Big Deadlines

Lots to post but big deadlines this week so it has to wait.

Topics for next week include the famous designers sketch laminates drawing. I heard back from the author of the sailing freighter article. I have heard from an Astus tri sailor. New cat pictures from China. Thoughts on all the multis being abandoned.  A new 85 cat design. And more. Deadlines come first.

MACM and Famous Designers

Last week I came across a drawing of some hull laminate work by a famous designer. It was three kinds of stuff done wrong. I sometimes wonder how that is possible, then I remember one thing; MACM, (marine applications of composite materials) conferences. I still say the best that ever existed.  Unfortunately they are no longer held.  Sorry, but IBEX was not even close. And in the 10 or so that I went to over the years, the only famous designers I ever saw were the late Lindenburg, and Roger Hatfield. It seems that most famous designers prefer to go to conferences where they are praised and learn little. I prefer the ones where I am the dummy and I soak it in. It seems like the famous designers don’t feel the need to be the dummy and learn?

Lightning Protection

I had a very interesting time talking to Ewan Thomson while at the 52′ Aerorig cat.   As we know, carbon fiber is a very good conductor of electricity, so carbon masts are particularly vulnerable.  They do not necessarily show the damage.  Black burn against black background.  Ewen works to get the surge down to the ocean while doing as little damage as possible to the carbon mast and the rest of the boat.  I will now urge my carbon mast people to contact Ewen before building the mast.  A few notes that I picked up by osmosis there.

  • Those fuzzy things people use, mostly protect themselves.
  • Ideal is a #2 wire running outside of the mast.
  • If it must be inside the mast, center it equidistant from the mast walls.
  • He uses a number of fusible links to protect boat electronics.
  • Goal is to get the charge into the water with the shortest path and fewest curves in the wire.
  • Because damage is so difficult to see on carbon masts, insurance companies will total a mast upon hearing a lightning claim.

lightnigprotect_g

Wand that goes on top of mast and two kinds of thru-hull grounds.

EwenSailing8

Ewen Thomson Ph.D
President
Marine Lightning Protection Inc.
3215 NW 17th Street
Gainesville, FL 32605
USA 352 373 3485
www.marinelightning.com

Updating the Sailing Cargo Ship

Machine Design Magazine had this. But they have not yet considered a catamaran. This unit they show would need ballast water even more than present cargo ships. Ship ballast is one of the leading causes of invasive species.
http://machinedesign.com/fea-and-simulation/updating-sailing-cargo-ship?NL=MD-04&Issue=MD-04_20150212_MD-04_528&sfvc4enews=42&cl=article_1&YM_RID=CPG05000002211482&YM_MID=1113

 And see from a few years ago a catamaran proposal.  http://multihullblog.com/2012/02/catamaran-container-ship/

On the cat, displacement would be 864,000 lbs per hull.  Draft 7′ and power to go hull speed 1050 hp per hull.  That speed 23 knots.

Pedigree Cats

I have had my differences with Gary over the years. He does not believe in the design process, weight studies, nor structure engineering, as nearly as I can tell.  He does do amazing work I have to admit. I was blown away at how wonderful the workmanship was.  This has to be one of the most luscious interiors I have ever seen on a cat.

IMG_20150211_083018_747

IMG_20150211_114456_605

52 Aerorig Cat

I had the occasion to visit this nearby 52′ catamaran project on a kind of forensic expedition. I always thought it odd that it looked so 70’s even though it was designed in the 90s.  I have always been amazed that it used a space truss to support the unstayed mast even though it has a substantial bridgedeck and cabintop right there. See Prior Art at http://www.multihulldesigns.com/pdf/aero56story2.pdf.   And I was shown some astonishingly bad laminate design. More on that next week when I get these deadlines met.

monroe52.jpg

Another Sliding Arm Trimaran

I think it was some 20 years ago that I first did my sliding cross tube trimaran design.   Several other people offered suggestions, some of which were included in the design, including the UHMW centerline dropboard.

Many commentators told me that it would never work.  Several have been built since then but nobody has ever filmed one sliding.  If I had any sense I would have built one instead of the Geko.

I did know that some other trimaran designs had started doing sliding tube designs, but I had not seen one.  Finally some video of  a design at

http://www.astusboats.com/   The tube connections to the amas are sketchy and I see no centerline compression resolution method, but.

the video http://www.astusboats.com/transportable-boat/trimaran/astusboats-sailboat.php?id=266&cat=Videos&page=Videos

ASTUS_20-2_Pres_3D_View1

and here I go again.  20 years ago or so.

csa31psp5g

Sunchaser Molds Update

Terrence tracked them down. ” He moved both the  tooling to his shop at Mclelland air force base near Sacramento. Planning on moving to a yard in Columbia to begin production next year. ”  Of course Ollie will forward royalties to both me as designer and Richard who built the molds……What?

He did declare that he invented infusion and a new epoxy that did not need any testing to prove.   Pic below of Teralani 3 that used the Sunchaser house molds.

teralani_kona.jpg