Help with power/sail cat hull design.

Failure is not guaranteed...

 

Where the picture of your boat ?

 

Despite your I'll informed opinions rw, insurance is not a problem. My mate who lives down the road has just launched his 4th 40ft+ catamaran. Ex used car salesman, no plans other than what he drew himself on graph paper. I'll get some pics for you tonight as I'm going down the marina later this afternoon, I have already build pics of it.

Read the op posts again, he has experience enough to get it done. Who are you to judge a level of success? It is the most subjective notion of all... initiative, researching information and a willingness to learn are what's required to succeed.

 

Seriously, is this a public forum about boat design, does it cater for the hobbyist or only professionals? Is starting threads to learn and discuss design of said boats an appropriate form of participating on a forum about boat design?

Or does participating on this forum mean having to buy a set of plans first?

This is my question to rwatson and the admin of this forum

 

This is professionally designed boat and I am sure they knew the restrictions of this hull and designed the pod specifically to those...

 

Here is one boat that am really keen to learn details on including stats. From what I have been able to glean so far, it was cobbled together in a hurry using modified racing hulls

 

I believe (maybe I am wrong) this boat was designed by M&M based on their sailing hull. Yes it was done fast and they reused the existing mold of sailing boat.

Again, You should start from study of weights for You boat. Hull shape is not the priority.

 

No you don't need to buy a set of plans first, although it can be a way to get information quickly. And yes starting threads to learn and discuss design of a particular boat or boat design in general is a perfect and good use of the forum. Sometimes professionals who know the amount of labor and experience that contributes to a successful boat and people who have a project in process, similar, larger, or smaller, will chime in and recommend that, in their opinion, the project at hand is too large a goal to set based on what they are reading (or have other observations positive or negative that they wish to share.) Sometimes alternatives will be presented which may or may not be better ways to proceed for the OP - buying a set of plans to use for a proven design, buying a set of plans for a base or to learn about a comparable boat, an introduction to a naval architect who can provide a custom design, or even buying an existing boat instead. It's impossible to know exactly what a given poster is capable of, but sometimes perspective on how difficult a task lies ahead or what ideas may not have been considered or what might be misconceptions will give some useful consideration before a substantial investment of money and time is at stake. Someone who has what it takes to see the design or even just the build of a boat through to completion is unlikely to be turned off by a few comments on the net; based on his or her own capabilities, resources, and commitment the OP can decide which advice to take and which advice to ignore as not applicable to the unique situation as they move forward.

 

Lets see " 4th 40ft+ catamaran" - he has had a bit of experience then. But lets see your insurance paper, though. They are not going to let you through on his coat tails.

No, its NOT a subjective decision. The success of a boat project is quite easy to quantify. There is is a minimum level of result that everyone should expect, and it all starts with an understanding of the principles and careful planning and calculation like everything.

You post a picture of a professionally designed, engineered powercraft and try to pass it off as an 'off the cuff design" ? There is NO WAY that they dont have a full brochure of engineering calcs behind it - like Alik says. Try sending out staff in a committee boat in litigious USA on a 'made-up' boat.

Like our Mod says, no-one has to buy a set of plans first - there are lots of pre-planning, investigative steps to go through.

You want to lob our OP into the maelstrom of design issues that you personally have had to face ? Like I said, just check out the threads where you have cadged advice and opinions since 23rd Jun 2011. ( wow - my birthday - it will be easy to remember that one )

Lets see a few of the choice topics "Structural panel bulkhead joining question.", "Bonding a pre-cured laminate to core", "Catamaran uneven tank location problem", "Fuel tank gasket goo?", etc etc

All this from you who have had a lot more exposure to the OP, who didn't even know why sailing hulls were so different to power hulls.

What would you say to his widow or the coastguard when he didn't read your "Catamaran composite beam design" thread ?

What value would a proper set of relatively cheap plans have been to him so he could actually comfortably order materials and start building instead of phutzing around this forum for the last 4 years, to end up with a boat he is going to have to gamble on getting insurance on ?

You didn't build this boat 'out of your own head', you took the long painful 'lets see if this works' route, and asked lots of questions. Hopefully its a good adventure for you, but to inflict it on some other poor schmeel is plain vindictive.

 

Im not sure why your comprehension is so lacking...? As if id expect to ride in on someone elses coat tails??? See i have access to information you dont, why is clearly why you cant understand so much of what i take for granted. :idea: The FACT is, that my mate has built 4 big cats, and never had an issue with getting insurance for them. You must pay a marine surveyer who will write a report, provide a builders plate if you require etc provided he is satisfied from his inspections during and after the build, that the boat is seaworthy. There is no problem here, and you aint allowed into any marina without insurance :!:

The success of a boat design, is simply whether or not it meets the owners expectations and requirements or not. This is implicit in professional design, where its simply a matter of acheiving the SOR. In the case of my friend, he loves his boat, it goes exactly like he wants it to, acheives the speed he expected it to, and does everything he wanted it to. So you cannot argue that his boat design, and home build, was not a success. There is no doubt that a professional probably could have designed it better in many ways, but thats not the subject up for discussion here. He did it all himself and is happy with the result. So are all his friends which get to spend time on the water with him :idea:

Again your lack of comprehension shines through... i did not try to pass it off as anything other than what it is - a sailing hull re purposed as a powerboat. It was also a success, so an individual making sweeping pronouncements that sailing hulls can NEVER be used sucessfully as a powercat, is poorly informed. One simply needs to get it right, no matter if they are a naval architect, or a used car salesman prepared to learn whats required...

And again you have it all wrong... i have not lobbed anyone into anything, the OP came here by his own freewill to seek information! Noone is forcing his hand to anything and not you, nor anyone else here, knows what issues he will have to work through himself or where he will seek help - its his business.

If one doesnt have all the information he seeks, then a wise man will go and find it. I have no shame in admitting i dont know everything and am thankful to those who have helped along the way, alot of it facilitated through this very forum... Helpful people dont try to drag others down... They remain open minded and are not prejudiced because of their own failures, limitations, or lack of understanding...

 

Groper, your mates power cat looks great. Good on him!

 

...laconic:

http://www.velaemotore.it/catamarani-del-futuro-vela-5093

 

Concept cat

r watson is right - I have a partly constructed 13.5m alloy displacement power cat (see alloycat.weebly.com) that is designed by Mike Waller and has been built to Vic survey. Its built for ocean/coastal cruising. Because of health/age I won't be completing it. Let me tell you don't underestimate cost - you have alot of building requirements - a factory with facilities to lift etc. rental and consumables. When you buy a design you have all the calculations, files and designers advice/instructions so 8-10,000 isn't expensive.
My hull is for sale at less than cost because I left it too late and built too many other boats before I started my retirement dream so don't stuff around start your dream now.
Jack Higgins - Searazor Boats