Category Archives: New Designs

Update

I got back from out of country to a truckload of rush projects. This blog fell behind.
Besides getting autocad files of hull lines to Owen, a new 50′ ferry for Lake Chelan in Washington here, a 79′ charter cat in Mexico, finishing up the new 79′ Sierra Cloud for Lake Tahoe, a new wingmast design, more on the 45 cat, and several little ones.

I did see that the heavily marketed Rapido 60 trimaran was only in the middle of the E-glass fleet in the ARC race when it lost it’s mast. I understand that no other masts were lost.
I also saw that Russell Brown took great exception on SA to my doing commentary on designs.
There should be some quiet here during the holidays where I can catch up.
Also, I keep the hot shot workstation off of the net. Just to be sure. My web machine is an ancient Pent4 using XP. Anymore it slams up to 100% CPU use as soon as I turn it on, and stays there. Everything is a big hourglass.
Nothing I’ve tried is able to cure that. It seems the antivirus software takes most of the bandwidth. So I bought a new computer. The handoff of programs, database, email and varous peripherals may or may not be seamless.  I will try.

Email Jamup, Again

Almost 1000 spam came in over the weekend. The online computer is choking on it, as well, the antivirus software keeps uploading new anti definitions. So, I may have to get back to some of you next week.
When Outlook crashes, it starts loading the whole lot from the beginning again.
I see a new web computer in my future. This one is pretty old. I do keep the workstation off line.

Fish Expo Time Again

And again, they have gone upscale and now call it Pacific Marine Expo. Fish expo it will always be to me.
Nov. 16 to 18th. Century Link Field Event Center. Seattle.
It is a PNW event, but mariners can always be heard speaking a dozen languages there.
It is the serious boat show.  I can’t find the link.  Google it.

Rapido 60

When the Rapido 60 trimaran first appeared, I figured it was some kind of a joke. The styling recalled an F27 from 20 years ago. I teased that they owed Ian royalties. It’s beam overall was just over 38’, which some of mine, and most modern 40’ + trimarans, equal.  My GS 60 beam overall, from 25 years ago, in E-glass, was 44.5’. Everybody knows that when you push a multi, wide is what keeps you right side up. So making it not wide had to be something to push onto the unsuspecting, right?


Almost all the pictures I saw of them had the crazy camouflage paint so it was never clear what was going on. I figured that they were not serious and didn’t think much more about them.
It was just pointed out to me that the R60s don’t have continuous mainstrength beams. Blew me away. Followers of this over the years have seen the importance of continuous fibers, fiber orientation, co-curing of mission-critical parts, not forcing composites into sharp turns…..
And here is one design that seems to ignore all that. What gives?
And that explains the narrow overall beam. That’s the only way to keep the loads down, besides throwing carbon at the problem.

Again, I have always declared that with enough carbon and enough money, one can have almost anything designed. This seems to be a prime example.
If we assume 24,000 lbs sailing weight, and a 12’ cantilever of the beam, then hit it with a shock load on one of the beams. The moment at the root will be something like a quarter million foot pounds. If the bury is 3’, then the load to resist will be some 80,000 lbs.
No wonder it is so heavy. Yes, heavy. 20,000 lbs. lightship. It is all carbon, right? That carbon has some 5 to 7 times the modulus of E-glass. Compare to my GS60 at 13,000 lbs., as designed, in mostly E-glass.
Main point. You can’t beat a continuous D section for the most beam strength and stiffness, the least weight, and least cost to build.
And again, all boats inhabit a place on a continuum between a habitat and a vehicle.
The R60 seems a bit confused.  All the carbon tells me vehicle, but chopping up the lightest, strongest possible connecting beams to get more cabin space is right back to a 1960s Horstman; habitat.
None the less, I’m sure they will sell a lot of them. The owners can “Hey baby, I got a carbon boat.”
I prefer direct, simple solutions to magical ones.

VHB Tape Fail

Part of what I am doing on the lunar lander dwelling project; building a tiny house using boat construction, is to test the limits of many techniques and products. I took the VHB tape past its limit.
I tried to use it to attach an acrylic shower door without any fasteners; a worthy goal.
While the VHB tape is amazingly strong, it has limits. Its weakness as I understand it, is long duration loading, while depending on peel strength. The shower door provided that.  It’s tepid resisting the energy of initiation, followed by energy of propagation, made it fail.

In the picture, the VHB tape attaches both the hinge and the angle brackets.  Both failed after a while.
On a window, peel strength would not even enter into it. I’m always curious about where the real world limits are.