More Boat Doodles

    Teething kids = sleepless nights = time to doodle boats!

The idea was to succeed where Bethwaite snr had failed and design a Tasar type boat (man/wife, fast and simple) that has a small assy kite yet can offer true apparent wind sailing (always faster to tack downwind than run square). Well, I thought I'd aim high...
The basic stats:
L = 4.3m (14ft) (might grow 0.2m with a raked bow)
B = 1.8m (6ft) as drawn, but may increase to 2.3m with mesh wings rather than flare
Total Boat Weight = 73kg
Design Crew Weight = 136kg
Mast height = 6.1m
Main = 8.6m^2
Jib = 3.25m^2
Kite = 11.0m^2
For those that know of, and care about, Bethwaite's critical ratios, this boat has:
SCP:Disp = 0.27 (increase to 0.31 at beam = 2.3m)
SA: WSA = 7.08
SA:Disp = 0.53
I will try and post the rig this evening, and tweak the hull a bit more.  
P.S. Unless I win the lottery, this only a fun paper excercise - so please, no complaining about yet more classes!
Chewie

Author	Message Share Topic Printable Version Delicious Digg Facebook Furl Google MySpace Newsvine reddit StumbleUpon Translate Twitter Windows Live Yahoo Bookmarks Topic Search Topic Options Post Reply Create New Topic
Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Topic: More Boat Doodles Posted: 28 Feb 09 at 8:27am
	Teething kids = sleepless nights = time to doodle boats! The idea was to succeed where Bethwaite snr had failed and design a Tasar type boat (man/wife, fast and simple) that has a small assy kite yet can offer true apparent wind sailing (always faster to tack downwind than run square). Well, I thought I'd aim high... The basic stats: L = 4.3m (14ft) (might grow 0.2m with a raked bow) B = 1.8m (6ft) as drawn, but may increase to 2.3m with mesh wings rather than flare Total Boat Weight = 73kg Design Crew Weight = 136kg Mast height = 6.1m Main = 8.6m^2 Jib = 3.25m^2 Kite = 11.0m^2 For those that know of, and care about, Bethwaite's critical ratios, this boat has: SCP:Disp = 0.27 (increase to 0.31 at beam = 2.3m) SA: WSA = 7.08 SA:Disp = 0.53 I will try and post the rig this evening, and tweak the hull a bit more. P.S. Unless I win the lottery, this only a fun paper excercise - so please, no complaining about yet more classes! Chewie

alstorer Send Private Message Find Member's Posts Really should get out more Joined: 02 Aug 07 Location: Cambridge Online Status: Offline Posts: 2899	Post Options Post Reply Quote alstorer Report Post Quote Reply Posted: 28 Feb 09 at 9:14am
	Is it a souped-up Tasar or a (especially if you give it mesh wings) a B14 with less rag and less beam?
	-_ Al

Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Posted: 28 Feb 09 at 9:22am
	Well, it started out as a tasar with kite (the white sails are tasar size), but it could be thought of as a scaled down B14 - which a scaled up tasar in many ways! But the B14 is more of a beasty - a very beautiful one - with, what, 30m^2 of kite? That puts it way beyond most weekend sailors grasp - especially the infrequent, time limited type. The RS200 is so popular because it is a clearly managaeble boat, which is what I have tried to keep hold of. So its sort of a tasar/RS200 that should sail to about 920-930.

boatshed Send Private Message Find Member's Posts Far too distracted from work Joined: 12 Apr 05 Online Status: Offline Posts: 457	Post Options Post Reply Quote boatshed Report Post Quote Reply Posted: 28 Feb 09 at 9:47am
	Isn't this what the 59er is all about ?
	Steve

Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Posted: 28 Feb 09 at 10:07am
	It sort of is, and sort of isn't. The 59er is targetted at 'elder' sailors who have gained a few pounds and lost a bit of mobility, I think the crew weight is minimum 150kg, which makes it too big for must hubby/wife teams. It also has a pretty big kite which is offputing to hoist, gybe and drop, and presumably the automatic rig doesn't work as well as claimed, else people wouldn't have put trapezes on them.

Phil eltringham Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 16 Mar 04 Location: England/Hitchin Online Status: Offline Posts: 1105	Post Options Post Reply Quote Phil eltringham Report Post Quote Reply Posted: 28 Feb 09 at 11:04am
	59er kite is 19m2 and is high aspect, having sailed one, its really not a lot of effort to get up and down, the chute is huge, and because its a wide boat its good and stable, but i'm off topic here, nice pics though!
	FLAT IS FAST! Shifts Happen

Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Posted: 28 Feb 09 at 11:10am
	Thanks Phil. I'm sure the 59er is an excellent boat, but I believe (rightly or wrongly) that it is perceived as being too much boat - it looks daunting even if it is more foriving than it looks. As a very good sailor you may not struggle, but coming from a 200 with 9m^2 kite, I don't think my wife would find 19m2 so easy! Chewie

I luv Wight Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 28 Jan 05 Location: United Kingdom Online Status: Offline Posts: 628	Post Options Post Reply Quote I luv Wight Report Post Quote Reply Posted: 01 Mar 09 at 5:57pm
	Something similar already exists ( though a bit in hibernation ) - the Suicide or Atkin 125. There's an SA thread. The idea is low drag easy hull shape, small sail area, 1 trapeze, with a tradeoff of weight to length and beam. Rigs are small, ie Tasar, 29er, IC size, and hulls would be Merlin Rocketish, narrower but 22 foot long. An old boat that looks really cool my design - 22' 6" long x 4' 6" beam, and about 70kg hull weight with ply construction.
	http://www.bloodaxeboats.co.uk Andy P foiling Int Moth GBR3467 Freedom 21 Codling

craiggo Send Private Message Find Member's Posts Really should get out more Joined: 01 Apr 04 Location: United Kingdom Online Status: Offline Posts: 1810	Post Options Post Reply Quote craiggo Report Post Quote Reply Posted: 01 Mar 09 at 10:27pm
	I havnt got my memory stick with me which includes my design on SA but I'll try and pop it on when I get a chance. Andy didnt think it would be too stable !

Guests Send Private Message Find Member's Posts Guest Group	Post Options Post Reply Quote Guests Quote Reply Posted: 02 Mar 09 at 12:30pm
	I've been following that thread on SA, they look quite good but 22' is pretty long - don't fancy keeping that in a boat park! Also, I'm all for a bit of length, but isn't 22ft excessive? The extra length is only good whilst displacement sailing, and would have a lot more wetted surface area (and weight).