The rise of the 4-6-0 and why were there none on the GNR

[Pebbles]

The steam engines main attributes are the ability to use a variety of fuels and mechanical simplicity. During its period of use the British 4-6-0 was presumably seen as adequate and cost effective. When coal quality fell, more power was needed and maintenance and staffing costs increased a switch was made to alternative motive power.

[Mickey]

The steam engines main attributes are the ability to use a variety of fuels and mechanical simplicity. During its period of use the British 4-6-0 was presumably seen as adequate and cost effective. When coal quality fell, more power was needed and maintenance and staffing costs increased a switch was made to alternative motive power.

Nothing to do with the attributes of the british 4-6-0 loco (although there is a slight connection) but after watching a dvd about the '15 guinea Special' run by British Railways to officially mark the 'end of steam' on B.R. on the 11th August 1968 and as most on here will know a 'last run' took place between Liverpool Lime Street & Calisle and return that involved at certain stages of the run a 'very clean' 4-6-2 Britannia Oliver Cromwell and three 'cleaned up' 4-6-0 Black 5s anyway in one of the sequences of film footage a fireman is seen standing in the doorway of a 'cleaned up' Black 5 (not the black 5 that took part in the first part of the run north from Liverpool Lime Street nor on one of the two black 5s that took part in the doube-headed southbound return run from Carlisle back over the S&C I mite add) but maybe a week or two before the '15 guinea special' ran is seen wearing a centre parted and layered Georgie Best mop of dark hair falling over the back of his collar complete with fireman's overalls as the black 5 he's firing on backs down onto it's train, somehow it didn't look quite right guy's so maybe August 1968 was the right time to call it a day after all?. lol ha ha ha...

Mickey

[billbedford]

I'd turn that round, as there is nothing remotely 'inevitable' about the 4-6-0, and by the 1940s it was clearly showing its limitations in power production. The telling marker for this: Riddles maximum power 4-6-0 was a class 5, everything bigger got a wide firebox, to the tune of 30% of his build.

The rebuilt Royal Scots were 7P

[Pyewipe Junction]

My understanding of the deficiencies of the GC 4-6-0s, from reading W A Tuplin's book Great Central Steam, is as follows:
(1) poor ashpan design, leading to suffocation of the fire on long runs
(2) inadequate grate areas on the later, larger designs
(3) poor valve timing
(4) poor blasting.

Sounds a lot doesn't it, but nothing that couldn't have been overcome with a bit of attention. Unfortunately, Gorton seemed disinterested in investigating solutions and their response was to keep producing new designs in the hope of striking lucky.

[Hatfield Shed]

I'd turn that round, as there is nothing remotely 'inevitable' about the 4-6-0, and by the 1940s it was clearly showing its limitations in power production. The telling marker for this: Riddles maximum power 4-6-0 was a class 5, everything bigger got a wide firebox, to the tune of 30% of his build.

The rebuilt Royal Scots were 7P

And the King was rated at 8P, despite having proven inferior to the rebuilt Royal Scot in power production. The rating does nothing to alter the fundamental limit on grate area and ashpan volume (with the consequent effects on draughting) of the narrow firebox; which ultimately make the wide grate firebox a necessity, if the sustained power production capability of the locomotive boiler is to increase.

[billbedford]

My understanding of the deficiencies of the GC 4-6-0s, from reading W A Tuplin's book Great Central Steam, is as follows:
(1) poor ashpan design, leading to suffocation of the fire on long runs
(2) inadequate grate areas on the later, larger designs
(3) poor valve timing
(4) poor blasting.

Sounds a lot doesn't it, but nothing that couldn't have been overcome with a bit of attention. Unfortunately, Gorton seemed disinterested in investigating solutions and their response was to keep producing new designs in the hope of striking lucky.

But Tuplin was writing with 40-50 years of hindsight. Had he come up with these insights in 1910 he might have made a difference, but he didn't. You might as well say that the the Sopwith Camel would have been a much better aircraft if it had been built of aluminium.

[Pebbles]

I think Bill has re-enforced the point about hindsight. To go back to the original question I can only give a personnel view.
At the end of the nineteenth and beginning of the twentieth century express locomotive development needed to address heavier loads and higher speeds. Two alternatives presented themselves the 4-4-2 and 4-6-0. Both the GWR and GCR produced engines that could be converted to either configuration but in both cases having narrow fireboxes. The GNR's principle express being the large Atlantic there was no option of developing it into a 4-6-0 without substantial re-design. That said, as was the case with the GCR, at that time six coupled wheels may not have been required bearing in mind that significant amounts of work on other railways was being undertaken by 4-4-0s.

[Atlantic 3279]

I'd turn that round, as there is nothing remotely 'inevitable' about the 4-6-0, and by the 1940s it was clearly showing its limitations in power production. The telling marker for this: Riddles maximum power 4-6-0 was a class 5, everything bigger got a wide firebox, to the tune of 30% of his build.

The rebuilt Royal Scots were 7P

And they quite sensibly had three cylinders, but if we go off on that tangential debate we'll lose the original point.


At the time of the design and introduction of the GN Atlantics, despite the great increase in adhesion that they offered compared to the previously favoured Stirling Singles, Ivatt seemed to see no reason to increase piston area to gain tractive effort in proportion to that extra adhesion. He concentrated instead on ability to raise steam continuously. Perhaps the GNR at that time saw no need to produce even a four-coupled loco with maximum ability to accelerate hard or run hard up banks, consuming "un-necessary" amounts of coal in the process. The GNR drivers were generally able to keep time by running "easy" up the banks and then opening out to take full advantage of the descents. By the time that further growth of train weights demanded six-coupled adhesion the GNR was so thoroughly wedded to the idea of the wide firebox for maximum continuous steam output I don't suppose that a 4-6-0 design would get much serious consideration. It had to be a Pacific. The Atlantics displaced from the top link jobs and the 4-4-0s would, for economic reasons, have to suffice for the lesser trains, bolstered when necessary by the moguls, so new 4-6-0s for secondary services wouldn't be justified.
Even so, I suspect the GNR could have come up with a 4-6-0 without too much difficulty had they really felt the need. Variations on the 5' 6" diameter boiler of the large Atlantics, but with narrow fireboxes, were produced for the 2-8-0s and for the moguls. Given the amount of bother that some CMEs got into as they first tried to produce boilers with proper proportions, proper draughting and decent ashpans for the first generations of 4-6-0s, perhaps it was just as well that the GNR didn't get involved.

[Pyewipe Junction]

I think Bill has re-enforced the point about hindsight. To go back to the original question I can only give a personnel view.
At the end of the nineteenth and beginning of the twentieth century express locomotive development needed to address heavier loads and higher speeds. Two alternatives presented themselves the 4-4-2 and 4-6-0. Both the GWR and GCR produced engines that could be converted to either configuration but in both cases having narrow fireboxes. The GNR's principle express being the large Atlantic there was no option of developing it into a 4-6-0 without substantial re-design. That said, as was the case with the GCR, at that time six coupled wheels may not have been required bearing in mind that significant amounts of work on other railways was being undertaken by 4-4-0s.

The GW solved all of the problems the GC had by 1910. The Saints and Stars set the standard for 4-6-0s (and other large passenger locos) for many years to come.

It beggars belief that a flawed design such as the B2 could have appeared in the light of the GW's experience, especially as Robinson was known to follow developments on the GW very closely. Gorgeous though they were, the B2s were a failure. Hindsight has little to do with it IMHO.

[Wainwright]

It's not clear exactly how much information the GWR shared with other railways in the Churchward era.

Robinson's brother was quite senior on the GWR (at Wolverhampton works), and was known to correspond with him, but Wolverhampton's secondary role in GW terms, may have meant he was not 'in' with the team working at Swindon on the new 'standard' designs. Robinson seems to have looked rather more to Crewe, from the little I've read.

Both Robinson and Holden could both be reasonably expected to have a good knowledge of Dean / Armstrong era practice, but how much they knew about the new designs and the detailed aspects of their construction is moot. It may not have been self-evident to them in the way we think it should be now, that GW-style designs were a) better b) effective outside the GW context c) cost-effective, d) achievable, or e) sellable to the directors of a different railway. They also may not have understood f) why GW-style designs worked. (Witness the LNWR approach of 'we gave it a Belpaire firebox and four cylinders, what else could we have done?')

GW knowledge seems to have cascaded to other railways slowly and in some cases relatively later, when Churchward's bright young things were broken up, either because they were bored (once the detail work was done on the new designs, less staff were needed), displaced by WW1, or ambitious - Pearson and Holcroft together going to the SECR was key for Maunsell's work, as was Stanier going to the LMS for their development. But only on the SECR were the Churchward principles immediately put to work effectively, in the 'N' 2-6-0s. Stanier had more of a wrestle getting the details of GW practice into compatibility with the preceding LMS culture.

But it seems to me that, in the pre-grouping world, to get the details of a 'foreign' railway's practice implemented in the culture of another railway, you needed key people with the key knowledge and experience parachuted into not one, but several points in the chain of command, with the opportunity, trust and autonomy to work together and to change existing practice. Having a CME who knew in principle that 'something' was going on in Wiltshire (or wherever) was not always enough.

And, as I said earlier, implementing Churchward-era GW designs on a railway with less well-engineered track and less money than the GW wouldn't necessarily have resulted in more 4-6-0s. It could have ended up with narrow firebox Atlantics, or in copies of the Counties, or the 43xxs...

[Wainwright]

And don't forget that to build a radically different style of locomotive, often you needed to rebuild the works in which said loco would be built.

[Mickey]

After watching several times recently the dvds The Power Of The Castles and also The Power Of The Kings released by Transport Video Pubishling about 10 years ago each mention was made specifically about the Kings that they were 'to powerful for there chassis' which was basically like the Castle class a 'Star class' 4-6-0 chassis of 1907 anyway apparently there were a number of problems attributed to the Kings in there early life such as front end frame fractures which were apparently a common feature of the class and also the initial 'lack of springing' to hold down the front end bogie on the track especially while running at speed over poor quality track the design having to be hurriedly altered by Collett early on in the Kings life. Another problem with the Kings was after the Kings were fitted with double-chimneys and had 'higher superheat' superheaters fitted there were more frame fractures amongst the class and because both the Castles and the Kings were both 4-cylinder locos mention was made that especially in the Kings case 'there was to many moving parts of machinery' crammed in-between the chassis frames which was basically 'rubbing against other moving parts of machinery' which inhibited or restricted there 'free running' at higher speeds because apparently the 'comfortable speed' of a King at speed was around 88mph and the comfortable speed of a Castle at speed was around 83mph as opposed to a Gresley A4 which would easily run at over 100mph!!.

Anyway my question is a speculative one how would the Kings have run if they had been built as 3-cylinder locos as opposed to being 4-cylinder locos?.

Mickey

[billbedford]

It beggars belief that a flawed design such as the B2 could have appeared in the light of the GW's experience, especially as Robinson was known to follow developments on the GW very closely. Gorgeous though they were, the B2s were a failure. Hindsight has little to do with it IMHO.

The B2s gave the railways 35 years of useful service with out having major maintenance problems such as cracked frames or broken crank axles. The only way I can see this being a 'failure' is if it was measured against some assumed intention of the designer.

[billbedford]

Another problem with the Kings was after the Kings were fitted with double-chimneys and had 'higher superheat' superheaters fitted there were more frame fractures amongst the class and because both the Castles and the Kings were both 4-cylinder locos mention was made that especially in the Kings case 'there was to many moving parts of machinery' crammed in-between the chassis frames which was basically 'rubbing against other moving parts of machinery' which inhibited or restricted there 'free running' at higher speeds because apparently the 'comfortable speed' of a King at speed was around 88mph and the comfortable speed of a Castle at speed was around 83mph as opposed to a Gresley A4 which would easily run at over 100mph!!.

I don't understand the comment about too many moving parts. All the GW four cylinder locos had derived motion for the outside cylinders, so the arrangement of cylinders and valve gear between the frames was essentially the same as on an inside cylindered 4-4-0.

Also the smaller wheels on the Kings should have given them a lower 'comfortable speed' than Castles.

[billbedford]

This simple answer to the original question of why there were no 4-6-0s build by the GNR is that 4-6-0 designs were almost always derived from 4-4-0s. As to why the GNR only ever built small 4-4-0s for secondary services is arguably a product of Mr Stirling's prejudices.