Rudder Failures

[robert sailor]

Polux,
Yes its easy to see your passion and its always more interesting to visit or debate with someone with passion. Family always come first but you seem to have things under control. If what you say about Jefa is born out then it will be a real plus for production boats. My worst dream is losing a rudder offshore, well I guess the keel trumps that, LOL but I would take a dis-masting before a rudder loss. Enjoy the winter!

[Polux]

Originally Posted by robert sailor

... If what you say about Jefa is born out then it will be a real plus for production boats. My worst dream is losing a rudder offshore, well I guess the keel trumps that, LOL but I would take a dis-masting before a rudder loss. Enjoy the winter!

Humm, when on this spring I dismounted my rudder on my new (to me) boat I saw that the rudder was hold only in one way. I looked at it and asked Luca, the guy from Comet, that is a Naval expert and know everything about Comets, why it had not a double independent holding system and explained how it could be easily made (I am an Architect).

He said to me that on some models they have, others not but they had never lost a rudder on this series of boats (Comet S). Well I ended up designing with him a new safety system to double the safeguards, easy to make without altering nothing substantial (two holes and two screws). Now the rudder is hold in place by two independent systems.

So as you can see I like to maximize safety even if no Comet s (and they are hard used on ocean racing) has lost the rudder and even if I probably would not lose mine in any circumstances...but I feel better regarding my rudder now

[transmitterdan]

Originally Posted by Polux

That one I don't understand. It was not always like that?

In the past some builders and designers would refuse to reduce design margins or do other crazy things when pressured by customers or competitors. Most of those builders are out of business today.

Finite element analysis of stresses and structural loading are great but only as good as the input data. There is a great deal that happens on the ocean that is difficult to quantify with precision and accuracy. Aircraft designers have a big advantage in this regard over yacht designers. For many decades yacht builders and designers used statistical modeling (sometimes unconsciously) to validate design changes (e.g. thinner fiberglass laminates over time). Over the past 20 years computer modeling has taken over but I am not convinced the input data is accurate enough. When I see rudders supported by plywood with no glass reinforcement I am even more unconvinced. Surely these designs survived on the computer else they would not make it to production but what about survival in the real world?

[robert sailor]

I share our thoughts. When you look at the way rudders and the associated support systems were built in prior years even by the same manufacturer you can see a huge amount of strength removed.

[sailorboy1]

So basically some of you are saying building a rudder based on a design analysis (today) isn't as good guessing (yesterday's). That is just ridiculous,

[barnakiel]

Originally Posted by Polux

Yes, let's talk about rudder failures: Statistic results, like the ones from the last 10 years of ARC or from some American rallies seem to show (...)

?

Where did you get access to ARC (rudder failures) statistics?

b.

[transmitterdan]

Originally Posted by sailorboy1

So basically some of you are saying building a rudder based on a design analysis (today) isn't as good guessing (yesterday's). That is just ridiculous,

With computer modeling there is empirical data and guessing going on. In the past it wasn't good enough that the calculations said all was well. They relied heavily on historical real world experience. Today I think there is less of that so I am saying there is more "guessing" to use your terminology now days than in the past. Exactly opposite of what you thought I said.

[sailorboy1]

Originally Posted by transmitterdan

With computer modeling there is empirical data and guessing going on. In the past it wasn't good enough that the calculations said all was well. They relied heavily on historical real world experience. Today I think there is less of that so I am saying there is more "guessing" to use your terminology now days than in the past. Exactly opposite of what you thought I said.

I don't buy it and believe it is just part of the "old boats are better" misplaced story. What data or designer statements do you have to support that in the "old" days they just when and over built the rudders regardless of what the design cals said?

Personally I don't really believe rudders are failing any more now than in the "old" days. The only thing that has changed is that there is now better information transmitting going on.

[Polux]

Originally Posted by barnakiel

?

Where did you get access to ARC (rudder failures) statistics?

b.

This article was made by the ones that make the ARC so they should have their number right.

http://www.worldcruising.com/content...lure_wcm25.pdf

This was published in 2007 and they refer problems in rudders on the last 10 years, so from 1997 to 2007.

From 2007 on It is easier since all incidents have been well documented on internet, by sail magazines, ARC news and in forums. If you search you will find them. I also said that regarding the last 5 years those were the accidents I could find out after an internet search. Also asked if somebody now or could find anything more...but it seems nobody could.

[barnakiel]

Define "more" vs. "less".

Absolutes or percentages?

I guess as a % of boats built today there are fewer failures.

I believe today a better rudder can be built: either by mixing the old and tested and improving on it (e.g. better profile, better materials, better technology, etc.), or else by building from scratch with computer aided modelling/design. The problem with the latter is we still need enough rudders, preferably broken, for feedback, analysis and fine tuning the digital model.

A walking (actually: foiling) proof is the foiling rudder of an AC boat - all computer aided design and very few fail/improve (prototyping) cycles. HUGE SUCCESS.

Now I think we are mixing up things here: that a better rudder can apparently be had does not imply it is had.

We can have excellent rudders but we settle on "good enough". Reason? Price.

There are great boats with bulletproof modern rudders attached to them. The only reason some people elect not to buy them is because we believe that good enough is good enough. As we can see from the many reports of mid ocean failures, it is not.

b.

[barnakiel]

Originally Posted by Polux

This article was made by the ones that make the ARC so they should have their number right.

http://www.worldcruising.com/content...lure_wcm25.pdf

This was published in 2007 and they refer problems in rudders on the last 10 years, so from 1997 to 2007.

From 2007 on It is easier since all incidents have been well documented on internet, by sail magazines, ARC news and in forums. If you search you will find them. I also said that regarding the last 5 years those were the accidents I could find out after an internet search. Also asked if somebody now or could find anything more...but it seems nobody could.

You, Sir, are the man!

These boats they have anything in common?

I mean I know Bavaria and Hunter do.

I also know that last time I saw an EC 37 for sale the asking was at below what we paid for our 26'er (EC is ... 37'). Dehler and Sydney may be one shelf up, still, they are paper boats, aren't they.

No Oysters, no HRs, no Contests, no Contessas, no Westerlies, no Moodies, no Malos, no Najads, no Rustlers, no Rivals, no Zaals, Koopmans, Hoeks ... OK, OK, I am beating a dead horse. I know.

For your record, past 2006 there were at least the following rudder failures:

- a German racer (make unknown but she looked great when she still had that rudder), possibly R&V,
- a small Sadler (26?).

The Germans bailed out, the Brits fixed up and made it allright.

b.

[cpa]

Originally Posted by Polux

This article was made by the ones that make the ARC so they should have their number right.

http://www.worldcruising.com/content...lure_wcm25.pdf

This was published in 2007 and they refer problems in rudders on the last 10 years, so from 1997 to 2007.

From 2007 on It is easier since all incidents have been well documented on internet, by sail magazines, ARC news and in forums. If you search you will find them. I also said that regarding the last 5 years those were the accidents I could find out after an internet search. Also asked if somebody now or could find anything more...but it seems nobody could.

Nice article! Thanks for posting.

[Polux]

Originally Posted by barnakiel

...
For your record, past 2006 there were at least the following rudder failures:

- a German racer (make unknown but she looked great when she still had that rudder), possibly R&V,
- a small Sadler (26?).

The Germans bailed out, the Brits fixed up and made it allright.

b.

That German racer, with a bit more than 50 ft was accounted for (it is one of the three). it is not a mass production boat but a one off.

That Sadler 26 I confess I did not hear about. I even thought that they did not allow on recent years boats so small. Can you post a link to it? Anyway that is an old boat and not what you call a modern production boat.

PS: I found out the boat but that Sadler, an old 25 with skeg rudder, does not count because it was not making the ARC. It was in 2009:

"We've had a fairly interesting day yesterday,another yacht ,too small to participate in the ARC, but sailing the Atlantic called 'Starfire',sent a message asking for our help as they had lost half their rudder.Starfire is a Sadler 25 being sailed by 2 young lads,Alan 22 and Tom 23.Alan's dad who met Ray on a sailing course asked Ray if he would keep a fatherly eye on them.Anyway they are a real pair of characters as you can imagine and apart from needing a few beers to be bought for them and the use of our mobile phone because of course their's was out of credit,they have been pretty independent, until yesterday when we got a call for help as they had lost half their rudder. Having notified ARC control we diverted SE to try to get back to Starfire."

http://blog.mailasail.com/raylawry/24

[DeepFrz]

Polox, I can tell you that not all rudder failures have been well documented on the internet. Only high profile and SAR incidents get posted and not even all of those. Unfortunately there is no central registry where accidents and things like rudder failures are kept track of. I tried to keep track of the abandoned and sinking boats. This year I had 11 of which I believe 9 to be loss of steering, mostly due to rudder loss, 1 was loss of keel but the boat survived and one was loss of propulsion. But sometimes it is hard to know the exact cause.

Edit: it is very hard to track these problems as many are not posted on these forums.

[minaret]

Rebuilding a Pacific Seacraft rudder now. How many rudders have I had to fix which broke first? Several. How many have I repaired, rebuilt, or replaced, which were headed for imminent failure? Many. Dozens, for sure.


Want to decrease the odds of rudder failure, or, much more likely, a rudder rebuild? Don't buy a cheap boat with under built steering gear.


I think all this talk of percentage of boats who suffer failure at sea means little. Most bad rudders are caught before failure. Percentage of boats which have had a rudder replaced or rebuilt might be more revealing.