Re: The rise of the 4-6-0 and why were there none on the GNR
Posted: Mon Sep 05, 2016 10:38 pm
Many thanks to everyone who has posted on this thread. A lot of interesting information has been brought out.
However, I still think that there are some fundamental questions that have not been answered.
The development of high speed locomotives for long(er) distances which took place prior to and after WW1 produced Atlantics and Pacifics on the lines that became part of the LNER, and 4-6-0s on the GW and LSWR. The points mentioned above about intended distances, primary air to the grate, and ashpan capacity are all very valid. The development of long-travel valve gear and adequately-sized valves is extensively discussed in many places!
What particularly interests me however, is the secondary, shorter distance, and sometimes heavier services. Here the engineering traditions and design philosophies differed. (For ease of reference I will refer to these as 'secondary' services, although in terms of revenue-per-train-mile they probably weren't secondary at all!)
On the NER, although the Vs and Zs dominated the fast passenger (and some of the faster freight!) there was a policy of providing large strong engines for the 'secondary' services. When combined with Raven's three-cylinder policy this produced the S3/B16. (Although it is interesting that there was an outline scheme for a larger-wheeled sister of the B16 for fast passenger work.)
One could say that the situation was similar on the GCR - with a series of big 4-6-0s clearly produced for the secondary roles.
There are two interesting parallels. The B15, with a boiler similar to the very successful Q6 was not developed further, or it's reputed steaming problems resolved. The three cylinder B16 was seen as the way forward.
The B6, with an 'engine' portion the same as the very successful O4, was apparently useful and well liked - but only three were built and Robinson clearly thought the four cylinder B7 was a 'better job'.
So - even during and after WW1, neither Gorton nor Darlington was particularly worried about complexity of maintenance. Clay and Cliffe ('The LNER 4-6-0 Classes') suggest that the six eccentrics sharing the leading driving axle with the inside crank webs made things ' a little crowded'!
Both B16 and B7 were broadly similiar in wheel-size and intended use. Both lasted, despite their reputed high coal consumption, to the end of the LNER and beyond.
So, while Gorton and Darlington, both with a tradition of building robust locomotives, were building these sturdy and strong 4-6-0s, what was happening on the GNR?
Well, of course, what was being produced for broadly the same role was a large-boilered 2-6-0, the K3.
The tradition, by 1920, of Doncaster did not include any 4-6-0s, but did include 2-6-0s, and there was a logical path of development, possibly stretching as far back as the short-lived (which is was what they were designed for) American locomotives of the tail end of the 19th century.
Again, a multi-cylindered locomotive was prefered, and despite all the supposed controversy, I would see Gresley's conjugated gear as being intended to reduce maintenance rather than otherwise.
So, at Grouping, three different engineering traditions, with three types of very useful engines. The K3 had the advantage of it's superior front-end design, but the other two were possibly more robust and certainly a lot better riding.
Gresley was not a product solely of Doncaster. The LNWR and LYR made extensive use of 4-6-0s as 'secondary' locomotives. Nor was he dismissive of the traditions of the other major works. Further B7s and B16s were produced (although probably at least some of the parts were ordered by the older companies). He also selected D11s as being suitable for ex NBR lines, and A5s for NE Area. In many areas, Gresley was clearly open to new and different ideas.
Why therefore, in reviewing the locomotive stock of the new company, did Gresley not take the opportunity to create a 'secondary' locomotive which combined the best of everybody's expertise, and could have been built in quantity when required?
After all, the J38/39s were designed at Darlington with valve gear refined from the GCR A5s.
When there was a perceived need for new 'secondary passenger' locomotives in the NE and Scottish areas, the J39 boiler was used on a Darlington 4-4-0 with a refined version of the Gresley 'front end'. In the activity created by the need by a new express locomotive for the lightly-built GE lines, Doncaster asked Darlington for drawings of the B16 and the D49.
Why was the need for a durable 'secondary' locomotive not seen earlier, and the experience available not used?
The pre-grouping locomotive stock was not going to last for ever, and despite the drastic reductions in revenue, some new locomotives were being built.
Of course, in any discussion of this sort, hindsight is always easy. But I think there are four questions, one minor and three key:-
Firstly, why did no-one recognise the potential value of the B6?
Secondly, why was the K3 built in quantity rather than an 'integrated' design (which might have had better riding characteristics and perhaps wider route-availability.) Perhaps there could have been a two and three cylindered variant.
Thirdly, why build the D49s at all, instead of a more versatile locomotive?
Fourthly, why did it take so long (most of the life of the LNER in fact) to create a locomotive like the B1?
Much though I would like to have seen a fleet of V4s, and much though I admire HNGs design practice, one has to wonder whether something better for a 'secondary' locomotive been acheived earlier than it was.
However, I still think that there are some fundamental questions that have not been answered.
The development of high speed locomotives for long(er) distances which took place prior to and after WW1 produced Atlantics and Pacifics on the lines that became part of the LNER, and 4-6-0s on the GW and LSWR. The points mentioned above about intended distances, primary air to the grate, and ashpan capacity are all very valid. The development of long-travel valve gear and adequately-sized valves is extensively discussed in many places!
What particularly interests me however, is the secondary, shorter distance, and sometimes heavier services. Here the engineering traditions and design philosophies differed. (For ease of reference I will refer to these as 'secondary' services, although in terms of revenue-per-train-mile they probably weren't secondary at all!)
On the NER, although the Vs and Zs dominated the fast passenger (and some of the faster freight!) there was a policy of providing large strong engines for the 'secondary' services. When combined with Raven's three-cylinder policy this produced the S3/B16. (Although it is interesting that there was an outline scheme for a larger-wheeled sister of the B16 for fast passenger work.)
One could say that the situation was similar on the GCR - with a series of big 4-6-0s clearly produced for the secondary roles.
There are two interesting parallels. The B15, with a boiler similar to the very successful Q6 was not developed further, or it's reputed steaming problems resolved. The three cylinder B16 was seen as the way forward.
The B6, with an 'engine' portion the same as the very successful O4, was apparently useful and well liked - but only three were built and Robinson clearly thought the four cylinder B7 was a 'better job'.
So - even during and after WW1, neither Gorton nor Darlington was particularly worried about complexity of maintenance. Clay and Cliffe ('The LNER 4-6-0 Classes') suggest that the six eccentrics sharing the leading driving axle with the inside crank webs made things ' a little crowded'!
Both B16 and B7 were broadly similiar in wheel-size and intended use. Both lasted, despite their reputed high coal consumption, to the end of the LNER and beyond.
So, while Gorton and Darlington, both with a tradition of building robust locomotives, were building these sturdy and strong 4-6-0s, what was happening on the GNR?
Well, of course, what was being produced for broadly the same role was a large-boilered 2-6-0, the K3.
The tradition, by 1920, of Doncaster did not include any 4-6-0s, but did include 2-6-0s, and there was a logical path of development, possibly stretching as far back as the short-lived (which is was what they were designed for) American locomotives of the tail end of the 19th century.
Again, a multi-cylindered locomotive was prefered, and despite all the supposed controversy, I would see Gresley's conjugated gear as being intended to reduce maintenance rather than otherwise.
So, at Grouping, three different engineering traditions, with three types of very useful engines. The K3 had the advantage of it's superior front-end design, but the other two were possibly more robust and certainly a lot better riding.
Gresley was not a product solely of Doncaster. The LNWR and LYR made extensive use of 4-6-0s as 'secondary' locomotives. Nor was he dismissive of the traditions of the other major works. Further B7s and B16s were produced (although probably at least some of the parts were ordered by the older companies). He also selected D11s as being suitable for ex NBR lines, and A5s for NE Area. In many areas, Gresley was clearly open to new and different ideas.
Why therefore, in reviewing the locomotive stock of the new company, did Gresley not take the opportunity to create a 'secondary' locomotive which combined the best of everybody's expertise, and could have been built in quantity when required?
After all, the J38/39s were designed at Darlington with valve gear refined from the GCR A5s.
When there was a perceived need for new 'secondary passenger' locomotives in the NE and Scottish areas, the J39 boiler was used on a Darlington 4-4-0 with a refined version of the Gresley 'front end'. In the activity created by the need by a new express locomotive for the lightly-built GE lines, Doncaster asked Darlington for drawings of the B16 and the D49.
Why was the need for a durable 'secondary' locomotive not seen earlier, and the experience available not used?
The pre-grouping locomotive stock was not going to last for ever, and despite the drastic reductions in revenue, some new locomotives were being built.
Of course, in any discussion of this sort, hindsight is always easy. But I think there are four questions, one minor and three key:-
Firstly, why did no-one recognise the potential value of the B6?
Secondly, why was the K3 built in quantity rather than an 'integrated' design (which might have had better riding characteristics and perhaps wider route-availability.) Perhaps there could have been a two and three cylindered variant.
Thirdly, why build the D49s at all, instead of a more versatile locomotive?
Fourthly, why did it take so long (most of the life of the LNER in fact) to create a locomotive like the B1?
Much though I would like to have seen a fleet of V4s, and much though I admire HNGs design practice, one has to wonder whether something better for a 'secondary' locomotive been acheived earlier than it was.