spikey Posted August 9, 2022 Share Posted August 9, 2022 If you look down a GWR chimney from the top, is the bore iron all the way down, or is the top of it copper? I've always wondered whether the copper part is a solid copper "extension" so to speak, or whether it's a "sleeve" fitted over the top part of the iron casting ... Link to post Share on other sites More sharing options...
Steamport Southport Posted August 9, 2022 Share Posted August 9, 2022 Any use? https://www.gwra.co.uk/auctions/gwr-castle-class-single-chimney-ex-5010-restormel-2015nov-0205.html https://www.gwra.co.uk/auctions/gwr-castle-class-single-chimney-ex-5010-restormel-2015jul-0311.html https://www.gwra.co.uk/auctions/gwr-copper-cap-top-half-chimney-from-gwr-castle-70-2017nov-0165.html Jason 1 Link to post Share on other sites More sharing options...
RMweb Premium John Isherwood Posted August 9, 2022 RMweb Premium Share Posted August 9, 2022 23 minutes ago, spikey said: If you look down a GWR chimney from the top, is the bore iron all the way down, or is the top of it copper? I've always wondered whether the copper part is a solid copper "extension" so to speak, or whether it's a "sleeve" fitted over the top part of the iron casting ... My understanding is that the 'copper cap' was, in fact, thin copper sheet formed around the cast iron inner - but I may be totally wrong. If it was solid copper, it would have been an expensive embellishment. CJI Link to post Share on other sites More sharing options...
41516 Posted August 9, 2022 Share Posted August 9, 2022 (edited) If you search for pictures of Hagley Hall on test runs on the SVR last month, it was running without the chimney cap - An example. Edited August 9, 2022 by 41516 spelling 1 Link to post Share on other sites More sharing options...
Wickham Green too Posted August 9, 2022 Share Posted August 9, 2022 Ah - is that why God's Wonderful Railway put caps on their chimneys ? ................ 'cos they were damned ugly without ! 2 1 2 Link to post Share on other sites More sharing options...
Paul H Vigor Posted August 9, 2022 Share Posted August 9, 2022 53 minutes ago, Wickham Green too said: Ah - is that why God's Wonderful Railway put caps on their chimneys ? ................ 'cos they were damned ugly without ! And for the same reason I wear a hat! 🥸 1 2 1 Link to post Share on other sites More sharing options...
Nearholmer Posted August 9, 2022 Share Posted August 9, 2022 Definitely copper sheet sleeves. Some years ago I saw one on the ground at Didcot partially dismantled. Link to post Share on other sites More sharing options...
Rivercider Posted August 10, 2022 Share Posted August 10, 2022 8 hours ago, Nearholmer said: Definitely copper sheet sleeves. Some years ago I saw one on the ground at Didcot partially dismantled. When I enjoyed the excellent guided walk around Didcot GWS in 2018 I took this photo. Didcot GWS 29/7/2018. cheers 4 1 Link to post Share on other sites More sharing options...
spikey Posted August 10, 2022 Author Share Posted August 10, 2022 Thanks chaps. So it's a sleeve. I wonder how thick it is. I assume it's a casting but could it be spun copper with a backing? Link to post Share on other sites More sharing options...
RMweb Premium rab Posted August 10, 2022 RMweb Premium Share Posted August 10, 2022 As previously mentioned, a solid copper casting would be expensive. AFAIK in is copper sheet, spun into the correct shape. 1 Link to post Share on other sites More sharing options...
spikey Posted August 10, 2022 Author Share Posted August 10, 2022 2 hours ago, rab said: ... AFAIK in is copper sheet, spun into the correct shape. In which case it must be spun in two parts, so the obvious question has to be how are they joined? Does the top part just overlap the bottom and be a good fit, or what? Link to post Share on other sites More sharing options...
Wickham Green too Posted August 10, 2022 Share Posted August 10, 2022 To misquote Eric Morecambe - you can see the join ! 1 Link to post Share on other sites More sharing options...
2251 Posted August 10, 2022 Share Posted August 10, 2022 1 hour ago, spikey said: In which case it must be spun in two parts, so the obvious question has to be how are they joined? Does the top part just overlap the bottom and be a good fit, or what? Traditional practice would probably have been to spelter braze them together unless the two parts would need to come apart. 1 Link to post Share on other sites More sharing options...
didcot Posted August 10, 2022 Share Posted August 10, 2022 (edited) I had a copper cap spun for the steam roller I once owned. It was about 1/8 " thick. I should add it was a two piece spinning split at the outer edge. The bottom portion was rolled over the top holding it in place. No braze used. They use a wooden former, so it has to be done in two halves to get the former out. I did see the Railmotor cap up close a few years ago whilst it was being repaired and it looked a similar construction. Edited August 10, 2022 by didcot 2 Link to post Share on other sites More sharing options...
Artless Bodger Posted August 10, 2022 Share Posted August 10, 2022 How long has metal spinning been used? Early on wouldn't it be a coppersmithing job to hammer it to shape on a former? Could you spin an oval cap for a double chimney anyway? Just asking as I've seen some interesting old craft making films for things like tinsmithing, basic tools and expertise. Link to post Share on other sites More sharing options...
2251 Posted August 10, 2022 Share Posted August 10, 2022 19 minutes ago, Artless Bodger said: How long has metal spinning been used? Early on wouldn't it be a coppersmithing job to hammer it to shape on a former? Could you spin an oval cap for a double chimney anyway? Just asking as I've seen some interesting old craft making films for things like tinsmithing, basic tools and expertise. The basic idea dates back to antiquity and does not require much in the way of complex equipment (although it does need a good deal of skill). This video gives the idea. 3 Link to post Share on other sites More sharing options...
Artless Bodger Posted August 10, 2022 Share Posted August 10, 2022 Thank you 2251 - I never knew it went back so far, presumably the ancients used a pole lathe of some sort, like the furniture bodgers? Looks like the man in the film had spun his own hat. 1 1 Link to post Share on other sites More sharing options...
didcot Posted August 10, 2022 Share Posted August 10, 2022 I think a double chimney would have to be hand beaten over 2 different formers. Top and bottom. 1 2 Link to post Share on other sites More sharing options...
2251 Posted August 10, 2022 Share Posted August 10, 2022 1 hour ago, Artless Bodger said: Thank you 2251 - I never knew it went back so far, presumably the ancients used a pole lathe of some sort, like the furniture bodgers? Looks like the man in the film had spun his own hat. Presumably reciprocating power in some form -- a pole, bow, cord pulled back-and-forth, etc. I think it is right to say that there is no real evidence that wheels were applied to bring continuous motion to lathes until the Middle Ages. 1 Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted August 10, 2022 RMweb Premium Share Posted August 10, 2022 I once watched Aluminium kettles being made on a spinning lathe. (Swan Brand , Birmingham) This sort of style: The former was made of wood in several segments as the spun kettle body overlapped the former when finished and the former needed to be removed. 3 Link to post Share on other sites More sharing options...
Rivercider Posted August 15, 2022 Share Posted August 15, 2022 On Sunday while walking around Didcot on the excellent tour arranged by Drew (Castle) we went past the chimneys again, this time in sunshine. They are all chimneys off Castle class. Didcot GWS 14/8/2022 cheers 2 Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted August 15, 2022 RMweb Premium Share Posted August 15, 2022 Anyone know why the double chimney doesn't have a capuchon? Or indeed how much difference they make? Also what is the third hole in the double chimney for? Link to post Share on other sites More sharing options...
Miss Prism Posted August 15, 2022 Share Posted August 15, 2022 The third hole is for the blower. Good thread on Castle double chimneys 1 Link to post Share on other sites More sharing options...
Michael Hodgson Posted August 15, 2022 Share Posted August 15, 2022 1 hour ago, Miss Prism said: The third hole is for the blower. Good thread on Castle double chimneys So how should Tri-ang have screwed to body to the chassis then ? 2 Link to post Share on other sites More sharing options...
Marshall5 Posted August 15, 2022 Share Posted August 15, 2022 (edited) 2 hours ago, Miss Prism said: The third hole is for the blower. I don't think so as the blower ring would be inside the smokebox. Would the 3rd hole not be for the vacuum brake ejector exhaust? Ray. Edited August 15, 2022 by Marshall5 Link to post Share on other sites More sharing options...
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