Desirable and Undesirable Characteristics of Offshore Yachts

[estarzinger]

Bizarre coincidence territory.

Sunstone was mentioned over on another  thread.  Another wooden one that did huge voyages - S&S design centerboard skeg rudder - a bit similar to our first boat but a better design.

The coincidence here .  . . we knew Tom and Vicky pretty well for many years . . .  . . but one night at dinner I made a side mention of a school (very small - annual intake size around 20) I had been at, and Tom said 'Really!! I was there also". Turned out we were a few years apart, just enough not to know each other. But it was a real small world moment. 

 

[shaggybaxter]

Sunstone was mentioned over on another  thread.  Another wooden one that did huge voyages - S&S design centerboard skeg rudder - a bit similar to our first boat but a better design.

The coincidence here .  . . we knew Tom and Vicky pretty well for many years . . .  . . but one night at dinner I made a side mention of a school (very small - annual intake size around 20) I had been at, and Tom said 'Really!! I was there also". Turned out we were a few years apart, just enough not to know each other. But it was a real small world moment. 

In a world of 6.6 billion people, it does seem hard to believe. The theory of six degrees of separation contends that, because we are all linked by chains of acquaintance, you are just six introductions away from any other person on the planet.

But yesterday researchers announced the theory was right - nearly. By studying billions of electronic messages, they worked out that any two strangers are, on average, distanced by precisely 6.6 degrees of separation. In other words, putting fractions to one side, you are linked by a string of seven or fewer acquaintances to Madonna, the Dalai Lama and the Queen. The news will come as no surprise to film buffs who for years have been playing the parlour game Six Degrees of Kevin Bacon, in which they link other actors to Bacon in six films or fewer.

Researchers at Microsoft studied records of 30 billion electronic conversations among 180 million people in various countries, according to the Washington Post. This was 'the first time a planetary-scale social network has been available,' they observed. The database covered all the Microsoft Messenger instant-messaging network in June 2006, equivalent to roughly half the world's instant-messaging traffic at that time.

https://www.theguardian.com/technology/2008/aug/03/internet.email

 

[IStream]

It's not even 6 if you consider social strata, geographic partitioning, etc. For many, it's probably closer to 5. If everyone is associated with 63 different people, a separation of 5 equates to 1 billion connections.

 

[estarzinger]

n electronic conversations among 180 million people in various countries,  . . .  instant-messaging network in June 2006,

I guess this is a bit skewed? Because the circle of people on MS IM in 2006 would be rather more closely connected than the entire world's population. Was the 6.6 only among/in-between that MS IM population, or did they somehow extrapolate out beyond it to the less connected.

social strata, geographic partitioning, etc. 

yea, would be many 'tribes'; and many 'small world moments' would be within tribal boundaries.  That was certainly the case with Tim & I.

given that CL is a climber/sailor, It it is not too surprising he knew someone who knew Tim.  But his brother - that feels perhaps more like the birthday paradox, layered on top of network theory. 

 

[olaf hart]

So if I have ten brothers and sisters, does that make my family well connected?

 

[estarzinger]

So if I have ten brothers and sisters, does that make my family well connected?

did you all married each other? Or did you branch out to marry the cousins?

 

[olaf hart]

did you all married each other? Or did you branch out to marry the cousins?

We weren’t born in Tasmania…

 

[shaggybaxter]

We weren’t born in Tasmania…

At least Tasmanians stick to two legged creatures. Now the Kiwis..... 

 

[shaggybaxter]

I guess this is a bit skewed? Because the circle of people on MS IM in 2006 would be rather more closely connected than the entire world's population. Was the 6.6 only among/in-between that MS IM population, or did they somehow extrapolate out beyond it to the less connected.

yea, would be many 'tribes'; and many 'small world moments' would be within tribal boundaries.  That was certainly the case with Tim & I.

given that CL is a climber/sailor, It it is not too surprising he knew someone who knew Tim.  But his brother - that feels perhaps more like the birthday paradox, layered on top of network theory. 

I had one of those horror trips once where I spent about 40 hours travelling between three continents and 5 nations before arrival in a wee little South American airport at some god forsaken hour. I  grabbed my bag from the trolley, turned around and ran straight into my brothers ex girlfriend I hadn't seen for quite a few years. Turned out she had moved to London and was there with Unicef whilst I was there doing fibre optic training. 

Funny how the world works sometimes.  

 

[toddster]

The first actual “vacation” I ever took (one of three, so far) I ended up on the beach in Christiansted, St. Croix.  I realized that I had no idea what the fuck one was supposed to DO on a vacation.  I sat down in a beach bar and ordered a multi-layer frozen juice and rum drink (A “Hugo” IIRC) and introduced myself to the only other person in the bar.  He turned out to be from the very same town, thousands of miles away, where I was currently “living.”  

“Well fuck!,” he said, “I didn’t come all this way to talk to someone from home!” And he stalked away.  I took my Hugo out to a beach chair and stared at the sea and drank rum.  

 

[olaf hart]

There is this thing where if two Tasmanians meet anywhere in the world, a third Tasmanian turns up.

It has happened to us a couple of times…

 

[Fah Kiew Tu]

There is this thing where if two Tasmanians meet anywhere in the world, a third Tasmanian turns up.

And they immediately start discussing who they know, finding out they're second cousins...

FKT

 

[[email protected]]

And they immediately start discussing who they know, finding out they're second cousins...

FKT

Working in the Whitsundays on the charter maxis (that may've once had many desirable offshore characteristics) nearly 20 years ago, I got chatting to some Californian girls (who certainly had some desirable characteristics)... I said I was from Tasmania, and was asked if I knew Daniel. "Daniel? Daniel who?" "Oh, I can't remember, but my friend Audrey married a Tasmanian named Daniel." "You mean Dan? Dan P***, and Audrey?" "Yah, Daniel P***, that's him!" "Yeah I Used to share a house with him..."

Also, hungover in a Paris hostel, trying to gather my thoughts and possessions to catch a train to the Med, a familiar voice said my name behind me... a girl I had lived with, neither of us knew the other was traveling, let alone the country, or even continent, where the other may've been.

Desirable traits of Tasmanians, beside the scar on the neck....? 

 

[olaf hart]

And they immediately start discussing who they know, finding out they're second cousins...

FKT

No surprise there, everyone down here is related…

 

[Fah Kiew Tu]

No surprise there, everyone down here is related…

Tell me about it, my long-term GF was born in Penguin and has relatives everywhere.

Fortunately I'm a blow-in mainlander and always will be even though I've been here for over 20 years now.

FKT

 

[MikeJohns]

No surprise there, everyone down here is related…

So what is a square or a triangle for Mr Obvious ?

They are all sailing vessels. It gives you an idea of the scatter. The squares were private yachts the triangles were vessels designated as sail training vessels. They have a much larger database now. That's a pre 1998 version.

Deakin at Wolfston said at the time that the  S-H stability casualties matched their model well enough and that they might even consider adjusting the criteria upwards slightly after looking at the data a bit more closely. They didn't in the end.

Wolfston is the world leading research center for small sailing craft safety. Wolfston and the MCA code for seaworthiness is based entirely on LPS relative to boat length. They use stability as the basis for the code because they consider it the most important factor.  

 

[MikeJohns]

No surprise there, everyone down here is related…

Some romote areas of Tas there are only 3 or 4 surnames. Some interesting rare genetic disorders were being studies by specialists when we came here 25 years ago.

 

[Panoramix]

They are all sailing vessels. It gives you an idea of the scatter. The squares were private yachts the triangles were vessels designated as sail training vessels. They have a much larger database now. That's a pre 1998 version.

Not sure why you don't want to give us the title and the legend!

What's the difference between the triangles pointing up and down, what angle did they take for the "angle of stability" did the non casualties go through a storm ? Where and when did the " stability casualties" happened. The title and the legend would help a lot... These "angles of stability" seem high to me as typically smallish yachts AVS are between 110 and 140º, but then we don't even know what boats they were looking at and how they define "their angle of stability" from what you gave us!

 

[MikeJohns]

Not sure why you don't want to give us the title and the legend!

What's the difference between the triangles pointing up and down, what angle did they take for the "angle of stability" did the non casualties go through a storm ? Where and when did the " stability casualties" happened. The title and the legend would help a lot... These "angles of stability" seem high to me as typically smallish yachts AVS are between 110 and 140º, but then we don't even know what boats they were looking at and how they define "their angle of stability" from what you gave us!

Non casualties are in the same storms as the casualties, I did say that.  Squares are Yachts ( as in private sailing craft ). That's what we are interested in here.

Triangles up sail training vessels. Triangles down other sailing vessels. Hourglass symbols for two sailing barges.

The data is from the Southampton/Wolfston project the paper is from  Barry Deaken "The development of stability standards for UK for sailing vessels"  1990

Does that help ?

 

[estarzinger]

The vessels in the graph seem to be a 'representative sample of sailing vessels' that Wolfson had studied.  They do not appear to all have been in the same storm or conditions. So it is not at all the sort of statistical risk assessment Mike suggests it is.  

And I might note that despite Mike's prior assurances that only full inversions were considered stability incidents ('by professionals') there are 4 categories of stability incidents defined and analyzed here, and none of them use the 'full inversion' criteria..

I dont see that this is moving the discussion forward.

Regarding the thread topic, I personally would be interested in discussion around:

(1) The 'small intense hot spots' and how to best avoid or deal with them.  I think it is pretty clear that getting stuck/caught in such small intense hot spots is a contributing factor in quite a large number of incidents.  And that shit can go downhill really rapidly in them - faster than the sailors can really react. Seems like there would be useful discussion about tools and technique for spotting or predicting high probability of such hot spots. And for avoiding them (certainly different than the conventional rotating storm avoidance). And pre-emptive actions to take when you reach some probability of not being able to avoid (some of which actions the racers will hate . . . leading to the point 3).  This is an area where aviation has made some progress but less so for sailors.

(2) Wave shape is the key factor, much more so than size. Yet there is really very little useful about wave shape.  We know quite a bit about size distribution - so we can say generally with a 10m significant height 1 in 100 (so like every 20 minutes of exposure) will be 15m and 1 in a 1000 (so like every 3 or 4 hours of exposure) will be 19m. But that is actually not so useful. It is all fine if they are all nicely shaped and is terrible if there is a high mix of bad shapes. And particularly when running, you can be going fast and everything feels really good, until one bad shape catches you and everything goes to shit instantly. So we have a critical factor which we dont really have much information about and the fleet generally has very little experience with and little guidance about.  Would seem worthwhile to explore a bit.

(3) Racers ofc dont like to carry extra shit and ofc dont like to slow down them they dont absolutely need to.  This means they tend not to deploy storm gear (like series drogues - none were deployed in the Hobart, I might be wrong but I believe none were even carried) and tend to delay doing things which will reduce their vmg ( like course changes to suit the waves).  This all means the empirical data from races, which we all pour over, is arguably fundamentally skewed and not representative or indicative of potential best practices.  It is a bit like racing rating rules have on occasion injected undesirable characteristics into the fleet.  Racing approaches to storms injects undesirable skew into the empirical data.

(4) How you get cruising boats to sail better in light air and swell - and I mean the non-obvious ways like a taller stick and a cleaner bottom.  There is a ton more light air than breaking waves, and in swell there can actually be quite a bit of fatigue damage done to a boat that can not sail and just rolls.

View attachment TheDevelopmentofStabilityStandardsforUKSailingVessels.pdf