Tags: 16 inch span, 300+ pounds, basswood bridge, fernbank bridge
22,297 views in 2012
Fernbank Project: Strongest Bridge Design
I built this bridge for the 2005 Fernbank Science Center bridge design event. This is the strongest bridge I have ever built. The bridge spanned 16 inches, weighed 37 grams, and held 346 pounds. That puts its efficiency over 4200! I had never even come close to getting this amount of strength out of a bridge design before. I was really surprised. One commenter said, “So if this bridge weighed one pound, it could have held up my car.”
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- The award I received
The first time the bridge was tested it did not break. The testing machine was set to only apply 250 pounds. This bridge was too strong for that! Here is the bridge after the second testing:
The secret of a strong bridge design
As you can see, the bridge stayed mostly intact. I talked to a couple engineers at the event and asked them what they thought made my bridge break. One suggested that the bridge failed in torsion, as I did not have any diagonal braces in the bridge. That is definitely a design flaw I will fix if I do this again. I would love to try and break an efficiency of 5000. That would be a strong bridge indeed!
For more information on this competition, see Atlanta Toothpick Bridge Competition. I encourage anyone in the Atlanta area to try and go to this event. It is free and open to all, both young and old. Try your hand at making the strongest bridge. And when you do, send me photos of your bridge 
oooh~ were making one like this… and were inspired with the idea… but the thing is…
we only can use bamboo sticks and sewing thread… no adhesives and glue… and not wood.. so….
kinda harder… hahaha….. what are the actual measurements for this?
what is the thickness of the amount of popsicle sticks
Unreal! I’d like to try building it myself; I realize this was made in 2005, but if you still have the plans or remember how it was built, could you email me instructions? I can’t tell what size the wood members are.
Personally, I”d love to take that bridge to an efficiency of over 5000 as well.
Hi
i think that it looks very cool
i am building one for my class and i was wondering if you know how far apart each vertical suport was placed
and are the top l beams two peices of 1/2 inch glued together
plz reply
verrrry cool. you should be very proud of yourself
thanks for the helpful tips!
AUS student !!!
Hi Garett,
First off, nice bridge. I have a school project in which I have to design a bridge made out of Q tips (cotton ear buds). The bridge has to be 10 inches tall, no damage can be done to the earbuds, all the earbuds have to be of the same length and only glue can be used (any type of glue, though). Most importantly, only the tips of the earbuds can meet. The tip of a earbud is not allowed to touch the stick of another earbud. The bridge has to carry a minimum load of 3 kgs. for at least ten seconds. I was wondering if you have any advice and if you could mail over any designs. Would be a great help.
Thanks so much,
Deepak.
P.s. The email id is deepakajit@hotmail.com
we are having a school competition and i was wondering if you could gives us some assistance with building a similar bridge. could you please provide drawings that include lengths and design of your bridge. PS what sort of wood did you use? many thanks.
send to
turtleboyrocks@hotmail.com
we are having a school competition and i was wondering if you could gives us some assistance with building a similar bridge. could you please provide drawings that include lengths and design of your bridge. PS what sort of wood did you use? many thanks.
Hi Garrett,
Im doing a bridgbe project for school, Im wondering how many popsicle sticks you used, or if you used something else, how many?
thanks,
andrew
I’ve created a bridge out of balsa using butt joints,cardboard gussets,(and some joints with pva glue,some with hot glue guns) before.It was a complete wuss when it came to testing it. It only held 18lbs before completely collapsing.Compared to your bridge,it would be like an elephant standing next to a pea!
who nice bridge!
so im just wondering first what you made the bridge of and how you made it i could totally kick but in science olympiad with a bridge that holds 200 lbs.
hey i am making a 14 by5 inch TOOTHPICK BRIDGE for my science class and i was wondering if you had any suggestions. it is being judged by how strong it is..
thanks
and they have to be to be 2 inches away fron each other..
help help help
hey dude i like the bridge, what kind of material did u use to make it?
i dont care about how much it weigh, but i need it very strong.
also i was planning on putting chopsticks together to make a bridge, but they cant be glued together. help
I would like to know if you did any blueprints?