Talk:Reed water tube boiler

GA Review

This review is transcluded from Talk:Reed water tube boiler/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Mike Christie (talk · contribs) 23:08, 31 December 2017 (UTC)

I'll review this. Mike Christie (talk - contribs - library) 23:08, 31 December 2017 (UTC)

• The lead seems a little short for the length of the article.
• There's quite a lot of information embedded in footnotes 2 and 5; any reason not to integrate some of that into the main text?
• In the lead image, I think the large external tubes are the "downcomers"; could this be stated in the caption? To someone unfamiliar with this sort of equipment every little helps.
• I found File:Water tube boiler schematic.png very helpful, particularly in understanding "the tubes joined the top chamber below the designed water line". Could it be included? I can see there's little room for more diagrams, but it would be helpful if a way can be found. Perhaps a gallery? Or the use of {{Multiple image}}? If not, perhaps we could make it clearer in the text that all the tubes, and the lower part of the top chamber, contained water, and steam was limited only to the upper part of the top chamber.
• If it can be done concisely, it would be good to clarify in footnote 7 why Maxim and Thornycroft would be regarded as authorities.
• Can we get a link or a glossing footnote for "firing flats"?
• Production of the Reed water tube boiler ceased in 1905: do we know what superseded it?

These are all minor points and I expect to pass GA once these are addressed. Mike Christie (talk - contribs - library) 14:13, 1 January 2018 (UTC)

Thanks for taking this on Mike Christie, and for the helpful and positive comments. Forgive me if I take a little while to get up to speed with this, apart from the residual effects of the season (for which greetings!) I haven't looked at this article properly for some months now, so there might be some digging around to do. For example, I only have 1905 for the end of production from a woefully brief page at the National Science Museum, and I suspect that this design of boiler was effectively made redundant by the Admiralty's own design of boiler, but would need to check. Cheers for now. Nortonius (talk) 19:52, 1 January 2018 (UTC)

No hurry, of course (and season's greetings to you too). And if there's no more information about why it ceased production, that's fine; I was just curious. Mike Christie (talk - contribs - library) 19:57, 1 January 2018 (UTC)

Thanks Mike. I've now attempted to address all of your points, although of course you must judge how satisfactorily! That is:

• I've expanded the lead, mostly with background information on the company, and the difference between a water tube boiler and a locomotive boiler, which seemed most helpful, and developed the main text to account for the additions.
• Almost all the information that was in those two footnotes (formerly 2 & 5) is now in the main text – I think I must have been aiming for brevity, under the influence of sparse and awkward sources!
• I've added "down-comers" to that image caption as suggested.
• About File:Water tube boiler schematic.png, I'm not sure how helpful it would be with reference to this type of boiler: although the principle is virtually the same, the differences between the boiler illustrated and the Reed boiler are many and detailed, so I think it would add an undue burden of textual explanation. Instead I've tried to clarify further in the text why the steam-generating tubes joined the top chamber below the designed water line. Have a look at the changes and let me know if you think they're adequate.
• I've added the briefest of qualifications for Maxim and Thorneycroft.
• I've changed the wording around "firing flats" to clarify what they were.
• It turns out that I have no idea what superseded the Reed boiler! I thought it might be the Admiralty's own design, but that didn't mature until the 1920s. I can only blame the sources, or my own failure to find this detail in them. For example, I shelled out for a copy of Cuthbert and Smith's Palmers of Jarrow only to find that its authors give much weight to the "social history" aspect – understandably, since the closure of Palmers in 1933–34 provided the main impetus for the Jarrow March – to the inevitable exclusion of greater detail on the company, in a volume of only 48 pages. Almost everything else in the article is the result of exhaustive searching among contemporary sources at archive.org. I'm pretty sure I'd have found this detail if it were there. It does bother me though, so I can try to focus on answering that question.

Cheers, Nortonius (talk) 18:44, 2 January 2018 (UTC)

No worries re the last point; if you find out what superseded it, of course it would be worth adding, but if the sources don't say that's fine.

With regard to the "designed water line" and the diagram I linked to, I was confused because I had thought the tubes contained steam, which meant they couldn't possibly join the dome below the designed water line -- the steam is always going to be above the water. The diagram was helpful because I realized that the tubes contain water, not steam, all the way up to some level inside the steam drum. Hence the tubes can connect below the water line. But isn't this in conflict with The lowest section of the lowest tubes of Reed boilers was originally bent into tight, "wavy" curves, also to maximise surface area, but this was discontinued by 1901 as it inhibited the flow of steam? That seems to imply that it really was steam flowing through the tubes. What am I missing?

All the other points are fine. Mike Christie (talk - contribs - library) 22:50, 2 January 2018 (UTC)

If I understand correctly, I think you're missing: "whereas the fire tube boiler consisted of a cylinder filled with water, which was heated by tubes passing through it carrying exhaust gases from a furnace, in the water tube boiler the situation was reversed, with water passing through steam-generating tubes mounted directly above the furnace" in the lead; and "while the tubes in a water tube boiler were subject only to tension from the steam and pressurised water within, a locomotive boiler's tubes were subject to compression from without", which I've just clarified in the body. And, by no means is steam always above water – watch an open pot of water boiling on a hob ...? The bubbles you see rising from the bottom of the pot to the top of the water are steam, and the same process occurs in this type of boiler, where the tubes might be said to take the place of the open pot. Once at operating temperature, the entire boiler was full of water, either in liquid form or as steam. HTH. Nortonius (talk) 23:02, 2 January 2018 (UTC)

p.s. I've also tweaked the sentence about wavy pipes to read "The lowest section of the lowest tubes of Reed boilers was originally bent into tight, "wavy" curves, also to maximise surface area, but this was discontinued by 1901 as it inhibited the flow of water and hence also steam." Nortonius (talk) 23:14, 2 January 2018 (UTC)

Reading through again it's all there; I just didn't put it together correctly. The key point I was missing was that steam is generated in the tubes, so they contain both water and steam. I'll pass this; thanks for an interesting read. Mike Christie (talk - contribs - library) 03:40, 3 January 2018 (UTC)

Great stuff Mike! For the interesting read, my pleasure; for the GA pass, thank you so much! :o) Nortonius (talk) 03:48, 3 January 2018 (UTC)

Steam dome

Andy Dingley, about this edit – I wouldn't dispute the idea that the steam dome was principally where the steam was collected, but I'm confused by the idea that it was only rarely where the steam leaves the boiler. From Steam dome, this, as I understand it, is evidently the case. And, per this source (p. 172), it seems to me strongly implied: "In the upper chamber and dome a simple but effective form of separator is fitted, which ensured freedom from priming even at the highest rates of evaporation." To me, that says that it was from the dome that steam was fed to the engines. I'm hampered in this by a severe lack of detailed sources, but would you object to a change of wording to incorporate both your meaning and mine? For example, "Steam was collected inside a dome on top of the top chamber, from which it was fed to the engines ..."? Cheers. Nortonius (talk) 23:54, 2 January 2018 (UTC)

• The point is, why is there a dome there at all, and what is its primary purpose?

The dome is there to provide a high point, above undisturbed water, in order to collect dry steam with minimal risk of carryover and priming. Steam is taken from there, but it's far from a given that this is where the pipework to the stop valve leaves the boiler's main shell. It was at one time, but as boilers became larger relative to the space they fitted into, it was more usual to take an internal pipe from inside the dome and lead it out through a more accessible piece of the steam drum.

For steam locomotives, it's usual to place the regulator itself inside the dome, but of course that's not relevant to ships.

I've no strong feelings about wording, but I think that the collection aspect should still appear first. Also is it worth mentioning that it goes to the stop valve, rather than directly to the engine? Andy Dingley (talk) 01:33, 3 January 2018 (UTC)

Ok – you are aware that there's no superheating of steam in this boiler? To that extent, I'm only interested in the fact that it appears that in this boiler, steam passed out of the confines of the boiler via the dome. I'd taken the interposition of a stop valve or regulator as a given, and probably felt that it was more relevant to the operation of the engines; so I'll happily add a word or two about that. Cheers. Nortonius (talk) 03:55, 3 January 2018 (UTC)

Who mentioned superheating? Andy Dingley (talk) 11:21, 3 January 2018 (UTC)

I'm sorry? I was just wondering where else steam might "leave" a boiler other than via the dome – I guessed that superheated steam might take a different route. But it's really no matter! Happy New Year. Nortonius (talk) 11:54, 3 January 2018 (UTC)

It leaves via the dome, but that doesn't imply that the dome has a steam pipe sticking out of the side of it. This was done for some destroyer-size boilers, but not AFAIK for the Reed. It was also very rare for steam locos - the few that do show it are quite distinctive, as they have a massive Y-shaped pipe that other locos don't.

Superheater supplies on firetube boilers were routed internally from the dome or collector to an internal header in the smokebox or combustion chamber, then through the superheater elements. On watertube boilers for ships though, they usually emerged from the boiler drum and casing, then back in to a rather separate set of elements, somewhere in the flue or nestled in the tube bank. You can clearly see them from the outside as two distinct sections. Andy Dingley (talk) 12:32, 3 January 2018 (UTC)

Understood, and yes, there's the problem: I haven't seen a single description or diagram of a Reed water tube boiler that shows the relevant arrangement, nor how feedwater entered the boiler, for that matter. The Science Museum in London has an excellent cutaway model that used to be reasonably well illustrated on the web, but they've updated their online format so the photos are gone, and the only snapshot at archive.org doesn't show them either. Although I'm sure it once did. And the only relevant detail that I would swear to is that there was no superheating. Anyway, I have no source. Hence my reluctance to say anything about steam leaving the boiler other than via the dome, which is where it was collected. If you know of a source, on the other hand ... Cheers. Nortonius (talk) 12:46, 3 January 2018 (UTC)