Tags: reader submitted, suspension bridges, toothpick bridges
7,822 views in 2012
Toothpick Suspension Bridge
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!
How can I make a Cable-stayed bridge that can hold up to about 10Kilos, what material do I use?
wow. can that hold up a brick? if it can, than i might try to do it. it can give me an A.
We need to make a 1.5 m suspension bridge. We dont know what materials were gonna use. It needs to carry a 2 kg item for 10 seconds.
very good
Technically, this is a Cable-stayed bridge. The cables run straight from the towers to support the roadbed in your bridge. A true suspension bridge would have one cable running from an abutment on one end up to and across the towers and into another abutment at the other end, with more cables running down to the roadway to attach them to the initial cable. But this is very good and I suspect it is very sturdy.
My litle boy wants to build this toothpick suspension bridge with no knowledge. That means I have to build it with him with no knowledge. It’s for a “show what you know” project at school where you pick a project and explain it. Can you help with the plans and directions? It has been super frustrating trying to find something on the net that’s not too baby for him that gives instruction. Elizabeth
wow that is amazing!
YOU ARE A GENIUS!!
great im doing my senor on suspension bridge. Perfect product. Thanks
this is fantastic!!!i thought that it would take at least 5 month to build.congratulations!!!
This looks amazing! I wouldn’t have guessed it took 3 months, it would probably take much longer. It actually does look very professional, so congratulations on making something this detailed!
Wow, i am building this bridge for math with my partner lol can u gimme any tip? at all? lol
Looks great! But I suspect it would not carry much load at all (so you shouldn’t bother testing it).
Center-point loading will cause an inward load at the top of the towers. You have attempted to brace the top of the towers against this inward load via the strings to the backspan of the bridgedeck. But this only increases the bending moment in the bridgedeck, and fails to provide adequate support to the top of the tower.
If you loaded your bridge, the bottom chords of your bridgedeck will snap quickly at centerspan, and your two towers will fall towards eachother. Try it – take a video – and prove me right!