Rudder Failures

[neilpride]

Originally Posted by colemj

It is always difficult to see your points in your photos because they are usually poor, close in shots. That isn't a dig at you personally - I understand you are head-down in a small, tight compartment with a camera phone trying to take a picture of something that is almost hidden.

However, in these pictures, it looks like the rudder tube is well-glassed through a longitudinal bulkhead underneath the horizontal plywood. In fact, I don't understand the purpose of the horizontal plywood at all because it looks like it sits on top of a fiberglass bulkhead. Then there is the picture that clearly shows the plywood tabbed with fiberglass and not plexus.

To me, it doesn't look like anyone forgot any plexus around the rudder tube - it looks like adhesive of any type isn't necessary at all there.

But again, it is difficult to understand what is going on in many of these pictures. Perhaps the next bene that you get will have had its deck fall off and you can get better lighting and more perspective on your shots?

Mark

Is not me who take the last pictures, btw if you scroll down to page i think 13 you can wacht my pics, this last ones are about a rudder tube with no plexus or fiberglass around the tube to hold the tube to the plywood top part, i have the link with the whole description but im sorry i think i have enough with this discussion and i dont want to continue with the same thing over and over, even Beneteau admit in this case its a isolated case , ok, thats fine.

Cheers.

[Polux]

Originally Posted by malbert73

Tartan had a blip, but overall they have produced a pretty well designed and built series of boats. My T40 is certainly one of those in my opinion, though I only have 5 months of it after upsizing this summer.

I have chartered Beneteaus. Perfectly fine boats. I'd sail them in blue water. The 46 we chartered several years ago wandered all over the place upwind in gusty tradewinds due to wide transom. Best of all, the rudder would aerate and stall out whenever we heeled above 20-25 degrees in gusts. This was in only 20 knots. And there were already loose locker lids, etc. Not a bad boat, but I had 10 days to poke around (I am a gearhead and have been around boats my whole life). Not bad, but a lot of little corners cut. Ironically the 393 we chartered 2 yrs prior was better mannered. No wonder Mark likes his.

My Tartan, while not perfect (none are) is in another class of build quality, and this matters to me. Looking at details of chainplate supports, bulkhead tabbing, keel bolt placement, joinerwork, rudder post reinforcement, among others- really no comparison. Sure, biased, but I also chose it over a bunch of other boats at similar prices, many newer more mass production-esque. Read up on the pedigree of the S&S design, and it's construction quality and bluewater manners and design. To me it also tracks and handles much better upwind due to more moderate beam and transom width.

Bob Perry has some opinions on transoms, just to produce a counterpoint to your earlier post which makes it sounds as if broad transoms make cruisers better sailing boats.
According to Perry;" Transoms;"
" Light , beamy racing boats with shallow hulls can get away with wide sterns because when they heel, they present narrow heeled waterlines to the waves... these boats have huge rigs and horsepower to drive their hulls despite drag"
" The family cruisers mass produced..... such as Hunter and Beneteau employ a wide stern for interior volume. Some might argue they are fast because they resemble racing boat sterns, but it doesn't work that way...you do not want the corner of a cruisers transom dragging when it heels because that produces drag"
" Making a cruiser fat aft can also create helm balance problems" ( weather helm) However, "boat buyers love volume"

Another Perry review:
Sometimes when you get a boat with too much beam aft the waterlines go quite asymmetrical when the boat heels over giving it a multiple personality, i.e., it’s balanced and well-behaved when sailed upright, but a real unbalanced bear when it’s heeled.

In any case, we're both (hopefully you own a boat? what kind?) blessed enough to be out on the water sailing- which makes our opinions much more similar than different. Every boat mentioned in this thread will be perfectly fine for 99% of folks 99% of time. all beat the heck out of sitting in front of a laptop in the offseason....

Yes, I own a boat, the one that is on my avatar.

The Oceanis 46 is a boat designed some years ago and not anymore produced by Beneteau. It is a beamy boat with but not one with a hull derived from Open solo racers. The Transom of those is very different, with chines, the beam all brought back and a two rudder setup. Compare the stern of the 46 with the 45, the one that is on their catalog now and one that used the knowledge that come from the development of solo racer's hull:




With such a beamy boat with a relatively large transom is not surprising that the boat loses grip at high angles of heel. For solve that the boat would need a deeper single rudder, that on a boat with a relatively low draft is problematic, or twin rudders.

Bob Perry designed some great and innovative boats several decades ago but nothing interesting, I mean innovative or contemporary, come from him on the last decades. He is outdated regarding contemporary design and what he says regarding the use of solo racer's type of hulls on cruising boats shows that.

If there was no advantages on that type of hull regarding cruising don't you find strange that almost all leading contemporary NA are using it on cruising boats? Do you think they are all crazy? that they are all designing bad sailing boats?

Pascal Conq, from Finot/Conq, a leading NA cabinet since the last quarter of the XX century, and the designers of that 45 (and also of the new 35, 38 and the line of Pogo cruisers) talked about the relevance of the use of solo racer's type of hull on cruising boats, already two years ago, at the Superyacht Design Symposium, in Miami:

"Advances in the design of performance cruising sailing yachts : Evolution of the architectural proportions

Let's start with "beauty". What is "beauty" for a yacht, anyway ?
: "Fast is beautiful !"...
The main recent advances and the evolution of performance stem from a major shift in proportions. ...
- Open : The open spirit comes from the open racing rules, it is an incentive to research in all directions. It allows to test new concepts, at a reduced scale in the Mini-Transat (that we have won 5 times in the last 25 years), and at full scale in the Vendée Globe that we have won 4 times. Furthermore, an essential point is that the open spirit is very close to cruising, because the boats are sailed short- or singlehanded.
- Studies : The new tools, like the CFD and FEA numerical codes, are now really affordable, precise and usable.
- Power : The open spirit provides almost free righting moment. Using solutions like increased width, water ballasts and canting keels, we completely transform the proportions, the ratios and the shapes. We dramatically reduce heeling as well. Power then comes more from the Gz term (horizontal distance from center of gravity to center of buoyancy) than from the D term (displacement) in the righting moment formula Rm=D*Gz.
Reducing displacement allows one to reduce it even further, that's the whole point ! The keel can be made lighter, the vertical position of the center of gravity is of less importance.

This changes proportions, hull shapes, width, and all the ratios like sail area/displacement, power/displacement,...Sailing yachts once were narrow, they will be wide, mark my words ! It works !

And by an amazing stroke of luck, when increasing the width, one gains inside volume, just what we want in a cruising boat...
The circle is now complete..."

[Polux]

Originally Posted by robert sailor

..
Polux,
You are a great defender of the European production boat builders..

No, I am defender of modern boat design, contemporary building techniques and contemporary materials. Production boat building is just a way of making the boats less expensive and allow more to buy them...and as I am not rich I see the merit on that.

I talk more about European production boats because almost all production boats are from European brands. There are some mass production American brands in America like Hunter or Catalina but in my opinion don't represent the best in what regards design.

There are some smaller production American brands that in what regards design do as well as European brands as: Jboats, modern C&C yachts, Corsair, Gunboat, Summit yachts ...I may have forget some but they are a very small number when compared with European brands that utilize top NA and lead contemporary cruising sailboat design.

There are some great American based cabinets that make true contemporary designs and contribute actively to sailboat development (Reichel & Pugh, Farr) but in what production boats refer they design exclusively to European Brands. There are also some American NA that develop their work out of the US, like Mark Mills that are on the head of the sailboat design development.

The American sailors are aware of that: that's not by accident that Beneteau and Jeanneau are by far the leading cruising brands in America. They are American built but design by leading European designers.

I have said repetitively that I would love to see Hunter or Catalina designed, like Beneteau or Jeanneau, by leading NAs (why not american leading ones?). I do believe that what makes them less competitive then the European brands is not a difference in boat building quality but a difference in boat design quality.

I hope to have made clear my take on this.

[Dockhead]

Originally Posted by Polux

. . .
Do you know that a modern led keel is more effective than an old designed lead fin keel? With the design of a torpedo keel the lead just makes the torpedo a bit thinner giving a marginal less drag and not a big difference in weight. That is justifiable only in performance boats where all 0.1K count as well as each kg but on a budget boat there are better ways to spend the money. Well treated with epoxy a steel keel will have no corrosion problems.
.

Sorry, but the advantage of lead keels is not "just makes the torpedo a bit thinner giving a marginal less drag".

Lead is a lot denser than iron -- 11,340 vs 7,850. So a lead keel of equal mass is not just "thinner" -- for less drag, but it also has less volume, for less buoyancy -- remember that even a keel weighing 100 tons but made out of material with density equal to water will give no right moment, since it will displace its own weight in water. So it's 44% better, right? No! Even more! If you subtract the mass of water displaced, then in water lead weighs 10,340 kg/m3 compared to 6,850 kg/m3 of iron. So the real difference is over 50%.

That means you need 50% greater amount of iron by volume to get the same righting moment as lead. That's a really big difference.

Besides that, lead absorbs impacts much better than iron, and is more resistant to corrosion (as I know from experience after whacking a rock in the Baltic this summer )

So lead is far superior as a material for keels. Tungsten or depleted uranium would be even vastly better than that -- a bigger difference to lead than lead is to iron -- and indeed these materials are used, at huge cost, for ballast in F1 cars and some cost-no-object racing boats.

But lead, while cheaper than tungsten, is much more expensive than iron, so maybe not worthwhile for cruising boats built to a tight budget.

[smackdaddy]

Originally Posted by malbert73

Smack-
Assuming that all boats from a builder are the same is the same as buying all the promotional materials hook line and sinker.
See, I take each boat individually.

Good. I do exactly the same...as you can pretty readily see in this thread.

Originally Posted by malbert73

Go ahead and spout your propaganda and be a "brand cheerleader"

Exactly which brand have I been "cheerleading" for? I've been talking about production boats.

Originally Posted by malbert73

By the way never considered a hunter so don't know much about their build. To each their own but I can't get over their looks- and there's plenty of boats out there so choosing one that is more graceful is pretty easy. Yes superficial but if one can't enjoy their boat's looks....

That's alright. Hunters aren't for everyone. I had the same superficial feeling about many, many boats when I was looking.

Originally Posted by malbert73

Looked up the tartan 115- a lightweight inshore race machine. Apples and oranges.

Not according to their "marketing hype":

the Tartan 115 will lead the fleet with award-winning performance on the race course and cruise back to her homeport in uncompromising family cruising comfort.

According to some in this thread, Tartan is threatening the very lives of those children.

[robert sailor]

Polux,
You are mixing up wine with water when you quote designers that talk about beamy boats having issues but solving them with canting keels and water ballast and twin rudders. Yup, for sure these methods have been around a long time now and certainly work but are not part of the cruising scene other than the odd boat with twin rudders. Facts are in lighter air these boats with the beam carried aft are not all that quick because of the extra drag. What "really" works on these boats is all the additional volume you get with that wide beam carried aft and the great cock pit layouts.
Yes a racing boat can carry more sail on a reach and this extra beam aft does make them very powerful in some conditions but these boats are also built very light and strong with huge sail areas. Cruising boats are overloaded from the get go and these days they have more heavy crap hanging off the stern than you can imagine causing them to drag their asses even more so. In light air unless you set a chute they are anything but fast off the wind but back at the dock they are wonderful for the extra space no doubt about that.

[Polux]

Originally Posted by Dockhead

Sorry, but the advantage of lead keels is not "just makes the torpedo a bit thinner giving a marginal less drag".

Lead is a lot denser than iron -- 11,340 vs 7,850. So a lead keel of equal mass is not just "thinner" -- for less drag, but it also has less volume, for less buoyancy -- remember that even a keel weighing 100 tons but made out of material with density equal to water will give no right moment, since it will displace its own weight in water. So it's 44% better, right? No! Even more! If you subtract the mass of water displaced, then in water lead weighs 10,340 kg/m3 compared to 6,850 kg/m3 of iron. So the real difference is over 50%.

That means you need 50% greater amount of iron by volume to get the same righting moment as lead. That's a really big difference.

Besides that, lead absorbs impacts much better than iron, and is more resistant to corrosion (as I know from experience after whacking a rock in the Baltic this summer )

So lead is far superior as a material for keels. Tungsten or depleted uranium would be even vastly better than that -- a bigger difference to lead than lead is to iron -- and indeed these materials are used, at huge cost, for ballast in F1 cars and some cost-no-object racing boats.

But lead, while cheaper than tungsten, is much more expensive than iron, so maybe not worthwhile for cruising boats built to a tight budget.

I believe you had to read my post again. It seems you did not understood what I said. I never said that in some parts, namely the torpedo, lead is not the best material. In fact the best efficiency keels are made with a steel foil and a lead torpedo.

Steel is much better for the foil since as it is a much more strong material it can provide a much narrower more hydrodynamic and light foil. If the foil was made of lead it would have to be massively more wide and what you would gain with the superior density of the lead would not compensate the possibility of having, with a steel one, almost all the ballast and keel weight much lower on a torpedo and not on the foil, not to mention the much bigger drag of the foil.

What I said regarding a all fin lead keel to be less efficient than a modern steel keel (torpedo keel) regards traditional keels all in lead, many of them without a bulb or just a small bulb. That has been studied with CFD and the results were clear.

I said that the reason why a lead torpedo was not used on a steel foil on mass production boats had to do with savings and the relative small importance that has on boat performance. There is a better way to spend that money on a cruising budget boat, improving the boat in other ways.

But you are right, I messed up the text and it does not make much sense since instead of steel, on the first paragraph I wrote led
Here it is what I wanted to say:

Originally Posted by Polux

...
Do you know that a modern steel keel is more effective than an old designed lead fin keel? With the design of a torpedo keel the lead just makes the torpedo a bit thinner giving a marginal less drag and not a big difference in weight. That is justifiable only in performance boats where all 0.1K count as well as each kg but on a budget boat there are better ways to spend the money. Well treated with epoxy a steel keel will have no corrosion problems.
..

[smackdaddy]

Originally Posted by robert sailor

By the way boys that old Swan will probably outpoint the bulk of the new cruisers, has a lot better ride offshore and it won't be until the wind gets behind the beam that it will have trouble keeping up.

So it's a great boat for a delivery captain.

Originally Posted by robert sailor

Look at how well it has retained its value(considering all sailboats are lousy financial investments) can you, using your best imagination believe that a 40 year old Beneteau or Hunter could ever sell for a price like that.

I see this argument a lot. And it's questionable to say the least. Sure the old Swans do really well holding their value, but they do have the moniker "purists benchmark" for a reason. They are really collector's items more than anything in my opinion. So it's not at all an apples to apples comparison.

Let's look at my boat. There is a 1989 Hunter 40 on Yachtworld that has just sold with an asking price of $84,900. I honestly don't know what the retail price for this boat was in 1989, but if you use a standard inflation calculator with today's retail price of Hunter's current 40 at $240K - you get around $125K retail back then.

So, from $125K purchase price to $84K sales price today. On the face of it, that's, what, a roughly 32% depreciation over 25 years? Sounds about right. Of course, if you factor inflation back in, you are actually making a tidy profit!

So, yeah, even a Hunter can do pretty well holding its value if you take good care of it - like any boat. And, if you wanted to, you could buy 2 or 3 of them for what you'll pay for a single Swan.

BTW - though I could actually afford one of those Swans, you couldn't pay me to own one. Seriously. Not enough bang for the buck I want to spend - and wwwwaaaaaayyyyy too much maintenance.

[robert sailor]

Polux,
You also could have said that a modern lead keel can, through design, be much more efficient than a cast iron keel. They are just words and the reason most production boats use cast iron is simply, its way cheaper and no where as good as a lead keel for reasons already brought forward by Dockhead.

[Polux]

Originally Posted by robert sailor

Polux,
You are mixing up wine with water when you quote designers that talk about beamy boats having issues but solving them with canting keels and water ballast and twin rudders. ....

What a confusion you make He is not talking about canting keels or water ballasts as a you to solve any problem created by that type of hull, but as further ways to improve a performance on that type of sailing boats.

If you knew more about that type of hulls and boats you know that there are many solo racing classes that use that type of hull without canting keels and that the water ballast don't solve anything just create more RM. In fact they act on a solo racing boat the same way all those bodies leaning out on the rail on a crewed regatta cruising race boat. Take all that weight away and the boat will sail just fine, being only a little less stiff and powerful.

You can see that cruising boats that have that type of hull and no water ballast, like the cruising Pogos or on the Cigale sail extraordinarily well.

http://www.youtube.com/watch?v=dbYWHGUcKiQ

Here you have a small 9.5m solo racer without canting keel (and that type of hull) going fast and steady downwind:

What happened to the Classe 950 - Coastal Classic 2014 - Crewless - YouTube

Here you have a more traditional hull, a good one also going fast downwind but look at how the crew has to be constantly making corrections.
More Shades of Grey on Vimeo
There is a huge difference, not in speed, but in easiness between the two boats and that's why solo racer's hulls are a good solution to cruising boats: They promote easier sailing, more stable boats and boats that sail with less heel.

[robert sailor]

Originally Posted by Polux

What a confusion you make He is not talking about canting keels or water ballasts as a you to solve any problem created by that type of hull, but as further ways to improve a performance on that type of sailing boats.

If you knew more about that type of hulls and boats you know that there are many solo racing classes that use that type of hull without canting keels and that the water ballast don't solve anything just create more RM. In fact they act on a solo racing boat the same way all those bodies leaning out on the rail on a crewed regatta cruising race boat. Take all that weight away and the boat will sail just fine, being only a little less stiff and powerful.

You can see that cruising boats that have that type of hull and no water ballast, like the cruising Pogos or on the Cigale sail extraordinarily well.

Here you have a small 9.5m solo racer without canting keel (and that type of hull) going fast and steady downwind:

Here you have a more traditional hull, a good one also going fast downwind but look at how the crew has to be constantly making corrections.
More Shades of Grey on Vimeo
There is a huge difference, not in speed, but in easiness between the two boats and that's why solo racer's hulls are a good solution to cruising boats: They promote easier sailing, more stable boats and boats that sail with less heel.

Some may very well be easier to sail but not all of them. I sailed a production boat with the real wide stern a few years ago and it was anything but easy in larger seas. It wanted to turn every time it rolled and you had to be real careful on the helm because the rudder would stall quite easily. In flat water it was easy peasy but going down wind in bigger seas not so much.

[Polux]

Originally Posted by robert sailor

Polux,
You also could have said that a modern lead keel can, through design, be much more efficient than a cast iron keel. They are just words and the reason most production boats use cast iron is simply, its way cheaper and no where as good as a lead keel for reasons already brought forward by Dockhead.

No, that is not true. I said that a steel/Lead keel could be more efficient.

As I said one of the characteristics of modern boats is that they or have a considerable draft or a swing keel to reduce draft. That's the only way to have a decent performance upwind.

With a considerable draft you can only have an all lead keel if you have a keel with a wide profile, increasing not only drag but having the weight, that could be almost all in a torpedo, spread out on the foil. that is this case it is not a foil, but really a big massive lead keel. There is no other way. Believe me I have a boat with the best that was made on that type of keels but even so a let loss efficient than the ones on the MKII of my boat that has a very nice steel narrow foil and all the weight on a torpedo.

A well done modern all steel Keel, a torpedo one with a narrow foil, like this one, is more efficient then an all lead keel and less then a steel (foil) and lead (torpedo) modern keel.

[Dockhead]

Originally Posted by Polux

I believe you had to read my post again. It seems you did not understood what I said. I never said that in some parts, namely the torpedo, lead is not the best material. In fact the best efficiency keels are made with a steel foil and a lead torpedo.

Steel is much better for the foil since as it is a much more strong material it can provide a much narrower more hydrodynamic and light foil. If the foil was made of lead it would have to be massively more wide and what you would gain with the superior density of the lead would not compensate the possibility of having, with a steel one, almost all the ballast and keel weight much lower on a torpedo and not on the foil, not to mention the much bigger drag of the foil.

What I said regarding a all fin lead keel to be less efficient than a modern steel keel (torpedo keel) regards traditional keels all in lead, many of them without a bulb or just a small bulb. That has been studied with CFD and the results were clear.

I said that the reason why a lead torpedo was not used on a steel foil on mass production boats had to do with savings and the relative small importance that has on boat performance. There is a better way to spend that money on a cruising budget boat, improving the boat in other ways.

But you are right, I messed up the text and it does not make much sense since instead of steel, on the first paragraph I wrote led
Here it is what I wanted to say:

Well, that makes more sense now.

But I still don't think I could quite agree with it. Cruising boats don't have the razor sharp, high aspect foils with lead torpedoes you see on some racing boats -- they have flattened bulbs on more or less normal fin keels.

Nor do they use steel at all in their keels -- they use cast iron, sometimes even scrap encapsulated in fiberglass.

So maybe you'd want sharp steel (not iron) for the foil part, above the lead (or depleted uranium? ) torpedo on your hot race boat, but this is irrelevant to cruising boats with lower aspect, normal fin keels with flattened bulbs, which are never steel.

For cruising boat keels, you are offered cast iron external, lead external (usually alloyed with antimony as a toughener), or encapsulated keels often with the metal not being structural. Never sharp high aspect steel keels.

Among the actual choice you have for cruising boat keels, the lead ones are far superior. Which doesn't mean that iron isn't "good enough" -- it certainly is plenty good enough for many applications. But lead, if you can afford it, makes a really noticeable difference in sailing performance compared to iron.

I do lust after the DU or tungsten, however, which must make an incredible difference.

[Dockhead]

Originally Posted by Polux

No, that is not true.

As I said one of the characteristics of modern boats is that they or have a considerable draft or a swing keel to reduce draft. That's the only way to have a decent performance upwind.

With a considerable draft you can only have an all lead keel if you have a keel with a wide profile, increasing not only drag but having the weight that could be almost all in a torpedo spread out on the foil. that is this case it is not a foil, but really a big massive lead keel. There is no other way. Believe me I have a boat with the best that was made on that type of keels but even so a let loss efficient than the ones on the MKII of my boat that has a very nice steel narrow foil and all the weight on a torpedo.

A well done modern all steel Keel, a torpedo one with a narrow foil, like this one, is more efficient then an all lead keel and less then a steel (foil) and lead (torpedo) modern keel.

We can agree about that

That keel will totally kick azz with the very high aspect ratio and deep draft.

My only quibble is that that is certainly no cruising boat keel.

And if you were going to have a keel like that, what a crying shame not to have the bulb made out of lead!!!!

[robert sailor]

I have a question for you Polux, your a guy with your head in design both by profession as well as your personal passions.

Is it just me or do you and others here find some of these real high free board boats something less than beautiful?? Things change I know and beauty is in the eye of the beholder but every time I see a beautiful boat from years past or some of the Italian boats that are current I just stop and take it all in. There is something about how these yachts have been penned that give them that something special. Now I walk the docks and I'm over 6 feet tall yet the anchors for many of these new designs are head height and I'd need a stool to get aboard from the side. Its like they have been designed from the inside out. Efficient maybe but pretty not so much, well to my eye anyways.