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Post by Deleted on Sept 18, 2014 22:34:57 GMT
-----------------speechless, eh ?? this clip of 5043 on the same run is perhaps even more impressive! www.youtube.com/watch?v=YfHdpMWV3cUi bet ray churchill was driving! cheers, julian
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Post by Deleted on Sept 18, 2014 22:35:06 GMT
loved that video Julian....truly wonderful.
Pete
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Dave H
Involved Member
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Post by Dave H on Sept 18, 2014 22:53:24 GMT
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Dave H
Involved Member
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Post by Dave H on Sept 18, 2014 22:57:08 GMT
I live about a mile as the Crow flies from Newport station, two weeks or so ago with the attic window open, I could count the blasts as 5029 left for Bristol at about 8.00ish on a still, balmy evening,,, "bliss from my own armchair"
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jma1009
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Post by jma1009 on Sept 18, 2014 23:01:03 GMT
sorry alan, dont know what happened there, but have edited out the huge gap! talking of 'gaps' or 'mind the gap', Met No.1 is one of the few non GWR locos that has a GWR type exhaust! here's a clip of same last year - the section in Earls Court being rather poignant as my great grandfather was a class A signalman at Earls Court www.youtube.com/watch?v=a5qO5b55SN4the point of all this is 'Listen and Learn' from the exhaust and sound of a well set valve gear - unlike the maxitrack example at the start of this thread! cheers, julian
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Post by Deleted on Sept 18, 2014 23:04:58 GMT
alan - 'whoosh'? GWR locos never went 'whoosh'!! they had a characteristic 'square' exhaust 'chonk'! cheers. julian 4247 on the Bodmin railway sounded nothing like that when I went behind it a few years ago! The beats were miles out John
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jma1009
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Post by jma1009 on Sept 18, 2014 23:18:07 GMT
you do (as said previously) have to train your ears to hear such things... the worst loco i heard was a ride behind PORT LINE when on loan to the Bluebell... atrocious! yet over very many years i was always incredibly impressed by how well a small railway like the IOWSR at Havenstreet managed superb valve setting on it's loco fleet. and i could hear quite clearly when the valve gear was being notched up just a tad too far with certain drivers! cheers, julian
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dscott
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Post by dscott on Sept 18, 2014 23:25:44 GMT
One of my uncles from my mothers side of the family worked as a Station Master at Alderley Edge Station, moving on to Signalman at Piccadilly Manchester! Meanwhile across town grandmothers husband to be was working for Cheshire Lines Committee!!!
It is so lovely to know that I am not alone in being a great fan of you tube in my non building of workshop at the bottom of the garden time!
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jma1009
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Post by jma1009 on Sept 18, 2014 23:42:48 GMT
hi david,
completely off topic but of somewhat more devastating family history i had a great uncle Lionel Markham killed as a motorman (ie electric tube train driver) on the london underground in 1911. so far i havent been able to find out the details.
my first loco that i started when 16 was painted in genuine LT (Met) dark chocolaty maroon direct from Neasden Works, as a sort of tribute to my great grandfather.
the lining out was done in vermillion with Stroudley 'clover leaves' on the corners. although i sold the loco many years ago the paintwork etc is still pristine.
cheers, julian
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Post by Roger on Sept 19, 2014 7:15:34 GMT
Julian, you mention a sharp sound to the exhaust but I'm not sure why that should be? We've talked about allowing more space in the exhaust ways for the steam to exhaust into, and surely that would take away some of the sharpness? Wouldn't a sharp sound indicate that the steam hadn't expanded that much in the cylinder? What makes an exhaust note 'wooly'?
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uuu
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Post by uuu on Sept 19, 2014 7:26:17 GMT
... but the 2 cranks are set at 90 degrees to one another so that 2 cylinders are exhausting together at any one time..... And I thought the Yamaha "big bang" crankshaft was a new idea! Nice clip, Julian. Wilf
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uuu
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Post by uuu on Sept 19, 2014 7:34:04 GMT
Julian, you mention a sharp sound to the exhaust but I'm not sure why that should be? We've talked about allowing more space in the exhaust ways for the steam to exhaust into, and surely that would take away some of the sharpness? Wouldn't a sharp sound indicate that the steam hadn't expanded that much in the cylinder? What makes an exhaust note 'wooly'? It will be sharp when you have the gear set to admit steam for the whole stroke (or most of it). When moving off. So when the exhaust opens you have a full cylinder of high pressure steam to let go. You're right that the exhaust will soften as you notch up, then you'll get expansion in the cylinder.
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Post by Roger on Sept 19, 2014 7:41:47 GMT
So not much expansion going on in full gear then. That sounds really wasteful. What sort of cut off is usual for full gear?
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Post by Deleted on Sept 19, 2014 7:52:09 GMT
Hi Roger.. I don't have my notes to hand but IIRC 4472 as built was 67% cut off which was then increased to 75%...I'm sure someone will correct me if I have these figures wrong..
Pete
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Post by ejparrott on Sept 19, 2014 7:56:34 GMT
Full gear is wasteful, that's why it's used so little, well in fullsize anyway. Tends to be used all the while in miniature because the valvegears are so bad. Full gear cutoff is typically set in the region of 85% for shunting engines and 70% for mainline express engines, or something like that, Don will put us right shortly I'm sure! The Talyllyn engines I#m most familiar with, full gear is literally only used to get a train moving, within a couple of revolutions we're up into first notch. No. 4 has four notches to mid gear if I remember right, I've yet to see a 5" engine driven in fourth notch!
Pete and I seem to agree on that!
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Post by Roger on Sept 19, 2014 8:05:57 GMT
That's very interesting. Hopefully with Don's valve gear it will be worth notching up SPEEDY. I did play with it on the Hunslet and that managed to pull ok on the flat but it was gutless on the climb. I suppose I should have notched up as soon as it started on the down grade but I didn't think of that at the time. I was more concerned that I didn't make an ass of myself with the water levels or messing up the fire and getting stuck.
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Post by ettingtonliam on Sept 19, 2014 8:52:38 GMT
Julian, you mention a sharp sound to the exhaust but I'm not sure why that should be? We've talked about allowing more space in the exhaust ways for the steam to exhaust into, and surely that would take away some of the sharpness? Wouldn't a sharp sound indicate that the steam hadn't expanded that much in the cylinder? What makes an exhaust note 'wooly'? I recall being told once that the charactaristic GWR 'bark' was caused by a combination of sharp valve setting and a relatively small smokebox. I have no idea if this is true or not. Richard
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jma1009
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Post by jma1009 on Sept 19, 2014 9:52:27 GMT
in good steam locomotive design, whether fullsize or miniature, it is important to get rid of the exhaust steam as quickly and as easily as possible. a well designed valve gear and steam and exhaust circuit is essential for this.
there were lots of locos in fullsize that didnt have these features. the L Billinton J and L class locos built by the LBSCR immediately spring to mind - the L class couldnt be notched up beyond 33% cut off because the front ends were constipated. there was nothing wrong with the valve gear in the case of the L class, but the piston valves, ports, and exhaust circuit were too small.
the ability of the exhaust to quickly exit from the cylinders is what creates what is called the GWR 'square' exhaust bark. this is irrespective of how far the gear is notched up. it is not just a 'full gear' thing. in fact when a loco is going fast (and we hope notched up) the ability to exit the exhaust quickly is very important.
anyway, that's my opinion!
cheers, julian
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smallbrother
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Post by smallbrother on Sept 19, 2014 11:09:28 GMT
It would be nice if you could get your loco pulling a load Julian and record the sound.
I only remember you or your daughter sitting behind and it was hardly making a sound as I recall.
Pete.
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Post by donashton on Sept 19, 2014 16:07:56 GMT
Hi All, 75% cut off in full gear is a good all round figure to remember. Old Ted Gowan (well I was the youngster then!)swore by 88% - being ex-Canadian National Railway he seemed always to be starting several thousand tons from a water stop half way up the Rockies. Now seriously, you who have talked of 'wastage', please tell me where the waste is.
75%+ to start the load from maximum resistance, 65% by the time the last coach passes out of the platform, soon be winding up even further. The engine only talks back to the skilled - listen and learn!
Don.
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