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displacement 12 hull?

Started by samdoman, 05 Dec 2007, 11:18

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Tim L


Mikey C

The rule change to stop the Vortex style hulls also eliminated some other options...

Either way, Timmy is right! sail better!
Carbon Toys for fast girls and boys!

//www.aardvarkracing.co.uk

Derek

...and you can add to the list of designs getting top 10 places -
...."Bouncer" or something that once looked like Bouncer.

Lukepiewalker


THG

#19
Double bounce?

Rebound?
THG

MikeDay

Ok, of course we won't get to a Twelve looking like the boat at the top in the foreseeable future, but what do people think it would be like to sail if it was ever built?  As a two-handed Moth type hull, would it tack on the river? and how would it plane?  And would it be very much more difficult to sail than a current 12?  Mikey - you have the Moth experience ...

Mike D
N3496

tedcordall

Not a 12 but stick a snout on it and you've got a Cherub.

Lately though, the Cherubs have seem to have moved away from solid wings and gone to bars as they have less windage and waterage (........well if you can have windage, why not!?)

JohnKn

John Claridge mada a 2 man Moth called the Tiger Moth

http://uk.geocities.com/dinghydata/TigerMoth.htm

John (1662)
JohnKn
N1662

Mikey C

[quote by=Mike_Day link=Blah.cgi?b=Cool1,m=1196853525,s=20 date=1196969343]Ok, of course we won't get to a Twelve looking like the boat at the top in the foreseeable future, but what do people think it would be like to sail if it was ever built?  As a two-handed Moth type hull, would it tack on the river? and how would it plane?  And would it be very much more difficult to sail than a current 12?  Mikey - you have the Moth experience ...

Mike D
N3496[/quote]

I've no idea really, teamwork would be key, it would no doubt be difficult, but as the waterline beam wouldn't be much narrower than normal I wouldn't say it would be outrageous - there would just be no safety margin when it heels as the buoyancy wouldn't ramp up.
Carbon Toys for fast girls and boys!

//www.aardvarkracing.co.uk

Derek

What strikes me as strange in this debate is that the shape shown is intended to be a displacement hull, so intended for light weather or inland. The sections are almost parallel and look very skiff-like. This means lots of wetted area for the required displacement.
There is even less displacement when heeled than when upright so if you roll it to tack, it will stop because it will sink deeper into the water, the corner of the transom and probably the wing will dig in.
If you are seeking to make a displacement hull, more rocker and some move volume in the topsides around the crew c-of-g would help. This will lift the ends out when you tack, shortening the boat as it tacks and losing less speed as you drag the ends through the tack.
If you take the hull shape and work out where the design displacement puts the waterline with the sheerline on the water, it will show you how long the waterline is when you tack. Short is actually good for tacking!
Baggy has no displacement in the topsides and a very low sheer so hard to tack.
Modern boats have less rocker and so tend to be harder, or at least slower to tack.
A great favourite for inland sailing is Pipedream which has a fine U'd entry and a straight rocker forward but loads of bussle (rocker in the last ~3ft) and a fairly small transom together with good volume in the topsides around 8-9 ft from the bow.
If you can find one it would be worth a look.
Does anyone have a set of Pipedream lines?

hairy dog

I have a set of Pipedream 'plans'.  They are just co-ordinates and detail sketches rather than lines but should be easy to convert.  I'll try and think of a way to copy them if anyone is interested
get a Mungral up ya! :o

angus

I would be interested in pipe dream plans. You can get me on angus3 at tesco dot  net
All smoke and Mirrors. N2153, 2969, 3411