AluminumAlloyBoats.com

G’day all, we started this boat in November and it’s almost ready to go to paint. It was designed by Member CTMD. 8.0m Power Cat with a 3.2m beam.
Some pics of the build, hope you enjoy. Cheers Pelagic Boats.

Wow, looks amazing, the Australian boats are always have such smoother lines than anything made here.

Thanks MacCTD, We work very hard to get the nice looking smooth lines on our boats.

Very nice! Glen

Keep us posted on the build PLEASE.
How much fuel and what power?

Will do, it’s not far from going to be painted and being fitted out. A pair of 150 4 stroke out boards will be rigged and it will hold 300L of fuel per side 600L in total.

We took the client's reps out on a sister ship with twin 225hp suzukis, but as the boat will be based on an inland lake system they decided to save some money on outboards and help staff avoid the temptation to travel everywhere at over 40 knots. With the 150s it'll do about 40mph.

I find it funny when you guys compliment the boat's styling. Daniel and I have had multiple conversations about how ugly it is but that it is ok because it is a commercial boat.

CTMD wrote:We took the client's reps out on a sister ship with twin 225hp suzukis, but as the boat will be based on an inland lake system they decided to save some money on outboards and help staff avoid the temptation to travel everywhere at over 40 knots. With the 150s it'll do about 40mph.

I find it funny when you guys compliment the boat's styling. Daniel and I have had multiple conversations about how ugly it is bit that it is ok because it is a commercial boat.

OK, if it had FORWARD slanting windows it would look WAY better.

Nooooooooo not the forward slanting windscreen.

Welder you are always stirring the pot - should we call you Jetty Weld?

I think its a great looking boat. What would it cost delivered to the US?

Keep the pictures coming!

Cheers

Rick

Not sure on cost to the USA, but id be guessing you could get the same thing built in the USA for quite a lot less than getting on built and shipped over. the Boat finished in Aus ready to go to work is $250,000.

Making a cat look 'nice' or even well proportioned is a very hard until the LOA gets big enough to overcome the almost plumb stem, and the cabin/house/helm being so high off the water.

Narrow long hulls move well with less resistance so pairing them together with a nice wide rigid deck make for a faster hull with less resistance. But, those narrow long hulls need to be heavy on the long, so the stem is rarely raked out too far because the designer needs as much waterline as possible to float the boat in less than a half fathom of water.

Rake of the stem helps a boat look more appealing to the eye and really compliments a nicely curved sheer. But, when the bow is nearly 10 wide (!) the curve of the sheer is sort of 'lost' in the turn to the stem and that is another design headache trying to make a cat look sleek.

Also a well raked stem gives the sheer ahead of the cabin/helm more 'hood' or bow. A car with decent long hood looks more appealing than the volks' beetle where there is no horizontal line ahead of the windscreen.

A work boat is a deck work area that moves around and floats reliably. To that end moving the cabin aft competes with the purpose of the boat- to provide (most) working area afloat. So the cabin gets stuffed into the eyes of the bow and left there. Hard to look stylish and sleek with your hat pushed down over your eyes. Which looks better the cab-over truck or a long hood old Peterbilt?

Monohull skiffs have the most difficult time looking proportional because the cabin is too tall for the length of the average skiff and until the LOA gets close to 26-28' a 6'6" cabin just looks like an outhouse in the middle of a nice hull. At that length the flush deck cabin/weather helm/dog house begins to look like it belongs with the rest of the boat. A sitting only cabin would provide a beautiful looking skiff, but nobody will accept that point of view while at the helm of their skiff, so the 'outhouses' have to prevail.

But, the poor cat hull has its deck that is nearly at the gunwale of a monohull of similar length- they start out higher and go up from there.

So the cats' cabins end up 'stuck' up in the air just because they're on a deck that starts by being somewhat higher off the water than a monohull's deck of similar LOA. The cabin of a larger boat (40+'er) begins to appear less tall, and more in proportion to the hull but they begin life so high up its not easy to put a stand-up helm in this size hull without getting tall.

I have not seen any stand up helm cat of this LOA that have as pleasing lines as the comparable monohull's but that is the nature of the design elements to use the gain of huge stability, higher speeds with lower power, greater working area and eventually (depending on waterline) an increase in all up displacement for hauling huge loads.

It is a work boat, but I'd have raked her windscreen just to get that extra 3' of cabin close in to the screen for instruments, electronics and helm. As long as she's going to be 'work boat looking' a raked windscreen wouldn't have hurt her any more than her natural features do at this size hull, in my eyes.

Chris which design package do you use, Maxsurf ? or another ? or a combination of applications? If that is something you don't mind remarking about?

Surely looks strong enough.

Cheers,
Kevin Morin

Hi Kevin, I can give you the quick answer on what software Chris uses, and ill let him know you asked the question. All the 2D drawing are developed in AutoCad and both Maxsurf & Rhino are used to develop the 3D models.

Here is a quick walk through Video of the boat before it goes to paint.

[BBvideo 560,340]http://youtu.be/hT7Pssg5pcQ[/BBvideo]

Kevin,

as Daniel mentioned I use a range of different packages for different parts and components. The software I spend the most time in during a normal design process is actually Excel as I start in it before I model anything doing a preliminary weight estimate and performance prediction then generating a target curve of areas and 50% buttock angle. I then move into Maxsurf to generate the Hull model and basic superstructure shapes (in fact with the simple deck house on this it was all done in maxsurf) If the deckhouse needs more complex shapes I'll generate those in Rhino. The only thing I used Rhino for on this boat was the side doors. Then because I've been using it so long I still use AutoCAD to do the 2D drafting and clean up the cutfiles. Once that is all done it is back into excel to revisit the weight estimate etc and if its not within a couple of percent of my estimate we go around the whole loop again. The final job on this boat will be the stability book after it is launched which will use Hydromax for the grunt work, Excel to generate the necessary curves etc, photoshop to pretty them up and then Word to turn it into a 25 page document.

No wonder I don't make any money :(

Chris,
Thanks for taking time to detail and example of your design cycle and software tools to go 'round & 'round the helix.

It was very helpful to confirm my experiences, I don't sell designs but build my own on the occasion, so it was most kind of you to review that with us, and me in particular.

On the other hand, we both know the way "to make small fortune in boat design and building"; is to begin with a large fortune; and move ahead designing and building.

But what would life be like without those software tools? Slower I imagine, at least mine would.

Of all your remarks I was most pleased to learn that you clean up panel outlines using splines in Acad! The reason is in all the developed surfaces I've done (28 years beginning with MACsurf before Andrew moved to Win/PC) I've not been able to output completely fair (out)lines and have used some form of spline routine when the outlines were flat.

I thought it was just my inability to learn the applications well enough to visually fair lines on screen? But when I used the various modeling app.s 'doing the fairing' the surfaces routinely became compound, and even then the outlines/profiles were not always fair when laid out or cut by NC. Frustrating. So for years I've resorted to laying out and cutting the panels by hand using extrusions to batten fair the lines (as offsets from a baseline) to 1/32"; 0.031"; 0.8mm so the joints between hull panels are fair when tacked edge-to-edge.

thanks again, I've learned more in a single post than in a couple decades or my own trial and error!

Kevin Morin
Kenai, AK

That's not quite what I meant with respect to panel clean up. I don't trim anything in Workshop. I export complete parts with intersections etc turned on then sort through them in AutoCAD. I find that doing this with precision set to maximum and accuracy set to 6 decimal places when you export creates a part plenty smooth enough and doesn't require tracing. Below is an example of the topside of a design I've just finished.

An up date of the cat build, she is now ready to have motors and electronics fitted.

Only the attachment is visible. The image links are not clickable. What am I doing wrong?

Crowsridge, if a link (web address or location) is not kept valid/updated/current, like at a picture stored @ Photobucket or some other online storage, then they can become 'false' or invalid. No longer a valid URL; a dead link may just show "image" where there was a picture/image/linked location address in the past?

Not positive about that (?) but it's what I think may have happened on this older thread?

Cheers,
Kevin Morin
Kenai, AK

That's a tough looking cat. I'd be interested to know how much fuel you carry and where the tanks are located in the hulls.