MV catapult

Build logs from members building catamarans, trimarans and other multi-hull variants.
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Jim
Posts: 691
Joined: Fri May 19, 2006 8:25 am
Location: Cairns

Re: MV catapult

Post by Jim » Sun Jul 28, 2013 7:05 pm

Nah forget about it, you're on the money with what you are doing, your boat will be a fuel miser. The wind is almost never where you want it to be up here anyway. We are heading down South early next month for a couple of months, so we shall see how that goes. At the moment it will mean smashing into SE winds, probably motor sailing at best, all motors at worst. We hope to get down to the Whitsundays providing we dodge all the whales and icebergs. To you "Mexicans" out there us Northerners don't do cold well, and anywhere South of here at this time of the year is cold.
Jim.

groper
Posts: 239
Joined: Sun Nov 18, 2012 11:23 am
Location: cairns

Re: MV catapult

Post by groper » Sun Jul 28, 2013 7:56 pm

I'm not thinking for around here jim... I'm thinking how will I get over to the Kimberley's or over to the solomons etc... Just jetting around up here the fuel bill is of little consequence like you said... I will want to travel longways before too long...

mikeb
Posts: 136
Joined: Wed May 26, 2010 3:01 am

Re: MV catapult

Post by mikeb » Mon Jul 29, 2013 9:42 am

Go for it!!! In my opinion every boat looks better with a sail. 8-)
Mike

44c
Posts: 1148
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Re: MV catapult

Post by 44c » Tue Jul 30, 2013 8:33 am

groper wrote:Well not really, the boat was always engineered and designed like a sailing cat - so the beam is quite respectable at 5.1m - so its twice as long as it is wide or near enough 2:1. The righting moment is 50kNm so it will handle a decent size rig if i wanted it to. The mast beam bulkhead is already reinforced from original sailing cat inspired design, just need to add a bit more to it - depending on how big i go with a rig. My biggest concern is dealing with the aft buoyancy distribution - which was to reduce sinkage and trim under engine power, and also what to do about daggerboards... i dont think i have a choice but to make cases and boards if i go down this road as the CE vs CLR would give a very lee helm on the current hull.
You'd only need daggerboards if you wanted to sail to windward. You'll need to think about chainplates and a forebeam too, if you do want to fit a rig.

Since you'll have decent sized engines, I'd suggest a headsail only rig. Mainsails are expensive, and the gear to operate them is complex and costly too - and the only time you really NEED a mainsail is upwind.

It's coming along nicely.

44c
Posts: 1148
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Re: MV catapult

Post by 44c » Thu Aug 01, 2013 5:12 pm

Another thought - you'll need rudders.

groper
Posts: 239
Joined: Sun Nov 18, 2012 11:23 am
Location: cairns

Re: MV catapult

Post by groper » Thu Aug 01, 2013 9:06 pm

Yep, going to make hinged cassettes and drop the rudders in so theyre removable and stowable.
The biggest headaches i have are the dagger boards and lack of forward buoyancy distribution. I really dont want dagger boards but ill have issues trying to reach without them unless I can balance the sail plan by shifting it a long way aft - which conflicts with keeping my back deck clear... which means I really need to balance the boat with daggers giving me little choice in the matter. Skegs and minikeels are out of the question....

44c
Posts: 1148
Joined: Tue Aug 08, 2006 5:08 am
Location: Hervey Bay, Qld

Re: MV catapult

Post by 44c » Sat Aug 10, 2013 2:03 pm

groper wrote: Skegs and minikeels are out of the question....

Why?

groper
Posts: 239
Joined: Sun Nov 18, 2012 11:23 am
Location: cairns

Re: MV catapult

Post by groper » Mon Aug 12, 2013 2:29 pm

Too much added drag 44c. They dont make a lot of difference at slow speeds, say upto about 10kts, but as the speed increases beyond that, the extra wetted area of minikeels adds a huge amount of drag. The reason im fitting 90hp outboards is so that i can cruise at 20kts, which is why the hull is designed the way it is - it has a minimum drag form for this speed regime. Im not going to compromise this speed potential for a secondary sailing function such as upwind sailing performance. Id sooner fit daggers and cases before minikeels...

groper
Posts: 239
Joined: Sun Nov 18, 2012 11:23 am
Location: cairns

Re: MV catapult

Post by groper » Mon Sep 16, 2013 6:15 pm

Taping the roof and the heat is pretty intense up under the tarp, so i pulled it back to do some work and it allowed some better pics;
Mad rush is on to get it painted before xmas... i dont wanna go through another cyclone season with tarps and shit everywhere...

How did you guys do the nonskid deck paint again? Ive read a few different options from guys on here, hows it turned out for you? Would you do anything different next time?

Trev
Posts: 160
Joined: Thu Jan 15, 2009 2:56 am
Location: Moruya NSW

Re: MV catapult

Post by Trev » Tue Sep 17, 2013 8:25 am

Hi Groper
Nice to stand back and see the big picture:)
I sprayed my non-skid and I am pretty happy with the results, nice and even, I used semi gloss paint and the international "rocks" and a $60 supa cheap auto gun. if I were to do it again I would tint the paint, ever so slightly to give some contrast to the gloss.
Trev
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