Rudder Failures

[neilpride]

Originally Posted by transmitterdan

The scariest thing I noticed in Neil's pictures is that it seems the laminate plywood is now a structural part of the boat. Instead of a platform for the fiberglass as in days of old the actual wood and glue in the laminating process is taking stress loads. Laminates are strong but only in certain axis. I think they are least strong when stress is trying to pull the laminate apart as could happen in a boat. The green goo is almost certainly stronger than the plywood panels.

The fender washer cleat is a joke, right?

The fender washers come from from the aft cleats. No kidding...

[robert sailor]

I'm told that the green glue is tenacious as hell but it has no flexibility and is brittle, nothing like the tabbing on the better built boats.

[colemj]

Originally Posted by Polux

To do that the autopilot has to be linked to the rudder through a sensor that in many cases is an option to the autopilot and deserves all the money it costs.

This season when they dismounted the rudder they did not connect rightly the sensor and I was not able to reconnect it the right way (the damn picture on the manual was misleading!). I thought I had a software problem and made the season without the sensor: What a difference!!!! for worst off course.
The thing was working in what she called "virtual mode" and the ability to anticipate was greatly reduced and in difficult sailing conditions I had to hand steer, or take some sail out. I was so happy when they found out that the sensor was just mounted backwards!!!

The sensor data I was speaking of was from things like the compass, rate and yaw sensors, wind sensor, etc - but yes, AP's certainly also need to know where the rudder is, and the rudder reference sensor provides one of the more important pieces of data to an AP. Virtual rudder mode isn't very good for much more than powering around on a lake.

Mark

[smackdaddy]

Originally Posted by giant

One issue I don't think has been mentioned yet is weather helm and other forms of rudder abuse.

Saw a Bavaria loose its rudder once. Sailing alongside them it was obvious they hand serious weather helm in 25 knots but they didn't realize and sure enough 15 minutes later their rudder snapped off.

The Bavaria was on its first 4 hours of a month cruise across the Coral Sea. Sure Bavaria rudders are probably not the toughest and it should have been checked....

In this case I think the rudder probably broke because the people didn't know how to sail more so than design or maintenance.

The crew, three navy guys in late 50s limped back to Cairns on a drogue and got a tow into port. Think they were trying to race us.

This is exactly the kind of scenario I'm most interested in. I definitely think a boat can be pushed way too hard in the wrong direction. And if you have the AP doing the steering with that kind of over-trim, you don't know the difference until something breaks.

Do you know if they were hand-steering or on AP?

[Polux]

Originally Posted by neilpride

Maybe you want the pictures with the plexus cracked?? and 2 dislodged bulkheads?? really?

The boat suffer damaged in a marina, they broke free from the dock and end in the rocks surrounded the marina, ..

Yes off course, it would be interesting to see how it breaks, even if under hurricane force winds against rocks.

[Polux]

Originally Posted by robert sailor

I'm told that the green glue is tenacious as hell but it has no flexibility and is brittle, nothing like the tabbing on the better built boats.

I cannot see how it can work if it is brittle. Under normal but heavy conditions a hull, specially a big one flex considerably. I cannot see how it will hold together the boat structure (bulkheads) on those conditions. It seems to me that it has to have some flexibility.

[robert sailor]

I guess I'm behind on the autopilot some how effecting the structure of the rudder. There are a variety of different types of pilots but I guess the one in question is the hydraulic arm hooked to the quadrant. The really good part of this system is that if your steering cables break you still have a way to steer the boat. Even windvanes can be hooked directly to the quadrant but most often are hooked to the tiller or wheel. If you don't think a wind vane has high forces in a good blow you might want to check into that because they can apply way more force than a human can. All that aside no one yet has convinced me that an autopilot or a windvane will somehow damage a well built rudder/quadrant assembly. I won't for a minute say that it isn't possible for a failure to occur but I'm afraid you will have to blame it on a design/build that was simply not up to the task and better used in gentler conditions. Many fin keelers offshore are very active on the helm in larger seas and this can go on for days but this should be a walk in the park for a well built boat.

[robert sailor]

Originally Posted by Polux

I cannot see how it can work if it is brittle. Under normal but heavy conditions a hull, specially a big one flex considerably. I cannot see how it will hold together the boat structure (bulkheads) on those conditions. It seems to me that it has to have some flexibility.

Well not wanting to be a smart ass but in the case of Blue Pearl it did not hold together.

I was told that Plexus is not designed to have flex strength like fiberglass but its a hell of a glue. I owned a French 30 footer years ago with a liner that was glued in place with this stuff and because of poor seamanship and too many beer I bumped the dock. Not enough to do any damage to the exterior but it did break 2 of the joints that were glued. No warranty on the repair as its impossible to see anything. Since then I have been opinionated on liners that are glued in place. Having said that I agree that most of these boats are holding together but to my way of thinking you are not going to see an offshore racer built this way and fender washers under a deck cleat really shows you the extremes these companies go to save a penny. To me its indicative of what your buying....the cheap seats!

[transmitterdan]

Originally Posted by smackdaddy

This is exactly the kind of scenario I'm most interested in. I definitely think a boat can be pushed way too hard in the wrong direction. And if you have the AP doing the steering with that kind of over-trim, you don't know the difference until something breaks.

Do you know if they were hand-steering or on AP?

Smack,

If one worries the autopilot might break the rudder then they have the wrong boat for that type sailing.

No matter how hard the waves push a boat and no matter the rudder position it should not fail. If it strikes an object then all bets are off but water alone should not break the rudder of a "blue water boat".

Blaming autopilots for rudder failures doesn't make any sense to me. Autopilots can even prevent damage that sometimes happens when the forces cause the helmsman to let go of the wheel or tiller and the rudder crashes into the stop. We should not be scaring people into thinking autopilots break rudders. People cause rudders to fail through poor choice of conditions, design, build and maintenance.

[Hud3]

Three boats in one of the Caribbean 1500s (2005, I believe) experienced rudder failures. Two Hylas and a Little Harbor--both brands normally considered to be well-suited for ocean passages. A number of other boats had autopilot failures. One boat was even dismasted.

That particular C1500 experienced a very strong front with Force 8-9 winds and wave patterns that put heavy stresses on the steering gear. I chose to have my crew hand steer during the worst of it. I wish I had had one of those "smart" APs that could anticipate the slewing effect of a quartering wave lifting the stern, but mine was a conventional version. when it was engaged, I could tell that it was laboring heavily from the sounds it made and the amps it was drawing.

The problem that I've always had with using an AP in certain wind and sea states is that the combination of the forces brought by the waves and weather helm created by the sails being out of balance can create huge forces on the rudder. If you're hand steering, you can feel it when the sails get out of balance and can correct. You can feel it when the quartering seas are pressing hard on the rudder and you can ease the helm, let the wave slide by, and then come back on course. Your standard garden variety AP can't do that, and just dumbly takes the abuse until something breaks.

p.s. three rudder failures out of 65 or so boats is almost 5%

[smackdaddy]

Originally Posted by neilpride

Smack you can add this pics to your production boats and the limits SN ...

I don't think anyone is holding that production boats should be able to handle grounding in a hurricane without damage.

As for the green snot, I'm just not seeing the problem in your photos. It looks like it's holding together pretty well. The most evident damage seems to be at the joints in the layup:



But I don't really know exactly what I'm looking at in some of these photos.

[Polux]

Originally Posted by Hud3

....
The problem that I've always had with using an AP in certain wind and sea states is that the combination of the forces brought by the waves and weather helm created by the sails being out of balance can create huge forces on the rudder. If you're hand steering, you can feel it when the sails get out of balance and can correct. You can feel it when the quartering seas are pressing hard on the rudder and you can ease the helm, let the wave slide by, and then come back on course. Your standard garden variety AP can't do that, and just dumbly takes the abuse until something breaks.

Yes, but you can also see if the sails are well balanced on the autopilot. If the wheel almost does not move, they are all right, if the steering wheel moves a lot, then the sails are out of balance. But I will agree with you if you say that most don't care enough to look at the wheel and if they hand steer they will feel the pressure.

Originally Posted by Hud3

Three boats in one of the Caribbean 1500s (2005, I believe) experienced rudder failures. Two Hylas and a Little Harbor--both brands normally considered to be well-suited for ocean passages. A number of other boats had autopilot failures. One boat was even dismasted.

... three rudder failures out of 65 or so boats is almost 5%

Yes but none that we can call a mass production cruiser and they were there certainly in bigger number than that "type" of buewater boat. That contradicts the ones that say that the main problem regarding rudders is on modern mass production cruisers. Curiously has I posted before on the last 5 years of the ARC, with way more than a 1000 boats involved there was also 3 rudder failures, all on non mass production boats. It seems a pattern is showing.

You need statistic relevance for having meaningful results. You cannot compare the meaning of thousands of boats on the ARC (if you consider the last 15 years) with a single year of the Caribbean 1500 with only 65 boats.

There was years on the ARC where two boast lost a rudder but more where not a single boat lost a rudder. To have statistic relevance you cannot consider a single year but all of them.

[smackdaddy]

Originally Posted by transmitterdan

Smack,

If one worries the autopilot might break the rudder then they have the wrong boat for that type sailing.

No matter how hard the waves push a boat and no matter the rudder position it should not fail. If it strikes an object then all bets are off but water alone should not break the rudder of a "blue water boat".

Blaming autopilots for rudder failures doesn't make any sense to me. Autopilots can even prevent damage that sometimes happens when the forces cause the helmsman to let go of the wheel or tiller and the rudder crashes into the stop. We should not be scaring people into thinking autopilots break rudders. People cause rudders to fail through poor choice of conditions, design, build and maintenance.

You're probably right. And I'm certainly not trying to scare anyone. I believe people are smart enough to understand that this is just a discussion.

But I have first-hand experience of and AP ripping out of what looked like a fairly hefty mount. So there are definitely forces there that I've never felt through the wheel of the same boat. That's all I'm saying.

[colemj]

Originally Posted by smackdaddy

But I have first-hand experience of and AP ripping out of what looked like a fairly hefty mount. So there are definitely forces there that I've never felt through the wheel of the same boat. That's all I'm saying.

Ah, but those forces are on the AP, not the rudder. Yes, most helm stations have a large force advantage over an AP - you can stall or damage an AP simply by holding the wheel or tiller with one hand while the AP tries in vain to turn the rudder.

As for this line of reasoning in rudder failures, I don't think there is a correlation, and one could cause a rudder to fail in this manner far easier by hand steering. I don't buy the argument that a helmsman will ease the rudder when the boat is broaching, etc - most will simply freeze in place applying as much pressure as possible to get the boat under control.

Like they stand on the brake of an automobile when skidding in the snow.

Mark

[neilpride]

Originally Posted by smackdaddy

I don't think anyone is holding that production boats should be able to handle grounding in a hurricane without damage.

As for the green snot, I'm just not seeing the problem in your photos. It looks like it's holding together pretty well. The most evident damage seems to be at the joints in the layup:



But I don't really know exactly what I'm looking at in some of these photos.

Your glasses are fogged hummm, read again the whole post, i dont mention anything related to hurricane damage, you guys are amazing defending the indefensible.

In the picture you see something similar to a watertight bulkhead or crashbox at the lower bow área, there is nothing inside , the anchor chain drain at the top by drains openings in both sides of the hull, question is?? why someone at the Factory cut the bulkhead or crash box open? the boat take a lot of wáter by there..

Plexus. Anyone in the serious boatbuilding business can tell you exactly the same , Tabing Gluing vital components with a fillet of plexus is lame and denote a lack of care in what they do in the Factory, Plexus is rigid and brittle , this boats flex , we see it in the past with the funny Lagoon claims about bulkheads problems..

Im still in shock after see the whole rudder ikea table assembled with pan head screws and fillets of plexus , not a single ounce of glass anywhere.
End of the history...