72xx question

[DCB]

G.J. Churchward insisted on horizontal cylinders to minimise vertical components in the motion, preferring an offset of the cylinder centre line. This must have still caused some vertical movement, I would have thought, but I've never bothered to solve the necessary vector diagrams....

 

That seems a logical explanation for the County tanks. It was only later that the 43xx moguls were added to the standard class list. I suppose there was still some of the 'freer running uncoupled axles' idea lingering,

 

I built an outside framed 4-4-2T once from the bits left over from a conversion of a 43xx from Kitmaster (that long ago!) 'City' and 'Prairie' kits. It must have ended up in the bin....

 

I thought it was the LNWR that objected to 4-6-0s, but it was a long time ago I read it. I'll have to try and track the reterence down. I only had about a dozen railway books at the time....  

 

Why were Midland compounds double red? or was it just that it took two of them to pull a train? Would the 1931 date have something to do with Sir William taking over and showing them how it was done?

 

(It's true this was actually 1/1/1932, but that would spoil the joke!)  

As I understand it the Compounds were over 20 tons max axle load, as were Coronations, Princess Royals (Paralell Boiler Scots ?) LNER K3s, A3,A4, 1940s A1 and A2. I think it was the bridge stress committee and William Stanier combined who sorted out the Midland  The GW seemed to have issues with axle loading and the Midland with weight per foot run.  I think there is a reference to 4-6-0s being allowed on the Bristol Gloucester line in "The Midland in Gloucestershire," which is somewhere at the bottom of my book pile.

Churchward may have disliked inclined cylinders on balance grounds but he could not have used the same cylinder and half smokebox saddle castings for both sides of the loco if the cylinders had been anything other than horizontal. I think he ended up with three, a low smokebox saddle No 1 / No4  boiler one for saint, county 3150, 43XX, a taller one for the 28XX and a No 2 boiler one for the County tanks and 3101series.   The 44/45/46 series had a smaller version.The valve setting must have been fun with a vertical offset.

The funny one as regards cylinders is the prototype Crab, at York. You can see where they moved the cylinders up the frame and bodged it when they found there was not enough clearance for the Midlands mythical wide platforms.   

Edited February 25, 2017 by DavidCBroad

[NCB]

The story goes that the Counties were Churchward's reaction to a LNWR ban on 4-6-0s on their metals. This is probably apocryphal, as it seems rather an extreme reaction and doesn't explain the County tanks.

 

Hind-sight (always 20/20) does suggest that large outside cylinders and a relatively short coupled wheelbase are going to result in oscillation at speed. (What the Italians call 'serpeggiamento' (snaking), though in their case from two cylinder compounds. One large and one small cylinder driving the same axle is another recipe for less than satisfactory running.)

 

Can't be true in general; the LNWR had plenty of 4-6-0s. The oft-repeated story is that the LNWR objected to 4-6-0s specifically on the North to West, Shrewsbury to Newport line, and the Counties were Churchward's reaction, to get around the restriction. Jim Russell in vol ii Churchward, Collett and Hawkesworth locomotives is one reference to the story. The North to West line was quite important to the GWR, as it provided access from the north to Bristol as well as to South Wales.

 

Russell also states that it was the large reciprocating masses which caused the rough riding of the Counties and County tanks.

[The Stationmaster]

Can't be true in general; the LNWR had plenty of 4-6-0s. The oft-repeated story is that the LNWR objected to 4-6-0s specifically on the North to West, Shrewsbury to Newport line, and the Counties were Churchward's reaction, to get around the restriction. Jim Russell in vol ii Churchward, Collett and Hawkesworth locomotives is one reference to the story. The North to West line was quite important to the GWR, as it provided access from the north to Bristol as well as to South Wales.

 

Russell also states that it was the large reciprocating masses which caused the rough riding of the Counties and County tanks.

 

There was a 4-4-0 outside cylinder engine in Churchward's standardisation programme right from the very start and in many respects that was simply a logical continuation of earlier GWR use of 4-4-0s displacing the singles from express passenger work.  And in fact their initial distribution seems not to have been to the North & West but to mainline work until sufficient 4-6-0s arrived to displace and even then they were used in plenty of places well away from the North & West.  So the LNWR 'restriction' would seem to have been more than a by-product rather than a reason to build them and they went all over the place with initial allocations to the London Division as well as the Wolverhampton Division.

[NCB]

There was a 4-4-0 outside cylinder engine in Churchward's standardisation programme right from the very start and in many respects that was simply a logical continuation of earlier GWR use of 4-4-0s displacing the singles from express passenger work.  And in fact their initial distribution seems not to have been to the North & West but to mainline work until sufficient 4-6-0s arrived to displace and even then they were used in plenty of places well away from the North & West.  So the LNWR 'restriction' would seem to have been more than a by-product rather than a reason to build them and they went all over the place with initial allocations to the London Division as well as the Wolverhampton Division.

 

O.S.Nock  in The Great Western Railway in the 20th Century, page 27, quotes from the Proceedings of the Institution of Locomotive Engineers of March 1950, where K.J.Cook read his paper on Churchwards Locomotive Development on the G.W.R, and Stanier made the following contribution:

 

"Churchward had built that engine with his tongue in his cheek. He knew the front-end was too powerful for the wheelbase. This engine was built for the Shrewsbury and Hereford line, which was a joint line with the LNWR, and the LNWR objected to the Saint class working over it. He was not going to be told by Webb! Therefore Churchward built the County, which had plenty of power to run the service."

 

Nock notes that by the time the Counties appeared Webb was actually dead, however reckons it was because of LNWR objections when the Saints were originally mooted that the Counties appeared in Churchward's diagram of 1901.

 

So there's a reasonably authoritative base for the notion that the North to West line was at the root of it.

[DCB]

That LNWR reference sound plausible, I suppose poor old Webb felt left behind by the Krugers and No 36 so he cobbled up an awful compound 4-6-0 the "Bill Bailies" just before Whale took over,  They were so bad that they were scrapped within 10 years.   Ironically in view of the LNWR not liking 4-6-0s  the  LNWR "The George the Fifths " were among the worst locos for hammer blow  tested by the Bridge Stress committee circa 1930 at around 33 tons max hammer blow per axle and the GW Stars were nearly as bad. The Saints were not as bad as the Stars which were rapidly re balanced to reduce the hammer blow.  Luckily the Bridge Stress Committee never got their hands on a County....

Edited February 27, 2017 by DavidCBroad

[The Johnster]

More prevalent on two-cylinder (outside) types?

 

It was very noticeable with the 56xx 0-6-2 tanks, inside cylinder engines with quite steeply inclined cylinders in contrast to 'normal' GW practice, a sort of giddy-up horsey movement, the result of big cylinders in a powerful engine with driving wheels too small to assist in smoothing the motion out.

Edited March 9, 2017 by The Johnster

[phil_sutters]

Dad's only photo of a 72XX, at Swindon after what must have been her last shop. 

GWR 2-8-2T 7205 Swindon 29 10 1962.jpg

Not true - I have found this pair in among scans of negatives. I don't have a location for the second photo - Lawrence Hill ??

Edited March 11, 2017 by phil_sutters

[HowardGWR]

Yes, Lawrence Hill.  The train will almost certainly turn east (left) at Doctor Days Junction and continue to Salisbury, picking up water at Foxes Wood troughs, west of Keynsham  (if they had pickup gear of course, I don't know about that sort of thing).  

Edited March 11, 2017 by HowardGWR

[phil_sutters]

Yes, Lawrence Hill.  The train will almost certainly turn east (left) at Doctor Days Junction and continue to Salisbury, picking up water at Foxes Wood troughs, west of Keynsham  (if they had pickup gear of course, I don't know about that sort of thing).  

Thanks, Howard. I had thought that it was. It was one of Dad's favoured spotting haunts, but I couldn't immediately find a photo of that building from that angle. Sometime I shall probably come across 7249 in the logs and can then put a date to it as well.

[HowardGWR]

Thanks, Howard. I had thought that it was. It was one of Dad's favoured spotting haunts, but I couldn't immediately find a photo of that building from that angle. Sometime I shall probably come across 7249 in the logs and can then put a date to it as well.

I looked it up and the 72xx did not have water pick-up gear.  The one experiment the GWR did with a tank engine did not end well, IIRC.  At the end, probably only the Cardiff to Brighton trains would have used those troughs, usually hauled by a Hall in BR times, but earlier by a 29xx or 40xx.

 

The photographer was standing at the base of the steps from Church Road, Redfield.  Lawrence Hill GWR station was not accurately named, IMO, as Redfield would have been more appropriate.  The Platform 4 building in the photo would, in earlier times, I think, have been obscured by what was a covered footbridge that crossed all platforms and was really supernumerary, as one could access all platforms from the pavement of Church Road, where the booking office fronted.  I don't remember ever using it. 

 

As we are on RMWeb, the real draw of that location was, of course, Max Williams model railway shop.  Sorry for OT. 

Edited March 11, 2017 by HowardGWR

[russell price]

On 27/02/2017 at 04:28, DavidCBroad said:

That LNWR reference sound plausible, I suppose poor old Webb felt left behind by the Krugers and No 36 so he cobbled up an awful compound 4-6-0 the "Bill Bailies" just before Whale took over,  They were so bad that they were scrapped within 10 years.   Ironically in view of the LNWR not liking 4-6-0s  the  LNWR "The George the Fifths " were among the worst locos for hammer blow  tested by the Bridge Stress committee circa 1930 at around 33 tons max hammer blow per axle and the GW Stars were nearly as bad. The Saints were not as bad as the Stars which were rapidly re balanced to reduce the hammer blow.  Luckily the Bridge Stress Committee never got their hands on a County....

I would have thought the reason being commercial!! The Saints would have allowed the GW to speed up timings on the Newport  Hereford section giving them an advantage over the LNW. 

[JimC]

My understanding is there was one specific bridge or viaduct with a weight limit, and it was later upgraded.

[88D]

On 09/03/2017 at 22:49, The Johnster said:

 

It was very noticeable with the 56xx 0-6-2 tanks, inside cylinder engines with quite steeply inclined cylinders in contrast to 'normal' GW practice, a sort of giddy-up horsey movement, the result of big cylinders in a powerful engine with driving wheels too small to assist in smoothing the motion out.

My most uncomfortable ride was behind 5698 from Aberdare to Quakers Yard HL. We thought it had square wheels.

[The Stationmaster]

On 12/05/2021 at 22:36, 88D said:

My most uncomfortable ride was behind 5698 from Aberdare to Quakers Yard HL. We thought it had square wheels.

Hard luck, I had a very nice run behind 6673 between Quakers Yard (HL) and Pontypool Road, and back

[JimC]

There were at least two balancing schemes on the 56s weren't there? RCTS says that cranks were altered to the "Stroudley" pattern with crank and coupling rods in line to reduce wear on the driving axleboxes.  What effect would this have had on the fore and aft motion felt by the train? I suppose, thinking about it, all outside cylinder locomotives are balanced on this pattern. I can't get a picture in my head of what difference this would make to eventual loads.

[The Johnster]

On 11/05/2021 at 15:05, russell price said:

I would have thought the reason being commercial!! The Saints would have allowed the GW to speed up timings on the Newport  Hereford section giving them an advantage over the LNW. 

Saints were probably used on that section anyway, just not (in those days at least) on the joint section to the north of Shelwick Jc.   The GW already had a significant advantage between Newport and Abergavenny, the LNWR route being via Tredegar and the M,T,&A route, which was not laid out for fast running, and if you describe the GW route as ‘hilly’, the LNW has to come in as at least ‘mountainous’ and my description would ‘precipitous’. 
 

A few years ago, I cycled the M,T,&A trackbed from Brynmawr to Abergavenny with some mates.  Half a turn of the pedals to start enough for the whole journey to Gilwern. 

Edited May 30, 2021 by The Johnster

[Hal Nail]

On 06/01/2017 at 13:29, PhilH said:

We had 4270 on the Mid Hants for a while. it could pull a house down but was by a huge margin the most uncomfortable engine I have ever driven. It felt like it was shaking itself to pieces at anything over 10mph

Interesting reading this. I had a cab ride, the only time I've ever been on a foot plate, and vividly remember it felt like it would pull itself apart under any significant power. I just assumed that was normal!