The Blue Pearl Sinking

[sailorboy1]

Originally Posted by Bluewaters2812

In January 2014 we were at Riverside boatyard and had the keel strengthened amongst other safety precautions for the crossing.

what does that mean?

[nigel1]

Originally Posted by sailorboy1

what does that mean?

Maybe larger backing plates for the keel bolts.

[sailorboy1]

Originally Posted by nigel1

Maybe larger backing plates for the keel bolts.

Maybe, but it would scare me to think that someone would feel that was needed on a boat and yet still feel it was acceptable for an ocean crossing. If I thought that of my boat I doubt I would feel safe in it.

[boatman61]

[QUOTE=sailorboy1;1591440]Maybe, but it would scare me to think that someone would feel that was needed on a boat and yet still feel it was acceptable for an ocean crossing. If I thought that of my boat I doubt I would feel safe in it.[/QUOTE]

Man... I was so close to saying..
"and this from a Hunter owner"..

Bollox...!! I said it..

[sailorboy1]

Originally Posted by boatman61

Man... I was so close to saying..
"and this from a Hunter owner"..

Bollox...!! I said it..

Yes I said it! If I thought my boat needed it's keel "strengthened" I definitely wouldn't be sailing it. I would be looking to sell it to someone else!

[beneteau-500]

So sailor boy would you tell the the unfortunate buyer that your keel would need strengthening

Why do we all make modifications to our boats we all try to cover every possible angle why do passenger airlines need 4 or 6 computers when only two are need to fly the plane

Why do we carry emergency beacons sat phones VHF ssb why do we put extra bilge pumps in

Until you have experienced a sinking then you may understand.

That's just my view As I have experienced it first hand

[boatman61]

From my viewpoint production boats have to meet certain criteria.. and I've found that often they will be just on the border of acceptable for the purpose.. which is why some advocate strengthening rigs before going offshore.. reinforcing some port lights etc..
If I heard my boat had broken/damaged its rudder in a grounding by a previous owner.. damn right I'd check the keel bolts.. and likely fit new backing plates.. done it with deck winches etc which are less dramatic if they fail..

[transmitterdan]

I am curious about an arcane detail of the design. It appears that the steering cables are led to pulleys on either side of the hull but can't see what the pulley's attach to. Are they fastened to the shelf that came free or some other strong point? Was the boat running on autopilot or wheel steering when the shelf failed?

[TeddyDiver]

Originally Posted by sailorboy1

Yes I said it! If I thought my boat needed it's keel "strengthened" I definitely wouldn't be sailing it. I would be looking to sell it to someone else!

Some dyslexia maybe? It was strenghtened, not just needing it...

[Bluewaters2812]

Originally Posted by mbianka

Bluewaters

Thanks for that very sobering video of the kind of things that can happen out there. Sorry for the loss of the boat but, glad all were rescued.

From a lesson learned stand point for others I wonder if some kind of sling could be fabricated or carried on board to support a broken rudder until repairs could be made. This would give some support to a broken rudder assembly rather than having it work its self to further damage in the waves. At the very least keeping attached to the boat minimizing water intrusion.

Thanks for the kind words and sentiments, much appreciated.

In a storm, the power of the water is so great on a 6-foot spade rudder the second it started the "ripping around" like it did, the end was signaled, believe me, I was there and I speak from first-hand experience. If I thought there was anything I could do under the conditions and circumstances thrown at us I would have done everything and anything to save the situation/boat.

Remember too; the seas were huge and the wind was powerful, visibility near zero and in the dead of night. It was unrelenting. There was truly nothing that could have been done other than what we did. If I have any lesson for myself; its that I might have got off our sailboat into the liferaft about 3-5 minutes sooner. It is obviously a judgement call for the Skipper at the time and not an exact science. Whatever the lesson, we managed to survive with our lives and for me that is what really counts. We were lucky.

My heart goes out to our sailor colleagues on Cheeki Rafiki ... I don't think they had the opportunity, time and warning that I was afforded to launch a liferaft. I always think of them whenever I think about our ordeal and I am grateful that our family and friends are not going through what those good mens' family and friends are going through.

Len

[a64pilot]

Originally Posted by Jim Cate

I think this is the wrong approach entirely. Rather than carrying a mickey mouse patch for this sort of situation, it would be FAR more useful to beef up the rudder structure so that a patch would never be required. After all, the vast majority of boats' rudders don't fail in this manner, even in severe sea conditions. The engineering isn't so demanding, nor is the shipwright skill needed to accomplish the augmentation. While one is about it, might as well make that aft bulkhead watertight and reduce the chance of sinking even more should rudder damage pop up.

Meanwhile, I too laud this skipper's responses to a deadly situation: well done, mate!

Jim

Only chance you have is keeping it from breaking loose in the first place, once loose there are enormous forces at work here due to waters density and velocity, your not going to shore up something with that much power in it, all you might could do is jettison it somehow, like when you get dismasted.

I'm not saying they could have jettisoned the rudder, I see no way at all that could have been accomplished. I think the most reasonable thing was done in abandoning the boat, trying to shore it up somehow would have been impossible, may have gotten someone hurt and would have wasted valuable time that was better spent preparing for abandoning the boat, getting out Mayday calls etc.

No, they had no recourse, once that rudder broke loose I don't see how the boat could have been saved.

Jim your statement about water tight bulkheads is interesting, I would have though it would be common for both ends to have water tight bulkheads, but I rarely see that, and never in a production boat, although I've not looked at high end boats as they are out of my price range. On mine it wouldn't be difficult to make both bulkheads water tight. Worth investigating.

[robert sailor]

Production builders throw nickels around like man hole covers, you will never find watertight bulkheads on production mono hulls even many of the Cats don't have them even though they used to think they did.

[Snowpetrel]

Thanks for sharing and the videos. It is much appreciated and the video really makes the magnitude of the damage clear.

Theres no question in my mind that the boat was sinking and nothing could have been done to save her at that point. Well done on a safe abandonment and rescue.

I am interested in the causes of the failure. To do this we need to know whats actually there. Does anyone have access to a similar boat to compare. Different models of the same vintage might be similar enough but ultimately a sistership would be good to get some actual specs from.

Questions

1) is the shelf structure the major supporting structure for the top rudder bearing? Or is the tube well tied into the hull with webs underneath and the shelf is only for the autopilot and wire blocks and not really load bearing.

2) Was there a bulkhead ahead of the rudder, was it watertight and how was the rudder structure attached to it?

Anybody got any photo's?

Cheers

[skipmac]

Originally Posted by sailorboy1

Yes I said it! If I thought my boat needed it's keel "strengthened" I definitely wouldn't be sailing it. I would be looking to sell it to someone else!

Offer it to Boatman. He will sail anything across an ocean.

[leftbrainstuff]

Originally Posted by a64pilot

I hope you don't mind me quoting you and of course we all seem to want to blame prior damage, I guess to convince ourselves that this won't happen to us or our friends, but you know on something like a rudder, there should be some damage tolerance built into the design, a designed failure point that doesn't sink the boat and a inspection procedure that is accomplished whenever a rudder is replaced etc.
This is the 21st Century with all the computer aided structural analysis available, and these are not one off amateur built boats.
Why so many failures, you can't blame them all on hidden damage.

Fatigue failures typically occur at loads much lower than the static strength of an engineered object. Sometimes as little as 5% of the day one static strength.

Miner's law is how we engineers build a fatigue history when conducting a forensic analysis or designing something to have a finite life.

Materials have varying cyclic lives as well. S-N curves for each material apply here.

The challenge in this instance is that we don't have actual load data to build a true history. Any large impact loadings, while not causing an immediate failure, are taken into account by miners law. Typically for each impact loading you get a reduced life, reduced outright failure load or both.

My hats off to the OP for posting the videos and well done on evacuating successfully.

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