When we were thinking about doing underwater engineering as our topic for D.E.E.P., we had no idea how we would do it. We didn't know how to wire batteries to motors or solder; we didn't even know what a soldering iron was. We were completely clueless on how we were going to build a sub. However, we had a lot of encouragement and we were very excited about it. So, we bravely decided to break the barriers, and be the first girls in the history of D.E.E.P. to do the topic of underwater engineering. One month, about a thousand trips to hardware stores, and about a million meetings with Mr. Kerlin and Mr. Harlan, we now know how to do all these things we never knew how to do before.
We learned how use tools such as a crimper, a hack saw, and a wire stripper. We learned about wiring and how to connect them together by soldering. The real test was when it was the day before we were going to run the sub in the pool and the sub wouldn’t turn on. On our own without anyone to help us, we had to go through all the wiring and fix the wiring by ourselves. And, we knew how to do it! We had the disadvantage that most people who choose engineering do not have: we did not know how to do anything, maybe with the exception of designing the outside of the sub. We had to learn practically everything.
Other than the things we learned about engineering, we also learned a lot in the departments of math, science, and web design. In math and science, we learned laws and their formulas that had to do with scuba diving, and then we learned how to plug numbers into the formulas. We also learned how to analyze error from results. When we were in 6th and 7th grade science class and we were writing discussions, all we could say was “there may have been error” and “this may have happened.” Now, we can calculate exactly how much percent error is in the results. We learned how to write a project proposal and what real scientists have to do when they want to do an experiment.
Another major part of D.E.E.P. is web design. There are few 8th graders that know how to design a website. D.E.E.P. allows us to be part of that few. We learned how to use so many programs that we would have probably never learned if it wasn’t for D.E.E.P.
We also learned how much hard work and time goes into making a submarine. There is the design, the electronics, and the buoyancy. In the design process, one has to expect to change the design, A LOT! We changed our design many times and finally came up with one we were happy with. Then in the electronics and buoyancy, one has to be patient and be able to play around with wires until the correct connection has been made. With buoyancy, one has to be even more patient than with electronics. We found getting the sub to stay neutrally buoyant and even floatation on all sides was the most tedious, frustrating, and difficult part of the whole construction process.
Unfortunately, a major factor in D.E.E.P. is the time period we have to complete it. D.E.E.P. is only a two month long program. Project design takes the first few weeks and by the time we were ready to really build the sub, we only had about a month left. Also, we only meet for D.E.E.P. a few hours a week. In that time, we also have to do things like web design, math and science classes. If we had had more time, we could have perfected the design even more before we started building it. This would have cut out many trips to hardware stores.The day we tested our sub, we decided not to test vertical speed of the sub. However, if we could had more time, we would have perfected the sub and we could have done the original problem statement, which would have involved testing the horizontal speed at surface, depth, and then the vertical speed.
For us, the design process was a very long, tedious, and frustrating one. We had to try so many different designs and when we came up with a design we thought would work, it didn’t. We found that the sub would always slowly fill with water, so we decided to drill holes in the sub to make it fill with water faster, because then we would know what we would have to be dealing with once the sub was filled.
See iBlog for a day by day detailed look at the work we put into our sub
With floatation, we just had to keep trying and never give up. We found that wrapping the top and front section of the sub holding the batteries, with lots of bubble wrap, and the other end with none, worked the best.
Once we finally got our sub 100% working, we ran seven trials. We got an average speed of 1.0 foot per second (0.68 mph). At this rate, it would take our sub about 38 hours to get to Catalina! Our times varied a bit mostly because the sub did not go in an exactly straight line; therefore each trial it did not travel exactly ten feet. It somewhat curved from left to right and up and down, as you can see in the video below. So because the sub went different distances each time, the times were slightly different each time.
There was 8.3% of error in our trials, which is not bad. We also found that our hypothesis was only .11 feet per sec off of the actual average speed.