Color of Smoke Box

a6et wrote:
> >> What are you on about? I know of *one* class of US loco that had a >> cast steel smokebox, and it was a special case. US locos had
>> fabricated smokeboxes, either rivetted or welded. > > Please tell me what sort of casting that smokeboxes were made of > please, maybe the use of the word steel is wrong but I am sure that > it was metal in general terms, not *one* particular engine
Of course the smokeboxes were metal. But they were *fabricated* - rolled up from flat plate and shapes such as angles, etc, and then put together by rivetting or welding. They *weren't* castings.
>> Asbestos was not the only lagging material used by US steam >> railroads, nor was it necessarily very thick. Magnesia, either on >> it's own, or mixed with asbestos, was widely used in the US. It was >> often applied as a cement or paste, and hence could be made as >> thick or thin as required. Asbestos was also commonly woven into a >> blanket - as an example the firebox sides and top on a NSWGR 38 >> were insulated in this manner, and the blanket was no more than 1 >> 1/2" thick.
> OK Point taken, but there was a big difference in what was > incorporated into steam loco's on different roads in the U.S.
Lagging methods, like most other aspects of US practice, were the subject of an Master Mechanics/AAR standard. The differences were not great, since most roads adhered to the standard.
> Bear in mind that the sides of the firbox was a higher temp than that > of the boiler, & extra grade insulation was needed in that region
Sorry, that's a furphy. The difference in surface temperature between the firebox and barrel is not significant enough to warrant differing grades of lagging. US and UK practice was to use the same material throughout. If you have any evidence that says otherwise, I'd be very interested in seeing it
> issue in this thread, as I understand it pertains to the > boiler.smokebox region of the engine. & on this basis the insulation > blanket used was a full asbestos blanket. & that is from personal > experience, it was also used in the 46 class as well around the HT > compartments.
??? Your comments about the 46 class are irrelevant. What NSW locos do you claim had asbestos blankets around the smokebox?
> There are, as I have indicated many variables in all of these issues. > Asbestos, was untill really recent history used in so many areas > that placed many people in potentially life threatening situations. > Some areas/countries responded in different ways in different times.
Yes - what is your point?
> larger proportion of US & UK engines were worked at much higher BP > than ours did & therefore needed higher heat shielding than others.
Again, a furphy.
> I come back to the point though, that while using photo's may not be > the best evidance for or against, it is in many cases the only way > that can get some idea these days.
As I mentioned before, I'm basing my comments on experience, research of source documents and observation of actual locomotives. If a GA drawing specifies the provision of lagging on the smokebox, and the actual loco has that lagging, then we can get the idea that the smokebox is lagged quite easily. There's no need to base an opinion on dodgy interpretations of photos...
> I base that on when you see the outside main cone of the smokebox > very clear, & then see the jacket on the outside that is oof the same > thickness as that used on the boiler, then there really is not the > room for lagging in the sense we are talking about.
Do you have an example? Because I don't really understand what you're trying to say.
> In regard to the 38's there was no lagging between tha SB jacket & > the SB itself
That's only partly true - what are you basing that statement on? In later years, many 38s lacked the lagging, but as delivered it was there on all 38s - that was the express purpose of the smokebox being jacketed in the first place. 3830 had it until it was rebuilt for traffic - I helped remove it. 3820 still has it today. Cheers.
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John Haskey wrote:
>>> Main reason is that a smokebox is not lagged. Boilers are >>> insulated, and the insulation is covered with sheet metal. That's >>> called lagging. >> >> Wolf, the sheet metal is called clothing or cladding. Only the >> insulating material is called lagging. >> > Or 'jacker' or 'wrapper'. Your mileage may vary.
Indeed. I wanted to make the distinction between the insulating material and the sheet metal covering over that. I must admit I'd forgoten about the terms you mentioned.
Cheers,
Mark.
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Yes, even though I fumbled with the typing! Substitute 'Jacket' for 'Jacker' (obviously?). I'll admit I know very little about UK practice.
                            ---john.
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*snip*

I read on the Trains Magazine forum some time ago that the graphite layer would get heated by the fire and solidify, providing a surface much harder than the metal it surrounded.
I don't know for a fact that it's right, but I'm just submitting what I remember of what I read.
Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm
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'Cause that's the way the North American railways liked to paint them.
-- Merry Christmas to all.
Roger T.
Home of the Great Eastern Railway http://www.highspeedplus.com/~rogertra /
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Reinhard Peters schrieb am 25.12.2006 22:23:

Deal all,
it was an impressive lesson about social behavior on Xmas you teached me. Thanks a lot for that but...
there is still the open question about the color of the smoke box on most US engines.
--
Reinhard Peters

mail: snipped-for-privacy@rub-peters.de
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Reinhard Peters schrieb am 27.12.2006 17:12:

I've got in another forum the information that the smokebox was not isolated as the boiler was. They did not have paint suited for that heat 100 years ago. So they used a mixture of oil and graphite to protect the thin. Later they got used to that typical graphite color and used paint of that color. A similar answer has been posted here too.
From my point the question is answered. Thanks to all the helpful answers.
--
mit freundlichen Gruessen Reinhard Peters

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