During my first semester as a Junior in High School, our teacher Mr. D for Engineering 1 gave the class a final project to end the semester off. He announced to the class that day that we were to create a truss bridge that would have to hold textbooks, and whoever won would get a 3-D printed item of their choice as their trophy. He allowed partners and I got the chance to work on the bridge with my friend, Francisco.
This is a real-life example of a truss bridge.
These are the strongest types of bridges that can withstand extreme conditions in the outside world. The problem here is that sometimes, a truss bridge can be costly due to the amount of materials it needs.
At first, the class took notes of what a truss bridge was, and what were the forces of nature that might come into play here. Afterwards, Francisco and I had to plan out what type of truss bridge we wanted to construct. We had only had certain types of trusses to build due to the limited time everyone had. These were the types of trusses we were allowed:
For reference, look at this:
Once we chose our bridge, we were to create the bridge itself using balsa wood and wood glue. Nothing else. The deck, or road of the bridge would be made of popsicle sticks. The requirements for everyone's bridge were that the bridge has to span between 20 to 32 inches, have a height of 3 to 6 inches, and a width of 4 1/2 inches. The road had to be only popsicle sticks that laid side by side to fillout the roadway, and the creation of the bridge must use wood glue to attach pieces together but no visible excess glue. We had to use wax paper to plan and draw the side of the truss and assemble both of the sides together.
We decided to settle on a Baltimore bridge with a through structure. So we began our process. Unfortunately, my friend got sick and I was left to create the proportions of the truss sides using wax paper. I managed to create one side, and the day afterwards, Francisco created the other side while I was gone. The situation here was that one side ended to be longer and ever so slightly taller than the other side. That worried me, but Francisco insisted that it was fine. We worked on the road of the bridge, and Mr. D had mentioned beforehand that it should be on top, laying on the sides. We deliberately placed the sides of the truss bridges on top of the popsicle sticks instead. This took us about three and quarter class days to create (or in other words, 3 hours and 15 minutes total). We were impressed because this build was a structure that needed time and material. The bridge measured 26 1/8 inches lengthwise x 6 inches in height x 4 7/8 inches in width. I was somewhat confident in our bridge.
The day that everyone was testing their bridges, I was perturbed on the simple errors that were on our bridge. I really thought that we were going to do horrible. So naturally, I panicked. But Francisco had hope. We saw that the highest amount of books that one bridge managed to hold was 14 books. It was a class from Mr. D's second hour, and they also had created a baltimore structure. Anyways, Mr. D. was adding our bridge into the data sheet and said that all of our requirements were met. He then drilled a hole in the middle of the bridge to hook up the wooden plate at the bottom (he accidentally broke a piece of the through top of the truss). And he started to place one book, then another book, then another book...
I should not have worried at all. Our truss bridge could withstand 14 books. They were small, heavy textbooks. We didn't know how much each textbook weighed, so we asked if we could weigh them. Each book was 3.5 pounds, meaning that our truss bridge could hold 49 pounds, roughly the weight of a young child, before it breaks. Our bridge almost held more than the one in Mr. D's second hour. We won in our class, and the day after annihilating all the balsa wood trusses, all the data was inputed. It turned out that we were the only bridge that held the highest amount of books and that did not get disqualified because we met all of the requirements and did not go over/under them. So as a reward, Mr. D, as promised, gave us our custom 3-D printed trophies.
Was this a happy ending? For me, yes it was. Should I have worried? NO! So what have we learned? Well, I learned that balsa wood is strong for its weight. It is quite light, especially when cut into thin sticks. Also, another thing I learned is that one should always have some hope in everything, even just a little. Life is unpredictable, and the odds of something can be favored towards you if you put the hard work into it. Worrying a lot does not help at all; worrying excessively ends in catastrophe. So yes, you can feel concern, but do not do so to the point that it can hurt you mentally, and everything else will topple down. Take a chill pill. Relax for a bit. Have some faith. You will see results. In the end, everything is going to be all right.
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