Interesting Sailboats - Page 394 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Boat Review and Purchase Forum
 Not a Member? 


Like Tree1262Likes
Reply
 
LinkBack Thread Tools
  #3931  
Old 04-14-2013
Junior Member
 
Join Date: Apr 2013
Location: South Sweden
Posts: 25
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 0
Anders B is on a distinguished road
Re: Interesting Sailboats

Thanks/ Anders B
Reply With Quote Share with Facebook
  #3932  
Old 04-14-2013
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Carbon blade Keels

Quote:
Originally Posted by Anders B View Post
Thanks/ Anders B
One more information about keels: the ones that seem to be the most reliable in racing boats are the ones in Carbon (not the ballast obviously). There is not probably any boat that has reunited more experience with top keels than the Open 60's. The Open 60's are not only used on the Vendee Globe but also used extensively in many other races, inclusive another duo circumnavigation.

One of the men that knows more about the race and Open 60's is the two times winner and mentor of this year winner, Michel Desjoeaux and when he says that the Carbon is the most resistant material, well...he knows what he is talking about.

"There is no miracle solution to choose a keel observes Michel Desjoyeaux, we move between price, reliability and performance. "his firm Mer Forte worked for two boats on the Vendée Globe: Savéol (Samantha Davies) and Macif (François Gabart). "For Samantha Davies we told her that the better option would be solid steel, recalls Michel Desjoyeaux.

She had no money for a carbon keel and then a solid steel one seemed to us the most reliable. "a not massive steel keel fabricated with a grid is lighter than solid steel and can be made with the adequate profile but the welding of the different sheet is very delicate. "In the industrial lambda landscape, welding is 50% as strong as the solid sheet, explains Michel Desjoyeaux. But if special care is taken to welding, you reach 75/80%.

"So for Macif, the mechanically welded keel was carried out by a specialized company Quimperlé with a welder and a welding specialist. This piece then requested an very careful maintenance because the welding "cook" the metal and makes it prone to rust. "At sea, the keels are close to the surface, immersed in saline oxygen-rich environment. This deteriorates the weldings and the steel tends to rust. "
(translated)

It seems that it is the more resistant material but not what allows for a lesser weight

He says that the Carbon is better (more resistant) but the boat that he prepared for the winner had a "Mecano" keel made of sheets of welded steel while the boat that come in 2th had a solid steel keel. The hulls were identical and I wonder if that difference in weight had to do with the marginal better performance of Macif.

Jean-Pierre, one of the three two that lost the keel had a solid steel as well as Alex while Stamm and wavre had carbon keels.

Riou had, like the winner a mechanically welded steel.

For keels I am referring to the blade.

It seems that Carbon on the blade of keels will be a technology that we will see more often in the future.

Regards

Paulo
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by PCP; 04-14-2013 at 08:22 PM.
Reply With Quote Share with Facebook
  #3933  
Old 04-15-2013
Junior Member
 
Join Date: Apr 2013
Location: South Sweden
Posts: 25
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 0
Anders B is on a distinguished road
Re: Interesting Sailboats

Thanks again, the structural reliability of the fin is part one. Part two is the design of the bulb. I think this is where much of the "ad hoc" comes in. In the IMOCA 60 class, some agreement seems to be there. However, you can find almost everything among 30-50' feet racing/cruisers available on the market today. For example the new Far East 31 bulb with chines, the J-boat L-keels with flat bottom, T-keels with maximum thickness in the same position as the maximum fin thickness, very flat, beavertail etc. And all claim that they have an optimized design. However, I have not found proofs for this (with the exception of the investigations at Chalmers, google on "Keel", "design", "Chalmers", they are available in full text).
It may be so that the performance difference between different keel/bulb designs is small compared to other factors and therefore almost everything can be accepted. And it is good to have the flat bottom of the bulb when your boat is taken out of the water?
Reply With Quote Share with Facebook
  #3934  
Old 04-15-2013
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Advanced keels

Quote:
Originally Posted by Anders B View Post
.. the structural reliability of the fin is part one. Part two is the design of the bulb. I think this is where much of the "ad hoc" comes in. In the IMOCA 60 class, some agreement seems to be there. ...... ....
It may be so that the performance difference between different keel/bulb designs is small compared to other factors and therefore almost everything can be accepted. And it is good to have the flat bottom of the bulb when your boat is taken out of the water?
That is an interesting academic work:

http://publications.lib.chalmers.se/...ext/148387.pdf

Today almost all NA use Computational Fluid Dynamics to design the hulls and keels. Some programs cost a fortune and smaller firms use them in time share.

I saw the keels on that study you mention and then went to the conclusions to see if there were some surprises, but no. What he found confirms what is common knowledge regarding keel performance and shape.

Regarding keels the most innovative study that I know is this one, by Lucas. Probably it will be the next step in what regards top racing boats keel design, not in what regards fluid Dynamics but in what regards the possibility of changing slightly boat CG. On the Open 60 they do that changing the quantity of water on the several water ballast tanks but this would provide the same effect without increasing the boat weight and that will bring an obvious advantages in performance...with some disadvantages in reliability due to the greater complexity of the system.

They are testing it on Mini class racers but I think the system would work better on bigger boats:

http://www.fr-lucas.com/images/techn...20quille3d.pdf

Another interesting approach is the one by Defline with two canting keels:

2qp double quille pendulaire - defline yacht architecture

Even if here I cannot see the advantages regarding substituting the vertical keel by a foil, except maybe to cruising boats. Probably this system will also increase the motion comfort, again in what regards cruising boats. They tested it on a small boat and they are using it now on bigger cruising designs:






Quote:
Originally Posted by Anders B View Post
However, you can find almost everything among 30-50' feet racing/cruisers available on the market today. For example the new Far East 31 bulb with chines, the J-boat L-keels with flat bottom, T-keels with maximum thickness in the same position as the maximum fin thickness, very flat, beavertail etc. And all claim that they have an optimized design
Max RM with minimum drag is not the only think that counts here and I believe that flat shapes on Bulbs or a larger format regarding the shape of a torpedo was nothing to do with the minimum possible drag but with create that lift that way. If a boat has a force pushing him up it would be like if that boat had a reduction in weight and that has obviously performance advantages that can (or not) be more advantageous than a slightly bigger drag. I believe the calculations to calculate if that is advantageous or not will be far more complicated than the ones to access the drag of a given bulb.

Regards

Paulo
Anders B likes this.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by PCP; 04-15-2013 at 02:02 PM.
Reply With Quote Share with Facebook
  #3935  
Old 04-15-2013
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Canting keels

Since we are talking about them let's have a historical prespective:

The first one was invented and patented by the great Hereshoff himself in the XIX century yet. For the ones that don't know him Hereshoff was the Leonard Da Vinci of boat design: He designed fin keels, canting keels, and catamarans when there were not available resistant, light and stiff materials to build his inventions on a sustained basis. I never saw the design and I would love to, so if somebody has it or know where I can look at it, please say so.

The next guy to use the concept was Jim Young back in 1957. I had posted about him:

Interesting Sailboats

The system did not seem much reliable and the boat, Fierry Cross, keep it only for a short time, beeing replaced for a fixed one. I don't know if that was due to technical problems or just for the boat to be able to compete.

Sail-World.com : Jim Young: A Contrast in Hull Forms

and the story goes on on the Micro and Mini racers probably the boats were more experimentation was made in the last 30 years. The first one to use the concept was Pascal Conq in, a kid that was also a NA student and a sail racer, back in 1982. He rediscovered the concept (did not know nothing about the previous attempts) and his keel is the one that give origin to the modern models. Contrary to the other two that was the only one that come inside the hull.

Back in 1981, the Micro rule is the only rule that cares about innovation in yacht design, although it is more of a rectrictive than open rule. It is also a rule meant for small budgets. Not a detail for 20 year old students!

Pascal and his pals brainstorm : Like him, Paul-François Coustou studies architecture in Rennes. Yannick Dupetit is his cousin, and together they will win the Tour de France à la Voile in 1985. They start from a blank sheet of paper, and apply the new thinking methods they are learning from their studies.

Pascal proposes to cant the keel to move its center of gravity to windward, thereby increasing the boat's righting moment. As far as they know, no one have ever done this, but they believe in their idea. They are not to be stopped !

Of course, on second thought, it is easy to see that this size of boat isn't the best to show the full potential of this innovation, because the weight of the crew has a far greater influence. But despite a few teething problems (rudder failure in Toulon, crash in Granville), they win a leg... in Granville in 1984. The same year, they take third place in the Tour de France à la Voile, and have an easy win the following year.

1985 is also the year when Pascal graduates from Architecture scholl and meets Jean-Marie Finot...


Those were the days



Jean Marie Finot, already a major NA was so impressed that invited him to work with him and later give him equal status on his firm (Finot/Conq), a firm that today continues to be an innovative and major one.

finot-conq architectes navals

In the words of Pascal Conq:

In 1982 with 2 buddies, I designed and constructed a Micro cupper that was called Urgent,with a canting keel. I was thinking it was the first canting keeler ever build. (More info Bateaux sail magazine on the Micro of 1982 and 1984).

Our research of stability involved crew displacing, stacking (all loose material inside boat) and a canting keel. It is a very heavy part of the boat that is geometrically easy to move from side to side.

Then we designed a canting keel for Michel Desjoyaux in 1989 on a Faroux minitransat and for Isabelle Autissier on her first Open 60, a design of Berret.

Then in 1997 Christophe Auguin participates in the Vendée Globe on a 60 feet with canting keel drawn totally by our office. It is the first boat to accomplish a tour of the world with this system.

The advantages:

One can increase the stability of the boat considerably, 50% more then normal keel in the best case. This while increasing the mass of the boat little. (system about 5% of the weight of the boat).
So be carrying more sails, a gain of speed upto 15%.
The system of the keel permits it to adapt quickly to the conditions of navigation's.


The inconveniences:

1-A lot of complexity around the axes. New source of mechanical problems that must not be treated to the light. Conception, manufacture and placement must be of a big quality.
2-A cumbersome system in the center of the boat, that also poses a problem of water tightness.
3-More expensive.
4-The lift force of a cantingkeel is bad, so you have to install a more complicated daggerboard.


The 29, that revolutionary boat, is still racing in Mini class races.

And of course great sailors have to be mixed in the story. who was that thought that the concept was valid and have the first to win in one? Of course, the two times vendee Globe winner, Michel DESJOYEAUX, when he was just a little more than a kid. In his words:
...
Harken made and launched in 1991 a cruiser "concept boat" wich was with, winglet canting keel, bipode mast, on rams. ..

In the same time, I made the first offshore race with one on a Mini Transat in 1991. I broke my rudders in the first leg, and won the second leg. ...


cantingkeel 29

Canting keels : A 30 years story ! | finot-conq architectes navals



A long story that starts on the XIX century with an Idea that has his first race offshore victory in 1991. 22 years of story. Not much bit a big evolution an evolution that is far from being finished.

I have saw along the years some performance cruisers with canting keels. The next step will be the first production boat (in considerable numbers) with one. Some say that it would not ever happen. I am pretty sure they are wrong

http://www.mshipco.com/pdf/SailingWo...TF_Sep2008.pdf

....
One and Anders B like this.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by PCP; 04-15-2013 at 12:09 PM.
Reply With Quote Share with Facebook
  #3936  
Old 04-15-2013
Senior Member
 
Join Date: Jun 2002
Location: Santiago, Chile
Posts: 212
Thanks: 4
Thanked 0 Times in 0 Posts
Rep Power: 13
DiasDePlaya is on a distinguished road
Re: Interesting Sailboats

Quote:
Originally Posted by One View Post
I'm not really in love with catamarans. I like trimarans. I think it has to do with it being a "proper" (singular) boat in the middle, whereas a catamaran is like two boats tied together. Not very rational thinking, but I do prefer trimarans over catamarans.
But this is a FOILED one!
Reply With Quote Share with Facebook
  #3937  
Old 04-15-2013
One One is offline
Always tired
 
Join Date: Mar 2013
Posts: 235
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 2
One is on a distinguished road
Re: Interesting Sailboats

Quote:
Originally Posted by DiasDePlaya View Post
But this is a FOILED one!
Yes, well, I still don't want one.
DiasDePlaya likes this.
Reply With Quote Share with Facebook
  #3938  
Old 04-15-2013
Senior Member
 
Join Date: Jun 2002
Location: Santiago, Chile
Posts: 212
Thanks: 4
Thanked 0 Times in 0 Posts
Rep Power: 13
DiasDePlaya is on a distinguished road
Re: Sensei by Felci

Quote:
Originally Posted by PCP View Post
and since we are talking about daysailers ...
One that I like is the Summit MD35. For me that I'm Chilean the main advantaje is this boat is made in Argentina, then I can go to Buenos Aires to buy one and transport it on a trailer to Chile.

Reply With Quote Share with Facebook
  #3939  
Old 04-15-2013
Junior Member
 
Join Date: Apr 2013
Location: South Sweden
Posts: 25
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 0
Anders B is on a distinguished road
Re: Interesting Sailboats

PCP, you are a true dwell of knowledge. Thanks again! /Anders B
Reply With Quote Share with Facebook
  #3940  
Old 04-15-2013
PCP's Avatar
PCP PCP is offline
Senior Member
 
Join Date: Dec 2004
Location: Portugal, West Coast
Posts: 16,160
Thanks: 21
Thanked 95 Times in 79 Posts
Rep Power: 10
PCP will become famous soon enough
Les Voiles de Saint Barth 2013

some nice boats and sunny days on Sant Barth:





__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 11 (0 members and 11 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Cruising sailboats for sale welch Cruising & Liveaboard Forum 10 04-25-2012 05:20 PM
THE Yacht Builder List T37Chef Boat Review and Purchase Forum 26 07-08-2011 05:51 AM
Noob wonderings and questions about sailing, life at sail and sailboats Vans General Discussion (sailing related) 49 06-20-2011 12:18 AM
A List of ALL sailboats made with layouts? Myblueheaven Boat Review and Purchase Forum 8 10-08-2010 11:32 AM
Failure to Navigate - interesting post on Panbo Blog & from the NewsReader Mass Bay Sailors 0 12-11-2006 06:15 PM


All times are GMT -4. The time now is 03:43 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.