I did get a chance to do an update to the Cylinder Mold Construction Manual. Its about 99% there, needing just a few more links and a few more graphics. I’m going to figure out how to make it available in both hard copy and PDF. Maybe put it on Amazon.
I took a picture of one of my charter cats in Cabo. Frank Rowden has been running this 46′ day cat for some 15 years. Thats a crowded harbor when the liners come in. http://www.cabosports.com/sailing/index.shtml
Just back and catching up on everything. I’m making my way through 248 emails, after I weeded out the spam.
I’m working on this little 17′ roto molded beach trimaran. It is intended for resorts.
I had not yet seen the updated website for the 65′ , 100 passenger Alii Nui. This KHSD charter cat was built in foam/glass by Schooner Creek.
One of the perks of the job is getting a visit from sailors of KHSD boats who rave about the boat. Brian Bell and crew stopped by today. Based in New Zealand, their cruising ground is the South Pacific. Somebody has to do it. Beautiful boat.
I will be out of the office Feb. 19 through 26. I might not even have email.
The 50m oceanography catamaran design keeps going on. It has become a black hole for time. I think I can pull off of it for a while now. It does look pretty cool.
Congratulations. The guys and a girl, Team Hallin, the trimaran rowing team using KHSD hull lines just arrived in Barbados to set a new world record across the Atlantic. See the arrival webcam at http://www.portstcharles.com/webcam_window.php?cam=3.
And http://www.teamhallin.co.uk/wp/ for the announcement.
For everybody who expected design work last week and didn’t see it. Here is why. I had my head down rushing to get this 50 meter sailing oceanography research vessel modeled. Client is Windhorse Lightships L3C.
I had forgotten there was a brave daycharter company operating right up in Blaine, Washington. They use one of my 36′ charter boats in a box. Bring your warm coat. See http://rapscallionsailcharters.com/index.html
Team Hallin, with KHSD hull design, is half way across the Atlantic. It is still leading the rowing race and is still on track for a new record. See the chart at http://www.oceanrowing.com/SaraG_2011_comparative.htm and articles on the race at http://www.teamhallin.co.uk/wp/
The KHSD designed 65′ catamaran for Lake Victoria is looking better than I have seen it look yet. I’m still worried about the weight. See also http://www.earthwiseventures.com/The_Ferry_Project.html
Carbon chainplates sound good for marketing, but E-glass is just as good. Here is why. Imagine a 30 trimaran that weighs say 2000 lbs. The chain plate vertical load at overturning will be about 1000 lbs. Add in vector of shroud angle and crew and lets say a static plate load of 2000 lbs.
Hand layup and vacuum bagged carbon uni should have a tensile strength of some 80,000 to 120,000 psi depending. That means a chainplate of 1/35″ or 0.7mm. Now, tensile is not the only load, but for now assume it governs. Double it for grins and put one at each end of a rod or something. Even at 1/15″ (1.6mm) it looks way too weak to most of us. Most of us do not have an instinctive feel for how much carbon looks right. Most of us would only be comfortable if the thicknesses look to be at least what Skenes would require in stainless. That gives dozens of safety factors just to get it to look right.
E-glass uni will not be that much less tensile strength than the carbon uni. Expect maybe 60,000 to 70,000 psi tensile strength. So even with e-glass you will still have a safety factor of dozens. Carbon fiber does have better than twice the fatigue resistance, but the safety factors are so many, it doesn’t matter.
E-glass does provide better shock absorbing, theoretically. Its stretch to failure of around 6%, combined with the same from the resin, should help absorb shock. The only problem is that with a safety factor of 20 or so, the e-glass won’t give anyway. Its not loaded enough to give.
Carbon fiber is fun for this job, but not at all necessary. I know, its heresy.