Step 6: Building the Deck

Once the bridge was in the air, the garden variety work of deck building got under way. 2x8x16 lumber for decking, 2x4x16 for the hand rails, 5/4x6x16 decking for the facing boards on the handrail system.

The handrail system is an integral part of a suspension bridge - the two handrails form the trusses that provide most of the rigidity to the bridge. Without the trusses, the bridge is an elevated snake. With them, it is incredibly stable.

To make the handrails into trusses, we placed cut-to-length 2x4s from the top of one handrail support to the bottom of the next, working our way from both ends to the middle. The bridge is all but unusable without adequate trusses - witness the failure of the Tacoma Narrows bridge, due entirely to insufficient stiffness.


Entirely unexpected was the genuine beauty of the bridge. Through what can only be sheer luck, the finished bridge is simply magnificent.

<p>Amazing project. <br>I noticed that as listed on the plan here: <a href="http://www.trailstobuild.com/Articles/PochuckBridgeEngineeringArticle/plan_sheet_1.pdf" rel="nofollow">http://www.trailstobuild.com/Articles/PochuckBridg...</a></p><p>Their truss is going the opposite direction of yours. The direction of truss supports is very important and I was wondering what factor made you change the direction?</p>
<p>I think that the direction doesn't matter as the job of the truss is to stiffen the suspension bridge to stop it snaking. This means that the force in each diagonal will change from tension to compression as the load moves across the bridge.</p>
That is some project. I'm sure there are several special words used to get it all together.<br>
That's freaking awesome!!
How big is this pond/river of yours?
The pond is about 3.5 acres when full. It is only full after a stiff rain, and then only for a few weeks. Most of the year there is no water below the bridge. It's not exactly dry, either. :)
Oh cool I bet you get lots of mosquitos
Not that many mosquitoes. LOTS of frogs and dragon flies, not to mention lots of fish in the pond! :)<br><br>Now gnats, that's a different story!
some people eat flys for protien
Do you think creosoting the anchors before inserting into the ground would be a good idea?
Any treatment of the anchors is a good idea, but I personally am not comfortable with the idea of creosote. There are other ground line treatments available, and I may use one of those. In the long run, I will probably replace the anchors with steel screw anchors. Greater, and more certain, uplift resistance as well as a far longer life.
Forgot about the steel screw type. What comes to mind is the tiedown anchors used for a mobile to secure it. Good amount of uplift resistance.
The manufactured home tie downs are also often screw anchors. Using those anchors I could double up each anchor and provide the uplift I desire. I haven't yet decided how I shall do it.
what high school class teaches this? i took an &quot;introduction to engineerig and design&quot; class on accident and thay had nothing but BS. what class would this be? it looks like it would be really helpful in the future.
I took a class called pre-engineering and it showed us our model bridges and we took an equation to see how much pressure it could take my 1 ft long bridge could withstand about 250 lb.
care to summarise all u learned in that class?
No high school class I know of teaches this. As for me, I thought it up, read it up, put it up.<br><br>More or less. :)
This is awesome!<br><br>I'm an architect and I can say that this bridge really brought something special to the property.<br><br>Bravo!
Wow, great job.
Magnificent. Congratulations!
Really cool. Do you have anymore images of the bridge?
One more, which I have added to this step as the last pic in the series.
*bows to greatness*
Thanks! There are so many great projects! I voted for several!
Astonishing. <br>Inspiring.<br>Intimidating.<br>Have you any photos of the critically important anchors and more info on how the cables attach to them?<br>Also, can you describe more about the spikes.<br>Thank you for an outstanding Instructable.
I added two additional pics to Step 2 and 1 pic to Step 6.
Did you install plates front and back of the laminated anchor?<br>What kind of glue did you use to laminate the anchor?<br>Wow.
Big washers on the other side of all 3 bolts. And I used construction adhesive to laminate the anchors (all the posts, really).<br><br>It is very difficult to line up plates on both sides of the posts. I had to do it on the towers, but it was no simple task to bore holes in the posts that aligned with the plates on both sides so that the holes pre-bored in the plates would work out.. Next time, I drill one side, bore the holes, mark the plate for the other side and then drill those holes!
I will take additional pics and add them to the instructable. The spikes are 10 in (I think) long and similar to a really, really big nail. They are pounded in about 40%. They are what the concrete bears upon, whether in up lift (anchors) or in down force (tower legs). There are 6, as I recall, in each anchor, alone with two bolt ends.
Fascinating - many thanks for writing that up. An amazing project!
Amazing project- thanks for sharing the process!
<br>Very nice!<br><br>That is a lot of work, but the feeling of getting the job (well) done is priceless.<br><br>Greetings,
So priceless that two months later I am still kind of stunned!
Excellent excellent job, and good write up. This is the kind of stuff you cant find elsewhere no the internet :)
Well, I couldn't find it anywhere else, excepting the Pochuck bridge reference I give in the intro.
Great job! very very nice; at university im studing bridges! are you an engineer?
Yes, I am an electrical engineer. I don't think that translates too well into bridge design. <br><br>Were I starting engineering school now, however, I might choose to study bridges, too!
A little bit of grease goes a long way on thoes turnbuckles. Also if you used gal ones they can be a bit harder to work because of the galvanising on the threads, stainless ones might be more expensive but would make it a lot easier.
Both those things are true - but I wanted them to stay put once they were adjusted, so I put no grease on them, and they were expensive enough that for one adjustment, or very few over the life of the bridge, I was okay with the galvanized.
Fair enough. Just thought id say. Great build anyways, its really good to see people building. Good on ya.
Well, step one eliminates me.&nbsp; This is awesome.<br>
Well, I'd be more than willing to do the spreadsheet part to whatever suspension bridge you think you might want to build. :)
Dang, this is cool. I wish I had a stream in my yard!!!
so nice. but i have doubts on the main columns are they enough deep as they are pretty close to the river if erosion persists it might falls. Just a point by the way super great bridge
Erosion is a concern over the long haul. I have a plan in mind should that eventuality come about. The plan involves a lot more concrete as well as steel to support the base of the towers, which will no longer be embedded.
I am so beyond impressed. Would love to have one but participating in building one would surfice..lol. Great Job Jake.
So, get a neighbor or friend hooked on the idea and we can make it happen together. :)
THAT's a nice piece of work! Good design: not only does it do what it's supposed to, but it looks awesome, too! And, it is very comforting to see another 'not-so-young' feller doing some some fine construction.<br><br>Congratulations on a super build.

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