Talk:Boiler explosion

message: Moved to article. --Dore chakravarty 07:55, 6 December 2005 (UTC)
thread_title: Early comments

message: 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)
replies: text: Possibly, but it doesn't really matter as none of what was written related to boilers or boiler explosions anyway. I've now removed the offending text... EdJogg (talk) 00:03, 20 October 2008 (UTC)
thread_title:  Steam engine invented by James Watt? 

message: Should it be noted that this is not a complete or exhaustive list?  --BenBurch (talk) 19:08, 2 March 2009 (UTC)
replies: text: I've added . EdJogg (talk) 01:51, 3 March 2009 (UTC)
replies: text: Excellent.  --BenBurch (talk) 01:04, 10 March 2009 (UTC)
replies: text: I agree with the need to completely rewrite as discussed below.  I can't do that, but I have tried to clean-up the list of boiler explosions by creating a new article that expands the list that was given here plus adds references and readings.  Hope everyone finds this to be acceptable.  If not, feel free to revert and best regards to all. JuniperisCommunis (talk) 14:21, 14 June 2009 (UTC)
thread_title:  List of boiler explosions. 

message: 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)
replies: text: Afterthought: given the gradual improvements to the article we might then be at the point where we remove the two-year-old  tag. --Old Moonraker (talk) 10:47, 13 September 2011 (UTC)
thread_title:  Duplication 

message: 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)
thread_title:  Awkward 

message: 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)
thread_title:  Edits to "Principles" section  2012.06.06 

message: 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)
replies: text: The point about "British steam locomotive enthusiast[s]" (plural) is valid, and other perspectives may well be needed. However, a remedy of including a large-scale WP:NPS from a U.S. source isn't the answer. RV. --Old Moonraker (talk) 21:28, 6 June 2012 (UTC)

text: Sorry: I had initially thought the extracts were from a copyright work and that would warrant swift action. The point applies to equally to WP:NPS: "Avoid including … lengthy quotations." and the outcome would be the same. Many other editors have changed "your" work here; after a quick check of the page history, I seem to have  done so only once before, two years ago. --Old Moonraker (talk) 06:40, 7 June 2012 (UTC)
thread_title:  Suggestions for further improvement 2012.06.06

message: 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)
thread_title:  note on rust 

message: 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:
 
* Heating of the firebox, tubesheets, and tubes causes a difference in temperature between the heated components and the rest of the boiler. 
* The more rapid the heating, the greater the differential in temperature between the heated and non-heated components.
* The greater the differential in temperature between the components, the greater the stress on the components. 
* Whenever a previously hot component is rapidly cooled, the stresses are reversed.
* The more often (or rapid) the change in temperature, the greater the fatigue.
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)
thread_title:  notes on fatigue 

message: 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)
thread_title:  2012.06.12 '''verification''' of my edits to "principles" section (finally)