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Post by delaplume on Jan 16, 2019 1:58:26 GMT
Alan, does it have a superheater? Brian Hi Brian, Not yet.......... but it will have..LoL !! As per the full size it's a 3-element, single pass type....I believe it was the Swindon No. 1 at the time.........Churchward was known to be in favour of superheating in general but only}---- "sufficient to dry the steam".... A fellow Kinver club member, the late John Hurley once told me that his constant success in winning our clubs mini-Imlec was due to the high degree of superheat that he employed on his GWR and LMS 4-6-0 locos... John was an Ex-BR Steam Driver, well experienced and knew what he was talking about.. The rolling chassis is pure Peter Riche 5" gauge Star with alterations where needed..........The regulator is a plain GWR double - beat type fitted on top of the wet header... Incidentally my 5" boiler has the correct feedwater trays fitted .... Alan
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Post by delaplume on Jan 16, 2019 2:30:52 GMT
Here are the 2 wheel sets for the locomotive bogie..............These were done some time ago and are amongst some other items under wraps at the moment... I've painted the axles Red only because GWR 4073 Caerphilly Castle on display at SWINDON, Museum of Steam has it's axles thus....I could do with a look at 4003 Lode Star at York as this is a genuine Churchward locomotive... Anyone going there in the near future ??
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Post by delaplume on Jan 16, 2019 19:17:11 GMT
Hello everyone, Well------- a bit more progress to-day--------the second out of four wheelsets for the Tender bogies machined and assembled... Also, have found the 8 shorter, laser-cut compensating beams and the two laser-cut top plates as well.......These were wrapped and stored pending building at some time... Every now and then some bits and pieces come my way, usually as the result of a bit of "Horse Trading" with fellow 5" gauge GWR chaps.....Recently I aquired a GWR tender water scoop --- and a loco fall-plate....Both of these have gone straight into No.111's box 'o bits !! [
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Post by delaplume on Jan 16, 2019 19:28:00 GMT
I avoided cross water tubs in my combustion chamber too - partly because I thought the joints might be weakened by later silver soldering and the repeated expansion/contraction forces, and partly because they would have got in the way of the radiant superheaters I fitted. But, of course, what I lost as a result was the staying effect on the crown of the combustion chamber... The club boiler inspector saw the design and drew in a big X shaped stay (1/8" copper sheet, about 1' high) on top of the combustion chamber. That, in turn, meant I had to fiddle a bit to get my blower tube through the boiler in the prototypical location just under the regulator - but I got there in the end and the combustion chamber didn't deform at all under test. How have you stayed yours, without having water tubes? Malcolm Malcolm Hi Malcolm, Yes John Ellis and I discussed at some length the idea of a short combustion chamber and it was because of his approval that I then re-drew the main drawing of the firebox to incoporate it........ From the photos you can see that the flat, upper part is well stayed but the lower part --- the "smile" if viewed from the front ---- was made stayless but with double thickness copper ... This has worked very well indeed and has been tested at 200 psi with no leaks, bulges, kinks etc... The Bear originally had a set of vertical water tubes within the firebox corners but these were soon removed....
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Post by Deleted on Jan 16, 2019 19:40:15 GMT
Love the boiler Alan.... FYI, Gresley pacific's also have a short combustion chamber as shown in this drawing which may be of interest? Pete
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mbrown
Elder Statesman
Posts: 1,718
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Post by mbrown on Jan 16, 2019 22:00:05 GMT
[/quote]Hi Malcolm,
Yes John Ellis and I discussed at some length the idea of a short combustion chamber and it was because of his approval that I then re-drew the main drawing of the firebox to incoporate it........
From the photos you can see that the flat, upper part is well stayed but the lower part --- the "smile" if viewed from the front ---- was made stayless but with double thickness copper ... This has worked very well indeed and has been tested at 200 psi with no leaks, bulges, kinks etc...
The Bear originally had a set of vertical water tubes within the firebox corners but these were soon removed....[/quote]
Interesting that John Ellis seems not to have shared Martin Evans's (and others') nervousness about combustion chambers - although it sounds as if he also avoided cross water tubes. What sort of staying do you have on the flat top of the combustion chamber? It's not quite evident in the photo (or have I missed something?). I bet it will steam like a good'un!
I didn't know the Bear had water tubes in the firebox - I am not sure I can envisage how they ran - top of the crown sheet to the lower part of the tubeplate??
Malcolm
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Post by delaplume on Jan 16, 2019 23:07:44 GMT
Love the boiler Alan.... FYI, Gresley pacific's also have a short combustion chamber as shown in this drawing which may be of interest? Pete Hi Pete, First let me say how glad I am to hear you're on the mend !!...........nothing worse than an illness that lingers on, is there ?? Many thanks for the FS drawings----interestingly we ( Nigel Greseley, John Ellis, Myself plus a few others ) all seemed to have opted for the short version......In our case it was a combination of trying to reduce those long tubes, plus making the firebox area a better volume to support combustion.... Although John had sketched out the general ideas at one of our "Brainstorming" sessions it was down to me to actually implement any changes on the main boiler development sheet.....I then showed this to John, and if he was happy with it I then transferred the changes onto the prototype sheet No 001..........Later, when all was done and approved that sheet No.001 became Production Master Sheet 001 ...........The whole of the Boiler design & development phase took place over a 3-year period.......This included 2 visits (by appointment) to York Museum reference library for R & D searches...... Each time I look at any of G.J's drawings of The Bear I still have to remind myself that his Drawing Office were busy beavering away producing them just after the turn of the Century ( 19th to the 20th that is ) ... Did their slide rules suffer from the "Millenium Bug" I wonder ??........LoL !!
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Post by Deleted on Jan 16, 2019 23:24:29 GMT
Glad you like the drawing Alan, I have a few of these now, this particular drawing I can scale from to work out the position of the Fire-arch support which I'll talk to Paul about once he makes a start on the boiler. Yes it's no fun being ill, you get to the stage when you think it's never going to end..lol Loving the updates on 'The Great Bear', she's going to be a beaut ... Pete
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Post by delaplume on Jan 16, 2019 23:25:59 GMT
Quote}----"Interesting that John Ellis seems not to have shared Martin Evans's (and others') nervousness about combustion chambers - although it sounds as if he also avoided cross water tubes. What sort of staying do you have on the flat top of the combustion chamber? It's not quite evident in the photo (or have I missed something?). I bet it will steam like a good'un!
I didn't know the Bear had water tubes in the firebox - I am not sure I can envisage how they ran - top of the crown sheet to the lower part of the tubeplate??..."
Hello Malcolm,
Initially it was John's suggestion that a combustion chamber go in but he was quick to qualify that it would be MINUS any water tubes........As most of you may be aware cross-water tubes, as well as promoting good water circulation, also act as stays for the combustion chamber BUT}--- are a real hindrance should you need to repair or change flue tubes in the future..............By adopting the "no-cross tube" chamber we now have an increase in combustion chamber volume and good tube accessibility...
Staying}--- There is an extension of the firebox crown stays for the top of the chamber..........The curved underside was made double thickness to increase strength.....
I've posted the top of the boiler photo where you can clearly see the stays for the combustiom chamber
Hope that's of help ??
I shall be exhibiting the Boiler at this years Manchester show on the Oswestry & North Shropshire Club stand...
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Post by delaplume on Jan 17, 2019 0:23:20 GMT
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Post by delaplume on Jan 17, 2019 0:40:51 GMT
Just as I was putting the bogie bits away I "found" these little rascals...........Now at this point I have to remind you good folk that my main thrust in Model Engineering is Repair & Restoration of any ME item in distress....This can be for £££ or just for the love of it......And as part of that I make free use of any Engineering Contractors who fit my needs.. These cylinders are a case in point.........Designed by the late Peter Riche, castings marketed by Polly Engineering and basic machining by John Dunn Engineering..........the idea is that I then go on to do the details and finishing work.... I was not at all happy with the one port hole that was meant to suffice so decided to have a proper annulus feeding a number of ports ( As per full size practice )....... John Dunn and I discussed the design parameters and then he machined and assembled the liners with ports...
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Post by delaplume on Jan 17, 2019 0:48:18 GMT
Here's a full size GWR Hall class cylinders for comparison.......This is one of the new castings for 4930 Hagley Hall at the SVR.....It's "As cast" so is minus the liners..
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Post by delaplume on Jan 17, 2019 0:52:54 GMT
--------- and here's the old one as removed...You can clearly see the liner with the ports in---------
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mbrown
Elder Statesman
Posts: 1,718
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Post by mbrown on Jan 17, 2019 7:28:17 GMT
Thanks for the photo of the combustion chamber staying Alan - very useful. I am coming round to the idea of rod crowns tags for my next boiler - the plate stays must impede circulation by comparison.
Those cylinder castings are simply beautiful... in both sizes!
Malcolm
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Post by Deleted on Jan 17, 2019 9:41:42 GMT
Love the cylinder castings Alan, they capture the full-size castings nicely..
Pete
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Post by delaplume on Jan 17, 2019 10:50:13 GMT
Love the cylinder castings Alan, they capture the full-size castings nicely.. Pete Hi Pete, I just hope they work OK !!.....I'll be sticking to convention with Cast Iron main piston & rings, with stainless steel piston valve bobbin & iron rings.... You'll notice that there is a slightly bigger than scale gap between the ports on The Bear's casting......this is to allow for pegging the rings against rotation.... The bobbin will be a single item secured on its' stainless shaft in a "floating" mode as it were....... Notice that there are the correct 3 mounting stubs for cylinder drain cocks ( 1 each end and 1 for the steam space between the bobbin heads )...
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Post by Deleted on Jan 17, 2019 12:12:49 GMT
I hadn't noticed the steam stubs Alan, nice touch, sir... I haven't made a decision on rings for 4472 yet, I'll need to take a closer look at this later in the year...
Cheers
Pete
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Post by ettingtonliam on Jan 17, 2019 12:38:52 GMT
Here's a full size GWR Hall class cylinders for comparison.......This is one of the new castings for 4930 Hagley Hall at the SVR.....It's "As cast" so is minus the liners.. Would these be from Boro Foundry by any chance?
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Post by delaplume on Jan 17, 2019 21:58:13 GMT
Here's a full size GWR Hall class cylinders for comparison.......This is one of the new castings for 4930 Hagley Hall at the SVR.....It's "As cast" so is minus the liners.. Would these be from Boro Foundry by any chance? Apparently it's the Shakespeare Foundry, Preston, Lancs........... Here's the Hagley Hall link}----- www.4930hagleyhall.org.uk/news/news.html
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Post by delaplume on Jan 17, 2019 22:29:55 GMT
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