Construction details of Rudder

[tsenator]

I have a 2003 Jeanneau 43 DS (shoal keel) and I was curious as to the internal construction details of the rudder.

On some boats like my previous one the upper half (of the actual rudder in the water) was where the actual structural metal that was holding the rudder was and the lower half was just foam (or fiberglass?) and did not have any metal of structural connection to the rudder post.  The reason for this was if, per chance, you hit something with the bottom of your rudder that part would "break away" but you'd still have the top half of rudder that had the metal connection to the rudder shaft and be able to steer in "emergency mode"

Does anyone know if that is the same on the Jeanneaus?   Has anyone pulled a Jeanneau rudder apart and looked inside ?

[MalcolmP]

Maybe not exactly the same on your 43DS but some good photos on the structure from a slightly older SO47 here
www.jeanneau-owners.com/hintsandtips/RudderrebuildSO47.html

[tsenator]

Malcolm thanks, that is very helpful.  So it appears as if the lateral armature welded to the rudderstock goes mostly through the whole length of the rudder. 

[markevans]

split rudder on 2003 43DS 2 years ago and rebuilt and overlaid with more glass before coppercoating due to surveyors unwarranted concerns. I had seen a split Bav rudder 2w before splitting ours and it was scary. By contrast ours was in excellent condition and is constructed as per the drawing with mo water or corrosion. So I'm afraid i spent over £1k to have a slightly stronger rudder but much peace of mind.

[achosenman]

I’m just going through the process now on a SO40.3. No de-lamination or bulges etc, but the rudder is saturated. I’ve elected to split the rudder, inspect and repair, I will have it strengthened too. No change from 2.4k but I’m not prepared to risk the boat or crew.

I intend to take pictures, I’ll post them here when I get them.

[Zanshin]

Don't neglect the possibility of crevice corrosion. I had a SO43DS which lost her rudder while at sea - it broke off right at the hull join and while the rudder was superficially undamaged it looked like an electrically active marina (Sunsail base in the BVI) accelerated the corrosion which wasn't visible to myself or the surveyor when I purchased her.

[achosenman]

The rudder is now done. I wasn't there due to the lock down, but I do have some pictures. I would post them but that has proven difficult to a level beyond my patience.

The rudder was wet, the stock was the ingress point. The stock and tangs were not glued to the filler anymore, but that was the extent of the issue.

Anyway, it's all sorted, the rudder was reinforced with extra laminates and re-constructed.

If at some point the issues with posting pictures on this site are remedied, I will post them.  

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[MalcolmP]

Mar 25, 2020 11:01:17 GMT achosenman said:

The rudder is now done. I wasn't there due to the lock down, but I do have some pictures. I would post them but that has proven difficult to a level beyond my patience.

The rudder was wet, the stock was the ingress point. The stock and tangs were not glued to the filler anymore, but that was the extent of the issue.

Anyway, it's all sorted, the rudder was reinforced with extra laminates and re-constructed.

If at some point the issues with posting pictures on this site are remedied, I will post them.  

Well done indeed. If you want to email me the photos I will add them. 


EDITOR - Images now inserted in above post

[achosenman]

Thank you Malcolm, I will get them across to you.

I did try Flickr and the work-around posted of this forum, but nothing seemed to get it done. I either walked away, or the computer was going out the window...


EDITOR - Images now inserted in above post

[tsenator]

Oh Wow -  Thank You !!    Those pictures are EXTREMELY helpful !!   What type boat did this come off of ?

It does appear that the lower 1/3 is not connected to the actual rudder post - that is what I was kind of expecting.    Thanks !

[achosenman]

The boat is a 2005 SO40.3. 

My understanding is the bottom third is not connected by design. It allows the rudder to snap in the event of a significant collision to protect the hull and retain some rudder blade for steering. 

[NZL50505]

I’m astonished (and disappointed) that modern production boats like many of ours here are suffering from rudder issues that need fixing (or preventative measures) at a relatively young age, to avoid potential catastrophic outcomes. Is there a fundamental design failure here? Or is it a cost issue causing sub-par materials to be used?

[MalcolmP]

Mar 27, 2020 22:20:03 GMT NZL50505 said:

I’m astonished (and disappointed) that modern production boats like many of ours here are suffering from rudder issues that need fixing (or preventative measures) at a relatively young age, to avoid potential catastrophic outcomes. Is there a fundamental design failure here? Or is it a cost issue causing sub-par materials to be used?

I don't see that these photos actually evidence that there is any design or cost based manufacturing fault.

The poster said  he was aware that it was water saturated. Whilst not ideal, it is common to many brands and in itself should not compromise rudder integrity. Jeanneau used to make their rudders from solid wood with a GRP skin, but then these rotted over time.

Mar 11, 2020 8:49:39 GMT achosenman said:

I’m just going through the process now on a SO40.3. No de-lamination or bulges etc, but the rudder is saturated. I’ve elected to split the rudder, inspect and repair, I will have it strengthened too. No change from 2.4k but I’m not prepared to risk the boat or crew.

I intend to take pictures, I’ll post them here when I get them.

Documented recent rudder failures seem to be principally due to electrolysis/stray current corrosion of the shaft due to 12v wiring faults or as a result of impact with objects.

In common with other critical yacht parts, such as standing rigging, it is vital that there is regular inspection then replacement of key items when necessary. 

It is good to see in the photos that despite being "saturated" and presumably for some time, that the stainless items all looked in fully serviceable condition.

After all it is is a relatively simple job to drop the rudder to ensure that the rudder shaft has no evidence of corrosion where it cannot normally be inspected.

[achosenman]

I agree Malcolm. Boats need regular inspection, just like aircraft. Unfortunately some boats seem to be neglected. All aircraft checks are mandated in law, no if's, no buts. If they aren't carried out, the aircraft is grounded. Private boats can get get away with this requirement. IMHO that's one reason we see failures. 

I checked the rudder because I was pretty sure it hadn't been done since new and I had a squeak. I've only had the boat a couple of years and it has an ongoing refit and improvement program. The intention is to do some significant cruising. Part of that program was an upgrade to a type 2 linear drive. We decided to re-enforce the steering quadrant to cope with the more powerful drive unit and it seemed like a good idea to do bearings and everything else at the same time. 

The rudder has been in the water for 18 months. In that time it has become saturated. Considering the other bodges I've discovered, I'm pretty sure the chap I purchased it from dried the rudder prior to the survey. The boat had been on the hard for at least 12 months. 

The surveyor I use knows my intentions. He explained that failure modes for rudders is well understood. Mine was on that journey. Because the rudder stock was not glued to the core any more, this would allow the blade to twist and work loose over time. After a while, the blade would separate from the stock. If you sail in the Solent probably not a problem, the open ocean is another matter.

ATB

[NZL50505]

I’m still not convinced. If you lose your rudder is could be catastrophic anytime, anywhere. At least in the open ocean you have time and space to respond. If you lose it in the Solent in fresh conditions and you round up into the path of a fast moving ferry it could all be over very quickly.

So I think the best principles of design should take into account much more than just ‘can it do its job’ but a realistic view of ‘how it will be used’. I think it’s realistic to expect the majority of owners to lift their boat every couple of years for a repaint and maintenance on the obvious observable parts eg anodes, shaft bearings and rudder bearings, if things like amount of play become diagnostic. But I don’t think it’s realistic to expect the majority of private owners working on a budget to undertake expensive preventative maintenance on invisible parts with the rigour of aircraft maintenance.

I’m no mechanic but what if rudders were constructed differently eg out of metal only with bolts and welds but no glue or wood or grp or any other materials susceptible to ingress and weakness?

[achosenman]

I meant that the forces in the Solent are unlikely to amount to much. They can be significant true, but an F8 in the Solent is not the same as an F8 in the open ocean.

The aircraft analogy is just a simple statement of fact. I come from aviation so perhaps I take a different view to maintenance, both ongoing and preventative. 

I'm sure there are better ways to construct rudders. I suspect the reality is that when it's time to put the money down, the vast majority will opt for the cheaper solution.

Skeg hung rudders fail, so do spade. I do know that the design working loads are calculated by the designer. Any rudder, regardless of design, if exposed to forces significantly greater than that for which they are intended, will fail. Personally I'd prefer a skeg, but as ever, sailing is a compromise. 

 

[NZL50505]

I wonder if there would be a market for better / stronger rudders to replace the factory-fitted ones on the major popular production boats? For people heading offshore or just wanting extra peace of mind...

[achosenman]

Jefa do after market rudders, they aren't cheap. 

IMHO the solution if you are worried, is to fit a Hydro-vane. They allow self steer without using power and they act as an emergency rudder. Again not cheap.  

[MalcolmP]

Mar 30, 2020 7:19:30 GMT achosenman said:

Jefa do after market rudders, they aren't cheap. 

IMHO the solution if you are worried, is to fit a Hydro-vane. They allow self steer without using power and they act as an emergency rudder. Again not cheap.  

Our amazing project maestro Sailbleu also has made his own DIY emergency rudder (plus outboard bracket) system for his SO40DS in readiness for his transatlantic jeanneau.proboards.com/thread/7840/emergency-rudder-propulsion

I was also wondering that with many of the new models featuring dual rudders, how these would function if one blade was lost, guess motoring would hard, but at least on one tack you could sail...

[achosenman]

I think it's a personal comfort thing. Some would never set foot on anything with a spade rudder and fin keel at sea. Others like us, take a more pragmatic view. 

I've thought about rudder failure at length. For me the solution is Hydro-vane, a BOGOF fix if ever there was one. 

Dual rudders? I don't know, the mischievous part of me would point out statistically you've got double the chance of a failure...

[rene460]

Hi achosenman, yes, increased chance of a failure, but a failure of less consequence, as you still have one which will give you steering capability.  You do have a much lower chance of both failing at the same time.

Obviously the situation is behind the racing rules which require a method of emergency steering.  As Malcolm has mentioned, Sailbleu recently did a beautiful job of constructing a really useful spare.  It would have to be deployed really quickly if a rudder failed in a busy shipping channel, in the open ocean there is possibly more time available.  But his design looks way better than many recommended emergency steering systems.

I suggest that steering with only one of the two rudders would probably not be a race winning tactic, but our boat steers quite well even when heeled so that only one of our very shallow rudders.  I think that motoring would be no issue, though docking may be more difficult.  We don’t have prop wash anyway, so need speed through the water to steer.  Might be only a little worse coming into the pen.  But that is my guess, I don’t want to break a rudder to test the theory!

I suspect that by the time you have two rudders, the chance of simultaneous failure might be less than some of the many other failures that can occur at sea, and probably way lower than some of the many other possible failures.  But all are generally less than the consequences of similar failures in aviation.  Boats are found afloat at sea sometimes years after they are abandoned by the crew, so presumably were able to limit the consequences until the crew deployed another option.  Unfortunately, aircraft have a different failure consequence.


Perhaps it is a matter of deciding the risk level you can accept and implementing appropriate maintenance and spare parts inventories accordingly.  Even if you tie up permanently in the marina and limit your boating activities to partying, there is still a risk of someone falling overboard and being unable to swim, or even the boat sinking.  Please don’t laugh, I saw one nearly sinking in the marina only a few weeks ago, and it was a boat that gets well used and maintained.  It had been out earlier that day.  Fortunately there were alert people in the marina who were able to alert the coast guard promptly.  They were able to deploy a very large pump and avoid the sinking.  Needless to say, they jumped the queue at the boat lift in the yard.  In fact they totally wrecked our maintenance schedule as we were due to be first lift.  But importantly, quick action saved the boat, though I suspect it needed some major repairs to equipment that had been submerged.  And I had previously seen another boat sink in the same marina.  So on a small sample, that may be a bigger risk!

And really, none of this is intended to make light of the original contention.  We all need to stay on top of maintenance to the best of our ability.

rene460

[achosenman]

I agree, you cannot cater for every possible failure and boats tend to be naturally more "fail safe" than aircraft simply because they don't fly.

A lot things surprised me when I got into sailing. The mindset that things shouldn't fail was one, and if it did, it must be a design flaw is the most surprising. It's simply not a realistic expectation. The sea is probably the harshest environment on the planet.

Everything mechanical needs maintenance and repair. Cost does't come into the "need" equation, only whether it gets done. 

Redundancy is a good thing, especially if the consequence is catastrophic. The downside is complexity and cost. 

In the end, each of us must find their comfort zone.  

[colinnz]

Mar 28, 2020 8:07:30 GMT achosenman said:

"He explained that failure modes for rudders is well understood. Mine was on that journey. Because the rudder stock was not glued to the core any more, this would allow the blade to twist and work loose over time. After a while, the blade would separate from the stock. "

We had this issue and pitting on the shaft just above the main body AND there was movement. Elected to get a new one as it was comparative in price and quicker to get to NZ from Jeanneau. Still THE most expensive postage I have ever paid.... ;-)