Hull form evolution for high performance superyacht.

[Guillermo]

I don't know if this has been posted before, but I think it deserves a place here.
http://www.sailboat-technology.com/links/Hull_Form_Evolution_For_High_Performance_Superyacht_Polli.pdf

[Raggi_Thor]

Interestiing and well written, I'll read it :-)

[Stephen Ditmore]

Very impressive presentation! But I have some questions & caviats. The shape of the immersed deck wing (best viewed in the inclined waterline view) might impart a turning moment to windward.... no? I haven't read through the entire paper yet.... does the author address the issue of heeled turning moment / weather helm?

I would also caution that the Gary Hoyt manta, with a similar form, was not entirely successful (problematic in waves), and led to Hoyt and designer/partner Richard Roake parting company. Also note the skeptical reception Doug Lord's ballasted trimaran (or monohull with training floats) has received in these forums. This is a road that has been explored before....

[xarax]

This is a water ballasted trimaran, isn’t it? When the hull is SO concave, we can no longer describe the boat as a monohull.

[Raggi_Thor]

Yes, it would not be allowed in any racing rule, but this is not a "rule beater", but a 30m fast yacht independent of rules :-)

[Guillermo]

Well, it seems like if Sailboat Technology site has dissapeared!
Just in case, I attach here the article.

[brian eiland]

..I would also caution that the Gary Hoyt manta, with a similar form, was not entirely successful (problematic in waves), and led to Hoyt and designer/partner Richard Roake parting company. Also note the skeptical reception Doug Lord's ballasted trimaran (or monohull with training floats) has received in these forums. This is a road that has been explored before....
When I first saw the aft-wing form in the paper, Hoyt's "Manta" was the first thing that came to mind.

Does anyone have some 'Manta' literature and/or photos they might post on this subject thread or another?? I can't seem to find any readily available.

[brian eiland]

This is a water ballasted trimaran, isn’t it? When the hull is SO concave, we can no longer describe the boat as a monohull.
Interesting some of the similarites with some power vessel projects:rolleyes:
Dick Newick Tri-Hull Power Vessel
http://www.yachtforums.com/forums/16142-post55.html (http://www.yachtforums.com/forums/16142-post55.html)

Trimarans & the Blade Runner
http://www.yachtforums.com/forums/13353-post20.html (http://www.yachtforums.com/forums/13353-post20.html)

White Rabbit & Trimaran Yachts
http://www.yachtforums.com/forums/general-yachting-discussion/3328-white-rabbit-trimaran-yachts.html (http://www.yachtforums.com/forums/general-yachting-discussion/3328-white-rabbit-trimaran-yachts.html)

[brian eiland]

The carbon fibre hull of Maiden Hong Kong is extremely narrow with a maximum waterline beam of 3.46 metres, and extends to 8 metres on account of the wings. Each wing has the capacity to hold 5 tons of moveable water ballast used to provide additional righting moment to the canting keel as well as to alter the fore and aft trim of the boat.

Juan Kouyoumdjian
http://www.juanyachtdesign.com/
http://www.dkyachts.com/p2_115.htm
http://www.sailingscuttlebutt.com/photos/04/pong0808/


Another feature of the boat is the rotating and canting mast which can be inclined up to 7 degrees and rotated up to 60 degrees each side.

[Guillermo]

Thanks, Brian.
'Shining', from German Frers jr, was a precursor to Juan's 'Maiden Hong Kong'. GF designed the ballasted wings to avoid the using of canting keel, and Juan put both things together, making beam much narrower.
But those were racing boats. What's interesting about Matteo Polli's design (also inspired in Shining) is to add extra stability when heeled, thanks to the submerging wings, and then bring the idea to performance cruising yachts.
The objective in this design was getting a fast and comfortable maxi, designed to sail in not very heavy conditions. Do you think the idea could be applicable to smaller boats, something in the 40-50 feet range?
Cheers