Most long, narrow hulls can be extended quite easily by cutting in half and adding a parallel section. This way you get maximum added volume for minimum added weight, It is a procedure that has been effectively applied to large ships. Depending on the original hull, it may or may not be necessary to add structural reinforcement to the ends, but if planning to do this later, will be less hassle if the hull is designed for the extension. Not ideal for a racing vessel, but for a cruiser it is quite practicable. For a vessel which is symmetrical about a transverse plane, like a proa, it is very simple. You cut the boat in half, set it up on supports spaced by the desired extension, and use sheet material like doorskin plywood or melamine laminate to join the two pieces on the outside, with any necessary stiffeners as external stringers, then use that as a mould for the extension. I have done this to extend a 40ft hull to something over 70ft with a gelcoat finish. Not the best gelcoat, and some polishing was required, but it was for a workboat, so it was good enough, and very economical compared to the options available at the time. We did it in hand layup solid glass, but it should adapt to infusion without any special modifications. The deck may be a bit more tricky. Ours was sheathed plywood.
Cheers,
Peter
From: harryproa@yahoogroups.com.au [mailto:harryproa@yahoogroups.com.au]
Sent: 02 July 2018 09:06
To: harryproa@yahoogroups.com.au
Subject: Re: Re:: Re: [harryproa] Questions on Elementary and Ex40
Gladious, your comment that the 40' is also a stepping stone to a 50+ footer reminded me of something I have thought about for a while. And that is if an upgrade could be designed in from the start instead of starting over?
Say building a 40' with a lee hull that is basically a chopped off 50', and could be readily extended when the time comes. You'd probably pay a slight penalty in that it would be a heavier (taller? Wider?) lee hull than the 40's seem to be drawn with, but you would be able to upgrade it rather quickly without selling the 40.
I imagine with some thought to lee hulls and beam configuration an entire series could be built to go from say a bucket list-ish 40' racer/day sailor/camp cruiser --> harry/air/exhilarator by upgrading the WW hull --> cruiser 50 via lee extension and new ww hull. I guess you'd be looking at mast upgrades as well, maybe just extensions?
Whether or not it really saves money I guess depends on the market for a used HP, and there is only very limited data on that. Yes, several have sold, but not in the US to my knowledge, much less say in my area. While I'd be overjoyed to find one on the market I am far from a typical boat buyer in my area.
And regardless of money savings, if the upgrade series was designed well, it might save significant build time overall which may be even more valuable. Something bucket listish is what 500 hours? Something air/exhilarator is 1000 hours? The cruiser 50 is 2,250 hours. That's a lot time cumulatively, 2 years of full time labor. Any reduction would just allow for more savings and more sailing. And for things like the WW hull upgrades, you'd still have a sailable boat while you worked on it. Say you reduce total build time to 3,000 hours (500 for BLish + 500 for upgraded ww hull + 2,000 for 50' cruiser upgrades). That saves 5 months of full time labor.
I've really just made pretty wild guesses at build time, but more to illustrate the point. Maybe Intelligent Infusion begs for "intelligent upgrades"
Posted by: "Peter Southwood" <peter.southwood@telkomsa.net>
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