Welcome to the new millennium for design software. I have used Microstation by Bentley for some 20 years now for my design software. My original $5000 purchase is augmented every year by a $900 subscription. When the new version had defects, I could always also use the earlier version that I kept for that purpose. With Windows 7, apparently they were able to cripple the older version so I could only use the defect ridden new version. (or pay an additional $900 to access the old version also). I wanted them to fix some defects (in the old version, the dozen or so printing settings only need to be entered once.  They were then kept for the whole session.  The new version has total amnesia and every setting must be entered new for every print.  I consider that a defect of the highest order)  before I paid my $900 this year. Their response was basically “In your dreams.” As of Monday they were able to pull the plug on the new version also, until I paid up. I have had no CADD available so far this week. Having run out of choices, I paid up. To punish me for my perfidy, they are apparently slow walking the license code that I need. If I had a couple of weeks to practice maybe I could use Rhino and VCADD to replace it. Too many demands; I don’t have the two weeks to get up to speed. I am not happy and will be trying to replace Bentley by next year. And losing a what is it, $23,000 investment so far? Not happy and not productive this week.

Today is Friday now.  Still no codes from Bentley to let the program work.  A full week without a CADD program.

Just back from picking up the plans on the lunar lander project from the building department over in the Basin. This may be only the second house that I know of built from composite boatbuilding materials, to be permitted by a building department. I’m trying to drag them into the future.  They are resisting.  Without help from Howard Apollonio NA, I would have been stranded.  I was getting comments like “How do we know that epoxy won’t just evaporate in 5 years?”
Next week I can get back to everybody’s real work. http://www.themarsoutpost.com/

And this was sent by Composites World.
http://www.compositesworld.com/articles/basalt-fibers-alternative-to-glass

Thanks again to Bill Gow for this.
http://cat2fold.wordpress.com/2013/02/28/zihuatenejo/#
I have to note that I designed Pantera back in the early 90s. It was the first design where I included the hull deck in the hull lines. More on Pantera when I get a chance.

From Industrial Designer Daniel Simon ” Wow – oleophobic coating. Put that stuff on anything, and it stays clean, no matter what. I have no info about how toxic or non-toxic this is, but it is for sure extremely impressive !” Maybe we don’t need the windshield wipers.

http://youtu.be/IPM8OR6W6WE

Thanks everyone. The response has  been great. Crowd sourcing works. I have been given valuable links and will forward to the USCG.
Among them, http://www.wumtia.soton.ac.uk/sites/default/files/CSYS2001BD.pdf

and

http://www.john-shuttleworth.com/Articles/NESTalk.html

the famous Richard Woods noted

“I saw the video Lock had made by the Wolfson Unit at Southampton University, and the evidence was very clear that catamarans behave as you drew.    In our ISO stability work for the RCD we always assume that a boat in waves is stable until the wave height exceed the beam of the boat, irrespective of the number of hulls.”

Materials Testing for USCG Certified Vessels

 One of my customers building my 36’ charter cat in the Ft. Myers area just got hit with an order to do all the testing highlighted in the list below. The price will be almost $4000.
In my experience, one of the surest indicators that your local OCMI is new or knows nothing about composites is if you are ordered to “test everything”. Customer would have been ordered to also do the C273, but I reminded the OCMI that those numbers are already available everywhere.
Old hands know that the most useful tests are those that can be plugged into structural calculations, such as ABS ORY. Those tests are: D790, D638 and D685. In fact many of us could simply from D790 results, tell you what the other test results would be within a few percent. You will not get a D790 result of 60,000 psi and a glass content of 40%.
An argument could be made for a shear test, but on long slender forms like our hulls, shear does not govern. And again, you would not get a great D790 result and a failing interlaminar shear result.
D3846 seems reasonable; if you have never been around modern composites. That test seems to be from the woven roving era. Any moderately well done hand lay-up of knitted fabrics will give around 55% glass content. Vacuum bagged and infused laminates can go even higher.
The C297 test is interesting. It seems reasonable enough. The problem is there is no threshold that I can find to use. What is the target number? ABS doesn’t have one. NVIC 8-87 has no target number. The customer is ordered to pay for a test where nobody can tell what a good or bad result is. Am I the only person amazed at the audacity? 
In these lean times we all have to work smart. Maybe in the flush 90s we could afford to do duplicate work. While the Coast Guard has the power to order builders to do anything, I urge them to use that power wisely to avoid duplication and wasted efforts. Work smart, work lean.

This paper will become a builders guide once I get time.  I have gotten the composite structures and testing guru Ron Reichard to agree to work with the USCG on sensible testing policies.  It seems so wrong that a local inspector who apparently knows little about composites can bully builders, with no recourse.

Catamarans and Waves

As I have noted before, the accident last November involving that poorly designed and narrow catamaran turned over by a wave seems to have now involved us all as multihull designers.

I was ordered, as I assume all other cat designers were, to create extensive static hydrostatic data at every possible and even impossible state of immersion. I even had to subcontract out GHS studies that could not be done with Prolines. Not one bit of the data shed any light on catamaran stability in waves. As my friend and naval architecture wunderkind Eric Sponberg wrote to me “I agree with you that running extensive hydrostatics doesn’t tell anyone anything” as to why a catamaran rolled over.
But the Coast Guard could and did order me to do that with the same tone of voice that the State Patrol uses when they order you out of the car.
I have heard it said that when a bureaucracy has no tools to deal with a crisis, they will rely on a blizzard of data. I seem to be seeing that.
I would have thought that they would have asked me or Roger or anyone else who has done a few dozen USCG certified cat designs what we thought. Not a word. Instead it was guns drawn and “you will comply”.
Eric recommended “For a better understanding of capsizing, the USCG should refer to C.A. Marchaj’s book “Seaworthiness–The Forgotten Factor”. It at least discusses the nature of capsizing, including catamarans.” I’m sure it was not done.

Actually there is a body of work that applied directly to this incident. Back in the ‘90s when I was in Tasmania, I had discussions with the late Lock Crowther on this very topic. He is the only one I know of who had done extensive tank testing on catamarans in large beam-on waves. The following is what I recall. I think it was published in Multihulls, but I have no idea what issue.
He explained that as the wave hits the first hull, that hull is of course flipped up in the air.
Then the wave charges along toward the next hull. During this time, the first hull stops moving up.  When the wave hits the second hull, it is also flipped up. The first hull however has started going back down.

The wave hitting the second hull slams the first one back down and moves on. The wide cat remains flat on the water.

As far as I know, Lock did not study very narrow cats. As I often say, I can tell you what works. I can’t always tell you how bad something done wrong will be.  So a wave hits a narrow cat beam on.

Ok that same size wave looks unfair to compare to.  Lets give it a wave 25% smaller so it looks more fair.  OK, smaller wave.  But the first hull keeps going up.

I have a theory that the relevant factors are first, a relationship between wave height and center to center of hulls. Of course a small distance between hulls will cause a cat to get rolled in smaller waves.
I also see a critical relationship between wave speed and distance between hulls.

My theory is that with the narrow cats, the first hull never gets a chance to start to fall back down again. The wave it trapped between them as the first hull is still going up.

This could be a very useful thesis study for some student.  I recall that Lock found that trimarans of the day behaved like the narrow cat above.

I believe it would have been smarter for the USCG to ask if any of us knew anything about this topic before going thug on us to help them generate a ream of useless data.