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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Sun Feb 07, 2010 8:50 pm 

Joined: Fri Nov 07, 2008 11:21 am
Posts: 384
Here is a staybolt from an ASME Section IV low pressure steam heating boiler (wet back scotch marine). The boiler was built in 1968 and scrapped in 2007. Notice the crevice corrosion along the bolt edge within the sheet, and the resulting crack which has turned transverse within the bolt/weld area. As this bolt does not have a telltale (not required by this part of the code), the corrosion and crack are undetectable.

The issue was found by the repair of a hole adjacent to an adjacent staybolt where the plate had thinned significantly, and I ordered several bolts w/plate removed and replaced. The two photos are of the same bolt.

This boiler was in the Federal Courthouse in Louisville, KY, and recieved good water chemistry/care and proper maintenance.


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Sun Feb 07, 2010 10:53 pm 

Joined: Sun Sep 12, 2004 1:41 pm
Posts: 814
Location: Bowling Green, KY
Were these bolts put in using stick or mig...dual shield maybe? If the chemistry was correct then why was the metal attacked? In the first photo, to the left of the bolt above the sheet, is there a line showing a seam between the sheet and the weld(poor penetration)? What was the PSI loading on the bolt? ASME allows for 1/4 the material strength...actually, I guess it is now factored for a factor of safety of 3.5 versus 4..., FRA limits to 7,500. Was the bolt of SA-675 or SA-36?

Were a bolt put in using standard European practice it would have a telltale showing any fractures that have the potential to show up in bolts in service following ANY type of application.

Thank you for taking the time to answer my questions Mark, Jason


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 1:32 am 

Joined: Mon Aug 23, 2004 12:57 am
Posts: 183
Location: Sandpoint, ID
The failure suggests high bending stress/plastic deformation of the staybolt at the point of failure. Note that staybolt failure almost always occurs next to the sheet or point of attachment on a plain shaft staybolt. The Tross BTH shaft profile might have kept this point and the entire staybolt shaft within elastic bending stress limits and greatly increased service life.


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 6:28 am 

Joined: Sat Feb 05, 2005 1:05 am
Posts: 399
From Henschel Locomotive Design Book
copper-bearing armour steel staybolts? Wonder what SA spec that converts too...???


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 10:40 am 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 5254
Location: southeastern USA
Similar spec to Unobtainium........

Thanks Matt, and a fine translation - is it available someplace apart from your library?

dave

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"Techies never minded eating bits and jots of their work. They were grit and grease inside and out and could turn a pile of junk into a magical kingdom."

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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 7:18 pm 

Joined: Thu Sep 16, 2004 6:20 pm
Posts: 26
Hello All:

Mark and mjanssen: Nice photos and I have a few questions.

On the low pressure heating boiler, ASHRAE requires only a twenty year service life and this one was in service for ~40years. Is the corrosion shown in your photos, typical or atypical of this type of construction after 40 years of service? My other question is why was this boiler being removed from service? Was the reason what is shown in your photographs or some other reason?

My main concern would be as to the type of NDE that could detect this type of failure mechanism prior to the ratio of working strength to ultimate strength reaching an unacceptable value.

Also, did you determine the amount of crack penetration into the bolt?

In DSCN1414 what is the ratio of the cut radius to the bolt radius; i.e., what percentage of the bolt radius are we looking at?

On the photo of the BDR26 staybolt, again the same question, is the shown typical or atypical of what might be expected for the length of service?

tia

PKurilecz


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 7:47 pm 

Joined: Thu Sep 16, 2004 6:20 pm
Posts: 26
Hello All:

"Copper bearing armour steel" is not as strange as it may seem.

Copper additions up to 0.5% reduce the atmospheric corrosion rates of steel. The trade alloy "Cor-Ten" was developed for use in bridge beams to allow for lower maintenance costs.

"Armour Steels" are moderate alloy wrought steels that have hardenability characteristics that after heat treatment still retain high toughness and high strength.

Having a staybolt with reduced diameter due to higher strength would result in lower bending stresses from the same applied moment. Corrosion resistance would definitely be a plus.

For a typical armor steel see MIL Spec A-12560.

hth

PKurilecz


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 8:02 pm 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 5254
Location: southeastern USA
I'm a little nervous about using low pressure heating boiler situations to illustrate any effect relating to consideration of steam locomotive boilers. There's been ample empirical evidence that stationary boiler practice - even higher than low pressure - doesn't hold up against the quantity of generating capacity per unit of boiler and extent and amount of temperature and output fluctuations between the two uses of similar technologies to be appropriately used in a crossover application.

That said, there's a lot about any technique of staybolt installation that I think must only be considered as an organic part of the entirety of its installation and use. Perhaps fillet welded installations must be done only with specific metals, using designs that elastically distribute stress like the Tross, and specific welding procedures and testing to be as safe and robust - if not safer and more robust - than our old threaded rigid friends or our FTP welded replacements. The extent of latitude of variation and just which variables are possible in all cases haven't been entirely explored - probably because there hasn't been a lot of reason to do so.

This is a great discussion, with a lot of good information. Thanks everybody.

dave

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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Mon Feb 08, 2010 11:22 pm 

Joined: Sun Aug 22, 2004 8:35 pm
Posts: 374
Direct from Switzerland and my study of the fillet welded bolt; Matt Janssen is correct in pointing out that the bolt broke near the sheet or fire side of the bolt.....easily concluding that the bolt was unable to move and took out stress at the point of attachment. Interesting to note that a Full Penetration welded bolt in the US will do the exact same thing! In some cases, in less time than the fillet welded bolt would.

I think it valid to point out that nobody can conclude that it was corrosion that caused this. Had the bolt been of the proper design, as the notes presented by Mr. Austin show, it is possible that even in the case photos above, we would not be having this conversation. Likewise, had the bolt been installed by means of a full penetration weld....we could be having the same conversation.

The discussion item that is being missed so far in this case is.....

Where was this bolt located? Was it in an area of the boiler that would be more prone to movement? Was the stress load on all adjacent bolts even? Was the water/fire tremprature around this bolt the same as adjacent bolts? We are focusing on the break....not the reason for the break. Corrosion is NOT the cause of this break. Movement and bolt design are the cause of this break/failure.

From Switzerland; There is and has been much discussion about stay bolt design in the fillet welded application. The Swiss Code (and correct me if I am wrong Matt J.) and the German code allow fillet welding with no consideration of bolt design. The fact that these codes do not require the Tross design says something. What does it say you may ask. Hmmmm......don't know....but they clearly don't care too much about the design.

I spoke to a leading Swiss Boiler Inspector about this issue. He agreed that the Tross design would allow more flexibility and in so doing make a longer lasting bolt, however stress was a concern. I have seen and installed both designs. I have concerns more about WHERE the bolt is placed in the boiler, than I do with what design was placed in the boiler. Example: In the high heat area of the fire box under the arch brick (coal fired) and between the grate, where we commonly see side sheets warp due to excessive heat (and other reasons) I would be more apt at putting in a Tross Style bolt to allow for more flexibility. However, in the same locomotive, above the arch, on the way to the combustion chamber, I would not feel bad about putting a straight bolt in....I still prefer the Tross design, but I would install a straight bolt if that is all I had.

I contend that if corrosion were the leading cause for this case failure, we would have seem a very clear break circumstantially; wider on the water side and becoming less pronounced as it entered the bolt. Even in this case, the leading cause is still movement of the bolt, not so much corrosion.

Corrections from earlier posts:

I was sent a very nice note from Kelly A. that I had miss quoted him and had actually quoted Matt A. None the less it was still a good quote and no offense to Mr. Austin or Kelly Anderson.

Mr. Austin: The degree you mention of mine in your post is incorrect. I have two degrees. None of which need to be hung on the walls of RYPN (I do not hang them on my own walls and for the record....I personally do not retain copies of either degree, my mother has them....I care that little about them.). If you wish to study my education, all I can say is you were close.....but, not correct...sorry about that! By the way Matt....who started the discussion on education anyway? Did I make a call for educational credentials? I don't think I did....but if you saw it that way....fine. It is clear who is in who's camps on this deal. Matt Austin and Robby P. are in the "can't do this camp cause we said so" and the rest of us are in the ....."hmmm....if the rest of the world does this, why can't we?" Camp.

Actually Matt....I take that back...you actually posted the Tross stuff tonight...right? I have to reconsider what camp you are in. Oh...you know what...this is a waste of time. Let's just debate the issue.

Matt...you and I know we don't agree...so why don't we settle on the fact that we can debate openly on the issue and let's leave our personal issues at the door...ah? It is much more fun that way!

I agree with Dave L.....fun discussion! Keep going!

John E. Rimmasch
Wasatch Railroad Contractors

http://www.wrrc.us

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Wasatch Railroad Contractors


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Tue Feb 09, 2010 2:06 am 

Joined: Wed Aug 25, 2004 11:16 am
Posts: 572
Dear jasonsobczynski
I want you to consider the following; in one telephone call I confirmed that the C&TS has continued to have spotty water treatment at best over the past several years of operation. At other times I know they did not have any water treatment program at all. Several years ago there were pictures on the internet of locomotive #487 with significant scale build up along the mud ring. In the pictures the firebox side sheet the lower sections had been removed and the scale was uncovered. This area had budged during operation but had not failed. The approved Colorado Contractor had recommended going to “South Africa” to study water treatment.

Another tourist RR (which WRC has worked at in the past year) has a habit of filling its tender out of a fire hydrant because it takes too much time to get softened water out of the engine house. To make matters even more interesting they have been approved to connect their standpipe up to city water which uses induced oxygen to kill biological organism. This induced oxygen creates an environment that is very susceptible to corrosion. Add to the mix that in many areas in the Southwest they are now going to desalination which has created new base chemistries to be both understood and dealt with accordingly when a locomotive encounters them.

On Friday evening (Feb. 5, 2110) I sat down to dinner with a PhD, and a P.E. in Mechanical Engineering. He owns a couple of 30 inch Narrow Gauge locomotives. Our first discussion was how different disciplines approach problems. Many times I find mechanicals and metallurgist looking at issues differently because of the focus of their education. We made the assumption in our theoretical world that the theoretical mechanical acceptability (aka the Differential Equation was solved) and what would be the effect from a material issue standpoint. A big issue for us was hydrogen embrittlement. So without further delay let us move on to the subject of hydrogen embrittlement.

From the book Mechanical Metallurgy by George E. Dieter (pg 490) states “Severe embrittlement can be produced in many metals by very small amounts of hydrogen. Body-centered cubic and hexagonal close-packed metals are most susceptible to hydrogen embrittlement. As little as 0.0001 weight percent of hydrogen can cause cracking in steel. Face-centered cubic metals are not generally susceptible to hydrogen embrittlement. Hydrogen may be introduced during melting and entrapped during solidification, or it may be picked up during heat treatment, electroplating, acid pickling, or welding. Hydrogen also can be introduced by the cathodic reaction during corrosion.”

The chief characteristics of hydrogen embrittlement are its Strain-rate sensitivity, its temperature dependence and its susceptibility to delayed fracture. Unlike most embrittling phenomena, hydrogen embrittlement is enhanced by slow strain rates. At low temperatures and high temperatures hydrogen embrittlement is negligible, but it is the most severe in some intermediate temperature region. For steel the region of greatest susceptibility to hydrogen embrittlement is in the vicinity of room temperature. Slow bend tests and notched and unnotched tension tests will detect hydrogen embrittlement by a dramatic decrease in ductility, but notched-impact test are of no use for detecting the phenomenon.

In the tourist RR world we can not have people dedicated to water treatment or other specific areas. The results are often good water treatments but not always consistent control of the boiler chemistry conditions. For one RR, the inability of the person treating the locomotives to understand the basic concept of only treating the untreated portions of the tender resulted in over treating and the situation of having a Jell-O pudding pop type material come out of their boiler. It is concerned that this over treatment helped create several issues in their boiler. Another RR had good boiler chemistries other than a propensity of the water to prime in the boiler resulting in some interesting deposits in the dry pipe which were left by the boiler treatment chemicals.

The next question that came up is how do you enforce or regulate a water treatment program. While I think we all agree water treatment has its advantages to promoting boiler life there is no real way to dictate or enforce boiler treatment programs. If they do not see the value in doing a water treatment program how do you force them to not only do one but do one that benefits them? After all what is easy for some is difficult for others.

The staybolt pictures shown above are interesting, but to me they have the value of “As Received Pictures” in a court case. A true failure analysis of the samples would have a detailed disassemble of such features as any cracks, chemical analysis of both the base metal and any impurities found, and a lot of other things done. To that end I ask everyone to consider any speculation with the actual cause of the failure based solely on the pictures with caution.

Respectfully

Robby Peartree


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Tue Feb 09, 2010 2:13 am 

Joined: Mon Aug 23, 2004 12:57 am
Posts: 183
Location: Sandpoint, ID
PKurilecz: I have a four staybolt chunk; two of the bolts appear original and two do not as the welds do not show cinder erosion. Two are flexible and two are not. The condition of the staybolts don't look much different. I was told by the Meinigen shop foreman it was a very typical looking example for an older boiler. The pic I chose was the one of two welds sectioned that showed-up best. The whole bolt is there - just cut the sheet away. I will bring them to ESC for people to look at.

I believe Jrimmasch is correct and many of the current boilers being produced appear to have straight shaft fillet welded staybolts. Tross profile appears to be up to the owner as it is certainly more expensive.

MAutsin: That looks like a really neat book!

Robby: Agreed, failure could be from any cause without more study.

Thanks All, Matt J.


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Tue Feb 09, 2010 11:16 am 

Joined: Tue Feb 02, 2010 2:59 pm
Posts: 18
PKurilecz,

and anybody else who's interested, the KPS (KupferPanzerStahl) staybolt is not really a copper-bearing steel staybolt, but a copper clad steel staybolt. The Tross papers at WRRC describe these bolts as coated with 1-2mm or copper. (I'm curious how this is done, but it is irrelevant unless you have a copper firebox.) They also include an illustration of a longitudinal section of one of these bolts. Both the Tross papers and the Henshel book suffer from imperfect translation of German engineering terminology to English or American engineering terminology. Especially in the case of the Tross papers, it takes careful reading and consideration of context to even get a tentative understanding of what is being said.

Going through the Tross papers, one thing that strikes me is that I don't see any discussion of full penetration welding of staybolts. Unless I missed something, it seems that fillet welds are assumed. Also, a number of the illustrations show the fillet not around the OD of the bolt, but around the ID of the hole and onto the end of the bolt.

MJensen's discussion of threaded bolts inadvertently converted to fillet welded bolts by seal welding, reminds me of the AMC welding instructions for seal welded bolts. They were restricted to the C&O on new sheets only with steel (not wrought iron) staybolts. The were a backshop repair, not a roundhouse repair. I suspect many of the worst attached of these bolts are the result of late steam era expediency and tourist railway era ignorance. This does not mean I'm convinced that seal welding is significantly better than a well hammered bolt.

The heating boiler staybolt has me wondering if the corrosion is really crevice corrosion? The crack and corrosion are in the weld heat affected zone, in an area of stress concentrations, and at the location of highest bending moment. Could this corrosion be actually be stress corrosion or fatigue corrosion?

Andrew Adams


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Tue Feb 09, 2010 5:13 pm 

Joined: Thu Sep 16, 2004 6:20 pm
Posts: 26
Hello Andrew:

Thank you for the clarification of the alloy. A 1 to 2 mm Cu coating could very easily be applied by an electroplating process.

Probably a result of a literal translation rather than an idiomatic translation which is very easy to do from German to English.

My favorite: "Die morgen Sonne hat Geld im Mund."

Literally: "The morning sun has gold in its mouth."
Idiomatic: "The early bird gets the worm."

Another one: "Stickstoff"

Literal: "Suffocating Material"
Idiomatic: "Nitrogen"

It may be possible that the translation was made as copper bearing and idiomatically is copper plated. Do you happen to have the german text for this?

"Kupfer Panzer Stahl" by itself is not enough for an idiomatic translation. The literal translation is "copper tank steel"

Hello mjanssen: Thank you for the additional information.

Sincerely:

PKurilecz


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Wed Feb 10, 2010 4:43 pm 

Joined: Mon Aug 23, 2004 12:57 am
Posts: 183
Location: Sandpoint, ID
Tross's work has been translated into other languages three times that I am aware of. His German is very difficult because he uses a short-hand style of grammar typical to high-level scientific papers such as engineers and doctors write. The style uses box sentencing where the subject may only appear at the beginning of a paragraph and then be followed by a series of predicate "sentences."

The best translation was probably done with oversight by Greenslade of Flannery Staybolt. Part of it was printed in the Master Boilermaker's Assn proceedings, but not all due to printing expense. The full translation is now lost. Porta translated it, most likely into Spanish, but this too is inaccessible being only in his personal library in Buenos Aires and perhaps his duplicate library at the transportation institute in Cuba. As I was not able to get either, I hired a retired German Scientific Toxicologist to do it. We translated a few sections of Tanspress's Die Dampflokomotive (which is much easier) for some practice and to figure out some of the steam-specific terminology. She then translated and untangled the sentences and rewrote the papers. The grammar was so cryptic that scanning /OCR/ trans software was a waste of time. She was very careful not to change the intent of the writing, but, some of the terms are a little off. I could probably go through it again with sections I now have of Henschel's and Greenslade's work and tune it a little bit, but I do not think it would be significant. If someone wants to have a try at it, I will send photocopies of the original German text and I will update to a new version for WRRC with their help.

I had Meinigen's English-Speaking Engineer/Sales Rep translate sections of German DR railroad practice to go with the staybolt paper to show the results from his work.

Most of my spare time for the last 2 years has been taken up with translating "Thermal and Thermodynamic Study of the Steam Locomotive," - the rear section of Chapelon's 1938 "La Locomotive a Vapor." This is the 600 page section on steam locomotive design that was not published in the 1952 edition and consequently not in the Carpenter/ Camden translation of it. It's a huge amount of material, but much easier work, taking about 1 hr per page with my High School French being sufficient to guide the LEC translator program. It is perhaps THE most important writing on the steam locomotive. Of course, I will make sure to share the results with those who are interested when I am finished.


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 Post subject: Re: From the TRAIN News Blog (Re: New Locomotive Boiler Code)
PostPosted: Wed Feb 10, 2010 7:48 pm 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 5254
Location: southeastern USA
OK, another good reason for TRAIN or some other trade organization to compile a library.......and many thanks Matt Janssen. A repository of such translations as well as reprinted or copied obsolete texts would be of great benefit to us all.

Panzer is if I'm not mistaken Panther. Translation might be "Copper Panther Steel" which makes much less sense. Some military tanks - armored assault vehicles as opposed to storage bins - were called "Panzer" probably after the cat, so confusion might be involved here.......but I like the idea of metallic cats for some reason better. More picturesque, and less likely to shoot at me.

Anybody else seen a historic reference to a spec for staybolt material called "Swedish Steel?" Wonder what alloy it might refer to.

dave

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Andrea Hairston


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