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The "Hammerhead" 1995 HPB
I began by designing and building some pontoon hulls, after finding out all I could about boat hull design at the public library (practically nothing). Then came building. The hulls were constructed of 2" thick insulation foam which I obtained from my local hardware store. This foam floats about 62 lbs per cubic foot. I glued them together using caulk recommended by a guy at the hardware store (later I found that 3M's "77" spray adhesive works much better) to get a hull size of about 8" wide by 12" high by 8' long. I then carved the ends of the pontoons so the forward and leeward (spiffy nautical term there) ends were boat-shaped, and sanded then smooth. To attach the cross-members and frame of the boat to the hulls, I installed some T-nuts in a 3/8" plywood deck, and epoxied it to the top of the hulls. I then covered the whole mess with one layer of fiberglass cloth, and a couple coats of "West Systems" 105 epoxy resin. (Wicks aircraft supply)

The frame and drivetrain were constructed with the aid of Bill Murphy, and consisted of a 2" OD (muffler pipe) rear cross member, and main tube, and a square tube front cross member. The mesh seat was borrowed from my ATP Vision recumbent bike. The drivetrain consisted of the cranks and bottom bracket assembly from a discarded bike, and a bunch of chain. I built it as a front drive to give the prop undisturbed water to run in.. The prop was a "14x12" fiberglass model airplane propeller. This mess was all brazed together. The boat weighed about 80 lbs. The boat's weight, plus my own 170 lbs were enough to sink all but about 1" of the hulls. I had cut it a little close.

I raced it at the Rockford raft race, on July 4th 1995, after a late night of last minute adjustments. The day was grim. It poured the whole way to Rockford, and I was concerned that they might cancel the race. When I arrived I discovered that my number 38 meant that I started 38 places from the beginning (about 1/4 mile back), and that all entrants were lined up along the shore. As the day progressed, it cleared up, until race time when it was the typical hot and muggy July afternoon. Most of the entrants were floats in more than one sense. They were floating parade floats. This makes more sense when you realize that the prize was more for creativity than for speed. A perusal of the area turned up what looked like about 5 serious racers. Then I was on the boat and we were in the water, and the starting gun went off. I started cranking. On a bike, you can relax between strokes, but I soon realized there was no reprieve on an HPB. It was like the stationary bike from hell. I could see Bob Buerger and Sean Costin on Bob's two person HPB, which started up in the front, off in the distance, and every once in a while their boat would sort of drift sideways, and I would catch up a little, and then they would take off again and I would fall further behind. (I would hear later that was because their chain kept falling off) I came in third, behind Bob Buerger and Sean Costin on Bob's two person HPB, and a homemade canoe with 5 paddlers. Good enough for a prize! I vowed to do better next year.

The Hammerhead seems to be highly adjustable, as is shown by Jami Brunkalla (age 11) racing it at the 2000 Hydrobowl. It will float a person up to about 200 lbs.

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