Any designers want to tackle a new build idea?

Hello everyone:

Here is my idea for my new build cat.
Self built in sunny Florida over a three year period.

As crazy as this sounds! I really think forward thinking designers will get the jest...

I want to create a hull shape that's In line with very modern thinking, gunboat, ect ect.

I want to cut the fluff off the build and have a small cuddy, low windage with high clearance, camping style...

I want the hulls completely sealed less one section for head other hull a very small galley

To save on cost, I will use lashings

The rig will use the wharram soft sail rig, with higher tech sail material

And carbon gaffs ect...
The mast in carbon
Wishbone in carbon
Ect

The hulls are ply and glass inside and out
Length I'm thinking about 40 ft

Im not looking for porker hulls,
The head area is at the widest spot
Same with the galley side
I need no more then 6 ft, the rest of the hulls are p watertight and sealed
No hatches, no drilled holes ..

So crazy ? Nah. I get almost the performance of a million dollar plus+++ cat (assuming proper hull design) and I cut all the fluff (I mean all) off the cat. What do I lose, the ability to cruise with 8 like I'm staying in Beverly Hilton..

This cat will sail as well, and it will leave the light on for ya!

Which designer as spent countless hours figuring out how these 6 million dollar hulls are designed, and can design similar, without the rich sucker tax ...

All I need is the hull design, ply and glass. I'll build the rest around the hull design.
Here is a photo, hull design I want (flexible) ....
Rip out the high tech sails, the high tech build (core cell)
The high tech mast ect ect

I use a well.proven soft wing sail
Ply
Glass

I will splurge on the cabin materials for weight savings core cell and carbon here...
Two more photos

 

You want very modern thinking, but then want a Wharram style and lashings. Then you want to outperform a 6 million dollar high performance boat. I suggest you first go mining for unobtanium. The design description is full of contradictions and oximorons.

 

The concept is simple
Build a boat with similar
Performance capabilities as a much more expensive cat, keep price low
By removing the extras that rich d.bags (maybe) pay out the backend for

Two hulls ply glass epoxy
30k built and painted

Carbon cross beams x2
10k

Carbon mast home built
Doesn't need to be high tech,
Wharram sails can fly on a wood. mast...
5k

Stop telling me that a well.cut wharram sail can't almost equal a modern square top,

Another 10k for the sprit ect
Im at 55k let's say the hull and rigging
70k and three yrs labor...
Add another 30k so for cabin

20k from sails


I'm at 120k
40k a year 3 yrs

Ending up with a 40 ft cat


Stop telling people they can't do something, you're full of vinegar
The way you condensed people..

 

No one is telling you you can't do whatever you like....but since you come onto a public forum seeking advice/comments, you better get ready to hear the cold harsh truth beyond your expected 'dreams' of sailing on the cheap.
No one is here to massage ego's.

You’re totally missing the point in your rush to get the holy grail – that doesn’t exists, other than in your head.

Hull shape – there is no magic, other than an amateur’s lack of understanding of hydrodynamics and what factors are important, beyond personal feelings and emotional thoughts. It is science based not religion based design.

Cost savings…ugh, how many times have the desperate to reinvent the wheel have ‘we’ heard this, only to – as always – crash and burn later, by ignore advice from those that they wish to garner and seek in the first place. Such predictions are based upon what…??

Wharram – is all about low tech. You’re introducing carbon – hardly considered to be low tech, or low cost.

And the the performance predictions based upon what? – just one’s own thoughts and ideas.
See comments above on hull shape.

Your comments on the – rich sucker tax – says everything about your MO and rationale, and has no basis in the SOR.

You can either listen to advice from those that you seek, or, waste your time and money proving what has been explained to you, but refuse to listen.

 

Fair enough, it's not the advice , it's the delivery.....rude don't work with me

Anyway, so lets start with
The hulls
Can I not build 2 say 36 ft hulls
Out of good ply, epoxy and glass for 30k?

 

Word of advice, you better check your ego at the door before you enter.
Since that is your interpretation of the facts presented before you - based upon your expectations - and then shot down in flames.
That's emotions, your emotions, no one else's!

In a word, nope!

 

Some numbers.
2 x 11m/36' hulls will have a surface area of maybe 2 x 60 sq m, plus say 20% for bulkheads, floors, etc = 144 sq m.
9mm gaboon ply in Aus costs $67/sqm, weighs 4.4 kgs/sq m. So $Aus9,650 and 633 kgs.
Maybe 6 stringers (no keel) per hull (132 m) of 20 x 20 any decent timber @ $5/m =$650, 26 kgs
1 layer of 200 gsm glass on the outside $5/sq m= $720, 30 kgs
3 coats of epoxy inside and out @8 sqm/l +20% for gluing @$20/kg= $2,600, 140 kgs
Total $AUS13,620, 839 kgs
Allows nothing for beefing up, fittings, doublers, hatches, etc. Plus at least 20% for wastage. Plus overheads, plus consumables and paint. Build it yourself in your own shed with your own tools and you may get hulls that weigh less than half a ton each and cost less than $AUS20,000. Both will be about a third of the cost and weight for a basic boat. Speed and good finish will add at least $100,000. The good finish (turning toxic chemicals into dust) will take years off your life, the speed (sails and rig) cannot be built by you, will have to be paid for.
Adjust the areas and costs (and check the arithmetic!) for your particular design and materials source.

Built in infused foam, the weight will be less than half the weight of the ply and significantly quicker, cleaner and easier to build. Optimised for the foam (thicker foam, no stringers), it will be lighter (and quicker to build) again.

Speed is about weight, sail area and length. Plus low wetted surface in light winds. The longest, lightest multi for a given sail area is a proa. Maybe check out www.harryproa for an approach to low cost and fast that is more likely to work.

Materials for a 15m Harryproa from China, incl carbon masts, beams, booms and rudders cost about $Aus50,000/$US33,000, incl shipping, duty and taxes. Built to the plans, they weigh 2 tons ready to sail.

Rigs and underwater appendages need to be of similar efficiency. A Wharram rig suffers because the shape moves aft in a breeze and because the top spar causes the twist to be wrong. Both regardless of sail material. The spar is also weight in the wrong place. They are great for slow reaching and running, not so much upwind. If the boat is fast, it will almost always be sailing closer to the apparent wind than 90 degrees, so will need efficient leeway preventers and an efficient rig. A cat with a conventional rig is a sailmakers and riggers dream. An alternative to the Wharram rig is an unstayed mast, with self vanging boom and full battens, no extras. More expensive than the Wharram, but much more efficient and a lot cheaper than a stayed rig with extras.

Lashing hulls is fine as long as rig tension is not required. For a Wharram rig, it's not, for a modern/fast upwind rig, it is.

Gunboats are heavy compared to Kiwi and Aus cats. I would not use them for a performance benchmark any more than I would a Wharram.

You cannot afford a custom design. Your requirements are not unusual. Many designers have tried to hit this spot with stock plans. Few, if any have. There are very good reasons for this.

Your prices may or may not be correct for your suppliers and boat. I would strongly advise you to start putting together a spread sheet of all the costs, weights and suppliers.

 

Thanks


Thanks for the reply.

I have read your posts over the years. I will contact you about splitting a order of foam when the time comes

I'm not set on the wharram sail and rig..as long as the system I use works and is within the budget.

I helped build a.pre preg small boat, I also have infusion experience. If I can get into foam for close to the same price as the bunz' I'm looking at, I will go that route

I'm in the tropics, so the foam has to have great heat resistance..

If you know a designer that wants to tackle these hull designs I'm all ears.

I'm not delusional, I understand the boat won't be the fastest racer on earth...
I just want good performance, low budget. Safe and well built

This cat is

Two hulls
A couple beams
Mast boom ect
Dymeema lines
A small cabin

The head is air head
The galley is camp stoves
The water is foot pump
The lights ar pop up led
The refrigerator is a yeti cooler
You get the idea, which as you know eliminated a whole ton of $$ off the build price...

I won't skimp on hulls
Rig
Tramps
Ect..
That's where the money goes..
Not Ac
Watermakers
Diesel engines
Fancy electronics
Ect ect...

I will have a small Ac unit. That runs, as needed, off a Honda gen in the future

So, yes a wharram idea, go simple, safe, and on a fair budget...

I'm just adding in upgraded hulls, built well, with a more performance edge. Look at those photos above..

That boat has two hulls beams and a pod...just like a tiki
With a much more modern rig and design....

Doesn't have to cost a million because it looks modern...that's for suckers...

I'm going to build this boat under 150k no problem

Thxs for your reply it's appreciated!

Let me know if you want to tackle these hulls completely or someone who will reasonable...

I'll get with you one day about the mast and foams, the foam sooner then mast

Thxs

 

I think you don't have a clue what your talking about...

You can build two hulls in ply glass epoxy for 15k USD each
Period ....I don't need your advice any longer, thxs for sharing though

 

Im open for suggestions on the following

1: what is the best way to attach beams to hull without a permanent connection.
I've seen lashing obviously
I also saw one boat that used rubber pucks stacked with a through bolt.
That allowed movement some, not sure if I was a better idea then lashing

Also, same for the cabin, or pod. I want to drop the cabin in place once the hull beams are in place. I draw a blank on how ton secure this pod to the deck beams

I don't want to create hard spots there. I want to allow some movement in the hulls and pod.

Suggestions welcomed on these

 

1) lashings

 

You seem to know everything now in less than 24hrs...that's amazing!

 

It was given in the same vein as your post.

 

Both you trolls reported I asked nicely, stay off my thread

 

At the risk of becoming a troll I 'd like to point out that a hull with a drop in pod structure will involve some compromise in structural rigidity and weight. A hull that's a closed structure is far more rigid than one with any openings, the larger the opening. the more additional structure (weight) required. Two examples, a convertible automobile is inevitably heavier than the equivalent sedan and still a little more flexible. The other from personal experience; I built a little geodesic dome greenhouse for my wife and after a couple of years I've had to go back and reinforce the one node cut out for a door opening even though I though the door opening had ~30 percent as much timber as the whole structure.
Oops my mistake, it's early in the morning, If you are planning on a pod between the beams, I'd lean towards lashing.