Post deleted by danfoley

[Jacket]

Re: Precisely

I guess we're just going to have to agree to disagree.

But as a final point in defense of modern analytical techniques and codes (because I always try and get the last word in!):

i) The example you quote isn't use of FE analysis, its missuse. Something that can and does happen, however you do things.

ii) If people are currently trying to design ships that are as weak as possible while staying within the codes, just try and imagine how weak the ships would be if there were no codes to stop them!

I'm off to the pub!

 

[Gunfleet]

Re: Liver Lilied Sailors

You said your speciality is bridge design. last year my son and I went under an awful lot of SNCF bridges on the Breton canals. We both noticed they were much more massively constructed than the UK equivalent. Is this a delusion? If not, what's going on?

 

[Twister_Ken]

Thx to Jimi

For those who were unable to see my 'prroof' Jimi has posted my pic at:

<A target="_blank" HREF=http://homepage.ntlworld.com/jim.robertson/indigo.htm>http://homepage.ntlworld.com/jim.robertson/indigo.htm</A>

 

[LadyInBed]

Re: Help please

I can see it ok, but I am a member of a Yahoo group.
Maybe it's a membership issue.

 

[alan_d]

Re: Besmirching my reputation

Works fine for me - Netscape, Demon, Windows ME, if that helps.

Alan

 

[Jacket]

Re: Liver Lilied Sailors

Without seeing the bridges in question, its hard to say, but as a guess (and assuming that they're concrete bridges:

i) In the UK many of the bridges built in the last 30 years have been constructed of prestressed concrete. In contrast the French seem to prefer to stick to ordinary reinforced concrete (despite inventing prestressed concrete). Prestressed concrete can produce stronger structures than reinforced concrete, so the bridges can be built thinner.

ii) I'm not sure, but I think UK designers usually specify a higher grade of concrete(stronger) than is commonly used in France. This again allows UK bridge decks to be built thinner.

iii) The bridges you saw may have been voided or cellular. These styles of bridges use less concrete as they are largely hollow, but have to be slightly deeper for the same strength.

vi) Finally, its very popular in the UK to try and make your bridge decks look thin and graceful. Therefore lots of optical tricks, such as tapering or stepping in the edge of the slabs, are used. Therefore it may be that the French bridges are the same thickness os UK ones, but just look thicker.

Its unlikely that the French bridges are actully stronger than the ones you see in this country. Although at present all the different European countries design to different codes, all based on slightly different design principles, they all produce bridges with similar factors of safety on their strength. Any differences you see from country to country are more to do with local preferences in type of bridge, construction method and so on, rather than differences in ultimate bridge strength.

 

[FlyingSpud]

Re: Precisely

I, for one, had found the discussion between Mirelle and Jacket very interesting and informative, an example of this forum at its best, but I do wonder if they may have drifted slightly off the point that was being discussed.

Jacket suggested earlier that ‘We’ would all recognise a good boat, well, I am not sure I would. When I think about it most of my assumptions about boats are built upon little knowledge, a lot of assumptions and quite a of prejudice.

I assume a certain pecking order of seaworthiness of modern boats
(a) Swedish Boats
(b) Other boats except
(c) Benjenbavs
Why do I assume this? We are all brought up to believe you get ‘owt for nowt’ therefore, as Benjenbavs are relatively cheap, they must be constructed down to a price, Swedish boats are relatively expensive, and so must be better built.
OK, once, I stood in a brand new Bavaria 36, looked OK though I felt some of it was a bit flimsy looking, though I’m not sure if it was really, and I also understand that a boat that relies for its stability on its form alone will not cope with the sort of conditions a boat that has a great lump of metal on its bottom can take. I sailed on an Oceanus once, and thought it was a bit of a caravan,
But, its not very scientific is it?

So the RCD at least gives me a chance to rate a boat and to know that someone with much more knowledge than I have (and I’ve been sailing boats on and off since the 60’s). has assessed the design of the boat.

What puzzles me though is that some benjenbavs are apparently as much a category A as, say, an HR. This must mean either

(a) Maybe my prejudices are all wrong, or
(b) The categories are too wide, that there should be perhaps Categories A-Z

I guess the latter, but I don’t know.

So what a know-nothing like me needs is more categories, a bit more specific about what a boat can do. This helps me, would allow the construction of boats outside the current limitations (but everyone would know that), would get round the problems some of the more ‘traditionalists’ have mentioned about classic cruising boats perhaps not getting a ‘be all and end all’ Category A and may encourage people to ‘build up’ to try to get the next category up

All in IMHO of course

 

[jimi]

Load of Crap

There's a load of rubbish talked about quality. Quality is not having a boat that is designed for safe RTW singlehanding (unless you wish to do that) its about having a boat that is fit for the purpose. I've got an Oceanis, purpose is safe family cruising IMHO it is fit for the purpose and yes I'd be happy in poor conditions in it in the sort of conditions I'd expect to encounter and also conditions I may encounter in the areas I anticipate sailing, and that would include a Biscay crossing if I choose to do that at some point. So there! Perhaps the old boats are good because they've survived and the other 9(% of old stuff has either sank or rotted away ... law of survival ...

 

[tcm]

Re: Besmirching my reputation

Hope they didn't charge you too much for that special "rock pool" berth!

 

[Twister_Ken]

Re: Precisely

Spudster,

From my jaundiced p-o-v of the RCD, I think it is trying to compare and rate and regulate lots of very worthwhile things like gas, fuel, electrical and plumbing installations, etc, but ignoring 'seagoing' factors except where they can be easily measured. Thus, it appears, a longer boat is assigned to a higher category than a shorter boat, with very little attention paid to factors like underwater shape which affect comfort (and thus the wellbeing, and therefore the ability of the crew to cope). Another example which isn't (apparently) rated is safe movement below decks - a skipper that has fallen across the 13 foot width of a cabin and broken a couple of ribs is not likely to be a skipper on top form for the rest of the trip. Cockpits is another area of concern - IMHO a small well sheltered cockpit where one person can attend to steering and all sheets with barely a shuffled buttock is more category A than a big open cockpit where you have to leap about to get from wheel to mainsheet traveller to genny sheet winches, but the RCD doesn't (apparently) attempt to factor this in. Less tiring too. And how about a measure for the effect of loading stores on stability, or a measure for how much water teh bilge can handle before water starts washing around the lockers and soaking all your kit. Or how easy it is to cook a hot meal in a seaway. Or how well ventilated the boat is when battened down for heavy weather.

So you're probably right - not enough categories, and not enough 'seakeeping' factors taken into account.

 

[Mirelle]

100 + A1

Good point.

There are ten major Classification Societies - Lloyd's Register (LR), the American Bureau of Shipping (ABS), Det NorskeVeritas(DNV), Germanischer Lloyd (GL) Japanese Register (NK) and Bureau Veritas (BV)(France) are the Big Six and the Korean (KR) Russian (RS), Italian (RINA)and Chinese(CCS) make up the other members of the International Association of Classification Societies (IACS), - who clasify 90% of world ships - thePolish Register was thrown out a while back for naughty business.

And every single one of them, from the highest quality of new tanker as mentioned by Pugwash above (look at the fleets of Chevron, Teekay,Concordia, Stelmar and a couple of others) or brand new passenger cruise ships like the new Queen Mary, or well maintained old ladies like the QE2, to desperate old bangers dogging around for one more cargo before going to scrap, or even loading a cargo en route to the breakers yard, like the Prestige, is

100 + A1

with one of those societies.

Not one ship is

70 + C3

they are all

100 + A1

Helpful, isn't it?

 

[Jacket]

Re: Precisely

I think you're expecting too much from the RCD, and possibly looking at it from the point of view of the type of sailing you do.

The RCD has to be applicable to all boats, used for all purposes. Therefore many of the points you mention as being desirable for offshore use would not be desirable for an offshore racing yacht. For example a small cockpits great when you're sailing shorthanded, but not much good when gybing a spinnacker with a full racing crew, and yet (most) offshore racers prove again and again that they're capable of sailing in extreem conditions, and not just with experienced profesional crews.

Realistically, in its present form, I feel that all the RCD can cover is build quality and a few technical areas such as stability curves. But then I feel that these are the important things, as they're the areas that a potential customer has trouble assessing for themselves. The factors you mention- keel type, cockpit size and so on, are all very much subjective factors that we can all decide on ourselves, with a bit of experience.

To cover the concerns you mention, I think the current A,B,C and D categories would have to be changed to multi-part classifications - AAA, AAB and so on, where maybe the first letter covers built strength, the second letter the uses the boats suitable for (racing, cruising) the third letter covers comfort in a seaway and the boats ability to look after itself (though how you measure this, I've no idea) and so on for as many letters as required.

 

[FlyingSpud]

Re: Load of Crap

Sure, I think we agree.

I think the current problem with the RCD is that your boat is classified the same as, say, a Vancouver, when clearly they are meant for different jobs and both do them excellently. The Oceanis I was in had great accommodation; there is no argument about that. I shouldn’t have used the word caravan, and I’m sorry about that, I was just trying to come up with a simple way of saying that she was optimised for accommodation rather than performance.

 

[jimi]

Shithouse Doors

No objections to the word caravan, I had one for a while. Point I was trying to make was that some people need the reassurance of a stability curve of a Contessa32 and a passage plan to get from the Hamble to Cowes! Just trying to point out that overengineering does not necessarily mean better depending on your objectives!

 

[FlyingSpud]

Re: 100 + A1

Why are they all 100 + A1? Is it competitive pressures between each of the agencies, or are their categories too broad as well? Do you find that one or other is more guilty that the others?

I wonder how they deal with aeroplanes?

Lots of questions I know, but I’m only asking because I’m nosey

 

[FlyingSpud]

Re: Precisely

All good points Ken, but I think Jacket’s comments also sound valid and the multi-assessment makes sense, though I am aware it all starts sounding terribly complicated and would cost a fortune to set up.

Why is it, when I read your comments, I seem to start visualising a Twister? You couldn’t be thinking of one could you?

 

[Tantalus]

Re: Help please

I think the fault must lie on th end of the people attempting to view it. From here in the US, using a cable modem hooked up to Comcast cable, I'm able to view it fine.

 

[Twister_Ken]

Was I thinking of a Twister?

Almost certainly, but also of Vancouvers, Rustlers, Rivals, Nicholsons, the S&S Swans, Van de Stadts, Hinckleys, Crealocks, etc.

 

[Twister_Ken]

Re: Help please

Thanks for that - I always enjoy blaming someone else!

 

[jimi]

Re: Was I thinking of a Twister?

You mean the last surviving remnants of a bygone era? Keep yours .. it might be worth something in a few years ..