John Winters wrote: > No one tests a ship with just one run down the tank. It would be poor > science and irresponsible professionally. The +/- 5% is based upon tens of > thousands of tests in tanks around the world. [snip] > Just to provide some perspective, every boat that I design (and those of > some competitors) is tested using a Brooks and Gatehouse Speed Boss. [To John: What is that? What does it measure?] > All tests are done by me using the same paddle on the same body of water in > calm conditions. Each test series involves over 100 runs. 50% are done at > cruising power (for me) and 50 % done at gradually increasing power output. > Suffice to say and without boring you with reams of data. I don't get > nearly the repeatability that others get in their tests. No doubt this is > because I am not so good a paddler but I suspect that I am closer to the > norm than the experts. I have tried some expert paddlers but have not yet > found one a whole lot better. Perhaps it is just more difficult to get > accurate results when the tests are controlled. John, it has occurred to me that perhaps an improved (or, maybe, just alternate) way to gather data on the paddler/paddle/boat system is to place a force sensor *between the paddler's hands and the paddle shaft* and an inertial displacement sensor *on the paddle shaft* at the hand position. These, coupled with a knotmeter, and with real-time data piped to some on-board data-gathering instruments, might allow each paddler to tune his/her stroke style and paddle choice to achieve a more objective estimate of what works best. The on-board data-gathering stuff could be as simple and cheap as the system I use extensively with my students (they are TI Calculator Based Laboratory units, interfaced with a graphing calculator). The force sensor I suspect could be cobbled together from thin pressure-sensing pads which could be made to conform to the shape of the paddle. Don't know about the inertial displacement sensors. Of course, knotmeters are off-the-shelf. Reason this came to mind is that it is *peak force* which is the prime determinant in exacerbating tendonitis, while it is some rude analog to "force times distance" that determines how much energy the paddler puts into the water. As one susceptible to tendonitis, I could really use an analysis which could allow me to "spread out" the force I exert on the paddle, while retaining the same total energy (work) expended on the paddle/boat system. Do you (or, others) have any knowledge of Olympic racers (or, similar) who might have developed such a system? Thanks. -- Dave Kruger Astoria, OR paddler/chemist/teacher *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Mon Mar 30 1998 - 07:45:27 PST
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:29:55 PDT