This is a popsicle stick bridge I built while in the last few weeks of my fall college semester. I used 924 popsicle sticks to build this bridge. Some of the popsicle sticks were modified, so this varies from the purist approach I have taken in building popsicle bridges in the past. I used only Weldbond glue for this bridge.
This bridge was 5 feet long, 10 inches tall, and 8 inches wide. I used a Pratt truss as the main design. Unlike my previous popsicle stick bridges, I did not have printed blueprints or plans when I built this bridge. Instead, I was building on the fly, and somewhat by ear. Because of this, some of the trusses are not completely symmetrical. I ended up making four separate trusses, and then gluing two together to make each side of the bridge. The clothespins I had did not open wide enough to accommodate the 4-5 layers of popsicle sticks, so I had to use heavy books to hold the bridge together while it was drying.
Other difficulties came up when building this bridge. I had to sort through 2600 popsicle sticks to find enough usable ones. I am pretty picky when it comes to popsicle sticks. I didn’t really have a good plan of action when I started building the bridge, I simply had picked out a design and was relying on my previous experience to get me through. For the most part this worked.
The first testing of the bridge consisted of 220 pounds worth of weights. The second testing included putting a piece of plywood on top of the bridge and me standing on it (170 pounds). The people acting as my spotters noticed that one end diagonal chord was bending tremendously, so I decided to call off any more testing until I could repair that one piece.
As you can see in the above photo, one of the end diagonal chords started to bend. I called off further testing until I could shore up this end. The next day we tested the bridge again, and I was able to completely walk across it. I then offered to let other people stand on it. Unfortunately, my camera which was set up looking through the bridge to catch the breaking of the bridge had turned off. The bridge broke when the first person attempted to stand on it. This was partly my fault for not clearly explaining how to stand on the bridge to distribute the weight evenly. Oh well, it was a fun project to build and test.