Guys, I highly recommend ‘friending’ Julian Everett on Faceplant, or checking out his terrific series of articles in Seahorse. He is a naval architect and one of those who innovated under the IOR very successfully .
Andy Andrew Burton 26 Beacon Hill Newport, RI USA 02840 http://sites.google.com/site/andrewburtonyachtservices/ +401 965-5260 > On Mar 17, 2022, at 18:57, Martin DeYoung via CnC-List > <[email protected]> wrote: > > > Matt and Rob, > > It sounds like the design evolution from the 1970 43’s to the more IOR based > 1975/76 42’s the boats lost a bit of reliability downwind. Was it mostly the > IOR rewarding max beam more forward and a pinched in stern, a increase in > sail area with a reduction on ballast (SA/Displ.), or a little of both? > > IIRC the 1970 43 hull design included something called a “high prismatic” > ratio. Maybe the swept back keel design makes it more forgiving when pushed > hard off the wind. It also has a fuller hull shape aft compared to later IOR > designs like the C&C 39. > > So Rob, what I’m asking is for something like a short study/discussion > similar to your “Good Old Boat” magazine Design Comparisons articles. The > current issue’s Design Comparison has some good CCA vs IOR discussion but it > seems the 1970 43s and 1976 42s are all IOR with no CCA influence. > > Martin DeYoung > Calypso > 1971 C&C 43 > Port Ludlow/Seattle > > From: Robert Mazza via CnC-List > Sent: Thursday, March 17, 2022 12:01 PM > To: Matthew > Cc: Stus-List; Robert Mazza > Subject: Stus-List Re: While we wait for spring > > So, what you are saying Matt, since I was the one steering when we went into > that broach on Burlington Bay, that it wasn't my fault! Thank you for that > reassurance 40 years after the fact. ;-) > > However, all those masthead rigged IOR boats were a handful off the wind. > However, I remember pegging the speedo at 20 knots on Marauder with the #2 > hoisted on the pole in over 30 knots of breeze during the middle distance > race in Canada's Cup. The bow wave was breaking at the chainplates. I'd > attach a photo taken of the crew at that point but know how that gets held up > for approval. > > Rob > > > Please trim your messages before sending to the list. Thankx
Please trim your messages before sending to the list. Thankx
