|
|
Post by andrewtoplis on Sept 10, 2021 11:06:30 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! Hi Nigel, thanks, hopefully the move will go reasonably smoothly...room for an up and down track in the new place too... Yes, the boiler seems to hold pressure fine, we just need to sort out these front end questions! It seems that we may have carried water over the first time, but a little later on the blower seemed to be ok, we'll try again next week and see. The gauge glass is tricky it seems to go from empty to full and then empty extremely quickly, if I was building a new boiler I'd see if I could move it to the side and put a taller gauge in somehow. |
|
|
|
Post by dhamblin on Sept 10, 2021 21:30:09 GMT
Our society owns a Canterbury Lamb built by a late member in the 1950s - in the few times it was steamed in 2019 it was a bit fickle as to whether the fire could be kept going. The chimney and smokebox is a push fit if I recall correctly and I wonder whether it suffers from the same problem as a poorly sealed smokebox on a more conventional boiler / smokebox design.
Regards,
Dan
|
|
|
|
Post by gingerneer on Sept 13, 2021 9:23:29 GMT
Good to see another Canterbury Lamb. Makes me want to dig her out of the storage box and have a steam up!
Mine (acquired mostly complete) took me about 6 months tinkering and practice to figure out how to steam it. Great fun, but it happens is a blink of an eye. One of the mod i did was to change the blower to a fitting on the pull out smoke box to keep the aliment of blower to the chimney. I also cut the chimney in 2 just above the blast nozzle to making cleaning easier. Even when runing i have the blower cracked. She runs well if you stay above 60 PSI any thing under that you need to start thinking about what you doing. Firing just a shovel at a time little and often, you can over fire and smother the fire. Keep the fire hot and water right up in top nut.
Any gradients have to be planed for, i find with planning traction effort is the liminting factor, i just push down on the boiler.
Great fun!
With out teaching you to suck eggs
Just to get it in steam, i use small almost grain size charcoal moist not soaking in white sprit or paraffin.
Meths burns cleaner, but its difficult to see it burning and easy to set light to the soaked charcoal!
My blower is a small 3 volt motor unit running on 2 AA battery's. Early on when i was first steaming i was using a large blower, it just seemed to put the heat and bits of the fire through.
Once a nice thin covering of moist charcoal is burning on the grate, i will change to same size dry charcoal. don't rush the fire, i look for an orange glow before adding more. Changing over to coal can be tricky, but i wait until 30-40 psi with a good depth of charcoal burning through, adding the coal a couple of grains a time 1/2 a shovel at a time. Hopeful the pressure is rising, the blower can be adjusted so it does not pull the fire apart, get the water up in top nut with lots of short pumps rather than a long pumping session, you can see the pressure dipping almost with each pump full of water at times.
The front end or rather lack of any finesse with the gas flow limits the boiler. My current loco (a Chimera) uses a Canterbury Lamb boiler married to a regauged Southern Maid chassis (not exactly the same but near enough cylinder bore, but smaller wheels). While improvements could still be made with the exhaust pipe work. She steamed well, almost docile compare to the Lamb.
A link to a clip of the Lamb running around Isle of Wight's ME track
Regards
William
|
|
|
|
Post by ettingtonliam on Sept 13, 2021 20:02:32 GMT
That chimney looks well coked up inside. Doesn't look to be anything like the clearance around the blast pipe that the drawing would suggest. Locomotion is the same, but, if anything, worse because the exhaust pipes both come into the chimney, but from opposite sides. The chimney is made in 2 parts, with a threaded joint just above blast pipe level, making cleaning out round the nozzle relatively easy
|
|
|
|
Post by andrewtoplis on Sept 14, 2021 16:36:47 GMT
Our society owns a Canterbury Lamb built by a late member in the 1950s - in the few times it was steamed in 2019 it was a bit fickle as to whether the fire could be kept going. The chimney and smokebox is a push fit if I recall correctly and I wonder whether it suffers from the same problem as a poorly sealed smokebox on a more conventional boiler / smokebox design. Regards, Dan Thanks Dan - I think the seal is reasonably good on this one, a "tight, sliding fit" indeed. But yes - a bit of a design flaw perhaps. Any tips your guys had much appreciated! |
|
|
|
Post by andrewtoplis on Sept 14, 2021 16:53:28 GMT
Good to see another Canterbury Lamb. Makes me want to dig her out of the storage box and have a steam up! --snip-- Regards William Thanks William - I'll have another go next week as we might have just jumped the gun taking the blower off too soon, and this was a very vigorous blower too. I'll try again soon and follow your advice, much appreciated. I'd be intrigued to see your blower and smokebox mods if you have the box out at some stage, the club guys did suggest cutting the chimney in half to allow access to the blastpipe end. |
|
|
|
Post by andrewtoplis on Sept 14, 2021 16:54:36 GMT
That chimney looks well coked up inside. Doesn't look to be anything like the clearance around the blast pipe that the drawing would suggest. Locomotion is the same, but, if anything, worse because the exhaust pipes both come into the chimney, but from opposite sides. The chimney is made in 2 parts, with a threaded joint just above blast pipe level, making cleaning out round the nozzle relatively easy Thanks Liam - yes the chimney looks almost blocked doesn't it! I'll try a few more test steamings and go from there...wish me luck ! |
|
|
|
Post by chris vine on Sept 15, 2021 17:04:14 GMT
An old friend built one of these in 7.25" gauge. It still goes brilliantly.
However, one day he just couldn't get it to steam. Eventually we worked out that there was a layer of oily soot in the chimney. It wasn't that thick, but the gap round the blast pipe is quite small and the gas flow area had been halved. A quick clean out and all was restored.
Chris.
|
|
|
|
Post by andrewtoplis on Oct 14, 2021 12:08:10 GMT
Quick update
Loco now has new water gauge glass and new pressure gauge and is ready for a steam test next week - hopefully we have more luck than the last one.
I've also changed the overly bouncy springs for a much stiffer set - is there any advice how much these need to be tightened? It is done pretty much 'by eye' at the moment and the loco sits nicely level, but my eye isn't very experienced about these things!
Pictures to follow next week.
Andy
PS just as an aside - I am finding the local club of immense benefit - not just the advice and facilities but it is great to be able to put a couple of hours properly focussed time into this, I'm really enjoying the hobby.
|
|
|
|
Post by chris vine on Oct 14, 2021 13:30:51 GMT
Hi Andrew,
For a small locomotive like this, I am sure that by eye will be plenty good enough.
Maybe just lift each wheel with your fingers to check that there is about the same load on each. It is possible to have it level but with diagonal wheels with very different loads on them!!
Chris.
|
|
|
|
Post by Roger on Oct 17, 2021 18:07:22 GMT
Quick update Loco now has new water gauge glass and new pressure gauge and is ready for a steam test next week - hopefully we have more luck than the last one. I've also changed the overly bouncy springs for a much stiffer set - is there any advice how much these need to be tightened? It is done pretty much 'by eye' at the moment and the loco sits nicely level, but my eye isn't very experienced about these things! Pictures to follow next week. Andy PS just as an aside - I am finding the local club of immense benefit - not just the advice and facilities but it is great to be able to put a couple of hours properly focussed time into this, I'm really enjoying the hobby. You're more than welcome to come and use my axle weighbridge which will show you what's on each wheel in real time. |
|
|
|
Post by andrewtoplis on Oct 20, 2021 14:41:24 GMT
Quick update Loco now has new water gauge glass and new pressure gauge and is ready for a steam test next week - hopefully we have more luck than the last one. I've also changed the overly bouncy springs for a much stiffer set - is there any advice how much these need to be tightened? It is done pretty much 'by eye' at the moment and the loco sits nicely level, but my eye isn't very experienced about these things! Pictures to follow next week. Andy PS just as an aside - I am finding the local club of immense benefit - not just the advice and facilities but it is great to be able to put a couple of hours properly focussed time into this, I'm really enjoying the hobby. You're more than welcome to come and use my axle weighbridge which will show you what's on each wheel in real time. Many thanks Roger, I'll bring it along the week after next if there is a day that suits you? I've got a blockade on at work next week that will keep me busy Andy |
|
|
|
Post by Roger on Oct 20, 2021 20:24:37 GMT
You're more than welcome to come and use my axle weighbridge which will show you what's on each wheel in real time. Many thanks Roger, I'll bring it along the week after next if there is a day that suits you? I've got a blockade on at work next week that will keep me busy Andy Hi Andy, If you want to just text me when you're thinking of coming a day or two before, then I should know what I'm doing. I try not to be too busy these days. |
|
|
|
Post by andrewtoplis on Oct 21, 2021 12:14:11 GMT
Thanks Roger, will do!
|
|
|
|
Post by andrewtoplis on Oct 21, 2021 12:22:25 GMT
So, an update from the second steam test.
Last night we put the loco onto the steaming stand again and built the fire up with charcoal, I was trying to do things nice and slow, gradually moving on to coal and seemingly not getting anywhere! So the fire died down a bit, at which point the boiler inspector took a look and we used a little charcoal to get it going again. Once we could see some decent flames it was back on to coal, again without much result. So the inspector took the shovel and bailed in a ton of coal, filling the box up to the door...at which point the loco took off and steamed its head off, blowing off happily and sitting with its own blower keeping pressure easily! Great news.
However, the water gauge behaves bizarrely, one minute being full and the next just disappearing! Next step is to take the gauge apart and make sure the passages into the boiler are fully clear, then perhaps look at a different gauge arrangement...
More to come...
|
|
|
|
Post by Roger on Oct 21, 2021 18:38:04 GMT
So, an update from the second steam test. Last night we put the loco onto the steaming stand again and built the fire up with charcoal, I was trying to do things nice and slow, gradually moving on to coal and seemingly not getting anywhere! So the fire died down a bit, at which point the boiler inspector took a look and we used a little charcoal to get it going again. Once we could see some decent flames it was back on to coal, again without much result. So the inspector took the shovel and bailed in a ton of coal, filling the box up to the door...at which point the loco took off and steamed its head off, blowing off happily and sitting with its own blower keeping pressure easily! Great news. However, the water gauge behaves bizarrely, one minute being full and the next just disappearing! Next step is to take the gauge apart and make sure the passages into the boiler are fully clear, then perhaps look at a different gauge arrangement... More to come... That's great progress. I've found that most of the locomotives I've driven like a deep bed of coal. I seem to recall that there can be issues with the way the fittings protrude inside the boiler. Perhaps someone can refresh my memory on what the problem is? |
|
mbrown
Elder Statesman
Posts: 1,718
|
Post by mbrown on Oct 21, 2021 19:17:43 GMT
You are right Roger, although I can't remember which thread the discussion appeared on.
I had the problem on my 2.5"g Bagnall 0-4-2T. I hadn't appreciated that the threaded part of the bottom water gauge fitting went so deep into the narrow water space between the backhead and the rear of the firebox that the opening to the water gauge was quite close to the firebox. Bubbles of steam, forming on the firebox plate, entered the water gauge and led to very unreliable readings. After trying to live with this for too long, I guessed the problem, shortened the fitting, and got much more stable readings.
There can be other reasons for fluctuating water levels, of course, but the problem of over-long water gauge fittings doesn't seem to be widely recognised.
Hope this helps.
Malcolm
|
|
|
|
Post by ettingtonliam on Oct 21, 2021 19:26:04 GMT
That sounds a likely explanation, Malcolm, and if so one that doesn't take long to rectify. I seem to recall that in full size, restrictions in the water gauge passage ways tended to cause sluggish movement, not rapid fluctuations which seems to be what is happening here.
|
|
|
|
Post by andrewtoplis on Oct 21, 2021 19:51:42 GMT
Hi guys,
Yes Liam is right, congested steam and water passages give a 'stiff' movement rather than a springy one as it restricts the flow in and out of the glass.
This glass seems to have an air bubble when the boiler is first filled, but this can be got rid of easily. It will then fill up and stay full, then suddenly empty in the blink of an eye and stay empty even though the boiler is full up to the safety valve!
We couldn't think of an obvious explanation...
|
|
|
|
Post by andrewtoplis on Nov 4, 2021 10:18:26 GMT
I've not spent much time on the loco in recent weeks, but problems continue with the water gauge which just doesn't reflect what is going on in the boiler. After stripping it down as far as possible, we've poked through the passageways and can put wire straight through into the boiler space, so both passageways are confirmed open, but the water doesn't seem to behave as it should.
Next step is to get a bit more drastic and gently heat the backhead with a view to removing the solder around the water gauge fittings, take the fittings out and see what this reveals.
We are also toying with the idea of modifying things to fit a turret, allowing for a much taller water gauge and the pressure gauge and blower take-offs to come from there instead. This hasn't been fleshed out in any detail, we'll try the above step first!
|
|
