• 3rd February 2007 - By greg
    Check out this NIFTY Within boat speed calculator that Rick Willoughby whipped up for me:

    You can change the cadence RPM, gearing for the prop, and drive efficiency and it will output an estimated speed and power requirement in watts. This is all based on the hull shape of Within’s Nimbus Hyak hull shape, weight and an optimized prop.

    The 24 hour HPB record

    The reason we are starting to run some estimates for speed and power for Within is because I would like to plan to make an attempt at the 24 hour human powered boat distance record this summer. The record stands at 168 km and was set by John Howard in his HPB called Pedalos. Some of you might recognize the name John Howard. He won Ironman Hawaii a way, WAY back in 1981. He’s also a 3 time member of the Olympic cycling team, and owner of the 24 hour cycling drafting distance record of 539 miles.

    I know from the 24 hour HPV record, that I can maintain an average output of 150 watts at 80 rpm for 24 hours, and with breaks and coasting, the overall average ends up at between 100 to 110 watts. My 100 watt speed in Within should be around 9 kph, so doing the math results in 216 km for 24 hours which is comfortably over the current record.

    I would really love to take a shot at the record this summer – perhaps right here in Calgary, since all we need is a large, flat, calm body of water and a nice, sunny day. It will be a great opportunity to generate some PR for the Pedal The Ocean Expedition, and for me to get a better feel for cranking out the watts in Within (the power from Within!).

    Within’s deck is finished!

    On Tuesday Ben, Matt and Greg Nuspel joined me in the shop to do the wet layup for the inside of the deck. It went way faster than I expected – we put down and wetted out a layer of Kevlar and the fiberglass woven roving. Then a layer of release film and blanket and it all went into my gigantic plastic bag. We used my vacuum cleaner to hog out the air to get it going, then two venturi’s connected to my air compressor to pull the vacuum. The vacuum pressure wasn’t very high, but high enough to press the wetted fabric tightly down to the decks edges.

    I was very happy with the result – we were able to bend that heavy woven roving fiberglass fabric around a very tight edge and it came out nice and square.

    I could not weigh it because I can’t see the scale read-out under the large shape, but it feels pretty heavy. Definitely heavier than the Nimbus Hyak kayak hull that the deck will be bonded to. This will create a top-heavy boat, but we know that. The plan is and always has been to either add a ballast keel to Within, or to place a heavy plate between the seat rails on the floor of the deck. Well, that’s what the prototype boat is for – to learn through trial and error in real, not simulated conditions.

    Now, since I have Pat at RaceRecon to help me with the logistics of this project, hopefully I will be able to make some better progress in the shop with boat building. I think the next item on the agenda will be laying down a thick layer of fiberglass to reinforce the Hyak hull floor, then I want to get on the drive leg. Once the drive leg is completed, I want to build the drive leg bay in the hull, the seat, then the bulk heads. Then I’ll join the hull to the deck and cut out the canopy.

    Hopefully, Within will be ready for water testing in late April.

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