Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

Go Back   Boat Design Forums > Design > Stability
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 09-23-2011, 12:07 AM
lead_ior50 lead_ior50 is offline
 
Join Date: Jun 2008
Rep: 10 Posts: 2
Location: los angeles
wind/wave limits for old IACC yachts

you might remember some of the '95 and newer boats breaking in relatively benign conditions (example one Australia 35 in San Diego in 1995, even though arguably there was some crew error involved) ). If I recall correctly, IACC race comittees would cancel races above 20 knots, but often wind speed is not even so critical as compared to sea state. Does anyone have knowledge of the design briefs for these yachts, specifically '92 and '95 vintage. Some of the charter outfits have taken these yachts out sailing in pretty strong breezes but usually flat waves.

For example, would you want to be on one of the old '95 vintage yachts beating into 6-10 foot waves for hours without a life raft on board ?

then, as a follow up question: Many of these older IACC yachts doe not have a lot of stringers / bulkheads..
has anyone seen people owning these yachts going ahead and retrofitting stiffening inside the boats to make them
more sea worthy. What about the keels? are they designed to last one season of IACC racing ?

apparently high winds are not the problem, it is the sea state and "user error". Once beating into steep choppy 6 foot plus waves, all bets are off ? I saw some IACC yachts inside, and there seem to be very few stringers / bulkheads forward. Also it seems - looking at some finite element analysis of IACC yachts (saw a stress distribution diagram of AUS 35 published somewhere) the highest loading is at the leward genoa track in the deck. so, shock loads there and slamming loads in the lower bow section would be the worst case scenario. What about the keel box? most IACC yachts have the "slotted" keel -hull connection which seems to be much stronger than the more conventional keel flanges bolted against the hull. Yes keels have fallen off but in many of those cases prior grounding or other issues were at fault..
Reply With Quote
  #2  
Old 09-23-2011, 06:42 PM
cracker cracker is offline
NA
 
Join Date: Sep 2011
Rep: 44 Posts: 12
Location: Queensland
I've approved one for 6 ft waves, but 10 foot, no way without a liferaft!

Keels, whole show is designed to be highly stresses and heeled in competition. In charter should not be anywhere near these loads. That said, I still wouldn't approve for 10 ft waves without a lot more information.
Reply With Quote
Reply



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wave Wind Power with Piezo at electric boat mtumut Boat Design 8 09-07-2009 03:00 AM
Wind/Wave and Current Effects on Cargo Ships MattD Boat Design 5 08-30-2006 03:10 PM
Quick question...IACC Numbers/Spec Matt Lingley Sailboats 1 02-14-2006 08:48 PM
IACC Rule DSP limits jboat Boat Design 0 12-28-2004 10:47 AM
IACC winged keels design question tim mcd Boat Design 5 02-04-2002 07:34 AM


All times are GMT -5. The time now is 04:47 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net