What is the best design for a toothpick bridge?

I am building a toothpick bridge for my school and I'm wondering what the best design would be that is fast+easy to build and is strong.

What is the best design for a toothpick bridge?
I am working on this with my daughter. I am an engineer but I don't build bridges, but I understand the concept. I have done some research and what I have found is that the best type of bridge to span an opening without any mid span support would be an arch truss. (click the link for a good example, also go to yahoo images and type in Bayonne bridge, there are lots of great pictures from different angles)





When I say best, I mean the strongest with the least amount of materials, which I think is what you want in a toothpick bridge.





When I read your post yesterday, I emailed Nate about his bridge. He said they got their toothpicks at Cracker Barrel. I searched and found another reference to using toothpicks bought at CB. I think this will be a big help, because the store bought ones are flimsy.





I found a great website where you can design your bridge, load it up and see what the forces on each member are. That way you can reinforce before you build. The link is also below.





Good Luck
Reply:Id say a truss bridge.
Reply:I don't know if it will be easy, but you could try an arc, which is considered to be one of the strongest basic structures. Try using angled joints for the infrastructure.
Reply:It is time consuming but round hickory toothpicks are the strongest. I sanded 45 degree angles on the ends and then built cross beams in a playdoh mold and painted it with wood glue on one side and then removed it from the mold and painted the other side. Then I notched the beams and interconnected them over each other. My requirements were an 8" by 8" loading surface and had to span a 9" gap. It held 220 lbs before structural failure. My dad is a mechanical genius and he deserves the credit for the design.
Reply:ID SAY A WOODEN ONE IS THE STRONGEST ITS A OLD FASHION LEGEN ITS STRONG AN DURABLE