Oceanis 485 steering failure

[neilpride]

Originally Posted by ontherocks83

Oh man that is funny!

I know hind sight is 20/20 but by attaching all the steering inputs above the upper bearing they turned the rudder post into a class 1 lever, which is good and all except for levers are designed to move things, even if it didnt want to be moved. Making the rudder post longer and attaching it to the deck "could" have prevented all of this.

Agree, the Beneteau 50 , not the Oceanis serie ,have the top bearing fitted in the deck , leaving the tube free from torsional or lateral loads.. no problems so far...

[estarzinger]

Well . . .

Probably pretty clear now where the source of the water was. The bottom of the tube cracked entirely around.

Probably happened because the plywood upper bearing tray came loose and the autopilot pushed the rudder shaft and tube back and forth.

The autopilot finally going wild was probably a symptom of the plywood coming loose - pushing back and forth no longer turned the rudder, just pushed it back and forth.

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.

And yes, I do think it has been a useful discussion (1) to point out an element of bendy design that owners should pay attention to, (2) the side discussion of pumps and water inflow rates.

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.

[ontherocks83]

Originally Posted by neilpride

Research again, i mean if the boat sport the same structure, FG tube , top resting in the ply partitions with plexus, then is a candidate for modifications , repair.

I do some work in few Oceanis, from a 50 to a 40 ft, single rudder , they have the same config, unless Beneteau is doing diferent with the double rudder designs, the problem is still there....

Now ask yourself how many cruisers out there are aware of this problem..

This is definitely getting added to my list of things to check before I buy another boat.

[boatman61]

Originally Posted by estarzinger

Well . . .

Probably pretty clear now where the source of the water was. The bottom of the tube cracked entirely around.

Probably happened because the plywood upper bearing tray came loose and the autopilot pushed the rudder shaft and tube back and forth.

The autopilot finally going wild was probably a symptom of the plywood coming loose - pushing back and forth no longer turned the rudder, just pushed it back and forth.

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.

And yes, I do think it has been a useful discussion (1) to point out an element of bendy design that owners should pay attention to, (2) the side discussion of pumps and water inflow rates.

Lucky for them they were with company and in sheltered waters.. unlike Bluewater's experience mid-Atlantic..

[transmitterdan]

I don't know if this has been posted elsewhere but it sounds eerily similar to the sinking we have been discussing:

UPDATE: $600,000 yacht sinks off King Island | The Advocate

[neilpride]

Yeah I posted that link in a new thread, seems to me something very similar.. Rudder problem, but in that case they hit a reef rocks...

[Polux]

Originally Posted by neilpride

Research again, i mean if the boat sport the same structure, FG tube , top resting in the ply partitions with plexus, then is a candidate for modifications , repair.

I do some work in few Oceanis, from a 50 to a 40 ft, single rudder , they have the same config, unless Beneteau is doing diferent with the double rudder designs, the problem is still there....

Now ask yourself how many cruisers out there are aware of this problem..

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.

[Terra Nova]

Originally Posted by Polux

...Being mounted on plywood is not a problem...

But mounting the top bearing to something vastly more substantial, like the deck, would have virtually eliminated these unfortunate losses.

[neilpride]

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.

HAHAHA everyday I am more convinced that you are a Beneteau seller lol.
I don't waste my time answering the rest of your brilliant post Paolo.

[minaret]

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.

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

[donradcliffe]

That plywood box is just not a good design for a number of reasons.

If you are an Oceanis owner and want to see how strong your rudder support system is, you can test it very simply and easily.

1. Make arrangements with the boatyard to have a travel lift standing by with the straps in the water.

2. Motor in reverse, and get the speed up over 5 knots.

3. Let go of the helm.

[neilpride]

Originally Posted by donradcliffe

That plywood box is just not a good design for a number of reasons.

If you are an Oceanis owner and want to see how strong your rudder support system is, you can test it very simply and easily.

1. Make arrangements with the boatyard to have a travel lift standing by with the straps in the water.

2. Motor in reverse, and get the speed up over 5 knots.

3. Let go of the helm.

I bet you a Cold Pack that if you are inside of the rudder post wachting the show you can be horrified...

[Polux]

Originally Posted by ontherocks83

This is definitely getting added to my list of things to check before I buy another boat.

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

[ontherocks83]

I would rather have a better design with "weaker" materials, over a shitty design that "could" be made strong with more robust materials.

[Polux]

Originally Posted by Terra Nova

But mounting the top bearing to something vastly more substantial, like the deck, would have virtually eliminated these unfortunate losses.

Off course but that would also imply a stronger deck with big reinforcements on that area. The point is that even if I don't like the design in what regards efficiency and lack of accessibility to the point where the rudder passes the hull, there is no reason a system like that cannot be built strong enough.