Keels and Keels Again!

Couldnt get that link to work, but found another one that not only provided those details, and also commentary on another boat 'incident' where 5 other people died.

http://www.theaustralian.news.com.au/story/0,25197,25763453-5006786,00.html

ie. sinking of the 6.5m Immigration Department vessel Malu Sara, off Badu Island on October 15, 2005.

"Mr Chaston "wilfully, recklessly or negligently" did not tell the builder of the Malu Sara that the vessel would operate in open waters. Mr Chaston also failed to test the vessel for seaworthiness, failed to fit safety equipment, failed to train crew, and wilfully provided regulators with false information about the vessel's use.

No charges have been laid against Mr Chaston or Don Radke, the boatbuilder who turned out the unseaworthy vessel. "

Thank god we live in a regulated , quality conscious 1st world country hey !!!

 

hi

Did you see the 4 corners documentary about this boat, it was on about a week and a half ago.

The entire episode was pretty disgusting. It seems that because the operators of this department of Immigration boat were to be Torres Islanders, they were given second (third) rate equipment.

From the documentary
The boat had no GPS
no charts
no depth sounder
no Radio
The welding was of poor quality
Buoyancy was a single air compartment (not foam, not multiple compartments)
The tender called for an inshore vessel but was to be operated offshore
Freeboard was low (as per an inshore boat)

The available funds were sufficient for about 3 boats, not 6, so things were done to reduce cost (example eliminating foam buoyancy and using air)

The vessel was taking on water whilst tied up prior to the trip, but the crew was instructed to set off anyway
The weather was bad with opposing current and winds creating 'boxy' seas
Satellite phone calls requesting assistance were ignored
Epirb activation was ignored
A night capable rescue helicopter was on standby (Bell 214 I think), and not far away
I cannot recall the exact time line, but the first phone call from boat (mid afternoon fist day?) to estimated sinking time was about 12 hours from memory. In afternoon I think they said they were bailing water.
Coroner found boat sank about 4am on second day, Rescue initiated about midday of second day, epirb was found but no boat and no crew.

The entire episode was pretty disgusting. If these were white people on board I imagine that things would have been different

To be fair, it was reported that there is a history of Torres Straight Islanders running out of fuel and setting off their Epirbs. But there still needs to be discretion and common sense used.


here is a link to the tv show and a transcript can be found here too.
http://www.abc.net.au/4corners/content/2009/s2609548.htm

The whole thing was shameful, there were children aboard, does not seem all that fair to them.

N Peter Evans

 

The University's report on the Cynthia Woods is out:

http://tamus.edu/offices/communicat...ments/Cynthia Woods Report-SIAD-OGC-FINAL.pdf

Earl

 

The Cynthia Woods report is very clear and nicely explained. I have some comments.

As an ex-engineer, again I have an issue with the application of safety factors; the definition given is Safety Factor = 1 / (Fatigue Value). In my experience SF and FV are not so simply related. The strength of the material after a reasonable service life can be taken as (Initial Strength) x FV: this might be considered the derated strength. SF is applied to the service load to obtain the design load, then the design is performed using the derated strength of the material to achieve the design load capability.

Safety factor is the margin you have after all possible factors impacting load and strength over a reasonable service life are taken into account, leaving only the unknown, which can be a very harsh judge. SF had better be more than 1 or a significant percentage of your boats are going to be lost at sea!

One can only sympathize with a boat-owning individual or organization: they can hardly be expected to have the skills and experience needed to spot a potential problem. Even with such knowledge it is difficult to spot such a thing as inadequate skin thickness without a serious investigation.

Nonetheless, there were opportunities for at least 2 presumably experienced bodies to note and report the deficiency. Payco Marine removed the keel and re-attached it apparently not noticing that the skin thickness was appropriate to a far smaller boat. Presumably there was also an inspection following the grounding incident that revealed the hairline cracks; was this just a visual? Was it performed with the keel still attached? Even if that were so, was no ultrasonic test done?

The non-availability of the as-designed and as-built data is highly suspicious.

It is difficult to see how the recommended actions would prevent a repetition of just such an incident as this.

 

Appears that they were right on the mark, good that some in the industry recognize deficient construction even from a few pictures.

So can we now say that another ‘yacht designers’ incompetence has caused another death.

Did he have any qualifications ?

 

ancient kayaker

All Class societies have an "in-built" factor of safety in a "global" and "local" sense for fatigue. It is not to suggest that fatigue is simply a 0.5, 0.7 or whatever issue. It is simply a factor of safety that exists within Class rules to accommodate designs where the function of Class, ie plan approval, has some degree of control, to ensure 'some dgeree' of safety which would otherwise not exist.

Class are not in the business of critiquing every design for every design flaw/detail. They have a set of prescriptive rules and all these 'rules' and one arrives at a Class Notation based upon said rules. This also equates to "level of service" being provided, ie money!

Almost every design uses the 'easiest' Class notation owing to cost/weight/performance.

As such Class can only provide "recommendations" for fatigue analysis etc. If the vessel does not comply, there is little that Class can do, as it is just a "recommendation". If the Class notation had "Fatigue" written in, then the situation would be entirely different. Class would go beyond "recommendations", they would become "must" in order to be compliance with the Class notation for a plan approval stamp.

As with everything in life, you only get what you pay for. In this case, if one pays for basic Class notation, that is all one gets...and that is all Class is prepared to comment upon, unless paid more!

 

Paul
We have the plaintiff's FEA. Refer attached.

I expect the second is being prepared right now:
http://www.chron.com/disp/story.mpl/breaking/6534133.html

I wonder if you can sell a boat built by Cape Fear Yachts right now. Also wonder if owners are sailing the yachts now.

Rick W

 

An FEA of an ostensibility very simple engineering calculation wont do anything except provide lots of pretty pictures.

If the designer had been formally trained, then this should not ahve occurred.

I have just recently been involved in a similar case, fortunately no loss of life, just structural damage. The insurers suggested an FEA report. Fine for me, i get paid more, but i just demonstrated very easily without FEA the inadequacies of the design. The FEA in the report above, I see as some form of "validation" of the findings in 3.5.1. but totally unnecessary. Didn't meet the rules, simple, case closed. An FEA will just 're-confirm it'.

Also when using FEA, it can come under extreme scrutiny, as to the applicability of the result. Just like any CFD type software. This then distracts the focus from the accident and its causes, to the software and the competency of those using it....which is exactly what the defence wants!

 

Mike
Attached is brief CV of the NA credited with the design of the Cape Fear 38.

It will be interesting to see if the boat was built as designed.

You are also jumping to the conclusion that the "expert" report is accurate. That seems destined to be tested in court.

You should be thoughtful when you draw conclusions that could harm someone's professional reputation and post them on a public forum. I wonder if Mr Marek can find you - how deep are your pockets - will it be worth his while?

Rick W

 

The report is not claiming to be "accurate", just a factual assessment of the situation. It is you jumping to an assumption of mikejohns's comment and its meaning.

It, the report, is pointing out the deficiencies, as noted in 3.5.1. The most shocking is that no drawings were available for review. Hence physical testing is the only fall back for any statements and conclusions. But why not approach the designer....sounds fishy to me.

Postscript
Nice to see another anonymous (yeah right!) user deciding upon giving me "negative" points for this comment which is way above their comprehension in the first place.! How sad...

 

"...There are so many people who take up building of yachts with no proper education and teaching of the many skills involved.."

Couldn't agree more..as noted here by this fine example.

http://www.boatdesign.net/forums/metal-boat-building/metal-frame-detail-28371.html

PS
No anonymous takers for negative points for this posting??....if not, why not, it is just as much beyond comprehension as the other posts

 

and another
ancient kayaker quoted the fabricator as saying he had great trouble, using heat to (distort torture) the metal to shape
I would have loved to given evidence for the designer at that hearing, if you cant do the job, why quote on it?

 

Concerning the Cynthia Woods report, has anyone measured the skin thickness of the sister vessel S/V George Phydias, for comparison with the skin thickness of the Cynthia Woods? Seems an obvious thing to do.

Rick: your point is well taken but I think Mike is covered by the conclusions of the report. However, what the authors of the report had to work with was the as-built vessel, not the design itself, which was -according to the report- unavailable. If this were a journalistic effort the designer would surely have been asked to comment, and any refusal duly noted.

Ad Hoc, I strongly disagree with your negative comment on the values of FEAs. The high peak load value in the FEA and the calculated “required skin thickness” of 3.11" made me take a second look at Figure 5, which clearly shows stress concentration at the sharp corners of the plates. The average value is much lower, but the report does not draw attention to this point.

Stress concentration and material fatigue are what caused the Comet crashes 50 years ago: have we learned nothing since then? The average load evaluates to a SF of around 2 if the potential for fatigue is ignored, or about 1 taking it into account. This boat might have survived for many years with a little bit of luck if someone had simply followed standard practice during construction and rounded the corners of the plates. Sharp corners are for cookie cutters!

Please note that I am not defending the design here. Failure to adequately reinforce a critical load attachment area, failure to round off backing plate corners and edges on top of failure to allow for fatigue in a composite subjected to high and repeated stresses is just the sort of concatenation of errors that destroys innocent lives.

 

A.K.

I appreciate you're not defending the design.

However, FEA is a minefield. For example, we have no idea how many elements were used. We have no idea how the loads were applied to the FEM. We have no idea which method of integration was used. We have no idea what the element types were used, nor their aspect ratio. We have no idea of the fixities used in the FEM and so on and so on..

In addition, the stress plot is not clear which plane of axis nor which type of stress plot. Further, it is impossible to read anymore into the "through thickness" of elements especially composite elements. To my knowledge, no one anywhere in the world has published data that has a strain gauge on every single layer in between the fibres for every fibre on a layup. Then mechanically tested and compared with the FEA result to established whether th FEM is correct or not. This is one of the basic fundamentals of FEA, validation. Nice pretty colours, but are they meaningful?

Most of this come down to the element size. It has been proven time and time again by many studies, including my own in my own thesis, that element size of approx 1/2t provides "acceptable" results for detailed analysis. Without knowing any of the above, which we do not, it is a nice pretty picture, but can in no way be considered conclusive evidence/proof.

 

Ad Hoc: of course you are quite correct, we don't have all the data for this one. It's true that analysis is merely a projection of what the real world might be if all the assumptions are correct, the material is uniform and to spec, the things actually built to the design, etc. But in the absence of instrumentation it is all we have.

My point remains, that we make up the difference between analysis and reality with the SF.

I'm not sure how old the boat's design is, but after the advent of computer-aided design, the application of methods such as FEA at the design stage became routine years ago, at least in my own area (Aerospace).

Yea, that's a bit of a give-away isn't it? Perhaps we depend too much on computers.

We don't really need a computer or FEA to tell us that sharp corners are bad. After I took my degree I went through an abreviated but formal apprenticeship. The machine shop boss, assembly shop foreman, model shop manager, plus the designers and QA and QC people that took turns to lord it over me would all have had my guts for garters if I had clamped a piece of relatively soft material under a sharp cornered plate of harder material, especially a composite consisting of fine hard threads in a softer matrix, even if it were not load bearing. It just wasn't done back then. A very long time ago admitted, but physics hasn't changed.