Dismasting - Why Does it Happen - How to Prevent it

[downunder]

hey Poo,

Just interested in the design of your 55ft cat you have under construction?

Thanks

[Mr B]

What country are you in PooBeetle,

If your in Aussie, I would like to see your boat,

[downunder]

Originally Posted by Mr B

What country are you in PooBeetle,

If your in Aussie, I would like to see your boat,

I expect he is in Aus. I would too.

[MIRELOS]

That's quite a bit of research, I hope you test all your bullet-proof materials coming from China. I love the Chinese but their manufacturing is suspect.

[PooBeetle]

carstenb

endless thousands of people get dismasted from 316, and Insanity is doing what you have always done - and expecting a different result.

the chemistry in 316 doesn't even exist. it is so old and stupid, you can rightfully say there is no understanding of chemistry at all.

316 is dead. the only reason the body still twitches is from old dogs that can't learn new tricks. mental inertia.

there are a slew of high tech, high nitrogen, zillionth of an extra gram of titanium (stops crystal grain boundary carbide precipitation) etc new alloys that are replacing 316 everywhere. better performance, at a cheaper price.

what do you think now that you've read Appendix Part 1 on the pathetic 316 SCC performance versus the performance of cheaper modern chemistry alloys?



zeehag

if you had to have the chainplates made for you anyway, i presume if you replaced your chainplates now you'd have them built out of any of the ten thousand PREN > 40 alloys available?

sleep much better at night knowing they'll never ever fail on you, and for the same cost or cheaper.



carstenb

"316 is not crap."

there is no chemistry or understanding used at all in formulating 316. you can add a bees dick of stuff that improves 316 performance incredibly. many many many cheap different elements can be added in insanely tiny amounts that boost 316 performance VASTLY. it is cheaper by far to add these trace elements and recieve the incredible performance increase than to NOT do it. we are not talking alloying additions, we are talking trace amounts.

so;
316 is so old and stupid there is NO chemistry or comprehension displayed whatsoever.

(but you did write this before reading Appendix Part 1, so i assume all is clear now)



Mr B

"Stainless steel work hardens. The stainless plates get exceptionally hard from moving backwards and forwards"

damn straight.

the old stainless engineer that did my mandrel bends said the inside of the pipes would completely rust out due to all the thousands of micro cracks, and so they had to be acid treated.

i've put 316 in a vice and given it ONE bend. it goes from a very very soft metal to very hard in ONE single bend. astounding.

totally rooted in ONE bend.


"Try getting practical experience instead of theory". like living on a yacht? or designing and building a cat? and all the engineering for the rigging done by myself?

you need to Google images "dismasted"




Sandy Feet
"Poobeatle, you need to stop studying and get some life experience!"


Sandy Feet, you need to stop posting and Google images "dismasted".

endless thousands of people loose their rig and all of them from 316 SCC.

get real.




Stumble

"I am not sure I want to be on Poo's side of this discussion since I I think he is majorly overstating the concern of 316ss"

i understand completly why you will never have the motivation to put in the minimal hours of Google needed to understand. if i were in your shoes, i too would focus all my efforts on titanium instead, as that reading is actually worth the time spent.




TexasPhil

"Wonderful post thanks for research "

mate, a rare treat and something actually good to read.

thank you.



roverhi
"I have seen chainplates that are obviously mis-aligned with the load from the shroud"

great call. same with tang mis-alignment, just asking for metal fatigue trouble, being bent back and forth under wind loads.



if i've missed replying to anybody, i presume you read the later sections and so now understand that predicting exactly when 316 is going to fail is a stochastic affair ie NOT random, but basically the stress, the temperature, the chlorine ppm exposure time, the amount of fresh water rain washing the chlorine out of the fittings all contribute to show how new fittings can break in 6 months in the tropics if sailed hard, or last for 50 years in a cold wet climate if parked in a marina.

[PooBeetle]

Rakuflames - "That was fascinating (and eye-opening.)"

a special thank you. a pat on the back does good to anybody. and good for both of us then because i found the full story all facinating as well.

"So what should critical parts, such as chain plates and stays/shrouds, be made of? "
there are ten thousand alloys out there that are easily obtainable. any PREN > 40 is a great start as almost nothing else is as old and primitive as 316, as almost ALL other alloys are more modern, and it is purely the very very primitive chemistry of 316 that is the problem, so basically anything else is better performing because the chemistry is modern.

a lot of guys have been whinging here, "ooo it's so hard, 316 is the ONLY stainless that exists, my brain really hurts" etc. but zillions of different things are available. if you want to get serious, you'd have to start looking at load cycles in hot chlorine (the key factor), but generally, just use anything with a PREN > 40 and you'll be never fail, never inspect, and never have to replace them.

32550 is the cheapest alloy that will do the job and still never fail (7 bucks a kilo from china!), everything else, all the true exotics cost more.



Stillbuilding - "Thanks Poobeetle."

and there i had just written my narwhal eulogy, and you 2 guys are nice to me. :o| ?



ShaunJ - "Poobeetle, In 17 posts you have typed more word than most have in a thousand. Go for it man. I would like to know what drives you "

thank you.

it's just a habbit. i was a bludger for decades (student), and then most of my jobs involved even more intense study than studying, so really, it's just a habit.

a bricklayer could lay more bricks than you, effortlessly. it's just a habbit he got into.

i'm also a retired bachelor. so i've got all the time there is, and some people here are actually interested in this topic, and are contributing their time and experience and what they've got, and so I'm doing the same.


i'm also building my new boat. designing the rig myself, so googling, and kept coming across broken 316 rigging fittings. if you see one photograph of a 316 stainless chainplate broken in half, you know that is utterly absurd, as it's just a lump of metal. a brick. an inert blob. it should never fail. it just ain't complicated, having NO moving parts and all, so something is very very wrong. jumbo jets don't fall down out of the sky, they work. and yet they have millions of parts.

get it?

so something is very very wrong, if you can't build an inert blob that has no moving parts not to fail.

so i googled, and in one instant, when seeing how many endless people get dismasted, the 316 love affair was over. all those endless photographs of people dismasted. and the ones you see are the tip of the iceberg.

realism dictates action.

ie that really should be taken care of. right now. so i did the study, put in the hours until i understood everything to my own satisfaction.

then i designed my own rig, my own rigging parts, and the alloy they are made from. (to never fail. not ever. easy as)


A Stainless CNC engineering shop close by is owned by a sailor, he has the 7 Kg hydrofoiling moth, and is 67 years old. The parts he has made for his moth are just astonishing quality.

He's said he will make everything i need out of higher alloys, but a small chinese factory will undoubtedly win the quoting.


I lurked for years here before saying very little, but this topic made me surface. As I'm passionate about this topic.

It is just so stupid to have your mast and rigging fall down and injure people, or dismast you in the absolute middle of nowhere, a thousand miles from land. When if you make your own chainplates from Super Duplex flat bar, it's even cheaper than buying rubbish that could kill you from a shop.

It's just so easy to avoid, but capitalists don't give a damn. Google images "dismasted". They are responsible for all this, and they couldn't care less.


And after reading all the answers I felt that nobody else was interested enough in the topic to put in hundreds of hours of research, or was taking the matter seriously enough to actually put in many hundreds of hours of work. But then i realised that perhaps most people have jobs, and so really can't put in all the time required studying needed for full understanding.

and so, i typed the words.

I tried to give the organisational framework of why such a perverted reality exists, so that everything was more easily understandable, and that is why there are so many capitalism references, so as to explain why an alloy is missing 3 cents of molly, or missing 0.7% of copper which gives 4000% less erosion in salt water and twice the usable long term strength, as well as an actually usable alloy. It sounds as though capitalists are just insanely evil, and nothing but evil to kill people for less than 1% more cost unless there is some comprehensible reason. It is insanely evil to do this to other people unless there is a very good reason. And it turns out that there is a very good reason. Capitalism simply demands that you do this or you go out of business.


What drives me? I did all this for my own benefit, as this is what i'm doing. Posting here to this forum is merely telling your neighbours what you are doing while passing by.

I just though i should tell my neighbours that the real deal, the straight and true reality was different from what most assumed. (in my opinion)

I thought this common sense to speak up, as this stuff is serious. Imagine your favourite entity getting squished.



Every single detail was straight, as this was me doing the best job that i could, for my benefit.

I thought every single detail was true. Straight, cold reality.

I thought all the different opinions being expressed should at least be based on the true reality of the situation.

[Rakuflames]

The alloys may have been developed, but can you point me to a website where I could actually purchase chain plates, bolts, screws and washers, cable, etc., made of these alternate alloys? Could they be combined with the 316 parts on my boat? I cannot afford to strip my boat of all stainless and replace it with something else all at once, so what would the chemical interaction between the two metals be? Safe or not safe?

I am aware of the brittle nature of 316, but are actual parts available of these alloys you speak of?

[stillbuilding]

I think Poo has generated some really interesting and persuasive work. To implement his findings will take some effort by the reader and discussion with smaller engineering workshops but very achievable. Maybe starts with replacing smaller items eg chainplates and develops from there. Well done Poo.

[PooBeetle]

Hi Greg Rubin of Allied Titanium. (long time admirer of all your posts. always good quality posts worth reading.)


You guys would be very attractive if you were a one stop shop,if you made sure that you could deliver every single part needed to rig a yacht mast, every single bolt, swageless fork, and tang.

On the web site there is always something missing. it would take forever to rig a 20 meter yacht mast, and with no guarantee of success.

and you don't have metric. and then missing prices. CALL us instead. even then we don't know if you guys can actually deliver. ie CAN you deliver every single part needed to rig a yacht mast, every single swageless fork, and tang and complete metric turnbuckle? in my experience no. there is always something missing.


"grossly exaggerating the failure speed of 316SS"

every single thing i wrote comes straight from Google. you too can find out all of this very easily, but you will never do it unless you have the motivation.

since we both have Google, the only difference between us must be the motivation to put in the hours of reading.




Lagoon4us

i also am using 316 bolts exactly as you prepared them, it's a good method. (only i also give them a hot sodium hydroxide for 2 hours, then rinse, then hot citric acid for 2 hours first though, and then coated in epoxy.)

and i also expect no problems.

i am also just like you using heaps of 316 on my boat. 316 flat bar, round bar, pipe, tube, angle, sheet, plate, plumbing and valves; the reason i'm using it is because it's the cheapest that will do the job.

but no underwater bolts, and not for chainplates or anything touching the mast. it will not do the job here.

i presume you read the article that came after your post and now understand about how extremely damaging cyclic loads in chlorine are to 316, but by having very stiff steel hulls you luckily managed to eliminated all of it, but 99% of other people don't have steel hulls.





noelex 77
"I don't quite share your passion for the inadequacy of 316 rigging."

i understand perfectly where you are. your brain is soaking in the soothing and delicious warmth bath of capitalist marketing. swimming blissfully in a sea of ignorance. you are very lucky.

you have no chance of understanding true reality unless you do the work yourself - as there is far too much inertia in all the years of 316 knowledge inside your head for 5 minutes of reading to overcome.

me? i love MacDonalds. they provide a valuable service to the community, and nobody can doubt this.
but i also Googled images "dismasted". endless misery. endless thousands of people being very very sad.


"Can you advise of some sutable suppliers? What are the costs?"

"The only drawback of the better SS seems cost and availability. Until will get some answers on this it does not matter how technically superior it is. It is still not an option that can be used."

to quote me;
there is no chance of ever getting never fail alloy fittings and rope. the numbers are too small.

so if you want them, you'll have to have them made by an engineering firm.

any engineering firm will do this for you, in any one of ten thousand different alloys, as this is exactly what small engineering firms do for a living.





jongleur "a standing ovation? "

thank you.




Mr B - please choose one. as i can't understand you.

Answer 1
you are perfectly correct. 316 IS used with hot fresh water. 316 is great in fresh water. i would use it in fresh water.

and there is even yield data suitable for design for 316 pressure vessels presented in Appendix 1, Picture 6, but you never read this picture, or you would have understood, and so would not have posted.

Appendix 1, Picture 2 clearly says on it salt water, and the verbiage was about sailing in the tropics, but you never read the picture, which came directly from the scientists who actually made the 316 you were using, or you would have understood, and so not have posted.

you couldn't be bothered to read the pictures?

yet could be bothered to comment? everybody else understood the statement was not fresh water, but water with chlorine in it. Chlorine makes an astounding difference to 316 failing.


Answer 2
you clearly are not following the conversation.

and so there is clearly no motivation to understand.

can i suggest that motivation to succeed in understanding this matter is the entire key.

if you have no motivation, then there is no real interest, and so you will not read, and so you will not understand.


Answer 3
Salt is chlorine.

Chlorine ions are different from fresh water. it's a catalyst. 100ppm to destroy 316 ain't much.

Hydrochloric acid is an example of chloride ions. Try putting some salt water and some hydrochloric acid on some mild steel. Leave them. One is faster than the other, but the result is exactly the same.

In Dutch HCl translates as marine acid air.

European alchemists first called hydrochloric acid spirits of salt.

http://en.wikipedia.org/wiki/Chloride

how highly motivated you are is the entire key to understanding all the reading above.

to have made such mistakes makes it SEEM as though you are far less motivated than the others here who clearly did the reading, and understood everything perfectly.


chlorine is a catylyst. 100ppm in a crevice is all that is needed to destroy 316.


i suggest this subject is perfectly clear to people who are interested.

we are talking about 316 yacht mast rigging fittings in salt water, in hot midday sun, at the equator, undergoing cyclic load cycles, in chloride ions, at 35000 ppm, at around 60 degrees Celcius.

chlorine is a catylyst. 100ppm in a crevice is all that is needed to destroy 316.


Answer 4
try clicking on a picture - they get bigger if you do that (i need to tell my mum stuff like that all the time)


Answer 5
i don't know what else to say. If i should have said "in SALT water, at 35000ppm, at a specific temperature, after so many load cycles" qualifying every single noun so lengthily would be astoundingly pedantic and unreadable. Nobody else was confused. So i don't understand your post at all. Real 316 engineering yield data suitable for design for pressure vessels was actually presented before your post. Appendix 1, Picture 6.

There is NO published engineering suitable data for design for use in chlorine, because that is just so silly.


this is what i thought you said, and i answered as best as i could. but i don't think you are even remotely interested in the topic. you've made no effort to understand or follow the conversation at all. i won't answer again.






Maine Sail


my apologies. you are in the right and i am in the wrong.


"If you had "hot linked" to them that's a different story, still mine located on my site, but you did not. You took them, hosted them elsewhere, and used them to try and make your point."

did you know it is much faster, quicker, and easier to do things exactly as you suggest?

and this is exactly what i tried to do using the this forums "post reply", as obviously, that is so much quicker, simpler and easier.

but when i tried, several times, this forum software refuses to let you do this. that feature, though appearing, has been disabled by the forum administrators.

try it your self right now.

see?



you obviously deserve credit for your pictures.

all i can do is offer an apology.



i understand my opinions of what capitalism demands from companies to stay in business may be upsetting to guys actually doing the hard work, actually producing the goods.

much easier to be a fat well fed whinger like me, an armchair communist fully intent on getting all the brilliant toys i can from companies like yours, all the time while complaining with a mouth stuffed full of cake.

i admit it's much easier to comment from the sidelines than to actually be in business myself.


as for the "point", i hope you understand the failure mechanism was Stress Corrosion Cracking. not old age, malnutrition, lack of inspection etc.

SCC is the heart of the matter, is how all 316 rigging fittings fail in salt water, and is exactly how your fittings failed.





A General Apology

to Corporations, businesses, riggers, salesmen, and business people in general etc.

guys,
a well known problem with academics is they focus on too small an area, and ignore reality outside the area of focus.

it has dawned on me that i lumped capitalism as a socioeconomic paradigm and business people in general together, and delt harshly with the stupidity of capitalism in general. Normal business people are perhaps feeling tarred with the same brush, and this was not my intent.

so;
i apologise to all business people in general that may think this.

were this a paper, i would have made it much clearer that only capitalism as a socioeconomic paradigm squeezing all the time downwards in quality was to blame, and that normal business peeps just have to play along to survive, and that it is the governments job, not theirs, to pass laws demanding minimum standards be met, and that this area is one of the very few remaining unregulated industries.

i understand you business guys are just normal peeps trying to get along, and are yourself at the mercy of the demands of capitalism, the same as the rest of us.

i don't consider any business person at fault for staying alive in a fun job he loves. there is no blame, except on the demands capitalism makes. this is just how the world is.

i suggest all riggers work to the best of their ability, and in good faith.

[Jim Cate]

[QUOTE=PooBeetle;1042131]
"endless thousands of people get dismasted from 316"

Poo, I do hope that when doing all the calcs for your design you treat numbers with more respect than this. There are NOT "endless thousands" of folks getting dismasted for any reason whatsoever, let alone solely from the evils of 316 s/s. There ARE however endless thousands of boats out sailing whose 304/316 s/s rigging has NOT failed. Your rhetoric may sound good to you, but to me it sounds like someone selling snake oil... methinks thou protest too much, mate.

I certainly agree that there are some better materials for marine applications, and I would be happy to utilize them if they were actually available to someone who is actively cruising. Those of us who already have successful boats and are out in the real world don't have the opportunity to negotiate contracts with your mythical small Chinese or Indian factory to supply the wire, terminals, shackles, rigging screws, nuts and bolts that we need as we travel the globe.

Many of your points are well founded, Poo, and I don't want to belittle your research efforts. I do wish that you would stick to science and leave out the rants about capitalism and the greed/stupidity of the folks who supply us with the things we need as well as the hyperbole about the sailing world and the disasters happening all around us (nearly invisibly).

Cheers,

Jim

[Lagoon4us]

Factor, this deserves an apology. I was wrong, I apologise, and I hope you understand that I was away from the forum actual and was researching for my huge 316 Manifesto at the time. This was poor journalism that slipped through proof reading due to the fact that i was moving as fast as possible (as it's all boring because it's all so obvious), and so was focusing too much on other facts, the big picture coherency etc, and so you slipped through the cracks.

LMAO This whole post has been very entertaining no one, READ NO ONE! Will ever beat POO's word count, i think i've anchored in 3 bays and tied stern to at three Quays since it started, i look up at my mast every now and then smiling and i remember a quote.......

Well done Poo Beatle! “If the person you are talking to doesn't appear to be listening, be patient. It may simply be that he has a small piece of fluff in his ear.”
― A.A. Milne, Winnie-the-Pooh Beetle. Cheers

[Mr B]

Over my many years with working in all metals, 50 off them,

A lot of the failures are a direct result in the material being used, is that it was too thin for the application it was designed for,

Thicker material costs extra money, Going from 3 mm to 5 mm will alleviate any problems of stress on the part, Thats just an example, dont take it literally,

But it costs extra, Most people dont realise that its only a few dollars extra, Not Mega bucks extra,

But the Bean counters in companys worry about those extra cents, But have no idea on the quality of the item, Must get the costs down,

So you get a part that is just barely up to the standard and not properly engineered to withstand years of hard abuse,

Im old school, What I build is virtually for ever, It doesnt fail under any circumstances, If you want cheap ****, simple, you go elsewhere, As I wont manufacture it,

But plenty of people will, So lack of knowledge plays a big part in it as well,

Cheers,
Brian,

[Lagoon4us]

PooBeetle can you explain why you do not advocate stainless bolts and nuts including washers be they spring or flat underwater? I, along with others, have never had a problem with them was this an error?

I've read most of your post's but i still do not understand your logic on bolts?

Cheers the fluff is removed i'm all ears so to speak.....like Noddy!

[noelex 77]

Originally Posted by Lagoon4us

PooBeetle can you explain why you do not advocate stainless bolts and nuts including washers be they spring or flat underwater? I, along with others, have never had a problem with them was this an error?

I've read most of your post's but i still do not understand your logic on bolts?

Cheers the fluff is removed i'm all ears so to speak.....like Noddy!

Apparently my "brain is soaking in the soothing and delicious warmth bath of capitalist marketing. Swimming blissfully in a sea of ignorance" but despite these shortcomings I do agree with the author of my nurological assessment, that 316 bolts underwater (where water has access to the bolt) are not a good choice.

They are not acceptable for critical applications IMHO.

The biggest danger is crevice corrosion, which can be quite rapid.

What applications have you used 316 bolts underwater for?

[Lagoon4us]

Basically every propellor shaft that isn't either, Monel, Bronze or Steel in the free and communist world except the Sahara and similar places of course.

A propellor shaft IS effectively no different to a bolt it has a nut, castellated at times, split or drive pin and washer. It is tapered and a Bronze hub slides on effectively creating a naughty environment for the longevity of the SS...

Most shafts i've seen are 316# every one beautiful after many many years subsurface..

Let alone drive shafts on outboards where replacement nuts are commonly 316# and washers varying from 316# to 304#. Don't see them crumbling worldwide.