Steam locomotive non history

[Niels]

Thompson did something to P2s

https://upload.wikimedia.org/wikipedia/commons/f/f0/York_Locomotive_Yard_with_A2-2_Pacific_geograph-2827807-by-Ben-Brooksbank.jpg

 

and mr Corbs did  better.

http://www.rmweb.co....-1505684845.jpg

 

The B16 and A2 designs from Raven before 1924 was known to mr Thompson,son in law of mr Raven.

The B16 earned their keep and the A2s did not really.

A2s changed crankaxles within two years from new and the B16s never did according to Yeadon.

Mental climate in the Raven house around 1926 (Son died WW1 and A2s indicating incompetence) cannot have been happy.

Can that have influenced the bad choice Thompson made 1944?

Edited November 4, 2018 by Niels

[The Johnster]

Imaginary locos thread, surely, Neils, but good stuff anyway!

[Niels]

Imaginary locos thread, surely, Neils, but good stuff anyway!

I do not know how to move it ,but thank You for comment.

A picture showing how a S3 bastard could have been spaced compared to a Raven A2

 

https://imgur.com/a/pGRHIgq

Edited November 5, 2018 by Niels

[The Johnster]

Think you're being a bit harsh about the Raven A2s; they were by all accounts very good engines which ran until the need for overhaul and the desire to standardise on the Gresley's, under Gresley's direction, understandably put an end to them.  The A1s were as good as anything in the country except perhaps a GW Castle when they were first introduced, and improved into A3s were very good indeed; to be a Raven A2, still a good loco but not up to that standard, is no real shame.  

 

A loco for the ECML's NER section needs to run fast from York to Newcastle with a heavy train while being within the fireman's capacity to keep on the boil, and while the bulk of the work both here and elsewhere on the route was still being done by atlantics that had themselves set a pretty high standard, the Raven A2s successfully worked the heaviest traffic, to time and apparently without attracting criticism from those who drove, fired, serviced, and maintained them here for over a decade until there were sufficient A3s available and the A4s were putting in an appearance.

 

Raven's family tragedy was mirrored by much of the nation's, and cannot have been a positive influence to his work, but to regard his pacific as a failure is unfair, especially when you compare it to Churchward's effort!

[Zomboid]

Wasn't Raven the LNERs preferred choice for CME upon grouping? Or have I got some wires crossed?

He had an excellent name too - Vincent Raven. Sounds like the bassist in an 80s Goth band. He's probably somewhere on the soundtrack to The Crow.

[Niels]

I do not think the Raven A2s were failures.

They were eliminated by Gressley who compared and found his own creations better.

Surprise,surprise.

They also had this nasty change of crankshafts .

The B16s had not so Raven (my Hero) was in good faith and small details can have been the cause.

A british journalist once wrote that british turners  killed more british WW1 aviators than the enemy by putting sharp concave corners everywhere in engine parts.

In 1926 ,when cranks had to be changed,Raven was out of LNER and must have felt very,very offended.

Eigteen years later Thompson had to decide how to make P2s usefull.

The easiest and simplest solution would have been to use Ravens front wheelset drive  scheme as did mr Corbs, but he did not.

The last picture is a comparison of wheelspacing for a A2 Raven  pacific and how it would have been if he had kept machinery from B16s  plus a trailing wheelset under a somewhat shorter A2 boiler

Edited November 7, 2018 by Niels

[RLBH]

Wasn't Raven the LNERs preferred choice for CME upon grouping? Or have I got some wires crossed?

He had an excellent name too - Vincent Raven. Sounds like the bassist in an 80s Goth band. He's probably somewhere on the soundtrack to The Crow.

That was, I think, the GCR's Robinson, on the strength of his seniority. This was also why he declined the post, feeling that he was too old to take it on as he intended to retire. He recommended Gresley for the job, and the rest is history.

 

Raven was the next most senior CME of the LNER's components after Robinson. Had Gresley not benefited from that recommendation, Raven would probably have got the job. This could have been interesting as he was a big fan of electrification, with the S3 class apparently designed for secondary, non-electrified routes.

[brack]

I'm sure I've read that upon assessment there wasn't a great deal between the A1 and A2 in performance at grouping, but that the A1 was regarded as having more headroom for development/improvement. The lineage of A3/A4s suggests that gresley was right about that.

Raven's true express loco lived out its life in the paint shop at Darlington. I suspect he'd be more upset that lack of cash for investment/renewal gradually undid most of the remarkable things the NER had been developing.

[Andy Kirkham]

Think you're being a bit harsh about the Raven A2s; they were by all accounts very good engines which ran until the need for overhaul and the desire to standardise on the Gresley's, under Gresley's direction, understandably put an end to them.  The A1s were as good as anything in the country except perhaps a GW Castle when they were first introduced, and improved into A3s were very good indeed; to be a Raven A2, still a good loco but not up to that standard, is no real shame.  

 

A loco for the ECML's NER section needs to run fast from York to Newcastle with a heavy train while being within the fireman's capacity to keep on the boil, and while the bulk of the work both here and elsewhere on the route was still being done by atlantics that had themselves set a pretty high standard, the Raven A2s successfully worked the heaviest traffic, to time and apparently without attracting criticism from those who drove, fired, serviced, and maintained them here for over a decade until there were sufficient A3s available and the A4s were putting in an appearance.

 

Raven's family tragedy was mirrored by much of the nation's, and cannot have been a positive influence to his work, but to regard his pacific as a failure is unfair, especially when you compare it to Churchward's effort!

I find the A2s visually disconcerting; you can mentally remove the section equivalent to the middle driving wheel and come up with an entirely plausible and well-proportioned atlantic. Similarly the Great Bear looked like a Star with an extra bit riveted on at the back. With the A1 it looks as if Gresley had started with a clean sheet of paper and conceived everything anew.

[brack]

I find the A2s visually disconcerting; you can mentally remove the section equivalent to the middle driving wheel and come up with an entirely plausible and well-proportioned atlantic. Similarly the Great Bear looked like a Star with an extra bit riveted on at the back. With the A1 it looks as if Gresley had started with a clean sheet of paper and conceived everything anew.

Absolutely - it looks visually stretched. If you look at the Bassett Lowke 15" Atlantics (themselves visually based upon NER designs to some extent) and how they were stretched into Colossus there's a definite foreshadowing of what happened to the A2.

[Zomboid]

I think it's because they had parallel boilers of pretty large (for the UK) diameter which highlights their length. The fire & smoke boxes are also proportionally quite short from what I can see.

They're not bad looking machines though.

 

As has already been said, 13 was Raven's real masterpiece. A real shame that once the LNER took on the rest of its empire they couldn't afford the infrastructure to use it.

[34theletterbetweenB&D]

He had an excellent name too - Vincent Raven. Sounds like the bassist in an 80s Goth band.

 Or even Vincent Litchfield Raven. (For those who don't know, one potential origin for 'Litchfield' is graveyard.)

 

What may also have further influenced the LNER board - on which the largest group were ex-NER - was that while Raven had a year of seniority as CME over Gresley, he was into his sixties, while Gresley was in his mid forties. It won't have hindered Gresley's chances that he had been setting the pace technically in contemporary UK steam developments.

 

They may also have had an eye on the LNER group's financial situation. Raven's team were based in easily the most wealthy of the LNER constituents, and their development direction toward electrification was possible on that basis. Once the NER's revenue had to subsidise the four 'financially challenged'  LNER constituents, it would be a very different position; one which Gresley with experience at the modestly profitable GNR was probably better conditioned for...

[The Black Hat]

Interesting notes coming from this thread: however a few things that I think have been mentioned could be expanded.

 

1. Raven was taken away from the railway work during WWI - to organise and develop productions of munitions. While this showed his skills and organisation to be excellent it should in my view have made him the No. 1 candidate for the position in the LNER, particularly given his work on electrification. However, given the situation and the stage in his career he did the honourable thing and resigned from being CME of the NER, in 1922 before the LNER attempted to get Robinsion to do the work in 1923, then selecting Gresley. This effectively ruled him out of contention.

 

2. The A2 was a design needed to fill a role in the fleet. Larger trains were needed, but Raven and the NERs idea wanted to go electric and not steam. While the comparrisons were done between Raven A2 and Gresley A1, its clear that Ravens machine did what was needed and was equal to the task. Its development could be done, as seen when Gresley boilers were placed onto an A2 later. However, the personal issue must have been a factor and Gresley with the LNER board chose his own machine. Yes it is possible that the Gresley A1 had more scope and room for improvement. Where as A2 would have probably been kept as they are and a new class designed for further orders. There was nothing to stop Gresley doing this with the A1 and in fact modifications to the class eventually led to A3, a rather different locomotive from the original specifications.

 

Its interesting to note that the Raven A2 was excellent in maintaining boiler pressure, needed for sustained high speed runs. It would have been interesting to compare the Raven A2, against the Western Region Castle class in the exchange that came later, especially with both engines being produce of companies sharing the virtues of standardisation.

[The Johnster]

Good points raised, Black Hat.  I am fairly confident that Nigel Gresley's choice of his own engine for future development was the correct one and not a mistake brought about by his own self confidence; he was happy to use NER and GER designs both for continued production and development; Collett at Swindon wasn't as accommodating with his constituent company's designs and tried his best to alter them to his own specifications.  It is arguable that the 56xx role could have easily been satisfied by cheaper Rhymney Rs, and that the Taff Vale A was the basis of a better machine for Valleys passenger work than any GW design.  The A1s were designed for the GN section of the ECML and the Leeds branch, but proved themselves capable of the NER and NBR work as well.  

 

The NER, had it continued in existence, could have afforded to electrify the York-Newcastle and probably Hull-Leeds lines, but the combined poverty of the LNER hobbled this idea.

 

I agree it would have been interesting to try out an A2 on a Paddington-Bristol, or the West Country main line as far as Exeter, but I suspect the South Devon and South Wales main line banks would have been a bit much for it.  A1s were less than ideal for this as well!

[Niels]

The Raven and Gresley Pacifics were both  open to improvements.

Bulleid proved that well balanced three-cylinder engines with 6 feet drivers were more than fast enough for UK passenger trains.

A six feet nine wheelset is at least 30% more heavy than a six feet two.

It is unsprung and does a lot of no no to the track.

One can maybe argue that even two cylinder Brittanias were fast enough.

By going from B16 five feet eigth to A2 six feet eigth drivers Raven got at least six tons un-sprung as ballast and maybe some crankshaft trouble as well.

Bigger wheels are much harder to cranks than smaller..

It is therefore interesting  (to me at least  ) if somebody know if the A2 crank changes has been described somewhere apart from Yeadon?

Improving UK steam  locomotive policy a sekel to late is just a hobby but I cannot help thinking that a B16 machinery with a bigger boiler and and wheelset under firebox could have been the only nessecary UK pacific solution?

Edited November 7, 2018 by Niels

[micklner]

A2 History here

 

https://traders.scalefour.org/greatcentralmodels/

 

A small class and were never going to have a long history ( I am surprised Gresley bothered fitting a A1 Boiler to one)  as more modern designs arrived.

 

B16 no obvious connection to the A2

 

b16.php

[Michael Edge]

They fitted one with the A1 boiler to create a spare for the others, there were no spare boilers for the Raven Pacific's.

[The Black Hat]

Good points raised, Black Hat.  I am fairly confident that Nigel Gresley's choice of his own engine for future development was the correct one and not a mistake brought about by his own self confidence; he was happy to use NER and GER designs both for continued production and development; Collett at Swindon wasn't as accommodating with his constituent company's designs and tried his best to alter them to his own specifications.  It is arguable that the 56xx role could have easily been satisfied by cheaper Rhymney Rs, and that the Taff Vale A was the basis of a better machine for Valleys passenger work than any GW design.  The A1s were designed for the GN section of the ECML and the Leeds branch, but proved themselves capable of the NER and NBR work as well.  

 

The NER, had it continued in existence, could have afforded to electrify the York-Newcastle and probably Hull-Leeds lines, but the combined poverty of the LNER hobbled this idea.

 

I agree it would have been interesting to try out an A2 on a Paddington-Bristol, or the West Country main line as far as Exeter, but I suspect the South Devon and South Wales main line banks would have been a bit much for it.  A1s were less than ideal for this as well!

 

The point about development of the engines is one that many go over between the Gresley A1 and Raven A2. However, most enthusiasts always compare engines with the exact things as they stand before them, when circumstance needs to be taken into consideration. Q6 is a far more powerful engine than many realise, its ability to haul heavy freight is enhance away from home turf as the NER had some serious gradients to contend with on some routes. The Raven A2 was built as a means to get a more powerful express engine, needed for the York - Newcastle section. Good steaming, fast running on sections where the gradients were often favourable, but some still were quite steep (around Durham in particular). To do this quickly Raven has obviously extended the successful Atlantic engine that was in the NER fleet. Raven did take good designs and update them where needed, but also understood the technological advances that electrification could bring. Raven was obviously also a pragmatist in some ways, wanting to push electrification for heavy mineral and passenger use, while using steam power for other areas, including those that might test the limits of electrification at that point. Hence Q7 to lift heavy freight, a masterpiece that in exchange trials walked away with hauling heavy loads compared to others.

 

Gresleys A1 was a good design and had a lot of potential. The Raven A2 might not have been displaying the same, but then I think Ravens design was more a case of a limited number needed, with the hope of electrification later, rather than a more comprehensive design starting from scratch. Gresleys adaptations for his A1 eventually produced a better engine, but not after subtle but substantial modification, eventually becoming A3. Comparisons with the castle showed where improvements were needed. The Castle would also be better at climbing given the weight onto the drivers being a 4-6-0, but its power and control must have impressed immensely. Gresleys designs to that point, in my opinion, were not as strong as what others had on other networks. Yet again, he favoured GNR designs, with his own becoming a group standard, much in the same way that British Railways adopted a load of Midland designs. K3 was another engine constantly tinkered with, until ultimately replaced by V2, whereas the NER's B16, was a design doing similar work but had many examples that remained as built and to the end of their working lives. While Gresley concentrated on express designs and technical innovations that could have modified the use of steam, electrification was virtually ignored. Some pregrouping areas were building relatively new designs, but other group standard designs away from the prestigious roles such as mixed goods and secondary passenger roles often saw Darlington used as the area of design and construction, with NER practice of standardisation continuing and clearly noticeable (D49, B17, J39).

 

I do think that Gresley was a good designer. He was able to try and push steam to its limit. It would be interesting how he might compare, if Mallard had not record the high speed run as that is the part that gets him the greatest accolade and rightly so as it was achieved. Scotsman has its legacy as much down to PR and interest, as much as engineering achievement - but this isn't to decry Gresley or his work. Really, Churchwood, Stanier, Raven and Riddles were masters of the art, much as Gresley was too.

 

So for all we look at the difference between the Raven A2 and the Gresley A1, I think Ravens A2 was built to service a need and a time, whereas the A1 was built for a role that could be extended and adapted over time and perhaps it was fortunate that the design could allow itself to be adapted more. It might have been interesting if things were different, but Gresleys work was some of the best and his legacy for many will be seen as such.

 

 

[The Johnster]

The Raven and Gresley Pacifics were both  open to improvements.

Bulleid proved that well balanced three-cylinder engines with 6 feet drivers were more than fast enough for UK passenger trains.

A six feet nine wheelset is at least 30% more heavy than a six feet two.

It is unsprung and does a lot of no no to the track.

One can maybe argue that even two cylinder Brittanias were fast enough.

By going from B16 five feet eigth to A2 six feet eigth drivers Raven got at least six tons un-sprung as ballast and maybe some crankshaft trouble as well.

Bigger wheels are much harder to cranks than smaller..

It is therefore interesting  (to me at least  ) if somebody know if the A2 crank changes has been described somewhere apart from Yeadon?

Improving UK steam  locomotive policy a sekel to late is just a hobby but I cannot help thinking that a B16 machinery with a bigger boiler and and wheelset under firebox could have been the only nessecary UK pacific solution?

 

Another point about smaller drivers is that they are helpful in getting away from standing starts, in that the chance of slipping is reduced and the rate of acceleration enhanced (you are effectively lowering the gearing of the loco).  The drivers are unsprung but balanced, and should not in themselves be a track issue beyond the weight.  

 

The imperative for the largest possible driving wheels in the pursuit of speed goes back to very early days, when fast running pushed the then available performance boundaries of cylinder and motion lubrication; the bigger the driving wheel, the slower your pistons move at any given speed on the track.  The GW Iron Dukes were state of this art when they were introduced in 1850, and capable of running a 70mph timetable.  By the early 1920s, lubrication had developed in to a more exact, predictatble, and better performing feature of locomotive design and use, and both the performance of the lubricants themselves and the delivery systems were much improved.   The later period of steam locomotive performance history features fast running from locos with smaller wheels, which enabled fatter boilers to be got in; this started with the GW Kings and was continued on the LNER post Gresley and the Southern under Bullied.  

 

Riddles' 9Fs with 5' drivers were capable of 90mph running, as proved on the ECML and for a brief period at Canton with Evening Star on the 'Red Dragon', but in both cases officialdom frowned.  A modern steam locomotive (if there is such a thing) with roller bearings in the motion and high performing lubricants can run all day at a very high piston speed without problem, and the limiting factor shifts to the exhaust, which has to vent very freely in order to deal with the huge amount of steam that has to be got rid of very quickly so that it does not impede the loco's progress.  

 

But railways were an extremely small c conservative environment, and much store was place in received wisdom.  Give any 1930s designer half a chance and he'll either be content with what is fundamentally a Victorian inside cylinder 0-6-0 for general goods work (LMS 4F), or he'll actually design a new one (Collett Goods, J38, J39, Q); even the iconoclast Bullied did this in the 1940s (Q1).  The idea of getting the largest diameter driving wheels possible on express locos died long and hard in the UK, and this hampered boiler size and hence steam raising for many years.  The issue was never really addressed on the LMS, and it is significant that a Merchant Navy can run just as fast as a Duchess in daily service.

 

The speed war between the LMS and LNER in the 30s probably perpetuated the 'largest possible driving wheel' concept, though of course speeds of 114, or 126, mph, while admirable in their own right, have little impact on daily running with full loads.  And one nearly ended in disaster while the other resulted in the loco being removed from the train as a failure at the next stop.

['CHARD]

He had an excellent name too - Vincent Raven. Sounds like the bassist in an 80s Goth band. He's probably somewhere on the soundtrack to The Crow.

 

You did know this?  

 

Paul Vincent Raven (16 January 1961 – 20 October 2007) was a bassist best known for his work in the post-punk group Killing Joke.

 

[Zomboid]

I didn't actually. Was that the name he was born with?

[Niels]

 

 

The imperative for the largest possible driving wheels in the pursuit of speed goes back to very early days, when fast running pushed the then available performance boundaries of cylinder and motion lubrication; the bigger the driving wheel, the slower your pistons move at any given speed on the track.  The GW Iron Dukes were state of this art when they were introduced in 1850, and capable of running a 70mph timetable.  By the early 1920s, lubrication had developed in to a more exact, predictatble, and better performing feature of locomotive design and use, and both the performance of the lubricants themselves and the delivery systems were much improved.   The later period of steam locomotive performance history features fast running from locos with smaller wheels, which enabled fatter boilers to be got in; this started with the GW Kings and was continued on the LNER post Gresley and the Southern under Bullied.  

 

Riddles' 9Fs with 5' drivers were capable of 90mph running, as proved on the ECML and for a brief period at Canton with Evening Star on the 'Red Dragon', but in both cases officialdom frowned.  A modern steam locomotive (if there is such a thing) with roller bearings in the motion and high performing lubricants can run all day at a very high piston speed without problem, and the limiting factor shifts to the exhaust, which has to vent very freely in order to deal with the huge amount of steam that has to be got rid of very quickly so that it does not impede the loco's progress.  

 

The speed war between the LMS and LNER in the 30s probably perpetuated the 'largest possible driving wheel' concept, though of course speeds of 114, or 126, mph, while admirable in their own right, have little impact on daily running with full loads.  And one nearly ended in disaster while the other resulted in the loco being removed from the train as a failure at the next stop.

 

 

A Stirling 8 feet single had 18 times 28 inch cylinders.Let us  rebuild it  with five feet drivers and 18 times 17.5 inch cylinders and  identical valve areas

Performance and piston velocity is unimpared.

The false idea was that big wheels rode better(Somehow true on uneven roads) and had better traction coefficient .

If true,electric trains would have 2 meter drivers today.

[34theletterbetweenB&D]

Well whatever the arguments on express steam driver diameters, the mostest fastestest locomotives had BIG drivers. Compare to Germany or the USA and there also over 2 metres / circa 80" was the choice for speed. The mighty F7 4-6-4 for the Milwaukee Road's 'Hiawatha' was 84"! (These probably were the fastest steam locos ever operated, which makes it a shame that no effort was made to formally test their speed capability. That they reliably operated the fastest booked steam schedule which required an 81 mph end to end average over just short of an 80 mile stage gives some idea of the capability.)

['CHARD]

I didn't actually. Was that the name he was born with?

 

Yes indeed!

[The Johnster]

Well whatever the arguments on express steam driver diameters, the mostest fastestest locomotives had BIG drivers. Compare to Germany or the USA and there also over 2 metres / circa 80" was the choice for speed. The mighty F7 4-6-4 for the Milwaukee Road's 'Hiawatha' was 84"! (These probably were the fastest steam locos ever operated, which makes it a shame that no effort was made to formally test their speed capability. That they reliably operated the fastest booked steam schedule which required an 81 mph end to end average over just short of an 80 mile stage gives some idea of the capability.)

 

The big US loading gauge enabled their designers to take advantage of the ability to include both large diameter driving wheels and very large boilers in a way that was never possible in the UK, and they tended to allow for much higher axle loadings as well.  The NYC's Niagaras were another very fast class, designed to haul a 1.000 ton train at 100mph in daily timetabled service; I believe these had 80 inch drivers.  I'd make the point that employing a large driver to achieve an acceptable ride quality was probably a justifiable concept in the early days, as was keeping your centre of gravity down as low as possible; who would have designed 'Cornwall' in it's original form for any other reason!