Oceanis 485 steering failure

[ontherocks83]

Originally Posted by Polux

Check also for a watertight bulkhead separated rudder area from the rest of the boat. Not very common but some production boats have them.

Already planned on figuring out how to make one if it didnt come with one.

[Polux]

Originally Posted by minaret

The guys at Beneteau should give you a raise. Not very convincing, but certainly persistent.

Maybe he deserves a raise too since he is saying or implying the same things

Originally Posted by estarzinger

Well . . .
.....
The plywood coming loose was probably a combination of poor design, fatigue on the poor design from heavy charter use (probably include groundings), and inadequate maintenance/inspection. I might note in that regards, the photos show some ugly corrosion on the pump and ram - not excellent maintenance.
....
These Bendy's are designed and engineered to stand up to 98% of their owner's usage. But it appears to potentially cause (relatively infrequent but serious) problems for boats that used 'commercially' and rode hard and put away wet (eg less than commercial safety grade inspection and maintenance) This case and Cheeki Rafiki being examples.

If you don't agree with something I say please explain with what and why. Comments like the one you made serve no useful purpose.

[transmitterdan]

Originally Posted by Polux

As I said, neither the ply structure neither the use of plexus with partial support on a ply structure of interior partitions is cause for alarm. Ply and bonding agents can be extremely strong, it is more about how it is done and about scantlings.

If you say that all Beneteaus with single rudder use this type of setup and since I seem to recall that Mark had said is Bene had not a top bearing, this set up is being used for more than a decade. That means about 20 000 benes and even if I had heard about some boats with problems it is very far to correspond to the numbers that would occur if that problem was so easely manifested as on the Oceanis 48 or the models Beneteau give orders to be reinforced by the dealers.

It continues to look to me as an inefficient design but being safe or not it will depend basically on the way it is built and calculated and I don't believe It will be the same on all the boats. Many Benes have been sailed extensively and have circumnavigated with any rudder problems.

Saying all this if I had a Bene with that system and if I would sail it extensively, I would reinforce it with the kind of additional support that was designed by Beneteau to, I believe, some models. That is a smart improvement, will not imply any modification on the previous system, just an easy to fit setup. I would also take care to see that the piece is solidly mounted. Even if the pre-existent setup was strong enough it will do not any harm to make it stronger.

But that is just me that like to have back ups. Recently when I took down the rudder of my boat, even if pretty solid I did not resist to introduce a improvement. I guess it comes with the habit of designing things and liking to see them well designed

Being mounted on plywood is not a problem since the efforts will be almost all lateral and it should not be dificult to secure the piece of plywood (where the metal piece is mounted) using plexus, laminated or even having it supported laterally, forward and backwards to the hull, stern and back bulkhead.

Polux,

Ok, if you want specific points where this post is full of it here goes.

Unsealed plywood is not a suitable material for supporting the upper rudder bearing period end of story. Aluminum plate would be lighter and stronger (but not cheaper). If the plywood were laminated with some glass and epoxy it might be ok but what is wrong with aluminum plate? The answer is, it isn't compatible with Plexus and so would cost a bit more to fasten to the structure.

The AP tiller arm is way too short and so creates unnecessary side loading on the upper support bearing and its supporting plate. This boat was heavily reefed according to the initial report. I'm betting it was not well balanced with loads of weather helm and the autopilot was shoving really hard on the tiller arm. Charter crews often don't pay attention to rudder position when sailing hard on the wind. They just push the AUTO button and get where it's warm and dry.

I don't care if a million of these plastic trash heaps sailed from here to the moon and back. A bad design is still a bad design. Please stop insulting people's intelligence with this tired old song of how many thousands of benes have circumnavigated. Anyone understanding mechanical design and the horrors of losing a boat at sea would not take one of these designs past the harbor breakwater no matter how many other crew may have got lucky and made it safely home.

The builder should be ashamed of this design and lovers of the brand should be screaming their heads off that a recall be made as soon as they can get a NA willing to sign off on a fix. That is if they can find one willing to tackle this lawsuit waiting to happen.

[Polux]

Originally Posted by transmitterdan

Polux,

Ok, if you want specific points where this post is full of it here goes.

Unsealed plywood is not a suitable material for supporting the upper rudder bearing period end of story. Aluminum plate would be lighter and stronger (but not cheaper). If the plywood were laminated with some glass and epoxy it might be ok but what is wrong with aluminum plate? The answer is, it isn't compatible with Plexus and so would cost a bit more to fasten to the structure.

The AP tiller arm is way too short and so creates unnecessary side loading on the upper support bearing and its supporting plate. This boat was heavily reefed according to the initial report. I'm betting it was not well balanced with loads of weather helm and the autopilot was shoving really hard on the tiller arm. Charter crews often don't pay attention to rudder position when sailing hard on the wind. They just push the AUTO button and get where it's warm and dry.

I don't care if a million of these plastic trash heaps sailed from here to the moon and back. A bad design is still a bad design. Please stop insulting people's intelligence with this tired old song of how many thousands of benes have circumnavigated. Anyone understanding mechanical design and the horrors of losing a boat at sea would not take one of these designs past the harbor breakwater no matter how many other crew may have got lucky and made it safely home.

...

I am confused the one that made a deselegante comment was Minaret not you.

Your comments regarding marine plywood and aluminium tells me that you are not a structures engineer neither an architect with experience in structures. There are very good voyage sailboats made of plywood, all of it, except the keel structure and the kells.

From the photos posted you can see that the marine plywood was sealed with 2 components epoxy primer and you don't know if the marine plywood was previously sealed with epoxy resin.

Aluminium is a good material for boat building, as well as plywood, but in what regards to built a support structure on a fiberglass boat given the choice of those two materials probably sealed marine plywood is a better material.

Anyway the better would be to avoid the use of any of those materials for a support structure and have a reinforced cockpit on that area with the rudder stock going there, supported over a bearing

Regarding not caring "if a million of these plastic trash heaps sailed from here to the moon and back", well you should care, it is for what sailboats are built for, for sailing and cruising for a long time and if they can do that it is because the rudder design of Beneteau works reasonably well on most of their models, otherwise many would not be able to circumnavigate. I don't understand your logic.

Saying all that I continue not to like that rudder design.

[transmitterdan]

Polux,

Assuming we have a language translation problem I will explain. It matters not even a little bit how many boats of a particular design/build safely make a circumnavigation. That is no proof the design is sound. Even so, several posters on this forum keep saying that like it is some kind of mantra. There is no logic in this reasoning whatsoever.

One way to tell if a design is sound is to look at it and analyze it against the loads that it might be called upon to accept. Another way to tell is to find even one example of the design that did not survive the loads it encountered. If there is one example of failure that is due to the design then all the identical examples are also faulty regardless of whether they have failed yet or not.

To reiterate, it is not proof of a sound design that several boats made it around the world without failure. That argument is using incorrect logic and can be proven so by finding even one example of a failure. In this situation we have more than one failure.

You keep telling yourself that a plywood plate with a bearing glued to the outer laminate layer which is maybe a mm thick is an ok way to support a rudder. Whether you like it or not isn't the question. The question is whether it is an acceptable design for a critical component that can kill people if it fails? I think you know the answer even if you don't want to admit it.

Somebody is going to die because of this design.

[neilpride]

Originally Posted by Polux

I am confused the one that made a deselegante comment was Minaret not you.

Your comments regarding marine plywood and aluminium tells me that you are not a structures engineer neither an architect with experience in structures. There are very good voyage sailboats made of plywood, all of it, except the keel structure and the kells.

From the photos posted you can see that the marine plywood was sealed with 2 components epoxy primer and you don't know if the marine plywood was previously sealed with epoxy resin.

Aluminium is a good material for boat building, as well as plywood, but in what regards to built a support structure on a fiberglass boat given the choice of those two materials probably sealed marine plywood is a better material.

Anyway the better would be to avoid the use of any of those materials for a support structure and have a reinforced cockpit on that area with the rudder stock going there, supported over a bearing

Regarding not caring "if a million of these plastic trash heaps sailed from here to the moon and back", well you should care, it is for what sailboats are built for, for sailing and cruising for a long time and if they can do that it is because the rudder design of Beneteau works reasonably well on most of their models, otherwise many would not be able to circumnavigate. I don't understand your logic.

Saying all that I continue not to like that rudder design.

You don know if is epoxy primer or not, could be white latex paint,,, Beneteau supply those ply panels with a poly varnish coating , and they plexus on top of the coating, worst way posible, no resin at all in the panels,, so go and figurate, those practiques are more common coming from a cheap coastal boat than anything else, even I see better rudder arrangements in boats designed for inshore waters,,

Beneteau don't use any kind of epoxy in the veneer, can you imagine the cost..
Even In the pictures posted here you can see a layer of glass glassed on top of the Varnish coating, no grinding or edge anywhere...

Overall, is a CRAP///
CRAP.CRAP.CRAP.

The design is horrible.
HORRIBLE HORRIBLE HORRIBLE.

Is not suitable for a boat with a CAT A decal.

NOT SUITABLE NOT SUITABLE NOT SUITABLE.

So, you don't like the design? be my guess.....

[Terra Nova]

Originally Posted by neilpride

...

Overall, is a CRAP///
CRAP.CRAP.CRAP.

The design is horrible.
HORRIBLE HORRIBLE HORRIBLE.

Is not suitable for a boat with a CAT A decal.

NOT SUITABLE NOT SUITABLE NOT SUITABLE...

I think we're now getting somewhere.

[estarzinger]

Originally Posted by Polux

If you don't agree with something I say please explain with what and why.

I was not specifically disagreeing, replying or responding to any of your comments.

But . . . this design is intrinsically less good than with the bearing mounted on the deck. For two reasons - under the deck has both a longer span, and provides less lever arm for the quadrant and tiller arm. (I think we all agree with this)

Yes, this design could be made stronger - with some combination of better construction technique, different materials, more materials, but all those things would add cost. (I think we all agree with this)

The thing to realize about Bendy is that they are designing their boats to suit the 95% which don't sail very hard and they are trying very hard to keep the cost down to be more competitive in that market. The primary reason they use this design (a Bendy engineer has told me this directly) is because it saves money by making the bearing alignment very easy/straightforward and because it suits the structural needs of the vast majority of their owners.

Previously I had discussions/negotiations about their brass thru hull fittings and mixed metal ball valves - again it was a cost issue. They said there were 100's of places they could do things 'better' on the boat, but if they did them all better the boat would cost $100k more and very few of their owners would notice, so it was a better business decision to do things this way.

It is pretty straightforward, they are designing to a cost, in order to be as price competitive as they can, and that requires meaningful compromises in the boat, including in important safety related areas. (we have not directly discussed this but I would guess we all agree that it is a fact)

The problem seems to come when these boats are put in hard commercial service, where there are a ton more fatigue cycles that the typical user, and/or in groundings where the structure is then not taken completely apart and completely inspected and rebuilt as necessary. Excellent maintenance and inspection to true commercial standards can (in large part) compensate for all this. But some of these structural defects can be very hard to identify (see the discussion above and quotes from the MCA report on Cheeki Rafik).

I do not know what the failure rate is in total, or among the subset of boats that are 'well used'. I do know that the failure rate of the valves is higher than the public is generally aware because Bendy works hard and successfully to keep them quiet. In fact the boat building industry generally has quite a reputation and history of covering up problems -The tartan hull problems as an example, and as quite topical - look at the long history of gunboats problems which have been at least partially hidden until the chapter 11 revealed them all).

But it is clear that the keel structure problem killed 4 sailors, and this rudder tube design could kill sailors.

As a particular comment . . . When you tab plywood, you have to taper the edges, so that the tabbing bonds to multiple layers of the plywood. But that costs labor/money, and at least the Bendy 48 I just looked at in Annapolis it was not done.

BTW, I believe if you look at MarkJ's tube (it is post 87) you will see a different structural solution to holding the tube in place. One which is probably more reliable (4x the bracing and tabbing structure, which also directly reinforce the bottom end of the tube) but also rather more labor cost.

[Terra Nova]

Originally Posted by estarzinger

...this design is intrinsically less good than with the bearing mounted on the deck. For two reasons - under the deck has both a longer span, and provides less lever arm for the quadrant and tiller arm...

Let's point out that a deck mounted bearing completely eliminates the rudder post cantilever.

[Jim Cate]

Originally Posted by Terra Nova

Let's point out that a deck mounted bearing completely eliminates the rudder post cantilever.

Huzzas to this and all the other posts involving this solution. I find it hard to understand why they would use the complicated and ineffective mid level upper bearing when the deck is always there and almost always strong enough without serious reinforcement.

Jim

[estarzinger]

Originally Posted by Jim Cate

I find it hard to understand why they would use the complicated and ineffective mid level upper bearing

Because (according to bendy engineer) it both eliminates the fussy labor involved in aligning a deck mounted bearing and(or) allows for the use of a simpler and cheaper sleeve bearing. They reckon it is less expensive for them and structurally satisfactory. We can debate the second part, but I think we probably should assume they understand their cost side of the equation pretty well.

[Jim Cate]

Originally Posted by estarzinger

Because (according to bendy engineer) it both eliminates the fussy labor involved in aligning a deck mounted bearing and(or) allows for the use of a simpler and cheaper sleeve bearing. They reckon it is less expensive for them and structurally satisfactory. We can debate the second part, but I think we probably should assume they understand their cost side of the equation pretty well.

Ahh, yes, bean counter engineering... how very depressing, how very common.

It is this sort of decision making that is the hidden difference between price point boats (not just Bennies) and those of higher quality construction. And this is what is hard for those who defend such boats as "just as good as..." to grasp. One wonders how many such decisions are made in each design review?

Thanks for the inside info, Evans.

Jim

[transmitterdan]

The builders of mass produced boats claim they get all their cost savings from robotics and superior engineering analysis. That allows them to produce a better product at a lower price point. Their marketing message tells buyers they can have their cake and eat it too. It is extremely frustrating that these companies have driven good builders out of business because they refused to buy into this illusion.

[neilpride]

Originally Posted by estarzinger

I was not specifically disagreeing, replying or responding to any of your comments.

But . . . this design is intrinsically less good than with the bearing mounted on the deck. For two reasons - under the deck has both a longer span, and provides less lever arm for the quadrant and tiller arm. (I think we all agree with this)

Yes, this design could be made stronger - with some combination of better construction technique, different materials, more materials, but all those things would add cost. (I think we all agree with this)

The thing to realize about Bendy is that they are designing their boats to suit the 95% which don't sail very hard and they are trying very hard to keep the cost down to be more competitive in that market. The primary reason they use this design (a Bendy engineer has told me this directly) is because it saves money by making the bearing alignment very easy/straightforward and because it suits the structural needs of the vast majority of their owners.

Previously I had discussions/negotiations about their brass thru hull fittings and mixed metal ball valves - again it was a cost issue. They said there were 100's of places they could do things 'better' on the boat, but if they did them all better the boat would cost $100k more and very few of their owners would notice, so it was a better business decision to do things this way.

It is pretty straightforward, they are designing to a cost, in order to be as price competitive as they can, and that requires meaningful compromises in the boat, including in important safety related areas. (we have not directly discussed this but I would guess we all agree that it is a fact)

The problem seems to come when these boats are put in hard commercial service, where there are a ton more fatigue cycles that the typical user, and/or in groundings where the structure is then not taken completely apart and completely inspected and rebuilt as necessary. Excellent maintenance and inspection to true commercial standards can (in large part) compensate for all this. But some of these structural defects can be very hard to identify (see the discussion above and quotes from the MCA report on Cheeki Rafik).

I do not know what the failure rate is in total, or among the subset of boats that are 'well used'. I do know that the failure rate of the valves is higher than the public is generally aware because Bendy works hard and successfully to keep them quiet. In fact the boat building industry generally has quite a reputation and history of covering up problems -The tartan hull problems as an example, and as quite topical - look at the long history of gunboats problems which have been at least partially hidden until the chapter 11 revealed them all).

But it is clear that the keel structure problem killed 4 sailors, and this rudder tube design could kill sailors.

As a particular comment . . . When you tab plywood, you have to taper the edges, so that the tabbing bonds to multiple layers of the plywood. But that costs labor/money, and at least the Bendy 48 I just looked at in Annapolis it was not done.

BTW, I believe if you look at MarkJ's tube (it is post 87) you will see a different structural solution to holding the tube in place. One which is probably more reliable (4x the bracing and tabbing structure, which also directly reinforce the bottom end of the tube) but also rather more labor cost.

Such a good post, really , thank you, interesting..

[malbert73]

Originally Posted by transmitterdan

The builders of mass produced boats claim they get all their cost savings from robotics and superior engineering analysis. That allows them to produce a better product at a lower price point. Their marketing message tells buyers they can have their cake and eat it too. It is extremely frustrating that these companies have driven good builders out of business because they refused to buy into this illusion.

And the thing is, these things probably do save money without affecting quality. Imagine if a builder actually used CAD and robotics to cut all bulkheads, furniture- saving money on hand fitting and measuring- but then tabbed in bulkheads, etc and didnt take shortcuts on build strength. I imagine you have to build a certain quantity to justify the tooling expenses, and you have to be bottom level price for size of boat to make that happen these days.
i think Catalina tends to do a better job of quantity/price/quality these days. Dont really hear of their rudders or keels falling off, nor major defects, right?


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