simonwass
Part of the e-furniture
Cecil Pagets 2-6-2 of 1908. Engine number 2299. Would make a fascinating model....
Posts: 472
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Post by simonwass on Apr 18, 2009 15:52:29 GMT
I attempted to join my local club, but was taken to one side and had it explained to me clearly that 28 year old IT guys who "wouldn't know proper work if it slapped them" were not the type of people the club was looking to have join. take from that what you will about my local club and it's willingness to support "new blood", let alone new concepts. Name and shame the club, they dont deserve anyone hiding who they are, it would save any other new members embarassing themselves.
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Post by peterseager on Apr 18, 2009 22:11:31 GMT
The buck surely stops at the club boiler inspector. He is the one who signs the boiler certs. I had an idea to modify a boiler for a Std class 4 tank. The boiler inspector and I sat down and worked through the calculations, just as suggested above. He was then happy to go along with the mods, especially since it was going to be made by a highly regarded boiler maker. Maybe our club is lucky in having a very experienced and practical person as Boiler Inspector but the system works for us.
Any inspector will only sign off up to the limit of their competence. It has to be so but perhaps that is the weak link in the system as it stands.
Peter
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Post by Shawki Shlemon on Apr 19, 2009 10:15:49 GMT
Hi Peter That is what I have been trying to express . That is what boiler inspectors should be doing . Give him my best regard from OZ .
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Julia
Involved Member
4" Burrell Little Beastie
Posts: 53
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Post by Julia on May 5, 2009 13:04:57 GMT
The published designs HAVE been checked and approved by a professional engineer, and that is what makes them automatically accepted. Alan, I am not convinced this is the case. In my dealing with Model Engineer I was not aware of any process in place to technically review the work of the author prior to publication. I would be very interested for DavidMEW to comment on the current position. The "Bad Sicence" thread is witness to the fact that material is published that is not universally accepted. Does Model Engineer/Engineering in Miniature have special rules for those writing about boilers? It a shame that "Published Design" was used rather than "Established Design" since it the body of knowledge within the Model Engineering community that makes the old design acceptable or as with my boiler enabled the boiler testers to tell me what changes I had to make.
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Post by peterseager on May 25, 2009 21:43:32 GMT
I see in the latest ME that the Northern Association is arranging seminars and lectures for boiler inspectors. A good step forward I would say, lets hope it spreads south. It should build up the knowledge of the less experienced inspectors and help eliminate the problems discussed in the thread above.
From experience of such seminars in industry, the opportunity to meet people with the same interest so that you have someone to contact later and talk over problems is a big bonus.
Peter
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dcc
Member
Posts: 6
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Post by dcc on May 26, 2009 12:57:23 GMT
Until recently the senior editorial staff of Model Engineer were all qualified engineers, and practising model engineers. One of them, for a period of about seven years up until earlier this year, was a Technical Editor whose main job was to ensure the technical integrity of the content. During my time as editor that was done to the highest standards, first by Neil Read and, latterly, Roger Bunce, both of whom were impeccably qualified academically and practically. I can assure Julia that her articles, like all others, were carefully assessed prior to publication and were, I recall, prepared for publication by the technical editor himself. I seem to remember he had one or two safety issues, but they were not regarded as serious enough to enforce changes. Overall those articles were refreshing, practical and, it is to be hoped, have encouraged people not to avoid boiler making. I do not know what the current policy is at the magazine. Regarding boiler design, this is a tricky area. The UK boiler safety committee did a great deal of work on the testing code, but had to defer a design code owing to the extent of the work involved. Meanwhile, the Australian boiler design code is the only officially approved one available to use, although some in the UK disagree with parts of it. Pete Rich uses it for his designs (all well proven) because there is nothing else. It will be interesting to see what is made of Pete's outstanding designs for the fabulous Dean Single and 4-4-0 which I commissioned for ME some time back, and what people will make of his Ausie rules boiler designs. Meanwhile, boiler testers will be guided by the testing code, and anyone building a boiler should talk to their tester first, before starting work, whether the design has been published or not.
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Post by Deleted on May 29, 2009 16:09:52 GMT
I reckon this thread needs a touch of the caulking hammer.
Some people seem to have too much faith in the paperwork. The insurance companies don't have much of a problem I'd guess, and the Model Engineers... They're just squabbling. Perhaps, "as usual".
I'm not really too clear if people want to imprison their fears, or pass the buck in the worst case. Personally, neither are traits I'd recognise in any candidate for consideration of the title Engineer. Let alone Model Engineer. It's not about the paperwork, it's about the attitude.
That's why Curly was an engineer.
When you think about it the evidence shows that the biggest danger from pressure vessels, comes from their operation, rather than their construction.
Notwithstanding, the competence of their construction is the next most significant factor.
Right at the bottom of the danger list is the design of the vessel.
If you run a boiler out of water, you've got a problem. If the safety valve fails (unsafe) then you've got a problem. No amount of formal testing or examination is ever going to resolve those problems. Training might help, but there's always going to be one that doesn't get it. You just can't tell me that people running little steam locomotives don't know about these things, and yet there is no formal training. Were there to be so, the hobby would almost certainly be relegated to the private estates of the wealthy. It wouldn't work.
So what are the failure modes in those situations? You run out of water, and the stays of the inner firebox melt. The fire goes out. If it's not your engine, then the owner is mighty peeved. If the safety valve is nailed down, perhaps it really will explode. Even if it does, with a small steam railway locomotive the maximum possible scale of the disaster is on a par with a moderate road accident. Most people dice with that every day of their lives. Though the scale of potential damage is similar, with a little steam locomotive, you have five or ten minutes to realise that there's something wrong, and put an old rag down the chimney. You pull out into traffic without looking, and it's but a split second.
If the boiler was poorly made then this could impact on its safe operation, but the chances are more remote. To my mind there are very few in the hobby that would consider the possibility of operating a boiler without a hydraulic test, irrespective of their affiliation with a society, or even the lone experimentalist. Any such details of poor construction that are not picked up by the hydraulic test would only be found in any case by destructive testing, and this is not a practical option.
So finally there is the design of the vessel. The hydraulic test is, once more, all. The issue of design over construction failings might be one for detailed analysis. If you really needed to know which, statistics might give you the answer. Given the numbers of vessels involved, experience is likely to yield better opinion. In the end it may be safe, or it certainly won't. If the range of all possible safety outcomes for an unbuilt boiler is considered, the "may be safe" category, at the point of inspection, accounts for almost all of the safety outcomes.
If there were a huge drive for regular testing of safety valves, to an regularly and independently calibrated reference gauge, then perhaps all of this debate would seem reasonable. It's one of the few meaningful things that any pressure vessel operator can do. Regular informal inspections too, are a good way to ensure nothing untoward is likely to happen. The really critical factor then is the margin between the safety valve lifting, and the "design" pressure of the hydraulic test.
It may be an unpopular perspective, but small steam boilers for the hobby are not mass produced. They do not suit pressure limits "by design". When the hydraulic test is performed the hydraulic pressure is the "design" limit. You may only have built the boiler, but in my mind you designed it too. That you used someone else’s drawing makes no difference. Unlike the mass produced approach to engineering anything, every single example has its own set of constraints. If you buy your boiler from someone, then it's different, and that's why the boiler maker is keen to CE mark. The boiler maker knows that the biggest possible source of problems is the operator of the boiler, and should something go wrong he must be able to show that the boiler was of a satisfactory standard.
On consideration one might come to the conclusion that looking at the boiler during its operation, and understanding what you see, is more likely to prevent a problem than any kind of tick box mentality. Allowing sums, qualifications, or any other intangible metric to get in the way of your responsibility to and for your machine, is at the core of the problem.
To magnify the importance of something that has a small overall effect on the actual safety of the boiler, leads to a false sense of security, when it comes to the overall picture.
Standards are good. From what little I have read the Australians see their code as just that. It's a code. Guidelines for best practice. You read it and understand it. In the best tradition of doing the best you can, you do what you can to follow it, and improve upon it where possible.
It's not an excuse by which you can absolve your responsibility, nor should it limit you where you feel it to be lacking.
The insurance companies don't really care about improving boiler design. For them it's just a strategic risk assessment. If you let them believe that it's more risky than it is, then they're going to be happy to charge you more for the privilege of doing what you always did.
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Post by havoc on May 30, 2009 15:51:54 GMT
Are you serious? This is so off limit I don't even know where to start. If you consider the design the least important step and confuse mass production, CE and intrisic safety then I want to stay away from any boiler designed/made/run by that person.
The only valid point I see in the whole mess is about safety valves. Those should indeed be better checked/tested/followed than during the -single and only- steam test for issueing of a certificate.
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russell
Statesman
Chain driven
Posts: 762
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Post by russell on May 31, 2009 8:03:40 GMT
Yes, of course the correct design of the boiler is the most important step. If the design is wrong the boiler will be wrong however carefully it is built. However, if it unsafe it should fail in testing. It is thus unlikely to cause significant danger but the builder would have wasted considerable time, expense, and effort.
On the other hand, if a design (good or bad) has been in use for the last fifty or so years with no accidents )other than those caused by bad operation) I don't see the point of changing it just because the rules have changed.
Regards, Russell.
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Post by Shawki Shlemon on May 31, 2009 9:54:26 GMT
Hi Streuth Operating the boiler (locomotive ) is of great importance ,here in Australia few years ago we started training drivers and issuing driving licenses . the training includes description/construction/operation and emergency situation such as high pressure and loss of water as well as other driving skills . It seems on the surface as too much regulation but now is accepted by all members and newcomers to the hobby . One can't drive and haul passenger/s without a license in public .
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Post by alanstepney on May 31, 2009 12:24:55 GMT
To me, the very first thing requirement is to have a safe design. Without that, no matter how well it is built, it wont be safe. Also, the design should have sufficient margin of safety that "the average model engineer" can build it and still end up with a safe boiler.
(That could then lead on to instruction on how to build a boiler, ( but I wont digress on to that topic).
Secondly, the boiler should be tested to ensure that it HAS been built properly, has not deteriorated since, and that all fixtures, such as safety valves, work as they should. All of that is fully coverered in the present testing regime.
Third, the operator should use some common sense, and / or have instruction on how to operate the boiler so as to eliminate or reduce risk.
It is interesting that, although I have seen several accidents occur, NONE have been due to boiler failures, so other aspects of design and operation should, perhaps, also be covered. (Again, I wont digress on to that subject.)
Overall, the system we have now (and here I am talking about in the UK) appears to work and work well. Therefore I dont see a need for any major changes.
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Post by maninshed on May 31, 2009 20:12:39 GMT
Alan says above 'the first thing is to have a safe design' what body says whether a design is sound or not. Say I designed a boiler for whatever steam driven thingy I was building, it would be common sense to provide drawings and all the calculations applicable to the boiler. But who then says okay is it the club boiler inspector? Another thing that always amuses me with boiler design, if you are rolling up the barrel from flat because the correct tube is not available it should be thicker material invariably this is never referred to? Lastly when's the last time someone worked out the stress on the studs holding their dome on, do they have enough studs, and have the calculations been done to allow for the twice working pressure test. Strikes me boilers have become a nightmare or rather we have convinced ourselves they are a nightmare. I think what needed in the UK is a manual for boiler design that covers everything in steps so the designer can fill it in as he goes along. Yes yes I know who's going to do it.
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Post by baggo on May 31, 2009 20:21:10 GMT
or rather we have convinced ourselves they are a nightmare. To me, that sums it up exactly ;D John
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steam4ian
Elder Statesman
One good turn deserves another
Posts: 2,069
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Post by steam4ian on May 31, 2009 21:52:23 GMT
G'day Maninshed et al
We Ozzies are generous souls, those who are not ripping Dr J off anyway!
We'll let you use ther AMBSC codes. I know the Pound Sterling has fallen against the AUD but even so our Code are not that expensive. Try the Australian Model Engineering magazine web site, they amongst others sell the Codes.
Do yourselves a favour, get and read the Ozzie codes.
Get over the cultural snobbery, good things can come from the colonies, after all you exported to this land some of your finest. Those who came of their own accord, saw opportunity for the taking and revelled in a creative and culturally free likestyle that encourages innovation, independent thought and self sufficiency.
Regards Ian
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Post by alanstepney on May 31, 2009 23:20:54 GMT
it would be common sense to provide drawings and all the calculations applicable to the boiler It would not only be common sense, it would be an absolute requirement. But who then says okay is it the club boiler inspector? If he is suitably qualified, yes. Lastly when's the last time someone worked out the stress on the studs holding their dome on As it is part of the pressure vessel, yes, that too is taken into account. have the calculations been done to allow for the twice working pressure test. Of course. I think what needed in the UK is a manual for boiler design Most of it is covered by an ONC, all covered by HNC, or a Degree. (In suitable subjects, of course. All the requirements of "our" boilers are just part of normal engineering, and, for example, hoop stress calculations, apply to many things apart from boilers. Strikes me boilers have become a nightmare Not at all. Follow a published design. If you dont wish to do that, get someone to design it for you. If that too doesnt appeal, design your own and get a qualified engineer to check out your design. Even better, learn and study and get the requisite qualification so you too can certify designs.
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Post by alanstepney on May 31, 2009 23:28:39 GMT
We'll let you use ther AMBSC codes There is nothing wrong with the Ozzie codes. As far as I know, nothing in them conflicts with the various legal requirements we have here. However, there are a couple of areas where existing designs wouldnt be acceptable. Also, like any rigid code, there are bound to be people who would object to it, or want to build something that wasnt "code". All the AMBSC codes do is gather (almost) everything in one place, but it does not give a complete "design-and-build-a-boiler" set of instructions that are like a "painting by numbers" kit, and it seems to me that that is what many people would like. Sadly, not possible. Any design is a collection of compromises.
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russell
Statesman
Chain driven
Posts: 762
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Post by russell on Jun 1, 2009 7:25:34 GMT
Well put Alan,
Any "proper engineer" (HNC, Degree, etc) should be capable of designing any pressure vessel. He would, of course verify the design by experiment, ie., build one and test it. If it is a design for series production perhaps even test to destruction.
The codes such as the Ozzie ones are useful as they enable someone who does not have the knowledge and experience to design from scratch to design a boiler which, provided the code is followed, will have an adequate margin of safety.
Where I think we go wrong is to assume that a boiler not complying with the code is unacceptable. If it has been properly designed by an engineer it will be safe. It the design has stood the test of time it will be safe.
Regards, Russell.
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Post by Shawki Shlemon on Jun 1, 2009 9:53:59 GMT
The AMBSC code is designed for boilers within a certain limitation ( in pressure/size/materials ). People wanting to have a boiler outside these limitations can design /construct a boiler but has to be checked and certified by Work safety ,a government department .The boiler codes are not retrospective ,boilers built before the last issue does not have to meet all the requirement of current issue . If a person wants to build a boiler of an old design that does not meet all the requirements of a current issue may have to make some minor modification which will not affect the overall finish of the boiler . The code covers everything from materials to studs from testing to operation. This is a hobby for all people not only qualified engineers , any model enthusiast can build a boiler provided he/she keeps within the code requirements , there is no need for any calculation , they have all been done and included in the requirements with the government acceptable safety margins for everything from materials to studs. If only qualified engineers can build a boiler and the rich can buy one then the rest of us has to give the hobby up . I suggest have a look at the code ,it is priced to cover cost not for profit, its dirt cheap . www.smex.net.au sell them on line .
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Post by Deleted on Jun 1, 2009 14:22:24 GMT
Hi Streuth Operating the boiler (locomotive ) is of great importance ,here in Australia few years ago we started training drivers and issuing driving licenses . the training includes description/construction/operation and emergency situation such as high pressure and loss of water as well as other driving skills . It seems on the surface as too much regulation but now is accepted by all members and newcomers to the hobby . One can't drive and haul passenger/s without a license in public . Sorry for not getting back! I'm glad at least that someone recognises the importance of safe operation. If it is in, what I would see, as correct proportion to the importance of safe design is not clear. Anyhow my aim is not to subvert, merely to state my view. I wouldn't assume to say how you folks should operate, "When in Rome" and all that! I do think that a driving licence is perhaps a bit extreme though. This is I think mainly because I can see problems with it. None of the problems are safety related, but that doesn't make them less important. I mean, this is a difficult enough hobby to pursue as it is. I'm currently thinking about a locomotive that doesn't have any drawings, and I'd like to build one, perhaps in 5"G. My point here is that the design of the full size locomotive, quite possibly falls outside of the code. Does this mean that the aesthetics of the model must be compromised against safety? Another angle is that my local track is in a public park. I don't get there much, but I'd like to run my engine, once in a while. Do I really need to have a piece of paper that says I'm allowed to drive my inspected boiler around the track? Especially since I literally grew up behind a model steam locomotive? If I take that bit of paper to a ten member society, with a rickety old track, what are they going to make of it? How do they know it's even worth the paper it's written on? I guess you could have a governing body, but then you're into megabucks. I guess I'll just do what I feel I should, and then on top of that I'll meet whatever external complications I have to. If those external complications prevent me from following the hobby in the way I want to, then I'll just not follow it. The thing for me is that in almost a hundred years of the hobby, you just don't read about the disasters that have happened in the paper, let alone see them. I mean, even the coffee can boiler didn't kill anyone (that I know of). Save for dropping it on your foot, the boiler isn't going to hurt anyone until it has a fire in it. Even then it's remote. Personally I've seen commercial boilers that give me some cause for doubt. I've also seen people trying to build their own boilers, and here's the thing.... They fall into two camps. There's the ones that are superb, and there's the ones that never even make it to a hydraulic test. The latter always seem to settle for an adequate commercial boiler in the end. If you asked me the place to look for problems, is not amongst clubs and builders, even commercial ones. The place to look for problems is in the second hand complete engine market. This is the scenario where someone could easily come to the hobby as a novice, and not know (or refuse to accept) that they have bought a timebomb. I'm quite well aware that a disaster could have serious consequences for the hobby. I don't want to see that. I'm not sure we should adopt those consequences unless there really is a problem. I look, but I just don't see a problem (that requires such a strict outlook).
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Tony K
Elder Statesman
Posts: 1,573
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Post by Tony K on Jun 1, 2009 14:32:06 GMT
I'm not sure where this is all leading us, nearly lost the will to live, irrespective of successful boiler test. ;D Confuscius, he say "the likelihood of anyone reading missive is inversely proportional to the number of words therein."
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