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Moved to article. -- Dore chakravarty 07:55, 6 December 2005 (UTC)
Removed the phrase "particularly to locomotive boilers." Boiler explosions happen to boilers, not to a particular type of boiler.
This section states that lower pressure causes water to boil rapidly, which in turn raises the pressure, resulting in an explosion. This is not possible. If the pressure drops, some water will boil. This addition of gas will raise the pressure, preventing the rest of the water from boiling; thus, no explosion will occur. Furthermore, the boiling water undergoes an endothermic conversion, which will lower the temperature and check the pressure of the gas. Pcu123456789 03:10, 2 December 2006 (UTC)
Would "low-pressure steam engine of the type developed by James Watt among others" be closer to the truth? Moletrouser ( talk) 07:15, 19 October 2008 (UTC)
Should it be noted that this is not a complete or exhaustive list? -- BenBurch ( talk) 19:08, 2 March 2009 (UTC)
Another editor has said that the advice in fusible plug differs. The recent additions to this article seem very valuable and I'd like to see them stay, but perhaps this is a good example of why WP:NOTHOWTO. -- CliffC ( talk) 16:21, 13 April 2009 (UTC)
Strangely enough (and speaking as someone who's around locomotive boilers quite a bit), I've been taught during the three years I've worked with them that the proper procedure, in any case of a very low water level, is to add water as rapidly as possible. A recent fusible plug failure with which I'm familiar was dealt with in precisely the same manner, with catastrophic explosion being averted; of course, the circumstances may be somewhat different, the failure in that case apparently being of the core of the plug, rather than a low water level. -- Hippopotamus Aeronauticus ( talk) 10:33, 27 April 2009 (UTC)
Check out the second case study at this link and then try to tell me that adding water to an over heated boiler can't possibly cause an explosion. It can and will if the conditions are right. In this case, the boiler’s water level was being maintained manually. The operator wasn’t paying attention and when he realized the boiler’s water was down, he switched on the feedwater pump. The result: he blew the end out of their facility and launching the boiler out of the building.
http://www.ais-forensic-engineering.com/casefiles.asp
-- Proaudio55 ( talk) 03:28, 6 May 2009 (UTC)
The important point to note here, methinks, is the use of the phrase, "if the conditions are right". My tuition has always been, if the water level is realised to be dangerously low (including by failure of the fusible plug), to bring both injectors into action as rapidly as possible. The objective is both to cool the boiler and to reduce the pressure within. I have also heard it opined, by colleagues, that the risk of thermal shock-induced failure, either of the stays or of the softened crown sheet, is too great to permit such an approach, and that the best policy is to, if possible, drop the fire and "run like the clappers".
Now, speaking as a man not trained in the arcane art of boiler design but able to discuss this question with those who have many, many years' experience of operating locomotive boilers, I would say that it was exceptionally irresponsible, given the variability of the conditions occurring in a low water level failure (steam pressure, temperature of the crown sheet, condition of the metal, durability of plates, and probably quite a few others that more specialised men than I could rattle off), for any advice whatsoever on "procedure" to be put forward by this article. I should sincerely hope that anyone in charge of a boiler would be appropriately trained for the job, and have been given not a few lectures on the preferable course of action to adopt in such a situation as this article describes; nonetheless, if someone reading this article were, in the heat of the moment, to remember its clearly-delivered didactic tones and make the wrong decision, lives could and would be endangered.
Incidentally, I trust you will note (when you have finished acting as though this were some sort of inane contest) that at no point did I suggest that the addition of feedwater to a boiler "can't possibly cause an explosion". I pointed out that, in my experience, the statement "never add water" is one not agreed with by those operating locomotive boilers. My view was, and remains, that expressed in the above paragraph: to administer advice, recommendations or (heaven forbid) actual instructions through this article is irresponsible, overly simplistic, and possibly downright dangerous. -- Hippopotamus Aeronauticus ( talk) 17:08, 12 May 2009 (UTC)
This article has been tagged for re-write since 30 Aug 2007. Thought it was about time it was mentioned on the talk page! EdJogg ( talk) 14:27, 8 May 2009 (UTC)
++Ear to ear grin++ Gee, did I get under somebody’s skin? :-) 66.173.87.242 ( talk) 13:32, 16 May 2009 (UTC)
Material relating to locomotive fireboxes is duplicated in "Fireboxes" and "Locomotive boiler explosions in the UK". Suggest a trim, but as there is a possibility that my instinct for tidiness may, once again, be mistaken for deletionist (☺!) a consultation here first. Views? -- Old Moonraker ( talk) 06:52, 13 September 2011 (UTC)
Reading this article is awkward. Many sentences are too short or too long with commas that throw off the speed of reading. It should be rewritten in a language that is more consistent and concise.
24.246.40.139 ( talk) 18:33, 8 May 2012 (UTC)
Hi all, I am trying my best to help this article in good faith. I have added reference quotations ("causes of boiler explosions" section) carefully transcribed from the original hard copy in my possession. I also made several other edits/rearrangements for grammatical clarity and technical accuracy. I rewrote a statement regarding the specific dangers inherent in "locomotive-type" boilers that is technically accurate.
I removed the statement "particularly to locomotive boilers" (again) A. Because many explosions occurred to traction, marine, and stationary boilers as well, and B. Because the statement does not have a citation to support it. This statement should not be added back without a proper citation.
I have removed the "bleve" interpretation and link from the "principles" section (again): A. Because it is not correct from a physics/thermodynamics point of view. B. It is not a legitimate reference by wikipedia standards. My previous"citation needed" challenge tags (added months ago) were removed by others, but no proper citations were added, so I have removed the reference in accordance with wikipedia guidelines. This statement has been removed before, and should not be added back without a proper citation.
Some of the original article appeared/still appears to be the result of "original research" and can be removed on those grounds. It is the right/duty of all wikipedia editors to comply with the guidelines of wikipedia itself, and since many statements previously made in the article do/did not comply with wikipedia standards for verifiability, they may be removed as well. Tomtroszak ( talk) 20:00, 6 June 2012 (UTC)
I appears to me that the original article was written by a British steam locomotive enthusiast, and all due respect is given to their interest in the topic and effort expended in creating the article. However, some of the statements originally presented were not properly supported by reference to published sources, so they have been removed in accordance with wikipedia standards for verifiability. Many of the details of boiler construction, etc. still remaining in the article are more applicable to a discussion of British locomotive design than the topic of "boiler explosions" in general. For the purpose of clarity I propose that the extraneous material be removed to a separate (or another existing) article on British locomotive design where it is more applicable; rather than offending the original author/editor by deleting material which is not necessarily incorrect, but not of material importance to this particular article. Tomtroszak ( talk) 20:49, 6 June 2012 (UTC)
Hi Moonraker! Thanks for the heads up on quoting. I made my original edits to the page many months ago saying basically the same thing, but in my own words. You deleted those edits as well. You seem unhappy that your "pet" article does not stand up to any scrutiny, and seem unwilling to accept that the original article does not meet wikipedia standards. I tried re-writing it once, but that went away pretty quickly as well. I thought perhaps this time the article could be "adjusted" politely, bit by bit, by removing the few "offensive" bits of unverifiable material as per wikipedia guidelines and leaving the rest intact. The wikipedia standards invite me to challenge and remove unverifiable material, and that is what I have done, and will continue to do. Please post only encyclopedic information that can be verified by external sources. Please maintain a neutral, unbiased point of view. Encyclopedic content must be verifiable. Tomtroszak ( talk) 23:43, 6 June 2012 (UTC)
Dear oldmoonraker, P.S. Please chill out a bit. You have always deleted my edits within hours of posting, before anyone else has had a chance to read the results of my edit. I don't think anyone is going to die as a result of having read a few paragraphs of technically correct, verifiable material. Try letting it stand for 24 hours if you can manage. I am trying to play nice here. Thanks! Tomtroszak ( talk) 00:05, 7 June 2012 (UTC)
Dear oldmoonraker, Thanks very much for the reply, and for allowing my recent edits to stay, at least for a while! I did not thoroughly review who changed what or when, apologies for that. I appreciate you taking the time to engage here, my main issue is lack of time needed to study wikipedia policy, much less actually make the edits that were so badly needed. Please note that the majority of my edits did not actually change the intent or meaning of the existing words, merely arranged them for clarity and neutrality. I'm OC, I can't help it. You could have simply "trimmed" down the "excessive" quotes yourself, and left the rest stand as an improvement of the article as a whole. The outcome would have been very different if you had taken as much time to review all aspects of my edits as I spent trying to "work" some clarity into the (entire) existing text without offending previous editors. I tried replacing the entire article before, that didn't work either. Click. Gone. When you or others reflexively keep hitting the "revert" button, it effectively destroys the process of "editing" as I understand it. It is more helpful to provide guidance on particular issues. So, here are some points I would like to make:
So, a little about me: I have more than 35 years of hands-on experience in the repair, maintenance, and operation of boilers, including VFT, locomotive, traction, Roberts, package, and power plant (B&W sinuous header). I have designed and constructed both mini and full sized VFT, Roberts, and Locomotive type boilers from scratch, including forging (flanging) the throat sheet, backhead and tube sheets by hand and hot riveting the joints. I have rebuilt, fired, driven, and operated many locomotive, traction engines, and all of these types of boilers in actual service. I have been fortunate enough to have worked extensively with several "mentors"; who were career "steam men" starting from the late 'teens of the previous century. I am also knowledgeable in the fields of physics and chemistry, and taught both subjects for a few years at the 12th grade (U.S.) and college levels. In the field of railway preservation I am a published author, and have worked for/with dozens of museums on several continents to preserve, restore, and operate historic machines of many types. I have also designed and constructed many custom machines, including a very specialized furnace that I created for the U.S. Navy, which was designed by me for use in studying the effects of corrosion on ferrous alloys at high temperatures (gas turbines), and is now on its way to a former NASA scientist to study ceramics at high temperatures (aerospace applications). Yep, I was born in the U.S. So sue me.
All of the above is completely irrelevant in this forum. What is relevant is that in my reference library I posses more than 600 volumes of primary source material (old books) pertaining to the technology, chemistry, physics and general science of the industrial revolution, dating from the 1840s - present. I have read at least some parts of every one, many all the way through. They contain a lot of information. A lot. Actually, nearly every book ever written contains some factual or technical errors, but more than 99 percent of the info is both in common to all and consistent with "Newtonian Physics". My real-life experience simply allows me to know what published information make sense and what doesn't. All of my edits are based upon my study of this material, not my personal opinion. I can and will provide citations for everything that I write, either immediately, or as time allows, as I stated in my original letter (see my "talk" page). If anyone has issue with what I write, post it here, we discuss, we fix. I think it could work.
(cur | prev) 19:52, 5 September 2011 Andy Dingley (talk | contribs) . . (13,394 bytes) (-366) . . (Rust and fatigue have specific meanings, neither of which are significant causes of boiler explosions. Undid revision 448613240 by Tomtroszak (talk)) (undo)
Hi, Andy. Thanks very much for putting your comments along with your edits, which allows me to respond: My previous edit had been removed as being "too technical", so I was trying to be more chatty and vernacular... how about this?
Stress corrosion can induce an extreme degradation of strength in highly localized areas of the pressure vessel; i.e., necking at the ends of crown stays, cracks in the the knuckles of the tube and side sheets, grooving along the inside of lap seams, etc. which can result in weakening the boiler until it is no longer capable of withstanding normal working pressure. This degradation is the result of unequal forces acting through the stays between the firebox and boiler shell during repeated thermal cycling, or the bending forces acting upon offset plates due to constant changes in pressure; and is greatly accelerated by poor water quality including dissolved oxygen, and the presence of minerals which can cause the ferrous alloy to form salts in the boiler water, thereby thinning the plates until they fail.
Is that better? I can go either way.
According to The Hartford Steam Boiler and Insurance Company statistics for the early 1900s, boilers that failed inspection and were considered dangerous due to accumulations of scale, rust, soot, and crapped-out flues outnumbered stuck safety valves and the like by a factor of ten or more. A new boiler was usually designed to withstand a pressure of at least 3-5 times normal working pressure before bursting and so can easily survive a stuck safety valve for decades if it is not over-fired and then left unattended... And many, many reports of "bagging" crown sheets indicate that most locomotive or marine (flat top) fireboxes can withstand a significant amount of overheating without catastrophe (usually caused by scale, or overfiring, or both), at least when they are relatively new...
So in fact, the vast majority of boiler explosions have taken place at normal working pressure. Therefore... (long drum roll) in terms of raw statistics, the number one killers really are... (cymbal crash): Rust and Fatigue.
If you compare information from various sources you can see a coherent trend:
Boiler explosions really don't "just happen", the great majority seem to have been caused by gross, criminal, aggravated, unjustified neglect combined with a serious operator error.
(cur | prev) 09:35, 6 September 2011 Andy Dingley (talk | contribs) . . (13,394 bytes) (-393) . . (rv - uncited claims. "Rust" is _hugely_ misleading here. If you have evidence for rust, in the sense of atmospheric oxidation of iron, then show it.) (undo)
Hi, Andy. One of my previous edits had been removed as being "too technical", so I was trying to be more chatty and vernacular by using the greatly oversimplified but commonly understood word "rust", instead of the all-encompassing but highly complex word "corrosion". IMHO, not hugely misleading, merely oversimplified. My verification for the use of the oversimplified term comes from this well-respected published source, and throughout the chapter the words rust and corrosion are used interchangeably:
Q. What is corrosion? Ans. Chemical action which causes destruction of the surface of a metal by oxidation, rusting. ^ Graham, Frank D. (1945) "Audel's Power Plant Engineers guide" New York, Ny: Theo Audel and Co. (p.333)
You or anyone could have simply inserted the better word "corrosion" in place of the simple word "rust" into my text, the meaning would have been the same. — Preceding unsigned comment added by Tomtroszak ( talk • contribs) 19:21, 7 June 2012 (UTC)
Andy Dingley wrote: I still don't consider that "rust and fatigue" are acceptable terms here. Rust implies simple atmospheric rusting, as a generalised process around the entire boiler.
Hi Andy! To most folks the term "atmosphere" perhaps implies only pure, dry air, and "rust" implies only a generalized thinning of metal plates by simple oxidation, due to the presence of oxygen in the atmosphere surrounding the plate. However, if ferrous metals are placed in an actual atmosphere of pure, dry air "rusting" (oxidation) occurs very slowly, or not at all. In an atmosphere of damp air, "rusting" (oxidation) proceeds more quickly as the moisture in the air acts as an electrolyte on the surface of the metal, and tiny charged "cells" form in each and every crevice of the surface of the material. In an atmosphere of liquid water, "rusting" (oxidation) is increased exponentially. The conductivity of the water allows any oxygen present in the water to couple with the iron in each "cell" in the plate, molecule by molecule, forming rust via simple oxidation. All you need is iron, water, and air. Every boiler that receives untreated water from any source has plenty of all three. Minerals in the water increase the conductivity and could also form salts with the iron and so contribute to either thinning or pitting, but they are not necessary for severe damage to occur, and not necessarily applicable to all boilers in all circumstances. To be sure, "fancy" forms of rust do help out, but simple oxidation is still king in terms of the tonnage of iron dissolved, and number boilers ruined in the last two centuries. Whether it be shallow or deep, localized or widespread, inside, or out... Rust is Rust. Mr. Graham is correct enough, and the citation makes the usage good enough for WP.
In all cases, if the surfaces of the plate and the level of exposure to moisture are both relatively uniform, the oxidation process removes iron from the entire surface more or less evenly. If the surface is rough, or some particular area collects moisture preferentially (like under a jacket, between studs and brackets, etc.) then "pitting" or highly localized oxidation occurs. Surface cracks from any cause such as stress, or any other crevices also form electrolytic "cells" which greatly increase oxidation corrosion in those specific areas whether inside or out, inherent in the design, or the result of previous corrosion. Some types of iron oxide also attract and retain water, so rust often begets more rust. Little pits collect moisture which begets bigger pits. Soot can make the moisture more acidic (more conductive) which speeds things up as well.
Hmmph. After I wrote all that I found these quotes for you:
''Qualitatively we describe corrosion as the deterioration of medals by a product-favored oxidation reaction. The corrosion of iron for example converts iron metal to red brown of rust which is hydrated iron (III) oxide Fe2 03 + H2O. The process requires both air and water and it is enhanced if the water contains dissolved Ions and if the metal is stressed (dents, cuts and scrapes on the surface) The corrosion process occurs in what is essentially a small electrochemical cell. There is an anode and a cathode, an electrical connection between the two (the metal itself), and an electrolyte with which both anode and cathode are in contact. When a metal corrodes there are anodic areas of the metal surface where the metal is oxidized and cathodic areas where electrons are consumed by several possible half reactions. With iron the rate of the corrosion process is controlled by the rate of the cathodic process."
"Of the three possible cathodic reactions, the one that Is fastest Is determined by acidity and the amount of oxygen present."
"If both water and O2 are present the corrosion reaction is about 100 times faster than without oxygen."
Chemistry and Chemical Reactivity, Fifth Edition. Copyright 2003 Thomson Learning Inc. Tomtroszak ( talk) 14:02, 12 June 2012 (UTC)
Andy Dingley wrote:
"Grooving caused explosions because it was unexpected and caught out conscientious operators too - at least until its cause was recognised. Nor is 'fatigue' appropriate. Yes, boilers probably suffered from fatigue too - yet a failure by fatigue has a specific meaning, contrary to that of grooving (grooved boilers fail because they're locally thin, fatigued would be a local weakness in full-thickness plates). I don't see fatigue failures as being the specific cause of significant numbers of explosions, in the way that grooving was. Grooving is caused by stress corrosion specifically. "Rust" is wrong. Where fatigue was a cause, it was almost always in firebox sling stays, not plates, and not even in firebox bolt stays."
Hi Andy! I think we can sort this out. The term "stress corrosion" refers to corrosion that occurs only in specific areas, due to microscopic cracks on the surface, caused by stress. The specific mechanism of "grooving" is stress cracking, followed by deep, localized corrosion of the cracks, in a self-reinforcing cycle:
Remember that the stress which is causing the initial minute fatigue-induced cracks caused is the same on both sides of the seam. These would be invisible to the naked eye at first, because the actual stress is relatively low. The microscopic cracks on the outside progress very slowly because it is relatively dry. The development of a deep, sharp groove in an otherwise sound plate progresses most rapidly under the water, less so in contact with steam, and hardly at all on the outside. So, the lap-seam "grooving" phenomenon is not so much caused by stress corrosion but rather, it is a specific example of it.
One definition of fatigue (used as a verb) is "to crack or break (a material or part) by inducing fluctuating stresses in it, or (of a metal or part) to become weakened or fail as a result of fluctuating stresses". So, as we see above, a lap-seam failure due to "grooving" is a specific type of fatigue failure that occurs in an otherwise full thickness of plate due to the fluctuating forces and the ever increasing concentration of stress caused by localized corrosion.
Fatigue due to thermal stress cycling, which is caused by the unequal thermal expansion and contraction of the firebox plates, the firebox stays, the tube sheets relative to the outer shell of the boiler, is a root cause of failure of those parts:
Stress corrosion can further increase the stress (and fatigue) on any component, by weakening it at the point of greatest stress. Fatigue compounded by stress corrosion is the exact same mechanism that causes "necking" at the ends of firebox stays. In addition, the minute cracks that form from fatigue near the ends of firebox stays can also act as "tooth" or a roughening of the surface which provides a better "anchor" for hard scale to attach, and the cracks hidden under a thick layer of scale then become "anodic", etc., etc.. Unless the boiler design itself is defective, the stress on any component caused by the working pressure of the steam is small by comparison to the stress caused by thermal shock. Tomtroszak ( talk) 16:14, 12 June 2012 (UTC)
(cur | prev) 01:03, 8 December 2010 EdJogg (talk | contribs) . . (12,353 bytes) (-313) . . (excessive use of templates -- assumed vandalism -- Undid revision 401142600 by 75.216.108.158 (talk)) (undo)
Dear EdJogg, That was me attempting to "challenge" the content of the article that I found questionable from both a scientific and verifiable source perspective. I hadn't logged in properly, my apologies. The excessive use of templates was based on the excessive quantity of content in the article that I found objectionable. However, regardless of the origin of the templates that were inserted into the text, instead of rising to the "challenge" to provide citations to prove that the material in question was verifiable by a published source, you simply removed the templates. Seems rather unsporting, don't you think?
I wrote my original description in my original edits to the article from memory, but I finally today (years later) found one of several descriptions of the "water hammer" explanation from a verifiable source:
"the following experiment made by the United states inspectors: A cylindrical boiler was tested and withstood a steam pressure of 300 pounds without injury." " When the [discharge] valve was suddenly opened at a pressure of 235 pounds the boiler gave way, the iron being twisted and torn into fragments and thrown in all directions. The reason for this was that the sudden rush of steam from the boiler into the discharge pipe reduced the pressure in the boiler very rapidly. This reduction of pressure caused the sudden formation of a great quantity of steam within the water, and the heavy mass of water being thrown with great violence toward the opening whence the steam was being withdrawn, struck the portions of the boiler near that opening and caused the fracture." The Colliery Engineers Company (1900) Locomotive Boilers (I.C.S. Reference Library #59) Stationer's Hall, London: International Textbook Company (Sec.12-p.76)
woop-woop. I knew I had it somewhere. Turns out it was in one of the books that I have been using already for other references, which was lying out on the floor all this time. No wonder I couldn't find it. Tomtroszak ( talk) 16:55, 12 June 2012 (UTC)
I came here from Technischer Überwachungsverein ( English ) and the initial comment:
The TÜVs originated in Germany in the late 1800s during the Industrial Revolution, following the explosion of a steam boiler at a brewery in Mannheim in 1865. This led a group of engineers to found the first Dampfkessel Überwachungsverein (DÜV, Steam Boiler Inspection Association) and soon similar associations were created in other German cities and these came together in an association in 1873.
So I was interested in when each country started regulation; nothing here mentions how or when each began, or influenced other countries' regulation, nor how severe different countries were in applying such.
This article and the corresponding
List of Boiler Explosions are almost entirely American and to a lesser extent British concentrated. I know for a fact that 19th century France had some bad accidents, and I would imagine boiler explosions happened from China to Peru.
A ( induced ) boiler explosion is a plot point in
Thomas Armstrong's King Cotton set in the 1860s ( decided upon as a teachable moment for an employer willing to ignore regulations ).
Claverhouse (
talk)
19:21, 30 October 2017 (UTC)
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Moved to article. -- Dore chakravarty 07:55, 6 December 2005 (UTC)
Removed the phrase "particularly to locomotive boilers." Boiler explosions happen to boilers, not to a particular type of boiler.
This section states that lower pressure causes water to boil rapidly, which in turn raises the pressure, resulting in an explosion. This is not possible. If the pressure drops, some water will boil. This addition of gas will raise the pressure, preventing the rest of the water from boiling; thus, no explosion will occur. Furthermore, the boiling water undergoes an endothermic conversion, which will lower the temperature and check the pressure of the gas. Pcu123456789 03:10, 2 December 2006 (UTC)
Would "low-pressure steam engine of the type developed by James Watt among others" be closer to the truth? Moletrouser ( talk) 07:15, 19 October 2008 (UTC)
Should it be noted that this is not a complete or exhaustive list? -- BenBurch ( talk) 19:08, 2 March 2009 (UTC)
Another editor has said that the advice in fusible plug differs. The recent additions to this article seem very valuable and I'd like to see them stay, but perhaps this is a good example of why WP:NOTHOWTO. -- CliffC ( talk) 16:21, 13 April 2009 (UTC)
Strangely enough (and speaking as someone who's around locomotive boilers quite a bit), I've been taught during the three years I've worked with them that the proper procedure, in any case of a very low water level, is to add water as rapidly as possible. A recent fusible plug failure with which I'm familiar was dealt with in precisely the same manner, with catastrophic explosion being averted; of course, the circumstances may be somewhat different, the failure in that case apparently being of the core of the plug, rather than a low water level. -- Hippopotamus Aeronauticus ( talk) 10:33, 27 April 2009 (UTC)
Check out the second case study at this link and then try to tell me that adding water to an over heated boiler can't possibly cause an explosion. It can and will if the conditions are right. In this case, the boiler’s water level was being maintained manually. The operator wasn’t paying attention and when he realized the boiler’s water was down, he switched on the feedwater pump. The result: he blew the end out of their facility and launching the boiler out of the building.
http://www.ais-forensic-engineering.com/casefiles.asp
-- Proaudio55 ( talk) 03:28, 6 May 2009 (UTC)
The important point to note here, methinks, is the use of the phrase, "if the conditions are right". My tuition has always been, if the water level is realised to be dangerously low (including by failure of the fusible plug), to bring both injectors into action as rapidly as possible. The objective is both to cool the boiler and to reduce the pressure within. I have also heard it opined, by colleagues, that the risk of thermal shock-induced failure, either of the stays or of the softened crown sheet, is too great to permit such an approach, and that the best policy is to, if possible, drop the fire and "run like the clappers".
Now, speaking as a man not trained in the arcane art of boiler design but able to discuss this question with those who have many, many years' experience of operating locomotive boilers, I would say that it was exceptionally irresponsible, given the variability of the conditions occurring in a low water level failure (steam pressure, temperature of the crown sheet, condition of the metal, durability of plates, and probably quite a few others that more specialised men than I could rattle off), for any advice whatsoever on "procedure" to be put forward by this article. I should sincerely hope that anyone in charge of a boiler would be appropriately trained for the job, and have been given not a few lectures on the preferable course of action to adopt in such a situation as this article describes; nonetheless, if someone reading this article were, in the heat of the moment, to remember its clearly-delivered didactic tones and make the wrong decision, lives could and would be endangered.
Incidentally, I trust you will note (when you have finished acting as though this were some sort of inane contest) that at no point did I suggest that the addition of feedwater to a boiler "can't possibly cause an explosion". I pointed out that, in my experience, the statement "never add water" is one not agreed with by those operating locomotive boilers. My view was, and remains, that expressed in the above paragraph: to administer advice, recommendations or (heaven forbid) actual instructions through this article is irresponsible, overly simplistic, and possibly downright dangerous. -- Hippopotamus Aeronauticus ( talk) 17:08, 12 May 2009 (UTC)
This article has been tagged for re-write since 30 Aug 2007. Thought it was about time it was mentioned on the talk page! EdJogg ( talk) 14:27, 8 May 2009 (UTC)
++Ear to ear grin++ Gee, did I get under somebody’s skin? :-) 66.173.87.242 ( talk) 13:32, 16 May 2009 (UTC)
Material relating to locomotive fireboxes is duplicated in "Fireboxes" and "Locomotive boiler explosions in the UK". Suggest a trim, but as there is a possibility that my instinct for tidiness may, once again, be mistaken for deletionist (☺!) a consultation here first. Views? -- Old Moonraker ( talk) 06:52, 13 September 2011 (UTC)
Reading this article is awkward. Many sentences are too short or too long with commas that throw off the speed of reading. It should be rewritten in a language that is more consistent and concise.
24.246.40.139 ( talk) 18:33, 8 May 2012 (UTC)
Hi all, I am trying my best to help this article in good faith. I have added reference quotations ("causes of boiler explosions" section) carefully transcribed from the original hard copy in my possession. I also made several other edits/rearrangements for grammatical clarity and technical accuracy. I rewrote a statement regarding the specific dangers inherent in "locomotive-type" boilers that is technically accurate.
I removed the statement "particularly to locomotive boilers" (again) A. Because many explosions occurred to traction, marine, and stationary boilers as well, and B. Because the statement does not have a citation to support it. This statement should not be added back without a proper citation.
I have removed the "bleve" interpretation and link from the "principles" section (again): A. Because it is not correct from a physics/thermodynamics point of view. B. It is not a legitimate reference by wikipedia standards. My previous"citation needed" challenge tags (added months ago) were removed by others, but no proper citations were added, so I have removed the reference in accordance with wikipedia guidelines. This statement has been removed before, and should not be added back without a proper citation.
Some of the original article appeared/still appears to be the result of "original research" and can be removed on those grounds. It is the right/duty of all wikipedia editors to comply with the guidelines of wikipedia itself, and since many statements previously made in the article do/did not comply with wikipedia standards for verifiability, they may be removed as well. Tomtroszak ( talk) 20:00, 6 June 2012 (UTC)
I appears to me that the original article was written by a British steam locomotive enthusiast, and all due respect is given to their interest in the topic and effort expended in creating the article. However, some of the statements originally presented were not properly supported by reference to published sources, so they have been removed in accordance with wikipedia standards for verifiability. Many of the details of boiler construction, etc. still remaining in the article are more applicable to a discussion of British locomotive design than the topic of "boiler explosions" in general. For the purpose of clarity I propose that the extraneous material be removed to a separate (or another existing) article on British locomotive design where it is more applicable; rather than offending the original author/editor by deleting material which is not necessarily incorrect, but not of material importance to this particular article. Tomtroszak ( talk) 20:49, 6 June 2012 (UTC)
Hi Moonraker! Thanks for the heads up on quoting. I made my original edits to the page many months ago saying basically the same thing, but in my own words. You deleted those edits as well. You seem unhappy that your "pet" article does not stand up to any scrutiny, and seem unwilling to accept that the original article does not meet wikipedia standards. I tried re-writing it once, but that went away pretty quickly as well. I thought perhaps this time the article could be "adjusted" politely, bit by bit, by removing the few "offensive" bits of unverifiable material as per wikipedia guidelines and leaving the rest intact. The wikipedia standards invite me to challenge and remove unverifiable material, and that is what I have done, and will continue to do. Please post only encyclopedic information that can be verified by external sources. Please maintain a neutral, unbiased point of view. Encyclopedic content must be verifiable. Tomtroszak ( talk) 23:43, 6 June 2012 (UTC)
Dear oldmoonraker, P.S. Please chill out a bit. You have always deleted my edits within hours of posting, before anyone else has had a chance to read the results of my edit. I don't think anyone is going to die as a result of having read a few paragraphs of technically correct, verifiable material. Try letting it stand for 24 hours if you can manage. I am trying to play nice here. Thanks! Tomtroszak ( talk) 00:05, 7 June 2012 (UTC)
Dear oldmoonraker, Thanks very much for the reply, and for allowing my recent edits to stay, at least for a while! I did not thoroughly review who changed what or when, apologies for that. I appreciate you taking the time to engage here, my main issue is lack of time needed to study wikipedia policy, much less actually make the edits that were so badly needed. Please note that the majority of my edits did not actually change the intent or meaning of the existing words, merely arranged them for clarity and neutrality. I'm OC, I can't help it. You could have simply "trimmed" down the "excessive" quotes yourself, and left the rest stand as an improvement of the article as a whole. The outcome would have been very different if you had taken as much time to review all aspects of my edits as I spent trying to "work" some clarity into the (entire) existing text without offending previous editors. I tried replacing the entire article before, that didn't work either. Click. Gone. When you or others reflexively keep hitting the "revert" button, it effectively destroys the process of "editing" as I understand it. It is more helpful to provide guidance on particular issues. So, here are some points I would like to make:
So, a little about me: I have more than 35 years of hands-on experience in the repair, maintenance, and operation of boilers, including VFT, locomotive, traction, Roberts, package, and power plant (B&W sinuous header). I have designed and constructed both mini and full sized VFT, Roberts, and Locomotive type boilers from scratch, including forging (flanging) the throat sheet, backhead and tube sheets by hand and hot riveting the joints. I have rebuilt, fired, driven, and operated many locomotive, traction engines, and all of these types of boilers in actual service. I have been fortunate enough to have worked extensively with several "mentors"; who were career "steam men" starting from the late 'teens of the previous century. I am also knowledgeable in the fields of physics and chemistry, and taught both subjects for a few years at the 12th grade (U.S.) and college levels. In the field of railway preservation I am a published author, and have worked for/with dozens of museums on several continents to preserve, restore, and operate historic machines of many types. I have also designed and constructed many custom machines, including a very specialized furnace that I created for the U.S. Navy, which was designed by me for use in studying the effects of corrosion on ferrous alloys at high temperatures (gas turbines), and is now on its way to a former NASA scientist to study ceramics at high temperatures (aerospace applications). Yep, I was born in the U.S. So sue me.
All of the above is completely irrelevant in this forum. What is relevant is that in my reference library I posses more than 600 volumes of primary source material (old books) pertaining to the technology, chemistry, physics and general science of the industrial revolution, dating from the 1840s - present. I have read at least some parts of every one, many all the way through. They contain a lot of information. A lot. Actually, nearly every book ever written contains some factual or technical errors, but more than 99 percent of the info is both in common to all and consistent with "Newtonian Physics". My real-life experience simply allows me to know what published information make sense and what doesn't. All of my edits are based upon my study of this material, not my personal opinion. I can and will provide citations for everything that I write, either immediately, or as time allows, as I stated in my original letter (see my "talk" page). If anyone has issue with what I write, post it here, we discuss, we fix. I think it could work.
(cur | prev) 19:52, 5 September 2011 Andy Dingley (talk | contribs) . . (13,394 bytes) (-366) . . (Rust and fatigue have specific meanings, neither of which are significant causes of boiler explosions. Undid revision 448613240 by Tomtroszak (talk)) (undo)
Hi, Andy. Thanks very much for putting your comments along with your edits, which allows me to respond: My previous edit had been removed as being "too technical", so I was trying to be more chatty and vernacular... how about this?
Stress corrosion can induce an extreme degradation of strength in highly localized areas of the pressure vessel; i.e., necking at the ends of crown stays, cracks in the the knuckles of the tube and side sheets, grooving along the inside of lap seams, etc. which can result in weakening the boiler until it is no longer capable of withstanding normal working pressure. This degradation is the result of unequal forces acting through the stays between the firebox and boiler shell during repeated thermal cycling, or the bending forces acting upon offset plates due to constant changes in pressure; and is greatly accelerated by poor water quality including dissolved oxygen, and the presence of minerals which can cause the ferrous alloy to form salts in the boiler water, thereby thinning the plates until they fail.
Is that better? I can go either way.
According to The Hartford Steam Boiler and Insurance Company statistics for the early 1900s, boilers that failed inspection and were considered dangerous due to accumulations of scale, rust, soot, and crapped-out flues outnumbered stuck safety valves and the like by a factor of ten or more. A new boiler was usually designed to withstand a pressure of at least 3-5 times normal working pressure before bursting and so can easily survive a stuck safety valve for decades if it is not over-fired and then left unattended... And many, many reports of "bagging" crown sheets indicate that most locomotive or marine (flat top) fireboxes can withstand a significant amount of overheating without catastrophe (usually caused by scale, or overfiring, or both), at least when they are relatively new...
So in fact, the vast majority of boiler explosions have taken place at normal working pressure. Therefore... (long drum roll) in terms of raw statistics, the number one killers really are... (cymbal crash): Rust and Fatigue.
If you compare information from various sources you can see a coherent trend:
Boiler explosions really don't "just happen", the great majority seem to have been caused by gross, criminal, aggravated, unjustified neglect combined with a serious operator error.
(cur | prev) 09:35, 6 September 2011 Andy Dingley (talk | contribs) . . (13,394 bytes) (-393) . . (rv - uncited claims. "Rust" is _hugely_ misleading here. If you have evidence for rust, in the sense of atmospheric oxidation of iron, then show it.) (undo)
Hi, Andy. One of my previous edits had been removed as being "too technical", so I was trying to be more chatty and vernacular by using the greatly oversimplified but commonly understood word "rust", instead of the all-encompassing but highly complex word "corrosion". IMHO, not hugely misleading, merely oversimplified. My verification for the use of the oversimplified term comes from this well-respected published source, and throughout the chapter the words rust and corrosion are used interchangeably:
Q. What is corrosion? Ans. Chemical action which causes destruction of the surface of a metal by oxidation, rusting. ^ Graham, Frank D. (1945) "Audel's Power Plant Engineers guide" New York, Ny: Theo Audel and Co. (p.333)
You or anyone could have simply inserted the better word "corrosion" in place of the simple word "rust" into my text, the meaning would have been the same. — Preceding unsigned comment added by Tomtroszak ( talk • contribs) 19:21, 7 June 2012 (UTC)
Andy Dingley wrote: I still don't consider that "rust and fatigue" are acceptable terms here. Rust implies simple atmospheric rusting, as a generalised process around the entire boiler.
Hi Andy! To most folks the term "atmosphere" perhaps implies only pure, dry air, and "rust" implies only a generalized thinning of metal plates by simple oxidation, due to the presence of oxygen in the atmosphere surrounding the plate. However, if ferrous metals are placed in an actual atmosphere of pure, dry air "rusting" (oxidation) occurs very slowly, or not at all. In an atmosphere of damp air, "rusting" (oxidation) proceeds more quickly as the moisture in the air acts as an electrolyte on the surface of the metal, and tiny charged "cells" form in each and every crevice of the surface of the material. In an atmosphere of liquid water, "rusting" (oxidation) is increased exponentially. The conductivity of the water allows any oxygen present in the water to couple with the iron in each "cell" in the plate, molecule by molecule, forming rust via simple oxidation. All you need is iron, water, and air. Every boiler that receives untreated water from any source has plenty of all three. Minerals in the water increase the conductivity and could also form salts with the iron and so contribute to either thinning or pitting, but they are not necessary for severe damage to occur, and not necessarily applicable to all boilers in all circumstances. To be sure, "fancy" forms of rust do help out, but simple oxidation is still king in terms of the tonnage of iron dissolved, and number boilers ruined in the last two centuries. Whether it be shallow or deep, localized or widespread, inside, or out... Rust is Rust. Mr. Graham is correct enough, and the citation makes the usage good enough for WP.
In all cases, if the surfaces of the plate and the level of exposure to moisture are both relatively uniform, the oxidation process removes iron from the entire surface more or less evenly. If the surface is rough, or some particular area collects moisture preferentially (like under a jacket, between studs and brackets, etc.) then "pitting" or highly localized oxidation occurs. Surface cracks from any cause such as stress, or any other crevices also form electrolytic "cells" which greatly increase oxidation corrosion in those specific areas whether inside or out, inherent in the design, or the result of previous corrosion. Some types of iron oxide also attract and retain water, so rust often begets more rust. Little pits collect moisture which begets bigger pits. Soot can make the moisture more acidic (more conductive) which speeds things up as well.
Hmmph. After I wrote all that I found these quotes for you:
''Qualitatively we describe corrosion as the deterioration of medals by a product-favored oxidation reaction. The corrosion of iron for example converts iron metal to red brown of rust which is hydrated iron (III) oxide Fe2 03 + H2O. The process requires both air and water and it is enhanced if the water contains dissolved Ions and if the metal is stressed (dents, cuts and scrapes on the surface) The corrosion process occurs in what is essentially a small electrochemical cell. There is an anode and a cathode, an electrical connection between the two (the metal itself), and an electrolyte with which both anode and cathode are in contact. When a metal corrodes there are anodic areas of the metal surface where the metal is oxidized and cathodic areas where electrons are consumed by several possible half reactions. With iron the rate of the corrosion process is controlled by the rate of the cathodic process."
"Of the three possible cathodic reactions, the one that Is fastest Is determined by acidity and the amount of oxygen present."
"If both water and O2 are present the corrosion reaction is about 100 times faster than without oxygen."
Chemistry and Chemical Reactivity, Fifth Edition. Copyright 2003 Thomson Learning Inc. Tomtroszak ( talk) 14:02, 12 June 2012 (UTC)
Andy Dingley wrote:
"Grooving caused explosions because it was unexpected and caught out conscientious operators too - at least until its cause was recognised. Nor is 'fatigue' appropriate. Yes, boilers probably suffered from fatigue too - yet a failure by fatigue has a specific meaning, contrary to that of grooving (grooved boilers fail because they're locally thin, fatigued would be a local weakness in full-thickness plates). I don't see fatigue failures as being the specific cause of significant numbers of explosions, in the way that grooving was. Grooving is caused by stress corrosion specifically. "Rust" is wrong. Where fatigue was a cause, it was almost always in firebox sling stays, not plates, and not even in firebox bolt stays."
Hi Andy! I think we can sort this out. The term "stress corrosion" refers to corrosion that occurs only in specific areas, due to microscopic cracks on the surface, caused by stress. The specific mechanism of "grooving" is stress cracking, followed by deep, localized corrosion of the cracks, in a self-reinforcing cycle:
Remember that the stress which is causing the initial minute fatigue-induced cracks caused is the same on both sides of the seam. These would be invisible to the naked eye at first, because the actual stress is relatively low. The microscopic cracks on the outside progress very slowly because it is relatively dry. The development of a deep, sharp groove in an otherwise sound plate progresses most rapidly under the water, less so in contact with steam, and hardly at all on the outside. So, the lap-seam "grooving" phenomenon is not so much caused by stress corrosion but rather, it is a specific example of it.
One definition of fatigue (used as a verb) is "to crack or break (a material or part) by inducing fluctuating stresses in it, or (of a metal or part) to become weakened or fail as a result of fluctuating stresses". So, as we see above, a lap-seam failure due to "grooving" is a specific type of fatigue failure that occurs in an otherwise full thickness of plate due to the fluctuating forces and the ever increasing concentration of stress caused by localized corrosion.
Fatigue due to thermal stress cycling, which is caused by the unequal thermal expansion and contraction of the firebox plates, the firebox stays, the tube sheets relative to the outer shell of the boiler, is a root cause of failure of those parts:
Stress corrosion can further increase the stress (and fatigue) on any component, by weakening it at the point of greatest stress. Fatigue compounded by stress corrosion is the exact same mechanism that causes "necking" at the ends of firebox stays. In addition, the minute cracks that form from fatigue near the ends of firebox stays can also act as "tooth" or a roughening of the surface which provides a better "anchor" for hard scale to attach, and the cracks hidden under a thick layer of scale then become "anodic", etc., etc.. Unless the boiler design itself is defective, the stress on any component caused by the working pressure of the steam is small by comparison to the stress caused by thermal shock. Tomtroszak ( talk) 16:14, 12 June 2012 (UTC)
(cur | prev) 01:03, 8 December 2010 EdJogg (talk | contribs) . . (12,353 bytes) (-313) . . (excessive use of templates -- assumed vandalism -- Undid revision 401142600 by 75.216.108.158 (talk)) (undo)
Dear EdJogg, That was me attempting to "challenge" the content of the article that I found questionable from both a scientific and verifiable source perspective. I hadn't logged in properly, my apologies. The excessive use of templates was based on the excessive quantity of content in the article that I found objectionable. However, regardless of the origin of the templates that were inserted into the text, instead of rising to the "challenge" to provide citations to prove that the material in question was verifiable by a published source, you simply removed the templates. Seems rather unsporting, don't you think?
I wrote my original description in my original edits to the article from memory, but I finally today (years later) found one of several descriptions of the "water hammer" explanation from a verifiable source:
"the following experiment made by the United states inspectors: A cylindrical boiler was tested and withstood a steam pressure of 300 pounds without injury." " When the [discharge] valve was suddenly opened at a pressure of 235 pounds the boiler gave way, the iron being twisted and torn into fragments and thrown in all directions. The reason for this was that the sudden rush of steam from the boiler into the discharge pipe reduced the pressure in the boiler very rapidly. This reduction of pressure caused the sudden formation of a great quantity of steam within the water, and the heavy mass of water being thrown with great violence toward the opening whence the steam was being withdrawn, struck the portions of the boiler near that opening and caused the fracture." The Colliery Engineers Company (1900) Locomotive Boilers (I.C.S. Reference Library #59) Stationer's Hall, London: International Textbook Company (Sec.12-p.76)
woop-woop. I knew I had it somewhere. Turns out it was in one of the books that I have been using already for other references, which was lying out on the floor all this time. No wonder I couldn't find it. Tomtroszak ( talk) 16:55, 12 June 2012 (UTC)
I came here from Technischer Überwachungsverein ( English ) and the initial comment:
The TÜVs originated in Germany in the late 1800s during the Industrial Revolution, following the explosion of a steam boiler at a brewery in Mannheim in 1865. This led a group of engineers to found the first Dampfkessel Überwachungsverein (DÜV, Steam Boiler Inspection Association) and soon similar associations were created in other German cities and these came together in an association in 1873.
So I was interested in when each country started regulation; nothing here mentions how or when each began, or influenced other countries' regulation, nor how severe different countries were in applying such.
This article and the corresponding
List of Boiler Explosions are almost entirely American and to a lesser extent British concentrated. I know for a fact that 19th century France had some bad accidents, and I would imagine boiler explosions happened from China to Peru.
A ( induced ) boiler explosion is a plot point in
Thomas Armstrong's King Cotton set in the 1860s ( decided upon as a teachable moment for an employer willing to ignore regulations ).
Claverhouse (
talk)
19:21, 30 October 2017 (UTC)