of vertical 2' long 2x6 cleats under the cross beams to support them. That would be a quick and cheap way to add some strength to it for years to come.
But like I said, it's a nice looking bridge. I wish I had one.

ford850, I was waiting for that point to be raised less I be accused of being overly critical.
CCA stands for Chromate Copper Arsenate.
Lumber is treated to specific levels of contention in pounds per cubic foot depending on the application. See the following file.
http://www.americanpoleandtimber.com/pdf/treated_wood_specguide.pdf
I would have chosen categories 4B and 4C for the lumber.
Bolts are normally hot dipped galvanized, however that would be very wrong for the application. Corrosion is a major factor with CCA treated lumber and at high levels of concentration more so because of the zinc coating reacting with the CCA in the lumber.
The proper choice of mettle hardware would be 306 and 316 Stainless Steel anything else would have a short service life.
As I said, the little details are going to do you in.

 

[sld]

My gosh Transit, please don't take this the wrong way, but have you ever built something and personally observed it over the years?

I made a walkover bridge over 20 years ago with treated wood and galvanized bolts. I was just looking at it the other day, and the bolts have a little surface rust but are as good as when installed (or close to it). Just for the heck of it I pulled one out and what was buried in the wood was cleaner than what was exposed!

A stout piece of steel used for a fastener will take a long time to fail. It may fail, but it will take a long time. That is why you over build to account for things like this.

You may have good intentions (chicken little did too) but my Dad used to say "If you don't have anything good to say, don't say it"

Sorry for the rant.