Ok then,?a reply to David with?a not so veiled attack on?me and my earlier reply?
Now, I wrote: "Some (...) pushed hard have gone over when racing"
Your sarcastic aside?--?"(when you call this pushed hard ok and have no problem righting a cruising cat with all its gear is no problem to your, up to you)" --?is a red herring diversion?from my example?pertaining to?racing. Trailersailer type cats, any?of them,?launched?to race are hardly likely to have "all its(cruising)?gear". The skipper will ensure they are as light as possible. Further, it's no race if a boat is not pushed to the limits.
OTOH, any idiot or inexperienced skipper can flip almost any boat at almost anytime there's a good sailing breeze, with or without waves.... and if it's of a relatively?narrow beam with a relatively large tall rig, and is relatively light, then so much the easier.
I doubt you understood the intended?meaning of the phrase I used that you?repeatedly pounced on.?"I believe" in general conversation generally means?much the same as "I recall", "I think",?"I recollect", "I don't have the data at my fingertips this minute but know I?have seen or heard it", and etc.
?As for assumed?"beliefs" vs the "facts" you've not referenced?for alleging many Australian cruising type?trailer catamaran designs?capsize, well, feel?free to link to those facts or to?put them?up.
There are many alternative multihull stability formulae, old and new,?with various software availability. One of the earliest to formulate catamaran stability, and to reformulate that in 1977, and apply it to design?is Wharram. (https://www.wharram.com/site/how-we-design/catamaran-stability) The Wharram designs have a?great?safety record re capsize.
Waller trailer catamarans (note?your?plural) are capsize prone?you say? Google apparently?says 'no' to a "waller catamaran capsized" search.
Did you mean the TC670 TRAILER CATAMARAN? From?its?design webpage?description:
"..Particular care has been taken to ensure that this boat is both a safe and reliable performer, with an efficient sail plan and low profile for windward performance. Note that its intended use is sheltered and semi sheltered waters, and not open water...."
Mike Waller himself?has commented in a Woodwork Forums>Boat Designs/Plans thread that:
"In fact, the standard boat is more stable than it seems, because the Hobie style outrider seats let you get a couple of hundred Kilos of (Bum) ballast much further outboard in stronger winds. Only one has ever capsized (to my knowledge) and this was in a gust measured at 100 kph by the nearby airfield. Notably, an identical TC670 sailing in company did not capsize, and they righter her and sailed her home. In the final analysis, safety in these narrow cats is more about the common sense of the crew than anything else. I have had several queries from builders wanting to make her into a blue water cruiser and I have tried to dissuade all of them." (http://www.woodworkforums.com/f33/waller-tc-670-a-105124#post1583184)
Perhaps you meant the TC750 CATAMARAN? A much bigger boat all round.
"Particular care has been taken to ensure that this boat is both a safe and reliable performer, with an emphasis on good cruising performance and accomodation rather than all out racing, in keeping with its intended use as a family boat. Note that its intended area of use is sheltered and semi sheltered waters, and not open water.
... Note that this vessel is wider than the standard road trailing width for most areas. Normally this yacht would live on a trailer frame at the local yacht club (much cheaper than a berth or mooring)."
DUO 425? Like I said, heaps of off the beach racing class type Australian catamarans have capsized.
Graeme
---In k-designs@..., <Bernd@...> wrote :
Hi David
Again, I know from more cats which are to small and from all designers and that the turned over above windforce 3. (when you call this pushed hard ok and have no problem righting a cruising cat with all its gear is no problem to your, up to you)?
I know that even Waller cats where turned over, nothing to do with belief. Look, I have developed programs where you can calculate the stability and speed of catamarans (with a safety factor of 90% by the way). See download page. You can lod them down and make the calculations for yourself. Calculations have nothing to do with belief, but are facts. It is of course up to you to belief, but this is not my strong point. I try to design safe boats for my clients that is all. Non of my boats ever turned over, besides one DUO 425 at the Baldenei lake in Germany.?
Bernd
