How does a chine work?

[Polux]

Originally Posted by malbert73

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I think there is no doubt that the wider and flatter aft hulls that are being developed allow more power and less heeling, and higher top speeds when reaching and running in heavy stuff. Also faster speeds under power due to more "powerboat like" aft sections. I think for them to steer well in all conditions they have to have twin rudders. The only problem is all that wetted surface aft requires more sail area to get the boat moving, especially in light air. This means higher loads, requiring more gear like electric winches to handle. If these go down, can be a handful in heavy air.
....

You are not seeing this correctly. The boats having a huge beam pulled back does not mean that it has a big wet surface while sailing. Wet surface on a well designed boat is more a function of displacement than any other thing.

This is the underwater hull of a hugely beamy Open 60 going upwind:


This is a frontal view of the boat:

[Steadman Uhlich]

Originally Posted by Polux

Looks good, but Pogo is making already that for some years with a more interesting keel (a swing keel) for a relatively small boat. A lifting keel of that type takes away lots of space on the interior of a 40ft boat, unless what is lifted is only about 80cm and it is not the case with that design.

Have a look at the Brand new Pogo 36 on my blog ( also with a chines and a similar hull).

Howdy Polux,

Since you are familiar with the Pogo brand boats, and mention a cruising design (36?) what is the cost of such a boat in USD $ ? You may have answered this before, but I don't recall the amount.

Also, earlier you used the analogy of training wheels on a bike to explain one aspect of the current Chines on the boats intended for singlehanded racing. I found that humorous but a good analogy.

As I recall, English is not your first language, but I do think you are communicating well and clearly on topics that may seem at odds with conventional thinking and design.

For many years I have heard sailors admiringly speak of the smooth round bottoms of boats (which I admire too) while dismissing the chines and hard edges common to metal boats (which I also appreciate when round or not) as ugly. So I think many sailors may have difficulty accepting the new styles of hulls that are using Chines as striking and noticeable features.

Whether some cruising boats' designers are using the Chines to emulate the lines of true racing boats seems without question. Boats that LOOK fast or look LIKE another truly fast boat, will always have an advantage at the competitive sales docks at shows or when presented to the public in brochures. The yacht Finisterre was a successful racer and in its day it's shape spawned many similar designs by other NAs, leading to a shift in what was considered fast design or beauty.

Sparkman & Stephens: Design 1054 - Finisterre

Finally, I have visited your blog before and did not consider your reference to a photo there to be shameless, but rather simply expedient. I do find it helpful when photos are posted here to illustrate discussions, but I also understand your blog may have more content than you might want to post here.

[Cadence]

Debating the maximum angle of heal seems foolish. I depends on the design. When the center of gravity become higher than the center of buoyancy it's turtle time.

[Polux]

Originally Posted by Steady Hand

Howdy Polux,

Since you are familiar with the Pogo brand boats, and mention a cruising design (36?) what is the cost of such a boat in USD $ ? You may have answered this before, but I don't recall the amount.

Also, earlier you used the analogy of training wheels on a bike to explain one aspect of the current Chines on the boats intended for singlehanded racing. I found that humorous but a good analogy.
....

I don't think Pogo is selling on the US and I don't think American sailors are much on the Pogo concept that is about max fun on a seaworthy cruising boat with functional but kind of spartan accommodations. On my blog there is a post by a owner of a Pogo 12.50, a Belgian surgeon, about 60 year's old. I believe that if you look at that you will have an insight about the ones that are buying that boat. Cannot be very young since a performance boat is always more expensive than a mass market main boat and even those are expensive for a young man.

Pogo started to be a French thing connected with the special interest French had for many years for ocean offshore racing, namely mini racing. Now that interest is spreading and there are many Europeans interested to the point that the major French Transat (every 4 years) was won on the biggest class (40class) by an all Spanish team The last ones seem to be the British, that traditionally are quite conservative about boast, almost as much as Americans On the last edition of Yachtingworld, a particularly interesting one in what refers modern boats, they have an interesting article by an old British sailor that seems to have been converted to the solo fast cruising concept. The Article is "The Pogo factor". You can download the magazine on Zinio if you wish.

Regarding the price, the Pogo 10.50 that this one is going to substitute costed about 165 000 euros. You may find expensive but the ones that know about boats and quality/price now that it is not. This is a 3 600kg 36ft boat and to have that weight it has to be built like a racing offshore boat, with top materials and great care. For having that price they don't bring their boats to boat shows (not even to Paris) they don't make publicity and they don't have dealers. You buy it directly to the factory.

Regarding the learning wheels maybe the idea that I wanted to express was not entirely clear: to be able to sail solo a powerful racing sailboat near their maximum potential even the best professional sailors need those learning wheels and on that sense the word "learning" is not adjusted to the reality, since they are the best. perhaps being better looked as a added help to tame alone those beasts. without them they would be slower not faster.

With more reason the same can be said to cruising and cruising boats. Modern cruising boats are more and more powerful, always faster and without those and other helps (furling sails, automatic reefing from the cockpit, chines, electric winches) they would be dificult to sail by small inexperienced crews, or solo.

Pogo is the more know brand but there are more belonging to the same "species" and they are increasing in number.

There is a nice guy circumnavigating on a boat from the same family, a small Django 7.70 and he accepts another sailor for each leg I believe he is in South America now, maybe that may be of interest to some forum member's:
Le voilier, un Django 7.70

https://www.youtube.com/watch?v=NmsReyMb2yY

Django is making two bigger boats that will be a direct competition with Pogo as it is already the Malango.

If someone is really interested why not a charter week in one? There is a Greek company that has a small fleet of them for charter. Here a movie made on one of them:

https://www.youtube.com/watch?v=iTzV18Yospk

[Steadman Uhlich]

POLUX,
Thanks for answering my questions with such detail.

I find those boats interesting, and that one may charter one is cool.

I also appreciate your other points too.

I used to race on a light and fast Santa Cruz 50, that had Spartan interior, but that was not the primary concern of the buyers. Fast is fun.

[Polux]

Originally Posted by Steady Hand

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I used to race on a light and fast Santa Cruz 50, that had Spartan interior, but that was not the primary concern of the buyers. Fast is fun.

A pity Santa Cruz had gone down and just when they had such an interesting boat as the Santa Cruz 37:

https://www.youtube.com/watch?v=pmxCMMVMQ80

Very expensive that's true but hard to understand how it could not find buyers on the US. It is really a fantastic boat with a sparkling performance and that has a price that I hoped some passionate american rich sailors would be willing to pay for the pleasure of sailing, racing and cruising such a rocket.

PS- Or maybe not, just look at the presentation movie!!! it is on the wrong definitions, the boat looks plain odd, it was seen by more than 2000 people and they did not bother to correct it????

[downunder]

Chines on multihulls can be used for different purposes than with monohulls.

Often used above the waterline to put more space into a hull whilst keeping a better and faster hull beam to length ratio.

Also allows adittional bouyancy if hulls are overloaded and can be used to deflect spray.

Morelli and Melvin certainly shows the technigue used in their design of the Leopard 46.

Richard Woods (Catamaran NA) appears to call a chine a knuckle and has some comments on his website.
Hull Resistance and Hull Shape Comparisons

[RKsailsolo]

taking it on the chin(e) | Sailing Anarchy

[Polux]

Originally Posted by Steady Hand

..
Finally, I have visited your blog before and did not consider your reference to a photo there to be shameless, but rather simply expedient. I do find it helpful when photos are posted here to illustrate discussions, but I also understand your blog may have more content than you might want to post here.

A better clarification about posting here contents of my blog:
I cannot do that because I would have to post the link from where that content was taken. By the forum rules it is not possible to post links on a post to a personal blog. By the same reason I cannot post a link to a post on the blog that I find relevant to any discussion. The only thing I can do is saying that there is information about this or that on the blog and if someone is interested it will have to look for it.

[Suijin]

So I got to ask Britton Ward about chines the other day. Paraphrasing his response, he said that it's a simple matter of getting maximum form stability for a given boat width, carrying hull beam out as far as possible. A hard chine aft does add abit of tracking stability when sailing deep off the wind, but introduce turbulence if carried forward which is why they soften pretty quickly leaving the stern. This is for a VO65, and he acknowledged that the tracking benefit diminishes significantly in lower performance boats.

[Jim Cate]

Originally Posted by Suijin

So I got to ask Britton Ward about chines the other day. Paraphrasing his response, he said that it's a simple matter of getting maximum form stability for a given boat width, carrying hull beam out as far as possible. A hard chine aft does add abit of tracking stability when sailing deep off the wind, but introduce turbulence if carried forward which is why they soften pretty quickly leaving the stern. This is for a VO65, and he acknowledged that the tracking benefit diminishes significantly in lower performance boats.

Well, dang if that does not agree with what I derived from all the rhetoric in this thread! Thanks for posting that, Suijin, and thanks to all the folks who contributed to the discussion. I learned a lot!

Jim