How strong is glass compared to plywood? Here is a table comparing strengths with out of plane loads (like water pressure).
Plywood/Glass Thickness Conversion comparing bending strength. (Assumed 60,000 psi bending strength for glass and 10,000 for plywood)
Assumed that triaxial amount is on both sides of a core
Ply thickness Triaxial thickness Core
3mm ply equals (12 oz) 400 gsm w/12 mm core
4mm ply equals (17 oz) 600 gsm w/12 mm core
6mm ply equals (22 oz ) 750 gsm w/12 mm core
9mm ply equals (34 oz) 1150 gsm w/19 mm core
12mm ply equals (2) (22 oz ) 1500 gsm w/19 mm core
This plywood/epoxy CM catamaran has been carrying passengers for more than 20 years there on Lake Tahoe. It was always one of my favorites. And its a demountable boat.
I understand that the USCG stability rules are catching up with the increasing girth of Americans. The official passenger weight for COI boats is to go up from 160 lbs to 180 lbs as I understand it. For monohulls, that can be a crisis. For catamarans, it will not actually change the stability at all. I expect that everybody will need to revise their stabilty calculations and stability letters. I have spreadsheets ready and can do that for everyone who needs it.
Related, I can’t believe that with all the budget cuts, a plans submittal and inspections for a COI vessel is still free. Where else can you get a building permit for free? I can’t imagine it will be free for long. Submit those COI plans soon.
The first Earthwise ferry is nearing launch at Lake Victoria. See http://ewventures.wordpress.com/ I worry about the weight and crossarm revisions, but its almost wet. It is cylinder molded plywood/epoxy vacuum bag design, though KHSD is never noted as designer.
The KHSD 63′ catamaran Profligate led the start of the 17th annual Baja Ha Ha race.
See http://www.latitude38.com/lectronic/lectronicday.lasso?date=2010-10-25&dayid=496 Profligate is the official cruising boat of Latitude 38 magazine and belongs to Richard Spindler. As an aside Latitude 38 magazine is far and away the best sailing magazine there is. Most issues are keepers.
I got to go sailing with Barry and Karen, the owners of Sarabi earlier this month. Sarabi is a KHSD 56 catamaran with an Aerorig. See http://www.multihulldesigns.com/designs_other/56aerocat.htm for more pictures. Its a fast, safe cruising machine. I enjoyed their stories about sailing in “aquarium mode” through green waves, or closing on monohull friends so fast at night that they were mistaken for pirates. She looked great for having done most of a lap around the Pacific. Thanks you two. It was a fun sail.
CSR Marine on Northlake Ave here in Seattle will be gone by the first of November. CSR has been a fixture there for some 25 years. They were not only the best, but they hauled out multihulls. And they owned the legendary trimaran CHAAK. Its almost like the space needle moving. They will have their two smaller locations near the locks and at Des Moines.
I have heard from several sources that the Puget Sound Waterkeepers threatened them and many other waterfront businesses with ongoing lawsuits unless they left. Or, I heard, they could pay protection money and stay. I will be finding out the other side later thi
s week.
I have worked in and with many boatyards over the years. I have never seen a more contentious boatyard with the environment.
I support the Greenpeace and all, but this seems wrong to me. I will get to bottom of this soon. CHAAK's last haulout below.
I got a bit behind on this blog when the computer went down then I got hit with serious deadlines. I'm back and there is a lot going on.
First, I got another great youtube video from those wildmen in Italy with my 24' trimaran Muffalo. See
I just got Makita 2.5 hp compressor (MAC2400). It keeps up with my volume spray painting and is quiet. Odd thing is I bought its evil twin a few years ago. A Master Power MPAC521, which looks almost the same. It was frighteningly loud, could not really keep up, and filled the garage with smoke. After only about 30 hours of work over the last 3 years, it finally could only produce about 20 psi.
What a relief it is to have the Makita.
Henk and Joke have been sailing their kHSD 45 all over the Atlantic doing fabulous tours for years. See http://www.zeevonk.nl/eng_index.htm
and http://www.youtube.com/watch?v=Ye9MUXAXG0g&feature=player_embedded I have not been able to contact them previously. A seadog moored next to them finally put us in touch. I’m going to try to set up something here to track where they are when. Hence the title. They are in Curacao now. There are other world sailors also that I will highlight soon.
I found this beautilful old style KHSD D-30 demountable trimaran on the web somewhere. I have no idea whose boat it is. I see it has the old style spade rudder that could kick-up even while turned.
The guys sailing the KHSD 24 in Italy (they have that great video at http://www.youtube.com/watch?v=RfSQg4s_LsU and they promise another one soon) sent some new pictures. One in a pretty good breeze,
flying
and look there, pulling a wakeboard in a storm. Guys, be careful.
The KHSD daycharter catamaran Alii Nui is shown in an ad on page 115 of Professional Boatbuilder. It was built by Schooner Creek of Portland, OR and operates out of Lahaina, Maui. See http://www.aliinuimaui.com/
Another cat featured with no designer listed.
IBEX is next week in Louisville, KY.
I guess I will be skipping IBEX this year. It was great last year, but half the draw was being in Florida. Besides too much work here to take a week off. See http://www.ibexshow.com/
Kurt Hughes on Catamarans, Trimarans, and Boat Design
