It took four days of failed attempts, and some duct tape, but we finally crossed the finish line on Thursday (June 27th)!

In my last post I explained that our fins were too small to produce enough force to steer the submarine easily. Our pilot was convinced that it was still enough force to steer the submarine, but it would take some patience and skillful piloting to keep the submarine running straight along the course. After three days of failed attempts to learn to pilot the submarine, members of the team began thinking of ways to enlarge the fins of the submarine. Larger fins would produce more force to steer the submarine with. The problem with enlarging our fins was that we had no materials to work with. We used up our sheet metal, ply wood was too thick, and the foam stock we had was not large enough. Come Thursday morning was scoured our trailer of supplies. We arrived with this solution: Cut up some thin plastic boxes we used to store tools, screw them to our wooden fins, and then wrap them in duct tape to help keep their shape. We quickly realized that we only had enough scrap plastic to enlarge two sets of fins. We decided to enlarge the dorsal and ventral (top and bottom) fins, which would give the pilot more control over the submarine’s yaw (left and right). Once the plastic was attached and taped with duct tape that the team from Waterloo kindly allowed us to borrow, we rolled our submarine back into the basin and started our race attempts once more.

Our first attempt resulted in the drive chain popping off, but on our second attempt the submarine breached (floated to the surface). However, the race course announcer never signaled the pilot to stop. So our pilot (who was Dakota now) continued pedaling even though our submarine had become a boat. Although the pilot had no control over depth, he was going straight down the course, which showed that our dorsal and ventral fin enlargement worked! Slowly the submarine lurched through the timing trap, and eventually reached the finish line! This finish boosted team moral immensely and gave us motivation to continue through the week.

Further attempts resulted in drive train issues and buoyancy issues. We did have one more successful run, but it the submarine breached then as well. Our fasted speed was 0.92 knots! About 1 mile per hour, which it pitiful compared to other teams, however it is impressive for a first year high school team. Many other teams never finished the course, some never made it into the water. A total of six teams never finished the race course, which included college level teams and high school teams that had done these races for years on end. For a team of high school students building a human powered submarine for the first time–a task that should take two years, but was done in less than one year’s time–reaching 0.92 knots is an achievement, one that we hope will be surpassed by future Dover teams that continue to make Dover proud.