Alloy powercat built, a report.

Hello all, especially Brian Eiland

I had originally started a thread titled asymmetrical cat + foils vs symmetrical hull form, but am unable to post a reply to it as it's too old a thread. But I'd like to give a bit of a report on what resulted from it.


I found myself back at this site and ran across my long forgotten thread. To answer, yes, I did in fact build an alloy cat, took about a year of intensive part time work to get her done. The design ended up being more conventional, due largely in part to never being able to find a designer willing to actually provide plans for a more exotic design.

The boat I built is a conventional planing symmetrical hulled cat, beautifully drawn and supported by a fellow named Roger Hill of NZ. It was, overall, a very fulfilling experience. We had the parts plasma cut here in the states and the fit and accuracy was astounding. She went together well and performs amazingly well for a 28' pilothouse style boat with twin 150 outboards. The ride, while not the magic carpet I was hoping for, easily exceeds the comfort of my prior boats including Grady Whites, Privateer, Shamrock etc. This is a very efficient hull, too, I average a bit better than 3 mpg at cruise in the 25-28 knot range. FYI, we invested in the best synergetic computer controlled welding machine we could find and put her together ourselves. After a year of hard running there have been no pops, cracks, leaks or other evil events. Many a wahoo and tuna has met its end on this deck.

Now...I discovered something about myself while building this craft. I'm actually more interested in boats than boating. I've been reading with great interest the exploits of a South African fellow who runs a RIB asymmetrical foil assisted cat and my interest is once again directed toward this theme. I'm thinking 22-24 feet long, asymmetrical alloy hull, flotation collar, foil supported, something that would go like blazes on fairly low hp., be unsinkable, and probably a whole lot of fun to build and run. The choice of alloy is primarily because that's what we're tooled up for...should the project be enough of a success to justify commercial venture it'd probably turn to glass. The alloy is really simple to tweak and modify, also.

Once again, if anyone has a lead,(to a designer or plans) I'd appreciate it. If anyone is contemplating building an alloy boat I'm happy to share my experience . Attached are a couple pix of the building process and initial launch of the somewhat unfinished boat.

Regards, Chuck

 

Nice job! It definately has that NZ look to it. Did you already know how to weld when you started it? What machine did you buy and what do they roughly cost if I might ask? Also, plans & cut parts for that boat . . . $$ plus all your hours @ $3.50 per hour!!! It was obviously a lot of work . . .

What do you like about asymmetrical hulls? The fact that they take a foil well?

 

The boat, including engines, rigging and welding machine, and free labor, ended up costing somewhat less than 1/2 of what it would cost to purchase this boat which is sold as a production craft. I'm a little hesitant to relay the plans cost as I'm sure they've gone up significantly due to passage of time and the great depreciation in exchange rate for the $USD vs $NZ. The plans and support from the NA Roger Hill were first class....email replies next day to any request for support.

The welding machine is a Lincoln Powermig 300 with a Cobra push pull gun. It worked flawlessly. I had never welded aluminum before this project. When the mtl was plasma cut, we retained the drops which gave lots of material to practice and tune settings on.

My interest in asym hulls is primarily the ability to fit a foil. I'm really interesting in playing around with this and a smaller center console boat would be cheap to build and less painful to modify.

Chuck