Swain BS_36 Stability curve

I disagree and stand by my statement: My interpretation is if FDS < 0.5, then FDS is taken as 0.5 for the subsequent STIX calculation. If FDS > 1.5, then FDS is taken as 1.5 for the subsequent STIX calculation.

0.5 and 1.5 are minimum and maximum values of FDS to be used in the STIX calculation. The wording used by ISO does not exclude my interpretation. FDS is a calculated value, but it is never taken as less than 0.5 or greater than 1.5 when applied to the STIX calculation. FDS is not a criterion, it is a factor.

 

Not not at all. Personally i think a lot of ISO is way over the top..it is knee jerk recation stuff...but it goes in someway to satisfy the general public what they are buying has at least complied with "some standard", rather than non. Why non..well, please ask Brent to supply such data, so you can see how safe the vessel is for your intended sailing usage. No data has even been supplied....despite repeated attempts...even the offer of a free Inc.expt. Draw you're own conclusions.

BUT, a designer must be able to demonstrate to anyone, what the level of safety their boat is deisgned to..if any. Otheriwse what is it designed for??You can pick and choose whatever you like...just say so from the outset.

Im in the commercial feild, i generally don't design using ISO...i have to comply with more onerous Class and Flag rules.

I'll wrap up with this:

Professor Richards who was then head of the Dep.t of Aeronautics at Southampton Uni in the UK, when speaking at the 1962 Conference on Yacht Design stated " Yacht design, as carried on at the present, is rather like making love to a woman. The approach is completely emprical. At the end, the male, even though he might be successful, usually had no idea of just how and why he had succeeded"

That sums it up nicely....yet here we are in 2011 with methods for measuring, in this case, stability...yet many elect not to...go figure.

 

I shall put it another way for you then by offering a question to all here:

Is there any country on this planet where a builder might purchase a set of plans for the BS36 and build it themselves for the purposes of private personal use (no intention to sell) that requires by legslation for someone to verify stability compliance with ISO 12217?

Canada - ?
Australia - No
Europe - No
USA - ?
Japan - ?
NZ - ?
Sth Africa - ?
Other - ???

 

Paul

I take your point.

I’m curious though. If in calculating STIX the values of each factor is thus:

FDS defaults to 0.5, because it is less
FIR defaults to 0.4, because it is less
FKR defaults to 0.5, because it is less
FDL defaults to 0.75, because it is less
FBD defaults to 0.75, because it is less
FWM defaults to 0.5, because it is less
FIR defaults to 0.5, because it is less
FDF defaults to 0.5, because it is less

Then plugging in the numbers to obtain the STIX.. because you have used the default values as a minimum, one arrives at a value of STIX of 2.4 which is less than Cat A of 32, for offshore/ocean going..and even less than the minimum of D value of 5.… would you say it is satisfactory? (using the hull length etc as other inputs for STIX)

All rules can be manipulated, but it would seem odd that if you can use a default value as a minimum rather than compliance, throughout the whole calculation it can still fail, is the rule/formula wrong? Perhaps you can elucidate further on how you address this?

 

Well when I registerd my BS26 a couple years ago they didn't even ask if it floats. That is here in California USA
Tom

 

I think I started this hare running by saying the design was non-compliant. What I *meant* given the context, was that it was non-compliant with the ISO standards as quoted by ad-hoc.

Honestly this should have been obvious from the context to anyone with half a brain so what's your excuse?

As for no applicable standards applied to home builders in Australia, great. I hate dealing with the ******** that always comes with Govt involvement. When I built my house here in Tas I did it first and told them after. It was cheaper paying the fine than paying for the stress-reduction drugs.

Nonetheless if people want to build a non-compliant design, they SHOULD KNOW THAT THEY ARE DOING SO!!!

Have you got my point now?

PDW

 

Ok, take a step back. If a standard is not required to be abided by for a project, how can it be considered non compliant?

Perhaps my problem is that I have more than half a brain to work with. I don't know much about you pdwiley, except that you are a tasmanian who talks about building boats and houses and is not a qualified practising naval architect or designer. I on the other hand, am not a tasmanian, though have lived there for a time and have never ever built a house nor do I intend to. I do live in one though.

Stop yelling...

Who mentioned houses? The term "home builders" I have used refers to those that build their own boats. Would you prefer hobby boat builder? Amateur boat builder? Non professional boat builder, backyarder?

 

I keep reading this "no intention to sell" but these boats are sold. Both the builders and subsequent owners should have a more realistic understanding of what the boat is about, shouldn't they?

 

Plainly and simply, you are wrong. (deja vu?)

Except for all the bad spelling in your postings, lets look at your statement.
Amateur design & build = exactly what it says - owner design and build his own boat.

When designs are sold to amateurs (or whoever) to be build, the designer is not an amateur anymore but a professional and should conform to ethics applicable in that discipline.
In fact, the designer of this design is on record in the past that he sold "hundreds" of his plans, and from his ramble in the past its his sole income if I'm not mistaken

Lastly, leave this tone of voice out of the debate, its uncalled for and not very professional.

 

Just refering to a loophole that allows for someone to build a boat for themselves in eu coutries without the need for a CE mark and all the rules and regs (eg iso standards) and cost that that brings with it. Essentially, build it for yourself, keep it for a minimum amount of time (5 years IIRC) before you sell it onto someone else. A commercial entity or business would go broke if they tried to use this loophole. As I said earlier, it has been some time since I have been through the whole CE homologation process so things are a little hazy

 

So I have dyslexic fingers sometimes when I type. Never made a typo yourself?

Sorry Wynyard, but I didn't want to refer to the specific designer as a professional. He may have made money, but is he professional? I think I (as a current professional ) and you (as a former professional) both know the difference.

What tone? CAPS LOCK MEANS YELLING.

Honestly wynyard, I have been reading posts here for some time (years) and respect nearly everything you do, but if I cannot defend myself in a civil manner against comments such as "half a brain" just because I have pulled someone up against the grain of BS bashing that is happening here, please tell me what to say.


For the record, I am NOT a BS supporter.



And I apologise in advance for any spelling mistakes my fingers may have produced.....

 

Well, because it doesn't comply with the standard. That's pretty straightforward. You can then add 'but no law says this boat, built in X country, has to comply' and that's fine. The compliance or non-compliance is separate from whether such compliance is mandatory.

Is that clear enough for you?

Actually, technically I'm a NSW resident and was born there. I just don't live there much. Tasmania is nicer. In addition, I am a designer, just not ships/boats.

As you've posted little or nothing about yourself and have no track record here, I give your assertions above little weight. Are you a naval architect, engineer or ship designer? What have you designed? What have you, personally, built?

I intended to make my point - people are entitled to know if a boat they are considering building is compliant with the standards which have been formulated for such vessels. If they choose to build one anyway, fine, they've made an informed decision. The fact that some/most Govts don't insist on home-built boats complying is IMO a good thing, I don't have a problem with it.

Your argument boils down to 'The BS boat cannot be said to be non-compliant with the ISO standards because those standards are not legally required for the boat'. That's an argument that only a lawyer would like.

On Tad's figures, the design is non-compliant. If you want to argue that it isn't required to be, fine, I don't care. It doesn't alter the compliance calculations one iota.

PDW

 

ABCDEFG;

I see you are a new guy on the block here and please let me enlighten you about what is cooking here - it is not about BS bashing, in fact, it is getting facts right on ridiculous claims made.

In the past this person bashed and trashed all whom did not agreed with his design, gospel and rants, from engineers to boat designers and everyone in between. I suggest you look at the following threads and please do take time to read it all and you will understand what this is all about now in quite a disciplined way.
BUT, these threads were "cleaned" by the moderator and all the real insults that will make your hair stand up removed, so will miss the real core of this man's ability to trash on others.
After having made a fool of himself (and banned elsewhere) he has the audacity to come and try to fool us with his new pseudonym.

http://www.boatdesign.net/forums/metal-boat-building/origami-steel-yacht-construction-248.html

http://www.boatdesign.net/forums/classification/transverse-frame-calculation-32584.html

Interesting reading and I apologize to the moderator and others for bringing this up in this tread, but it is related in a sense and to give this member insight into this ongoing BS saga.

 

Fact: ISO standards were not developed to be applied to amateur canadian steel boats and their builders.

Fact: From the documentation we have seen here and elsewhere that forms a BS Design, the BS 36 would end up in the rejection bin well before stability is considered.


And as to my own credentials, I'll maintain the right to keep the details secret. I will say however, that I hold a recognised engineering degree in naval architecture, and practice professionally in the field designing small boats say 5-50m in mostly power but also sail, recreational and commercial. I have also built a boat I designed. And you?

 

Wynyard,

I have seen that. saw it happening, and know the story. As I said above, been reading here for a while.

Its all very well to do the admirable work that tad has done in the absence of detailed data from BS and access to a sample boat and show claims of positive stability to 180 deg to be false, but to then condem it completely on the basis of a rule that does not need to be applied to this particular yacht and circumstance is quite simply misleading. The fact that Brent uses bait and switch tactics and misleading arguments is no excuse in my book.