Select to expand quotejulesmoto said..THREADPOLICE said..julesmoto said..
Well common sense tells me not to go on yachts with keels that look like that. If the harbour bridge was made out of steel girders two inches by two inches I wouldn't go on that either no matter how many engineers signed off on it. Typically that type of keel is held in its pocket by two bolts and compared to the length of the keel the pocket is usually ridiculously shallow.
Interesting however that the boat floated as I doubt mine would.
The report is probably wrong but it said that they had to clamber back onto the hull of the boat to raise the alarm. If so no one was wearing a personal e-pirb. Maybe life jackets offshore should be mandated to include personal e-pirbs. Keel loss usually gives no time to grab the boats e- pirb on the way out if you are below.
I certainly have one in my life jacket but then I don't usually wear the life jacket. Mind you I don't sail a yacht with a ridiculous keel like that.
What about multihulls they don't even have keels!
I didn't think we were talking about multi-hulls although if buying one, which I have considered, I would definitely be looking at the cross beam and bulkheads together with the general history of that model if a production boat. That rules out lagoons or recent leopards (if there's luggage performance hadn't already ruled them out) plus a few lesser known designs.
I was replying the comment from Jules saying he would not sail on that boat due to its keel. I assume that means he wont sail a multihull or a dinghy because they don't even have keels. Best to outlaw those boats.
Select to expand quoteD3 said..THREADPOLICE said..D3 said..THREADPOLICE said..
AS implemented keel & rudder inspections. Accidents happen, 1266 Persons died last year in car accidents last year in Aus & more than 160,000 died in car accidents in India. Don't want risk, stay at home.
And what have we done to reduce our road toll?
Alongside mandating safer vehicles, improving roads, training requirements etc?
1970 was the last time the national road toll was 80/100,000 vehicles.
Since then it has been steadily reducing. (1970 was when Victoria introduced seatbelt mandates, and there's been more since then)
I wouldn't think that people's attitudes to driving have changed much, but in 2014 the toll was 4.5/100,000 vehicles.
In 2020 it was 4.4/Billion vehicle kilometres.
If you want to compare vehicle safety to yachting safety, it helps to put the data in to context.
What have we done to make sailing safer?
-What are the lessons we learned and implemented from disasters like Fastnet, 98 Hobart, Cheek Rafiki?
-Do we have any data on number of yachts racing to relate keel loss and/or deaths to?
How does this number compare to vehicle related deaths?
How does it compare to Motorsport related deaths?
Road toll is UP 4.8% despite billions being spent.
& if you don't know what was implemented from the lessons we learned from 98 Hobart & Fastnet then you haven't been ocean racing in the last two decades.
We've managed to reduce the road toll by 66% since it peaked in 1970, despite the massive increase in vehicles on the road since then.
The rate of deaths per 100,000 vehicles has been reduced by 95%.
Have we done anything near that well with looking after our sailors in the same period of time?
My point stands, more deaths this year despite billions in "government intervention"
Select to expand quoteTHREADPOLICE said..Trek said..
Well said Threadpolice.
The only ones who know whats going on are those who have been ocean racing in the last two decades.
Most haven't. That's exactly why some kind of design safety standards are needed.
If you'd been racing in the last two decades you'd know there are design standards. Stricter than the Governments in fact.
And yet, we have keels coming off and people dying a little Too regularly in our small sailing community.
Select to expand quoteTHREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..
AS implemented keel & rudder inspections. Accidents happen, 1266 Persons died last year in car accidents last year in Aus & more than 160,000 died in car accidents in India. Don't want risk, stay at home.
And what have we done to reduce our road toll?
Alongside mandating safer vehicles, improving roads, training requirements etc?
1970 was the last time the national road toll was 80/100,000 vehicles.
Since then it has been steadily reducing. (1970 was when Victoria introduced seatbelt mandates, and there's been more since then)
I wouldn't think that people's attitudes to driving have changed much, but in 2014 the toll was 4.5/100,000 vehicles.
In 2020 it was 4.4/Billion vehicle kilometres.
If you want to compare vehicle safety to yachting safety, it helps to put the data in to context.
What have we done to make sailing safer?
-What are the lessons we learned and implemented from disasters like Fastnet, 98 Hobart, Cheek Rafiki?
-Do we have any data on number of yachts racing to relate keel loss and/or deaths to?
How does this number compare to vehicle related deaths?
How does it compare to Motorsport related deaths?
Road toll is UP 4.8% despite billions being spent.
& if you don't know what was implemented from the lessons we learned from 98 Hobart & Fastnet then you haven't been ocean racing in the last two decades.
We've managed to reduce the road toll by 66% since it peaked in 1970, despite the massive increase in vehicles on the road since then.
The rate of deaths per 100,000 vehicles has been reduced by 95%.
Have we done anything near that well with looking after our sailors in the same period of time?
My point stands, more deaths this year despite billions in "government intervention"
Are you suggesting that the government imposed vehicle safety standards, roads, licencing rules and regs etc are ineffective due to a 5.7 percent increase from 2022 to 2023?
Was the increase due to sudden reduction in design and build quality of vehicles?
Unlikely that 72 people died from catastrophic vehicle failure due to design or construction issues.
Yet, in the sailing world we can have a fantastic, safe season until a keel falls off and 2 people die.
Select to expand quoteD3 said..THREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..
AS implemented keel & rudder inspections. Accidents happen, 1266 Persons died last year in car accidents last year in Aus & more than 160,000 died in car accidents in India. Don't want risk, stay at home.
And what have we done to reduce our road toll?
Alongside mandating safer vehicles, improving roads, training requirements etc?
1970 was the last time the national road toll was 80/100,000 vehicles.
Since then it has been steadily reducing. (1970 was when Victoria introduced seatbelt mandates, and there's been more since then)
I wouldn't think that people's attitudes to driving have changed much, but in 2014 the toll was 4.5/100,000 vehicles.
In 2020 it was 4.4/Billion vehicle kilometres.
If you want to compare vehicle safety to yachting safety, it helps to put the data in to context.
What have we done to make sailing safer?
-What are the lessons we learned and implemented from disasters like Fastnet, 98 Hobart, Cheek Rafiki?
-Do we have any data on number of yachts racing to relate keel loss and/or deaths to?
How does this number compare to vehicle related deaths?
How does it compare to Motorsport related deaths?
Road toll is UP 4.8% despite billions being spent.
& if you don't know what was implemented from the lessons we learned from 98 Hobart & Fastnet then you haven't been ocean racing in the last two decades.
We've managed to reduce the road toll by 66% since it peaked in 1970, despite the massive increase in vehicles on the road since then.
The rate of deaths per 100,000 vehicles has been reduced by 95%.
Have we done anything near that well with looking after our sailors in the same period of time?
My point stands, more deaths this year despite billions in "government intervention"
Are you suggesting that the government imposed vehicle safety standards, roads, licencing rules and regs etc are ineffective due to a 5.7 percent increase from 2022 to 2023?
Was the increase due to sudden reduction in design and build quality of vehicles?
Unlikely that 72 people died from catastrophic vehicle failure due to design or construction issues.
Yet, in the sailing world we can have a fantastic, safe season until a keel falls off and 2 people die.
Miraculous more keels don't fall off.
Having the government tell us what to do about keels is a stupid idea.
Select to expand quoteJonE said..
For heaven's sake.
There are rules. You can't race Cat 1 or 2 if you can't prove your boat was built to the rules.
Here is a link to the rules: cdn.revolutionise.com.au/cups/austsailclubs/files/lhyvm6pc6cqytoho.pdf
Because someone died there will probably be an inquiry and if you want to know what happens in an inquiry, google one or go to the ORCV site because there are links there: www.orcv.org.au/safety/useful-articles-and-links
Maybe the rules are strict enough, maybe they aren't but it's completely ignorant to suggest that the sport is not regulated in regard to safety.
Here is some correspondence between World Sailing and the International Standards Organisation (the people whose standard you have to meet if you want to race cat 1 or 2): www.sailing.org/tools/documents/OC4aiiWorkingPartiesKeelImprovements-[27597].pdf
What's racing got to do with it?
Were they racing?
Personally I avoid racing because one of the main attractions of yachting to me is the freedom of going where I want when I want and not being told what to do or how to do it.
I'd be pretty sure that there are far more cruisers than racers so racing rules don't solve the problem.
In this case it was an ex racing yacht that was the problem. As is common racing yachts are sold at a greatly depreciated price after a few years when they are no longer flavour of the year or competitive and then adapted by cruisers to be a bit more suitable for cruising with perhaps some low key racing occasionally.
Select to expand quotejulesmoto said..
What's racing got to do with it?
Were they racing?
They were on their way to a race start.
It was a race boat.
The only reason people would buy such a lightweight boat (2.8 tonnes at 36 foot) with that keel type is to race.
This whole thread is a discussion about a race boat heading to a race losing it's keel, the reason for which we won't know for a while.
Now, second comment in the thread, you said "Hopefully we find out what brand of yacht eventually. I know what my money is on."
I assume, that you were counting on it being a beneteau or Jenneau? So that would be a European boat, the construction of which is strictly controlled by a LAW called the Recreational Craft Directive. This actually has nothing to do with racing.
Next quote:
"In this case it was an ex racing yacht that was the problem. As is common racing yachts are sold at a greatly depreciated price after a few years when they are no longer flavour of the year or competitive and then adapted by cruisers to be a bit more suitable for cruising with perhaps some low key racing occasionally."
Yes that does happen but in order for those boats to get drawn and built with the intention of racing they have to be designed and built to the standards imposed, in this case by the race rules - otherwise they wouldn't exist in the first place. QED.
Select to expand quoteJonE said..julesmoto said..
What's racing got to do with it?
Were they racing?
They were on their way to a race start.
It was a race boat.
The only reason people would buy such a lightweight boat (2.8 tonnes at 36 foot) with that keel type is to race.
This whole thread is a discussion about a race boat heading to a race losing it's keel, the reason for which we won't know for a while.
Now, second comment in the thread, you said "Hopefully we find out what brand of yacht eventually. I know what my money is on."
I assume, that you were counting on it being a beneteau or Jenneau? So that would be a European boat, the construction of which is strictly controlled by a LAW called the Recreational Craft Directive. This actually has nothing to do with racing.
Next quote:
"In this case it was an ex racing yacht that was the problem. As is common racing yachts are sold at a greatly depreciated price after a few years when they are no longer flavour of the year or competitive and then adapted by cruisers to be a bit more suitable for cruising with perhaps some low key racing occasionally."
Yes that does happen but in order for those boats to get drawn and built with the intention of racing they have to be designed and built to the standards imposed, in this case by the race rules - otherwise they wouldn't exist in the first place. QED.
Well if it was built in accordance with race rules it appears the race rules were crap.
I'm with Kankama on this one. I don't think the race rules would have a clue about keels and I don't really think most naval architects understand them properly either.
My understanding from engineer friends is that even bridge builders do lots of fancy calculations and then add a safety "fudge" factor of something like 100% which is a tacit admission that they don't really know the proper answer.
Obviously the European rules and certifications under which production boats like Benateaus are produced are also pretty useless. Especially without any third party inspections during the building process.
It's like we're stuck in the days of the original Comet aeroplanes except nobody is doing anywhere near the caliber of research on it (and probably never will) and in any event most of these boats are backyard jobs when compared to airline manufacturers. Fancy materials like carbon fibre as well as super high aspect ratio keels have been around for many many decades and the problems aren't going away or being solved.
I prefer to rely on my own eyeballs and common sense. If it looks right it probably is and boats like that look all wrong to me and everything I know about physics and the sea.
Select to expand quoteTHREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..
AS implemented keel & rudder inspections. Accidents happen, 1266 Persons died last year in car accidents last year in Aus & more than 160,000 died in car accidents in India. Don't want risk, stay at home.
And what have we done to reduce our road toll?
Alongside mandating safer vehicles, improving roads, training requirements etc?
1970 was the last time the national road toll was 80/100,000 vehicles.
Since then it has been steadily reducing. (1970 was when Victoria introduced seatbelt mandates, and there's been more since then)
I wouldn't think that people's attitudes to driving have changed much, but in 2014 the toll was 4.5/100,000 vehicles.
In 2020 it was 4.4/Billion vehicle kilometres.
If you want to compare vehicle safety to yachting safety, it helps to put the data in to context.
What have we done to make sailing safer?
-What are the lessons we learned and implemented from disasters like Fastnet, 98 Hobart, Cheek Rafiki?
-Do we have any data on number of yachts racing to relate keel loss and/or deaths to?
How does this number compare to vehicle related deaths?
How does it compare to Motorsport related deaths?
Road toll is UP 4.8% despite billions being spent.
& if you don't know what was implemented from the lessons we learned from 98 Hobart & Fastnet then you haven't been ocean racing in the last two decades.
We've managed to reduce the road toll by 66% since it peaked in 1970, despite the massive increase in vehicles on the road since then.
The rate of deaths per 100,000 vehicles has been reduced by 95%.
Have we done anything near that well with looking after our sailors in the same period of time?
My point stands, more deaths this year despite billions in "government intervention"
Are you suggesting that the government imposed vehicle safety standards, roads, licencing rules and regs etc are ineffective due to a 5.7 percent increase from 2022 to 2023?
Was the increase due to sudden reduction in design and build quality of vehicles?
Unlikely that 72 people died from catastrophic vehicle failure due to design or construction issues.
Yet, in the sailing world we can have a fantastic, safe season until a keel falls off and 2 people die.
Miraculous more keels don't fall off.
Having the government tell us what to do about keels is a stupid idea.
One might argue that they shouldn't fall off at all.
They've been falling off for decades, we shouldn't accept that.
Select to expand quoteD3 said..THREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..
AS implemented keel & rudder inspections. Accidents happen, 1266 Persons died last year in car accidents last year in Aus & more than 160,000 died in car accidents in India. Don't want risk, stay at home.
And what have we done to reduce our road toll?
Alongside mandating safer vehicles, improving roads, training requirements etc?
1970 was the last time the national road toll was 80/100,000 vehicles.
Since then it has been steadily reducing. (1970 was when Victoria introduced seatbelt mandates, and there's been more since then)
I wouldn't think that people's attitudes to driving have changed much, but in 2014 the toll was 4.5/100,000 vehicles.
In 2020 it was 4.4/Billion vehicle kilometres.
If you want to compare vehicle safety to yachting safety, it helps to put the data in to context.
What have we done to make sailing safer?
-What are the lessons we learned and implemented from disasters like Fastnet, 98 Hobart, Cheek Rafiki?
-Do we have any data on number of yachts racing to relate keel loss and/or deaths to?
How does this number compare to vehicle related deaths?
How does it compare to Motorsport related deaths?
Road toll is UP 4.8% despite billions being spent.
& if you don't know what was implemented from the lessons we learned from 98 Hobart & Fastnet then you haven't been ocean racing in the last two decades.
We've managed to reduce the road toll by 66% since it peaked in 1970, despite the massive increase in vehicles on the road since then.
The rate of deaths per 100,000 vehicles has been reduced by 95%.
Have we done anything near that well with looking after our sailors in the same period of time?
My point stands, more deaths this year despite billions in "government intervention"
Are you suggesting that the government imposed vehicle safety standards, roads, licencing rules and regs etc are ineffective due to a 5.7 percent increase from 2022 to 2023?
Was the increase due to sudden reduction in design and build quality of vehicles?
Unlikely that 72 people died from catastrophic vehicle failure due to design or construction issues.
Yet, in the sailing world we can have a fantastic, safe season until a keel falls off and 2 people die.
Miraculous more keels don't fall off.
Having the government tell us what to do about keels is a stupid idea.
One might argue that they shouldn't fall off at all.
Those people wear masks in their own cars.
We should leave the boat building to boat builders.
Look at the foiling IMOCA's, blank cheque engineering, load cells & alarms everywhere and they still break them.
But without a mandated minimum standard a commercial boat builders incentive to become safer is that they only have to be marginally safer than their competitors, or even just matching them.
The old "to out run a bear, you only have to be faster than your friend".
Imoca boats are pushing the limits of performance as well as the envelope for technology not building entry level cruisers and racer.
Yet, keels are falling off across the spectrum. Old race boats, brand new race boats, old cruisers, new cruisers.
I get that you're passionate about this, and I'm not trying to diminish the work that has already been done.
You're also correct that this is still not an everyday occurrence, but it's happening a little too frequently for such a small community.
Select to expand quotejulesmoto said..
Obviously the European rules and certifications under which production boats like Benateaus are produced are also pretty useless. Especially without any third party inspections during the building process.
Just speculation but I wouldn't mind betting the big production boat manufacturers have a large influence on the EU standards, most likely actually writing them to suit themselves.
Select to expand quotejulesmoto said..
.
The report is probably wrong but it said that they had to clamber back onto the hull of the boat to raise the alarm. If so no one was wearing a personal e-pirb. Maybe life jackets offshore should be mandated to include personal e-pirbs. Keel loss usually gives no time to grab the boats e- pirb on the way out if you are below.
I certainly have one in my life jacket but then I don't usually wear the life jacket. Mind you I don't sail a yacht with a ridiculous keel like that.
It is so easy nowadays to take some responsibility for our own safety with the availability and affordability of personal safety devices.
Personal epirbs (PLB's) are quite tiny and can be attached to an inflatable PFD, which can then be worn as a matter of course whenever we go sailing; a simple habit which doesn't affect comfort or impede mobility.
Everyone should really consider doing this, without needing legislation to enforce it.
I do agree that there should be standards that all new boat constructions should have to meet, and some means of policing boat-builders so they can't cheat on those standards. But. how to ensure that there are no unseen flaws in an older keel /hull is a much more difficult question.
Select to expand quoteTHREADPOLICE said..
If you'd been racing in the last two decades you'd know there are design standards. Stricter than the Governments in fact.
I am interested to read about these. Can you point me to any strict design standard that has resulted in improving our keel integrity issues?
The only thing I could find is the ISAF/WS Special Regulations Section 3.02 (which is also AS' Special Regulations Part 1) that talks about keel inspection requirements.
Not exactly a 'strict' design standard....
AVS, STIX et al are stabiility and boyancy measurements, so they dont talk about it .
And come to think of it, I'm not aware of any Government standards either.
So what standards are you referencing?
Thanks!
BTW, here is Appendix L, the inspection form that is referenced in Section 3.02.
Nope, no strict design standard here...
Select to expand quoteshaggybaxter said..
BTW, here is Appendix L, the inspection form that is referenced in Section 3.02.
Nope, no strict design standard here...
However if the keel has whooping great big cracks, the cracks will be noted and the boat will not pass, which is a significant improvement on what they had previously. I've seen quite a few boats out there with shocking keels that shouldn't be racing.
It has to be built to ISO12215.
It's here: cdn.standards.iteh.ai/samples/55339/7a7b322a16be4c18a230800fc71c8a02/ISO-12215-9-2012.pdf
Ok I hate government regulation but the keel issue is absolutely deadly.
Long ago car manufacturers were forced to consider the inevitability that a certain percentage of cars will have crashes. This lead to energy absorbing subframes side intrusion bars and the like which are actually tested by various bodies worldwide including ancap. This has caught on to the extent that it is newsworthy and a reason to shy away from a car if it doesn't get a five-star rating from these testing bodies. You can of course still buy a low volume AC Cobra; Lotus 7... or similar if you want in the full knowledge that it has no secondary safety.
Similarly it is inevitable that a certain percentage of yachts will run a ground and some of them quite hard and at speed.
How about legislation to the effect that the bottom half of a keel or perhaps even two-thirds needs to be sacrificial in the sense that the bolts holding it on will sheer before the attachment to the hull does? This needs to be in conjunction with a requirement that sufficient ballast remains in the top half or third of the keel so that the boat will slowly right or at least not turn turtle. This requirement could easily be tested by ancap style tests which would become compulsory for let's say manufacturers producing 20 or more of a particular design. If the sacrificial portion worked they wouldn't even have to sacrifice a whole boat just the bottom of the keel. This would force people who run hard aground (charterers and charter companies this means you) to do something about it as they couldn't just forget about it and eventually on -sell the boat to some hapless unsuspecting soul.
It would also probably put paid to ridiculously high aspect ratio keels with bulbs on the bottom as well as dingy style hull profiles (good riddance). Those who wish to risk their lives with one off designs just to win races could still do so with their one designs but everyone would be aware that it had no ancap style safety rating.
The risk with a catamaran is that you rip the bottom out of the boat if you run aground as the bottom of even very large cats has nowhere near the strength of a keel yacht as it is not designed to support a keel. Cat sailors are also used to taking their boats into quite shallow water. Manufacturers have recognised this issue and many production cats have sacrificial keels comprising foam with a light layer of fiberglass thereover sitting into pockets in the bottom of the hulls. The basic concept of a sacrificial keel is therefore not new although it has to my knowledge never been proposed in relation to a keel yacht which is a totally different proposition.
Jules - I hadn't thought of that idea for monos, but I certainly used it on my cat. I made the cedar/glass daggerboards and cut off the bottom 30cm and then glued it straight back on with epoxy glue, no glass.
For 23 years all was well and good, until last year I came into Swansea bar and my self made autopilot drive hub fixing fell off. I should have been hand steering over the calm bar but didn't for a few dumb reasons. Anyway, we went off course and hit a rock with the port daggerboard. There was an almighty bang, and then boat kept on turning away from the rocks under (now) hand steering.
After telling myself off and giving myself a few uppercuts for being an absolute idiot, I anchored and dived on the boat. The board was a little wedged but there was no damage to the hull and the bottom 30cm was gone.
No real worries, I took the board home (where I had a spare tip from when I built the boards decades before) and glued on an new tip. All good now. So a sacrificial tip can save high aspect foils from causing massive damage to the structure. Getting it to work on a ballasted boat is trickier. Lots of cat sailors don't do the sacrificial tips idea even though it saved my bacon.
As for sacrificial cat keels - I don't get them. A lot of cats with these keels can't sit on their keels on the sand or in some lagoon. What is the point of owning a cat if you can't sit on the hard at low tide? A truly awful idea, to go past Percy lagoon, Hill inlet, Zoe Creek, Leekes Creek and not be able to dry out would be terrible. I don't get them at all and think they are a catamaran design travesty. Drying out is a cat super power and not being able to sit on the hard negates a huge reason for buying one.
cheers
Phil
Select to expand quoteAndrew68 said..
However if the keel has whooping great big cracks, the cracks will be noted and the boat will not pass, which is a significant improvement on what they had previously. I've seen quite a few boats out there with shocking keels that shouldn't be racing.
I agree in principle Andrew. But....
-- In the case of whopping great big cracks, that's no longer an issues about strict design standards, but an issue about skipper competency, If the boat came out of the water, it wouldn't be just me, everyone would check out the keel and mating. Call it survival instincts or common sense, but you have a legal responsibility to your crew. If that doesn't self motivate a skipper, then I'd suggest they shouldn't be in charge of a boat in the first place.
-- She was in delivery mode for a race start and hence, I assume she would've already had the keel inspection compliance submitted to be eligible for the race. Yet the keel fell off. so the inspection didn't discover an issue.
Select to expand quoteJonE said..
It has to be built to ISO12215.
It's here: cdn.standards.iteh.ai/samples/55339/7a7b322a16be4c18a230800fc71c8a02/ISO-12215-9-2012.pdf
The First 40.7's are ISO12215 compliant.
So are Lagoons.
I should state I am for regulation, I'm not rubbishing governance and standards.
But like most standards, they need to open to allow for some interpretation. I simply believe the current standards are lacking if we want to guarantee suitably robust keel structures. Irrespective if the root cause is buyer demand for cheaper/lighter/faster.
But blaming deficient standards does not absolve skippers absolutely. We are responsible for the safety of our crew, a legal obligation as well as a moral one. Accordingly, keel integrity was an oversized influence in my purchasing decision, as well as vacuuming up a considerable amount of time in the purchasing cycle.
Select to expand quotejulesmoto said..
How about legislation to the effect that the bottom half of a keel or perhaps even two-thirds needs to be sacrificial in the sense that the bolts holding it on will sheer before the attachment to the hull does?
Great idea!
We have forepeak crash bulkheads, so some form of keel crash bulkhead makes a lot of sense.
Any ballast being at the deepest draft might add some engineering challenges, but it would be so cool.
And then there's this guy on a yachting Facebook page who has just bought a boat and asks if he should be concerned. One bolt is actually snapped off inside the nut!
Select to expand quotejulesmoto said..
And then there's this guy on a yachting Facebook page who has just bought a boat and asks if he should be concerned. One bolt is actually snapped off inside the nut!
.... there are racers out there that will continue even with this sort of stuff in their boats ^^^^^^
I am not a metallurgist but I have done a smattering of engineering for my own boats.
In most structures there is a critical crack length, a length at which a crack will be self perpetuating when a load is applied. We can see this with a small rip in a kite. As long as it is not too long we are usually fine, but when it gets too big or the load increases then the whole kite rips in half.
When designers start to use higher and higher stress steel in their designs the critical crack length drops. It is a major problem in surveying structures if the critical crack length is too small for a user to easily observe. You really want the critical crack length to be something that paint can't cover, or that is obvious when the boat is antifouled. It is hard to find a material that is very stiff, very strong, very tough (good at crack stopping and coping with stress concentrations) and not very very expensive. In multis I have had problems with lightweight carbon laminates - they hold fine until they just explode - whereas an E glass or timber structure can deflect, groan and make cracking noises without going to ultimate failure straightaway. It suits my style of boat ownership better. If the critical crack length is very small, you may not be able to blame the owner for a keel failure, even if they gave the keel a good going over last time it was antifouled. (Another good reason for lower stress keel roots - you can see when they are becoming a problem and they fail slower)
cheers
Phil
Or some other methods of being able to identify that a keel has been over stressed.
I just think about all the ways we have off being able to identify when a vehicle has been in a crash, or if it has serious safety issues.
Just think of the value difference between a 2nd hand car and a racing yacht.
And yet it is so hard to be confident in the material state of a vessel that may be 10 times the value of the vehicle I transport my entire family in, every day.
Select to expand quoteKankama said..
I am not a metallurgist but I have done a smattering of engineering for my own boats.
In most structures there is a critical crack length, a length at which a crack will be self perpetuating when a load is applied. We can see this with a small rip in a kite. As long as it is not too long we are usually fine, but when it gets too big or the load increases then the whole kite rips in half.
When designers start to use higher and higher stress steel in their designs the critical crack length drops. It is a major problem in surveying structures if the critical crack length is too small for a user to easily observe. You really want the critical crack length to be something that paint can't cover, or that is obvious when the boat is antifouled. It is hard to find a material that is very stiff, very strong, very tough (good at crack stopping and coping with stress concentrations) and not very very expensive. In multis I have had problems with lightweight carbon laminates - they hold fine until they just explode - whereas an E glass or timber structure can deflect, groan and make cracking noises without going to ultimate failure straightaway. It suits my style of boat ownership better. If the critical crack length is very small, you may not be able to blame the owner for a keel failure, even if they gave the keel a good going over last time it was antifouled. (Another good reason for lower stress keel roots - you can see when they are becoming a problem and they fail slower)
cheers
Phil
One a crack starts on a critical component with repeated loads, failure is just a matter of time, due to stress concentration.
The ISO standard relies on engineering calculations, which may not be carried out correctly. The poor guy in the Golden Globe race who's stern cracked and boat sank, had very fancy stress simulation calcs done, but they lacked the old basic rules of stress concentration when you suddenly stop reinforcing.
Yacht design has to include assumptions of load conditions. These are only guesses. Better to start with some arbitrary common sense parameters like a minimum fat keel root, and then do your design from there.
Thats why it would be good to have a more updated global standards body like ABS or Lloyds register of shipping yacht scantling standards that covers all the modern methods of construction. It levels the playing field if everyone has to build to the same scantling standards.
Its incredible how hard it is to get scantling or structural standard design details from modern mass production yacht makers. I also wonder why even today its such a struggle to find the Limit of positive stability data from manufacturers. In the absence of a certification body its a bit much just expecting people to accept "trust us" It also clear that the so called CE standards are not working when Beneteau keels are failing on a regular basis!
Select to expand quoteTHREADPOLICE said..D3 said..THREADPOLICE said..D3 said..THREADPOLICE said..
AS implemented keel & rudder inspections. Accidents happen, 1266 Persons died last year in car accidents last year in Aus & more than 160,000 died in car accidents in India. Don't want risk, stay at home.
And what have we done to reduce our road toll?
Alongside mandating safer vehicles, improving roads, training requirements etc?
1970 was the last time the national road toll was 80/100,000 vehicles.
Since then it has been steadily reducing. (1970 was when Victoria introduced seatbelt mandates, and there's been more since then)
I wouldn't think that people's attitudes to driving have changed much, but in 2014 the toll was 4.5/100,000 vehicles.
In 2020 it was 4.4/Billion vehicle kilometres.
If you want to compare vehicle safety to yachting safety, it helps to put the data in to context.
What have we done to make sailing safer?
-What are the lessons we learned and implemented from disasters like Fastnet, 98 Hobart, Cheek Rafiki?
-Do we have any data on number of yachts racing to relate keel loss and/or deaths to?
How does this number compare to vehicle related deaths?
How does it compare to Motorsport related deaths?
Road toll is UP 4.8% despite billions being spent.
& if you don't know what was implemented from the lessons we learned from 98 Hobart & Fastnet then you haven't been ocean racing in the last two decades.
We've managed to reduce the road toll by 66% since it peaked in 1970, despite the massive increase in vehicles on the road since then.
The rate of deaths per 100,000 vehicles has been reduced by 95%.
Have we done anything near that well with looking after our sailors in the same period of time?
My point stands, more deaths this year despite billions in "government intervention"
The road toll over time is enormously lower, with government intervention. One or two blips is not evidence that sensible rules have failed. Variations happen.
Yes, there were rule changes after 19 (?) people died in Fastnet '79 and 8(?) died in Hobart '98. Over thirty people have died due to the loss of short-chord keels and there have been NO effective rule changes. It's ridiculous.
