I just finished this bridge a few days ago after working on it on and off for 3 months. It’s a cable stayed bridge design made with standard round toothpicks and wood glue.
The bridge is 31 inches long and just under 20 inches tall. The main road truss is 2 inches by 2 inches, constructed of beams of laminated toothpicks (3×3) and held together by individual toothpicks in a triangular truss pattern. The towers were constructed of laminated toothpick beams as well, but thicker (4×4). Then the suspension was created with 4 strands of thick string wound back and forth across the top of the towers.
I didn’t make this for any particular occasion or contest; I just wanted to see if I could make a sturdy suspension bridge. I’ve built a toothpick bridge before. It won a contest by supporting 350 lbs. over a two foot span, but obviously it was destroyed in the process. I don’t plan on testing this one, although I imagine that someday my curiosity will probably get the better of me. Besides, I really don’t think this bridge will hold nearly that much weight. I’d love any comments or pointers you guys might have. Enjoy!
There are a few more pictures of this bridge (higher resolution too) on my Flickr photostream at http://www.flickr.com/photos/razokylava/ I’d love any comments or pointers you guys might have. Enjoy!
This type of bridge is actually called a cable-stayed bridge, but I think that is is very well put together. I hope to see a popsicle version of this type of bridge.
Very accurate and interesting work. Nice to see.
I want to ask you to do a new design (new type) of suspension bridge with a large span – http://blog.dp.ru/post/5191/.
Suspension cables are anchored at each end of the bridge. The load that the bridge bears converts into the tension in the cables and is transferred to the support bases.
Cables stretch beyond the support bases up to the dock-level supports further to the anchors in the ground. The top tether system keeps stove roadway, bear the weight of the deck, and transmits the weight roadway through struts on the lower cables.
One advantage of this bridge design is that it can span long distances and resist earthquakes. It requires less construction material, which reduces its cost of construction.
I think that, this type of rope bridges could be called a “green bridge” judging by the favorable opportunities in the construction of such a bridge – substantial reducing the amount of materials (cement and reinforcing steel), which are now being spent at the device numerous concrete supports and pylons for modern large-span bridges. And after all, the production of cement and steel production – are not only energy intensive, but also extremely environmentally unfriendly.