Z40 Roadster (Its a sailboat, not a car)

[Inquisitor]

Fluff...

sarcasm: Those dying for more fluff...
I've uploaded the High Definition Video... basically the same content as the earlier one, with minor differences. Mainly, the HD and raising of the roof and sliding of the Bimini are more apparent.

High Def Z40 Video!

Remember to press the HD button and let it start reloading (the button will turn red) and then press the full screen.

 

[Robjl]

Need more detail...

What a great video. Have you got any more details of the hulls to deck join. The sealing groove posted looks fine. Is the section used available or do you make it? How are the hulls to bridgedeck mechanically clamped together to take the loads?

 

[Inquisitor]

Assembly

I was planning on making a video showing the expanding, assembly and launching. I started the above HD video above, about a month ago. However, lately, I’ve been spending a lot of time on the hull design and making some changes based on stability, performance and some other recently learned aspects from other parts of the forum. So I haven’t started that video generating.

So, let me see if I can describe it in words… the pictures will have to follow some other day.

• When sitting on the trailer, the hulls are side by side (total width 8.5’)
• There are six cross beams. Four of those do the main supporting of the bridge deck.
• The four beams are pulled off the trailer and slid through tunnels in the hulls at their locations hanging out one side of the twin hulls. The beams are fully trapped vertically and longitudinally within the hulls. Bolts are used to keep the beams from sliding transversely.
• The beams are bolted to the flush hull only.
• The hulls are slid apart to the full width, plus say… another inch or two.
• The floor panels (described in #42) are placed over the beams. The panels are placed just like hard wood flooring tongue and groove style. The panels are basically flat between beams, but have the inverted hat shape at the ends to lie over the beams.
• The hulls are then squeezed together the excess inch(s) via large transverse bolts at the ends of the beams till the panels are all compressed up, sealing the joints.
• The beams are then bolted to the free hull.
• Panels are then bolted to the beams.
• The bow and stern beams then slide down into the hulls from the top. In other words, the boat can almost hold itself together like those wooden 3D puzzles… even without all the bolts.
• Most of the interior pieces are then just slid/rotated into position.
• Cross ceiling beams are placed.
• Roof panels are placed in a similar manner as the floor panels.
• The masts are slid back to the mast steps and attached.
• The mast heads, now reaching the ground, are brought together.
• The mast head fitting is attached.
• All mast head paraphernalia is attached… antennas, rooster, etc.
• Dual rear stays are attached to stern and masthead
• Dual roller furling, head stays are attached to mast head.
• Booms are used for lever arms
• Dual anchor lasses are used to pull up masts.
• Load beer
• Launch.

I have no disillusions about the time it will take to do all this. There is no way this can be launched for a day sail. I’m just hoping to shoot for being worthwhile for three or four day extended weekend. I think someone categorized what I’m proposing as “transportable”, not trailerable due to the assembly time. Purely, semantics… I consider transportable to be those big yachts that require a flat bed 18 wheeler and special road and driver’s licenses. I consider trailerable to be something I can pull myself with a truck that comes from Ford, Dodge or Chevy and not have to ask anyone’s permission… cept maybe the Admiral’s.

As far as the joint itself, I haven’t started looking, but finding an off-the-shelf item would be nice. If not, the deck panels will all be built on one set of tooling. Thus having male on one side and female on the other, they’ll all be essentially the same… again, like hardwood tongue and groove flooring.

 

[Robjl]

Read the book but I'm gunna wait for the movie...

Thanks for the words Inquisitor but I'm gunna wait for the assembly movie, a bit hard to take it all in for me.
If you can pull this one off you will have achieved greatness. My hat off to you. For your tongue and groove joint (as shown in an earlier post) have you considered getting a piece of 16G sheet aluminium bent up to the cross section (shape) you need and using that to produce the male, one side, and the female, other side, guaranteed to fit together with a 16G gap (1.6mm). I can foresee some difficulty getting good sharp edges though....maybe vacuum bagged?
Then fit these on the edge of your panels, and glass them in.
You could seal it with a piece of adhesive backed neoprene rubber say 1/2" x 1/8" in the bottom of the trough, maybe simpler??
Following your design process with interest.
Regards

 

[designz]

Inquisitor,

I see that the last on this topic was back in November 2005, - I am wondering what has transpired since then, have you built the catamaran?, or maybe built several models (of various sizes) to test your ideas? I'd be most interested to hear what you have been up to?

Regards,

Designz

 

[Inquisitor]

Stale cheese...

Inquisitor,

I see that the last on this topic was back in November 2005, - I am wondering what has transpired since then, have you built the catamaran?, or maybe built several models (of various sizes) to test your ideas? I'd be most interested to hear what you have been up to?

Regards,

Designz

Thank you for your interest Designz. Although, stale... it hasn't started getting that much mold on it. 11/05 is Robjl's date becoming a member. The last message for this thread was 7 months ago. To answer your question... no, its not built. I have no team of designers or fabricators plugging away.

In the intervening months (besides my day job) I have furthered my education on boat design and have progressed the design. I have also been working on my current boat and sailing (for pleasure)... so the progress is slow, but not abandoned.

I have recently thought of reviving the thread, but the interest seemed rather small. The professionals and knowledgeable amateurs of this forum have seen too many "pretty pictures" before with others and certainly with my thread. The "substance" for this thread has not been published. I am looking to remedy that, as I would truly appreciate any constructive criticism. My work has been centered around several aspects:

• Simplifying the bridge deck to permit the trailering.
• Research on the fluid dynamics of hull design. These days it is still not "in stone" and there are many individuals pushing the theoretical and experimental envelope... sometimes in opposing directions.
• Structural design of the hull.
• Structural design of the major stressed members

I have also purchased the materials needed for my first glassing experiments. Much of the design hinges on two techniques. One, being an extreme (for the boating industry) fiber percentage of 60% or even 70%... thus resin infusion. And the second, is a technique that was proposed in Fiberglass/Epoxy Mast for Cruising Much of the design hinges on my optimistic belief that I can attain the results (in my basement) that I routinely expected in my former career. If those experiments fail, then I will not be pushing forward.

 

[designz]

Inquisitor,

Yes you are right I read the wrong date, (serves me right for reading the E-mail VERY late at night!!).

I would be very hapy to assist you, - maybe you could also share some of your advanced knowledge of exotic composite engineering with me, - thus making it mutually advantagous. May I suggest that you contact me via my directly E-mail (see my profile) so that we can expediate the process.

Regards,

Designz

 

[Inquisitor]

Hydrostatics

I have arrived at the following hull properties so far. Please feel free to tell me why I shouldn't have something as I do or if there are any other properties that would help describe the design better.

Hull Properties
LOA = 42'
BOA = 4'
LWL = 41.6'
BWL = 3.9'
Draft = 1.3'

Midship coefficient = 0.74
Prismatic coefficient = 0.63
Water plane coefficient = 0.80

Displacement = 6,300 lbs
Wetted surface area = 166 ft2

Boat Properties
BOA = 23'
Deck clearance = 3'
EU Size factor = 69,000

Drag (KAPER) = 210 lbs @ 8 knots, 12600 lbs

 

[Mtnsailor]

Z40 Roadster--Valuable momentum/ practical steps forward?

After months of reading and searching on-line/ from knowledgable folks, I was very interested to recently review these Z40 postings. The Musts and Wants and ideas by INQUISITOR are consistent/close to mine; but, has much of these good efforts come to many road-blocks??

Inquisitor--probably many sailors are still interested/ lurking on-line:
a) any recent ideas/ updates/ basement demo projects?
b) maybe you've identified some adaptations needed/ forced by economics--so that your main, strong body of work can proceed?

So far, my take is that: a) your ideas re: TP dual mast system (with lower windages, failure risks & stresses on center beams), and "pop-up" center cabin (like our hard-sided, High-Low camper) are most important- along with many others ideas; b) your dual helm stations seem too exposed to the weather/ spray/ sun & maybe too much blocked by sails/etc. for good view (maybe consider one, well-protected station near front of center cabin).
c) hope your very high goals- such extraordinary accomodations for a trailerable boat- don't stop useful efforts toward a cruising, practical cat.
Fair winds!

 

[Inquisitor]

The Psychosis continues...

After months of reading and searching on-line/ from knowledgable folks, I was very interested to recently review these Z40 postings. The Musts and Wants and ideas by INQUISITOR are consistent/close to mine; but, has much of these good efforts come to many road-blocks??

Inquisitor--probably many sailors are still interested/ lurking on-line:
a) any recent ideas/ updates/ basement demo projects?
b) maybe you've identified some adaptations needed/ forced by economics--so that your main, strong body of work can proceed?

So far, my take is that: a) your ideas re: TP dual mast system (with lower windages, failure risks & stresses on center beams), and "pop-up" center cabin (like our hard-sided, High-Low camper) are most important- along with many others ideas; b) your dual helm stations seem too exposed to the weather/ spray/ sun & maybe too much blocked by sails/etc. for good view (maybe consider one, well-protected station near front of center cabin).
c) hope your very high goals- such extraordinary accomodations for a trailerable boat- don't stop useful efforts toward a cruising, practical cat.
Fair winds!

Ntnsailor,

I guess a thread doesn't get too old to send out notifications. And thank you for your kind words. I have done a complete re-start from My first principles (my Must and Want's as you described it) and have gone even more radical. But first, I'll address your questions... in case... my miscellaneous ramblings and the issues I ran into might help someone of a like bent. Besides the radical isn't many people's cup of tea.

dual helm station - I read an interesting article (Helm Comparison) on a comparison and contrast of helm stations... Out front (Gunboat), Top (Lagoon 440), Bulkhead (Most common) and then stern corners (Catana). My main take from it was that its highly subjective based on the owner's priorities. For me... I decided that...
(1) the fact that while cruising, it'll be on autopilot 90% of the time or controlled from remote/internal station.
(2) Single handed docking, I can back up to the dock, tie off, then gently rotate it into the dock (able to see the closing distance) with the far motor... all without leaving the cockpit.
(3) And mainly when racing and being one with the sailing, I couldn't imagine a better place. You can check the sails, sight lines, waves all without even turning your head.

Downsides -
(1) It was getting WAY to complex trying to get accommodations of one hull to actually slide into the other.
(2) All the seals that had to work reliably.
(3) When (de)rigging with each hull (fully loaded with cruise gear) was reaching 3+ tons and sliding that around with the tolerances needed to get the seals right just seemed to big an undertaking in the price range I could afford.

Which threw me into another Internet research binge. So I found something faster, easier to trailer, easier to single hand, easier to build and still met my criteria. So if you have several more hours to read my ramblings...

Z40½ Roadster