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Post by andrewtoplis on May 17, 2021 12:36:06 GMT
New arrival in the household - found in a local auction amongst piles of old Hornby (and a tasty but over-my-budget 5" Stirling Single). She looked very ratty in the auction pictures, but there is a nice engine under the grime and surface rust which is cleaning up with a little wire wool. After putting the picture on facebook in the LBSC group the previous owner identified himself as danlank of this parish... It's on my shelf for the present, but I'll think about where to go with it.
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Post by andrewtoplis on Jul 29, 2021 16:57:48 GMT
Hi All, I've had a chance to look over the loco (work is very busy at the moment). The good news: -The loco turns over happily with no tight spots -I've managed to free up the blower which was stuck solid using some WD40; it is still a bit stiff but useable. -I removed the safety valve, filled the boiler with water and left it for some time without leakage (albeit at no pressure). -It is missing a few bits but these are simple pieces to make again like the hand pump handle. The big question: The backhead fittings appear to be soldered on! Has anyone seen this before? Would it be turned down flat for a boiler ticket? How would one test it with these in place? PS it isn't as dirty as it looks here, I promise! Thanks in advance, Andy
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JonL
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Post by JonL on Jul 29, 2021 20:24:04 GMT
Isn't it funny how good modern camera phones make something that looked clean to the naked eye look like a metal detectors find?
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Post by Nigel Bennett on Aug 1, 2021 13:10:01 GMT
LBSC's boiler for Canterbury Lamb didn't have any bushes in the backhead. All sorts of bits and pieces were soft-soldered to the boiler. Try scratching the fillets under the fittings and see what manner of material is revealed. I would imagine they're screwed in but have been soft-soldered to caulk them. I would scrap the boiler and build a new one if it was mine. And how de-zincified are the boiler fittings?
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Post by andrewtoplis on Aug 2, 2021 19:49:28 GMT
Thanks for your thoughts Nigel.
I'll scratch the paint off as you suggest and post a picture tomorrow.
I thought that it looked like needing a new boiler, and factored this I to the price I paid. In at the deep end for a newbie!
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Post by chris vine on Aug 2, 2021 20:50:40 GMT
On the other hand:
This may not be a locomotive that you will steam very often, especially as it won't be very good at hauling lots of passengers etc.
For private use, maybe you could give it a hydraulic test to twice working pressure and then only run it at perhaps half working pressure - something like 30 psi. By that I mean set the safety valve to that pressure.
I don't think it has an injector, so it can work at a lower pressure to demonstrate that it runs.
I am not intending to you take dangerous risks, and you could always do this with an experienced model engineer who has a good sense about these things. Then at least you would know that it is a working model, even if it doesn't work very hard or often.
All best wishes Chris.
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Post by andrewtoplis on Aug 3, 2021 11:05:37 GMT
Thanks Chris, that is an interesting idea. Yes you are correct, it will not be anyone's go-to passenger hauler, but I have had some invites from friends to visit their club tracks and thought it would be fun to go touring with it. Presumably this needs a full boiler cert, but it could be one at lower pressure than the 80 pounds it was designed for (as long as it would still pull me, I'm six foot plus!).
Just as an aside, you and I met earlier in the year, I was firing the ivatt tank on the IOW when you were filming on the footplate!
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stevep
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Post by stevep on Aug 3, 2021 12:20:16 GMT
At the risk of being contentious, isn't the point of the hydraulic test, to twice working pressure, to prove that the boiler is sound. If it passes that test, then steaming it to the designed working pressure should be fine.
If there was dezincification on the fittings, leading them to being unsafe, they should fail in the test. If they don't, then they should be OK to use.
I agree that boilers were, in times past, built to different standards to those we use today, but the validity of the hydraulic test still holds. And of course, the hydraulic test should be repeated at the prescribed intervals to continue to provide assurance that the boiler is safe.
If you wish to visit other tracks, you will need a boiler certificate, and only by going through the whole boiler testing process will you get one.
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Post by keith1500 on Aug 3, 2021 21:21:19 GMT
I think as boiler examiner you would have to take a view of the overall condition of the boiler and whether it poses a threat or not. This would be regardless of it passing said tests.
Example. Club loco has boiler off inspection and will pass hydraulic test. However the centre group of tubes are so thin that if one should fail it is like the fail spectacularly and dump the contents of the boiler rapidly, not just leak. This in turn may well send the contents of the fire out of the cab! Not nice.
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Post by springcrocus on Aug 3, 2021 21:48:35 GMT
An interesting situation. I agree with Keith that the opinion of an an experienced boiler inspector is a valuable thing, but so is a specified test. If a boiler inspector can decide that the results of a hydraulic test are to be discounted, then what is the point of the test at all?
Those of us with little or no experience of the resilience of boilers need to have a fixed point of reference to measure our efforts against. At present, this is the 2X hydraulic test which, if successful, suggests that the boiler is capable of withstanding an internal pressure twice that for which it will be expected to withstand in normal operation.
At which point is a personal opinion considered to have more relevance than a scientifically-controlled test?
I'm 100% with stevep on this one, otherwise any form of testing seems to be a waste of time.
Regards, Steve
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Post by chris vine on Aug 3, 2021 21:59:16 GMT
Hi Andrew,
I hadn't put two and two together, but thank you for a very memorable run on the footplate with you on the IoW!! Certainly, firing full size, you are aware of the risks of boilers.
While a hydraulic test is certainly scientific, I don't think you can ask a boiler inspector to do this "blind". It is clear that he will use his eyes to make an assessment of the boiler.
One area which isn't really covered by the 2 x test is the strength of the fittings, especially if made of brass and very old. The pressure forces are tiny compared to the forces of screwing them shut or maybe handling slightly roughly.
Chris.
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Post by John Baguley on Aug 3, 2021 22:40:00 GMT
One area which isn't really covered by the 2 x test is the strength of the fittings, especially if made of brass and very old. The pressure forces are tiny compared to the forces of screwing them shut or maybe handling slightly roughly. Chris. Chris,
The 2X test is purely for the boiler shell and as such does not include the fittings. The 1.5X test after that does include the fittings. Obviously, as it seems that the fittings have been 'caulked' and cannot be removed easily then it is not now possible to do the shell test on it's own.
Have you scraped the paint off yet Andrew? It would be interesting to see what has been used to 'caulk' the fittings. The fillets seem very large for Comsol which runs like water when it melts making it very difficult to build up a fillet so I would suspect something like plumbers solder or even braze.
My experience is that brass fittings below the water line do tend to suffer badly from dezincification but those exposed to just steam seem less affected.
John
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Post by Nigel Bennett on Aug 4, 2021 13:42:14 GMT
Taking things to perhaps a ridiculous conclusion, if you solder (or braze) brass fittings to a boiler, then the fitting is "permanently attached" like a boiler bush, and technically the boiler could be deemed to be partly made of brass. The Boiler Regs only cover copper and steel boilers...
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Post by John Baguley on Aug 4, 2021 16:12:14 GMT
Taking things to perhaps a ridiculous conclusion, if you solder (or braze) brass fittings to a boiler, then the fitting is "permanently attached" like a boiler bush, and technically the boiler could be deemed to be partly made of brass. The Boiler Regs only cover copper and steel boilers... Yes, I condemmed a friends 5" King boiler because the original builder had made the backhead and throatplate from 1/4" brass. He wasn't very happy!
It would have no doubt lasted for years but not allowed nowadays.
John
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uuu
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Post by uuu on Aug 4, 2021 16:33:19 GMT
Taking things to perhaps a ridiculous conclusion, if you solder (or braze) brass fittings to a boiler, then the fitting is "permanently attached" like a boiler bush, and technically the boiler could be deemed to be partly made of brass. The Boiler Regs only cover copper and steel boilers... What about bronze bushes then? By the same argument, these are not allowed either. Wilf
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Post by Nigel Bennett on Aug 4, 2021 16:53:19 GMT
Interesting point, Wilf! However, there's only about 12% tin in bronze, so I presume its "coppery" enough to pass muster - and it doesn't suffer dezincification. In any case, as we all know, custom and practice have specified bronze bushes over the years. Then there is the use of Monel as stays...
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Post by andrewtoplis on Sept 2, 2021 11:00:01 GMT
A quick update
In the last few weeks, my local club (East Grinstead Model Engineers) has re-opened and I've taken the loco along. As I guess any 'new' loco does, it generated a fair bit of interest and they gave it a good coat of looking at; the general consensus was that it is an older model and the side stays on the firebox are a bit sloppily done (see the picture at the top of the thread), but we agreed to test it and see.
So, last evening, we hooked up an air line and propped the loco up on some wood. I'm pleased to say it ran reasonably happily, though much better in reverse than forward. Forward produced quite some vertical movement in the rear axle, probably because the springs are very weak and the guys thought the valve gear needs adjusting. I'll upload a clip shortly. Next step was to connect the boiler to the club testing gear and put some hydraulic pressure in and amazingly she went up to 150psi with no leaks from the boiler, though we had some minor drips through the blower and the regulator which may take up under steam and the boiler inspector said he was ok with them at this stage as we can clearly identify the source. I'm quite pleased with my auction gamble so far!
So, short term plan is to give it a steam test next week. I'll clean out the blower and order a new pressure gauge as well as the current one is hard to read.
Medium term plan is to remove the boiler from the chassis and give it the formal hydraulic test at 160psi. Whilst the boiler is off, remove and re-turn the wheels to give a better profile, replace the springs and adjust the valve gear. The smokebox has a choke point where the opening into the square box part is restricted, this could be opened out to help the flow of gases. For cosmetics I'll remove the drivers footstep and add a sheet of boiler cladding to hide the untidy firebox sides before reassembly. At that point it will be good to go!
That said, we are moving house in October so I don't want to take it apart just yet as I'll only end up losing the bits...
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Post by andrewtoplis on Sept 10, 2021 8:53:16 GMT
Next update..
Well, we tried to steam it up but we struggled! External blower fitted, charcoal fire built up, coal being added slowly and all seemed well. 30 pounds on the clock and we tried to switch to the loco blower. The blower sounded a bit wet and the fire died rapidly. Trying to rescue the fire proved difficult so eventually we pulled the pin out, cleaned the grate and decided we would try again next week.
So, the blower wouldn't provide enough draw for the fire. On further inspection the blower does seem to align with the chimney, however the chimney itself if very restricted by the way blast pipe joins into it (on this loco it comes in part way up the chimney). Much head scratching ensued after this - do any CL builders have any advice? I'll get a picture up later.
A very interesting experience at any rate, the fire on this loco seemed to need constant attention.
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Post by Nigel Bennett on Sept 10, 2021 9:05:39 GMT
Stupid question - had you over-filled the boiler so the blower was dragging water from it rather than steam? It's very pleasing that the boiler is holding pressure and not leaking. Oh - and good luck with the house move!
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Post by andrewtoplis on Sept 10, 2021 10:56:49 GMT
Pictures down the chimney - apologies for the poor quality but you can see how much of an obstruction this potentially is... And the drawing from the ME articles all those years ago
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