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November 1, 1999 Issue
November 15, 1999 Issue
November 1, 1999 Issue
Nothing This Issue
November 15, 1999
Commentary ... The Amateur Yacht Research Society -- September 1999 Meeting
Bob Hicks, EditorIt had been my intention to bring you a feature report on the AYRS Boat Design Symposium at Newport, Rhode Island on Septem-ber 25th and 26th but I wasn't able to stay around over the two days to hear what all the participating speakers had to say. My stay on Saturday encompassed the talks from four of the speakers only. Well, three of these turned out to be numbers guys, their enthusiasm and expertise focussed on measuring how fast certain boats would, or could, or did go. All three made extensive use of graphs, both linear x/y type and polar, with lots of dots marking data points and connecting curves or straight lines, all to explain to us what they had measured about certain boats indulging in high speeds.
I have found the AYRS folks to be an intellectually stimulating bunch, and so I maintain contact and attend their New England gatherings. Their journals are often packed with pages of formulas and graphs and much discussion of data significance, generally attempting to establish some point or other chiefly about boat speeds achievable by various design concepts (wind powered typically).
As the boats are often very far out leading (ragged) edge designs I am interested, but it's been a long time since my differential equations days at college, so I do not even attempt to comprehend how the data guys arrived at their conclusions. The conclusions do get my attention, and the methodology in layman's terms I can understand.
The first speakers were onstage together, forming a sort of Abbott & Costello give and take scenario, two professionals who appar-ently compete for speed analysis business but are also friendly. Richard McCurdy of Ockham Instruments designs instrumentation for the all important measurement of "speed" (sailboat version) and so does Lex Brincko. Brincko developed instrumentation and analyzed per-formance data for Steve Clark's Little America's Cup winner (catamaran) Cogito and Buddy Melges' America's Cup contender Heart of America. These two guys do custom measuring of speeds for those in the high end racing yacht world, they go to race sites, such as the America's Cup event held in Australia several years ago to measure local wind currents and conditions so their clients can better compete against the local knowledge of the home team. Costly stuff, like the boats and gear. All for that elusive fractional knot or degree of pointing.
What I got out of their give and take was the knowledge that it is not easy to measure absolute speed of wind or boat from the boat, a moving platform travelling in a moving medium of water (currents), propelled by force from a variable medium (air currents). One example, it appears that the ideal place for a windspeed anemometer sender is maybe 50' to 100' ahead of the boat. The air at the top of the mast has bad habits, like the end of an airplane wing it creates local turbulence messing up accurate measurements.
The human dimension emerged from this sea of data at one point when the discussion focussed on how certain "seat of the pants" racing skippers were reluctant to accept the numbers guys' numbers and change their ways. It was at this moment that 92 year old Olin Stephens, designer of several America's Cup winners, commented that while he designed a boat to do its job a certain way, his main skipper, one Bus Mosbacher, drove the boat quite differently than the back up guy who had been hired just in case Mosbacher met with a traffic accident or something on his way to the races.
The third speaker, Richard Boehmer, is founder of the Sail Performance Center, and currently is speed data analyst for Steve Fosset's PlayStation super cat which is going for an around the world speed record soon, I believe. Richard told us all about how the reported speeds, distances travelled in a day, and overall elapsed times of trips, down through the history of sailpower record keeping, fol-low some sort of similar curve on his graphs, the highest speeds achieved early on, etc. Like, nothing has changed since clipper ship days really.
What interested me was how highly placed still are those great clipper ships of the 1850s era racing to and from China or Australia. They set some top speeds only bested by very few modem superboats built just to set records. And they were carrying cargo in huge (by today's record setter boats standards) hulls driven by clouds of sail, vast areas up there grabbing the winds.
Apparently when the last of the windjammers in the guano trade, sailing from Chile to Germany in the early years of this century, the German "P" boats, great five masted steel hulled monsters, couldn't match those clipper ship speeds, some revisionist thinking emerged, like maybe those old guys of yore weren't measuring very accurately. Between dead reckoning estimates, irregular sightings to establish accurate positions, and the ship chip logs, perhaps there was margin for error?
All this fuss about measuring speed pro-vides these few experts with their arcane livelihoods providing their clients with instruments and data they apparently need to refine that already super sharp edge in sailing at speed. But as we broke for coffee, Andy Vavolotis, who has just hit 20 knots this past summer in his home-designed and built trimaran (version #6 as I recall since he started this hobby), said to me, "All I really want to know is am I going faster compared to the other guy." Any other guy he happens to run up against.
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