Garrett Boon Basswood has been my wood of choice since I won the GA state Science Olympiad bridge building event back in 2004 (the good ‘ol days). I have since used Basswood with much success in bridges and towers. My Fernbank Bridge was built completely using Basswood, as well as many others.
Here is the story of the Prairie Popsicle Stick Bridge told in video format. As far as I know, this is the longest working popsicle stick bridge that a person can walk across. If you know of a longer bridge that does the same, please let me know. The largest popsicle bridge was built back in 2008 in my dorm room at Prairie Bible College. For many nights I slept on the floor, as I was using my bed space as a worktable to glue the bridge together.
I have always wanted to build a model suspension bridge, and finally I have finished one. This is a popsicle stick suspension bridge. I created it from scratch, coming up with the design on my own. After testing it to failure I learned quite a bit about how suspension bridges react to loads. This model suspension bridge uses popsicle sticks as the main building material. The decking is cardboard, and the “cables” are 550 parachute cord (military surplus)
To help clear up any confusion when I talk about the “efficiency” or “efficiency score” of the bridges I build. This is a mathematical equation to determine how well a bridge performed
This is the updated design of my Short Pratt Truss Bridge made from popsicle sticks. The only difference was the addition of 4 more popsicle sticks in key areas. I doubled up the angled sticks on each end, and made the lateral bracing into an X shape rather than a zig-zag pattern
This is a popsicle stick bridge I built using the Pratt Truss design. This bridge is 13.5 inches long, 4 inches tall, and 3.75 inches wide. This bridge weighed about 70 grams and held 73 pounds before breaking. I used 46 popsicle sticks to build this bridge. That gives it an efficiency score of 474
Nic’s design held a weight of 224kg and had a final efficiency of 1020. It did not shear or snap at any member, but bowed in the second third of member C-E. This member did have angled bracing to stop bowing and this brace did not snap it was only the glue joins in this brace that failed. The truss ballooned out at the point when 2.2kN of force was applied. It was at this point that the test was stopped
Video of a large Pratt truss bridge being loaded to failure
This is the absolute best video I have seen about building model bridges. Roy Coleman, the founder of the International Bridge Building Contest, gives a very informative presentation in this video. The presentation is over an hour long. He shows how to build a bridge from scratch. He is gearing his video towards the…
Here is the Science Olympiad bridge J.C. Booth built for the Georgia State Tournament in 2005. I don’t remember exactly what place it got, but am pretty sure in placed in the top 3. This bridges uses the typical design for that year, with slight modifications