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.”
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!
Here is the rather cool certificate I received at the testing site:
For more information on this competition, see atlantatoothpickbridge.org. 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 
Similar Posts
- Matt’s Balsa Bridge
- First Timer’s First Bridge Design
- Popsicle Bridge #3
- Forces that Act on Bridges
- Fernbank Bridge Numero Dos
Post Meta
Post Category: photos
Post Tags: fernbank bridge, photos
85,181 views
(39 votes, average: 3.79 out of 5)
Loading ...
AUS student !!!
verrrry cool. you should be very proud of yourself
thanks for the helpful tips!
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
what is the thickness of the amount of popsicle sticks
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?
We wanted to use this for our experimental design structure for science olympiad, and I was wondering if you still had the plans, and what you made this out of. please respond.
Sara, this bridge was made out of Basswood. I do not have the plans anymore.
we have to do this for 3rd semester science project, only with smaller measurement, and i was wondering what type of glue as used?
Anne, I used two different glues on this bridge, Probond and Weldbond. Both are good choices.