Imaginary Locomotives

[Traintresta]

There has been quite a bit of interest in the so called A0 Pacific of the LNER in relation to people recreating Gordon from Thomas the Tank Engine, in various forms. 

 

One proposal for the LNER Pacific that seems to have been overlooked is the development from the 1915 proposal that appeared in 1920 on the drawing boards of Doncaster. This image was taken from Brian Harsnape’s Gresley Locomotives a pictorial review.

 

Please excuse the glare from the lights, I’ll scan it properly at the weekend. 

 

 

[timbowilts]

50 minutes ago, Traintresta said:

One proposal for the LNER Pacific that seems to have been overlooked is the development from the 1915 proposal that appeared in 1920 on the drawing boards of Doncaster. This image was taken from Brian Harsnape’s Gresley Locomotives a pictorial review.

 

What a very odd tender that is, unequal wheelbase and a very lightly loaded middle axle. I wonder what the thinking was?

Tim T

[Gibbo675]

7 minutes ago, timbowilts said:

What a very odd tender that is, unequal wheelbase and a very lightly loaded middle axle. I wonder what the thinking was?

Tim T

Hi Tim,

 

The unequal wheel base is standard for LNER six wheel tenders such as were trailed by B1's, V2's, K4's and the rest. I don't know the actual reason but I think it is something to do with the an even distribution of coal and water at a median loading over the axles.

 

Gibbo.

[Traintresta]

How about Thompson’s original Pacific design? Divided drive, 6’2” drivers, I think an A4 style boiler and A3 style cab, again with a 6 wheel tender. 

[AlfaZagato]

Have evolutions of Raven's Pacific ever been discussed here?   As though Raven had taken the helm in stead of Gresley after grouping?    I sadly don't know enough of Raven's work to say may where he may have gone with development.  

 

I did have a kit-built City of Nottingham some years ago, but I sold it on as not in line with my interests at the time.    Came and went cheap.     I found the actual and apparent length in comparison to a Gresley Pacific attractive.   Maybe a shortened driver wheelbase to allow a larger, deeper firebox and a trailing bogie?

[Zomboid]

Raven was into electrification is about all I know. I suspect he would have pushed harder in that way, though whether he'd have got anywhere is another question.

 

His A2s do indeed look very long, probably because of the parallel boiler - a tapered boiler counteracts the effect of perspective in a front 3/4 view (and increases it in a rear 3/4, but those are less commonly taken), so the whole loco appears a bit shorter. The drive being to the front axle may be a factor as well.

 

I don't know the dimensions, they may also have actually been very long...

[Niels]

The Raven A2 had a loco wheelbase of  37 feet and two.

Three cylinder pacifics do not really need big wheels.

He could have put B16 machinery with five feet 8 drivers on and would have had a more pleasing apperance.

Edited May 30, 2019 by Niels

[Satan's Goldfish]

All the mention of 2-x-4 tender wheel bases I thought I'd explore it. The 2-8-2 I rustled up using a Coronation boiler with 9f wheels always had a big gap from the rear driver to the rear axle. So I've replaced the rear axle with the front bogie from a King with slightly reduced spacing. The outside bearing axle sits under the fire box,  and the inside bearing axle sits under the cab.

 

No reason it couldn't also work under a 2-6-4 with bigger driving wheels.

[Traintresta]

4 hours ago, AlfaZagato said:

Have evolutions of Raven's Pacific ever been discussed here?   As though Raven had taken the helm in stead of Gresley after grouping?    I sadly don't know enough of Raven's work to say may where he may have gone with development.  

 

I did have a kit-built City of Nottingham some years ago, but I sold it on as not in line with my interests at the time.    Came and went cheap.     I found the actual and apparent length in comparison to a Gresley Pacific attractive.   Maybe a shortened driver wheelbase to allow a larger, deeper firebox and a trailing bogie?

I strongly believe that the NER pacific was simply Raven's attempt to place himself in the lead for the CME's position at grouping. Had he made a real attempt, that wide fire box wouldn't have been hanging around on the end there like an afterthought.  The wheelbase from the rear driver to the trailing axle and then the distance to the back of the cab is far to large. Plus the boiler tubes were four foot shorter than the bar fell. This loco definitely wasn't thought out properly but could have become something much more successful.

 

3 hours ago, Zomboid said:

Raven was into electrification is about all I know. I suspect he would have pushed harder in that way, though whether he'd have got anywhere is another question.

 

His A2s do indeed look very long, probably because of the parallel boiler - a tapered boiler counteracts the effect of perspective in a front 3/4 view (and increases it in a rear 3/4, but those are less commonly taken), so the whole loco appears a bit shorter. The drive being to the front axle may be a factor as well.

 

I don't know the dimensions, they may also have actually been very long...

This was probably the other reason why there was little effort put into the Pacific.

 

2 hours ago, Niels said:

The Raven A2 had a loco wheelbase of  37 feet and two.

Three cylinder pacifics do not really need big wheels.

He could have put B16 machinery with five feet 8 drivers on and would have had a more pleasing apperance.

This was something I pondered a few pages back, would a 5'8" drivered Pacific be of any use and would it be able to run at the speeds usually typical of pacifics on express trains?

 

I've got a V2 shell that I was going to use for a Thompson Esq fantasy build but a 5'8" pacific could be a tempting prospect.

[Niels]

32 minutes ago, Traintresta said:

 

 

This was something I pondered a few pages back, would a 5'8" drivered Pacific be of any use and would it be able to run at the speeds usually typical of pacifics on express trains?

 

 

 

Bulleids were 6 feet two and surely fast enough.

Many express pacifics hauled trains were less than a mile per minute on the level.

ISBN: 978-3-88255-770-1

 

Pacifics main force was  big grates that kept clean longer than on 4-6-0s

Edited May 30, 2019 by Niels

[Traintresta]

33 minutes ago, Niels said:

Bulleids were 6 feet two and surely fast enough.

Many express pacifics hauled trains were less than a mile per minute on the level.

ISBN: 978-3-88255-770-1

 

Pacifics main force was  big grates that kept clean longer than on 4-6-0s

So better for distance or prolonged running rather than pure speed?

[Traintresta]

5 hours ago, AlfaZagato said:

Have evolutions of Raven's Pacific ever been discussed here?   As though Raven had taken the helm in stead of Gresley after grouping?    I sadly don't know enough of Raven's work to say may where he may have gone with development.  

 

I did have a kit-built City of Nottingham some years ago, but I sold it on as not in line with my interests at the time.    Came and went cheap.     I found the actual and apparent length in comparison to a Gresley Pacific attractive.   Maybe a shortened driver wheelbase to allow a larger, deeper firebox and a trailing bogie?

I forgot to say that it was the extreme wheelbase of the Raven pacific, and the poor layout of the GCR pacific that got me looking at 4-6-4's.  Both w9ouldhave been good candidates in my opinion, especially given the not so hilly routes they ran, albeit the GCR pacific was originally intended for the Woodhead route but could have taken over from the directors on the London extension.

[Compound2632]

1 hour ago, Traintresta said:

I strongly believe that the NER pacific was simply Raven's attempt to place himself in the lead for the CME's position at grouping.

 

This loco definitely wasn't thought out properly but could have become something much more successful.

 

 

 

These locomotives had the approval of the NER's board - or at least the Locomotive Committee thereof - as would all locomotive construction. So it cannot have been a case of Raven's personal motives. (Robinson was the senior man by three years but both he and Raven were well into their 60s, so Raven can have had no expectations. The story usually told is that Robinson was offered the job but declined, recommending Gresley.) 

 

By the accounts I've read, the five locomotives of this class were at least as successful as Gresley's first pacifics. 

[Niels]

New Pacific

The best UK 4-6-2 will be a Pacified B16/3.

Will look and perform better than the Thompson A2s.

Raven B16s have cylinder Throw-over  clearance problems  due to utilizing cylinders and valve gear from a three-cylinder mineral engine.

On such an 0-8-0 animal 6 feet 8 is the absolute minimum outside cylinder centerline distance.

On a front driven 4-6-0 or 4-6-2 it can be 6 feet two or three as on Midland Compound or Adams 4-4-0s.

And most American 4-4-0s.

Using B1 cylinders and valve gear outside is possible because pacifics do not need to have frame plates as close to wheel insides as 4-6-0s.

That is the Bulleid  pacific scheme that is  tranfered  to BR Britanias and gives frame cracks.

Two big piston thrusts farther out from frames with no inside cylinder to stiffen the cylinder zone is not smart.

Wheelbase not longer than other UK pacifics and much better  accessability to inside mechanic.

Edited May 31, 2019 by Niels

[melmerby]

12 hours ago, Compound2632 said:

 

By the accounts I've read, the five locomotives of this class were at least as successful as Gresley's first pacifics. 

The spiel on Wikipedia doesn't cover them with glory as they were reputedly poor steamers.

Even the LNER encyclopedia doesn't give them much praise, considering them inferior to the A1

https://www.lner.info/locos/A/a2.php

Gresley didn't dismiss them completely as he tried to improve their performance  by fitting one (2404) with an A1 style boiler, without improvement.

 

Mind you even the A1 was initially less successful than a GWR Castle, a much smaller loco

[Compound2632]

12 minutes ago, melmerby said:

The spiel on Wikipedia doesn't cover them with glory as they were reputedly poor steamers.

Even the LNER encyclopedia doesn't give them much praise, considering them inferior to the A1

https://www.lner.info/locos/A/a2.php

Gresley didn't dismiss them completely as he tried to improve their performance  by fitting one (2404) with an A1 style boiler, without improvement.

 

Mind you even the A1 was initially less successful than a GWR Castle, a much smaller loco

 

I suspect an element of history being written by the victors.

 

I've found the previous discussion: this and the following posts: 

 

[PenrithBeacon]

1 hour ago, melmerby said:

The spiel on Wikipedia doesn't cover them with glory as they were reputedly poor steamers.

Even the LNER encyclopedia doesn't give them much praise, considering them inferior to the A1

https://www.lner.info/locos/A/a2.php

Gresley didn't dismiss them completely as he tried to improve their performance  by fitting one (2404) with an A1 style boiler, without improvement.

 

Mind you even the A1 was initially less successful than a GWR Castle, a much smaller loco

The conventional view of these locomotives, which I believe was originated by OS Nock, was that the the boiler didn't stream well. However this is contradicted by the RCTS series on LNER locomotives where it is stated, quite categorically, that when comparative tests were done the NER boiler steamed better than Gresley's.

 

I have learnt to be very wary of Nock's opinions.

 

Regards

[Compound2632]

Nock is good enough on the general, romantic, survey - I've long had and enjoyed his The Golden Age of Steam - although his recollections of the pre-grouping railways are projections back from his actual experience of the 1920s. (He was born in 1905.) Read more than a handful of his books and you'll soon realise how much he repeats himself. 

 

The topic on which he is genuinely competent is train speed timing; Speed Records on Britain's Railways remains authoritative, as far as I'm aware.

[runs as required]

30 minutes ago, Compound2632 said:

Nock is good enough on the general, romantic, survey - I've long had and enjoyed his The Golden Age of Steam - although his recollections of the pre-grouping railways are projections back from his actual experience of the 1920s. (He was born in 1905.) Read more than a handful of his books and you'll soon realise how much he repeats himself. 

 

The topic on which he is genuinely competent is train speed timing; Speed Records on Britain's Railways remains authoritative, as far as I'm aware.

Who do RMwebbers recommend as reliable commentators on contemporary railway engineering ?

I so agree about Nock and his repetitive writing.

A writer who was active in the regrouping period was Cecil J Allen - working as QC procurer of rail for the GER. He covered many a mile to rail rolling mills around Britain but, like Nock, I find his writings annoyingly light on plain speaking about technical aspects.

I suspect this was because they were dependant upon General Managers'  PR departments granting them 

For steam I return to the retrospective memoirs of Cox and Cook,  HAV Bulleid's (familial) engineering biographies 'Last Giants of Steam' and compilations such as Talbot's on the LNW.

I enjoy Tuplin's highly opinionated writing -though have little trust in his judgement about reliable effective steam motive power 

 

Other recommendations please?

dh

Edited May 31, 2019 by runs as required

[Michael Edge]

2 hours ago, melmerby said:

The spiel on Wikipedia doesn't cover them with glory as they were reputedly poor steamers.

Even the LNER encyclopedia doesn't give them much praise, considering them inferior to the A1

https://www.lner.info/locos/A/a2.php

Gresley didn't dismiss them completely as he tried to improve their performance  by fitting one (2404) with an A1 style boiler, without improvement.

 

Mind you even the A1 was initially less successful than a GWR Castle, a much smaller loco

That was only because there were no spare boilers for the Raven pacifics and they were too new to scrap. Fitting one with an A1 boiler left one boiler spare for the others.

[Compound2632]

E.S. Cox is, I think one can safely say, widely acknowledged as being partisan in his views. 

 

Charles Rous-Marten is really the equivalent of O.S. Nock but a generation earlier - Nock of course draws on his writing extensively. Both were writing for a popular enthusiast audience. W.A. Tuplin is another who had a general engineering background but is really rather suspect on locomotive matters.

 

If you want trenchant, independent-minded opinions based on contemporary observation, E.L. Ahrons is your man.

 

My impression of what I have seen of the technical press of the day is that it is stronger on reporting and description than on independent evaluation.

[The Johnster]

Ahrons was seminal for many years, and heavily influenced the later writers, but a bit light on hard detail and (IMHO) too heavily influenced by the aesthetic aspects of design.  Perhaps this is understandable from a man who'd actually experienced the likes of SECR D's, Dean and Midland singles, and late Victorian or Edwardian standards of spit and polish; those were glory days!

 

Tuplin is a good read, but I take anything he says with a pinch of salt, especially his alleged tales written by footplatemen but actually, as can be seen from the commonality of style, written by Tuplin.  I particularly like his story of the driver being asked to take a down Cornish Riviera non stop to Plymouth with 4007 instead of the booked 4077 due to an error at Old Oak, told from the fireman's perspective; great fun, but a bit unlikely...

 

He gives a good overall impression of what it was like to work a heavy job in poor conditions on a footplate, though; it may be fiction but it's good fiction!

[melmerby]

2 hours ago, Michael Edge said:

That was only because there were no spare boilers for the Raven pacifics and they were too new to scrap. Fitting one with an A1 boiler left one boiler spare for the others.

That sounds like a not especially cost effective/engineeringly sound solution.

As there already existed all the blueprints & jigs etc., producing a new A2 boiler would have been fairly straightforward, whereas all the mods needed to fit an alien boiler in the frames needed to be drawn up, pipe runs re-evaluated etc.

You then end up with one non standard loco in a small class, unless HNG did intend that maybe all would receive an A1 boiler as they needed re-boilering at some time in the future.

 

That the A2s actually lasted 12-13 years suggests they were still an asset to the company for some years.

Edited May 31, 2019 by melmerby

[34theletterbetweenB&D]

If you want an experienced engineer as author prepared to tell you 'how it was' then D.W. 'Bill' Harvey is your man.

 

He gives an interesting overview of how his experience was acquired from entering upon an apprenticeship at Doncaster, through some years at many different locations, concluding at Norwich where in particular he had charge of the Britannia allocation for working the Liverpool Street expresses. Sections of the notes he made at the time, with data, dimensions and sketch diagrams as appropriate to illustrate the points he is making; well demonstrate how he sought to overcome the many design deficiencies of the Britannia in order to produce a reliable supply of power for the workings these locos were intended for.

 

Bill Harvey's 60 Years in Steam, pub David and Charles, ISBN 0-7153-8712-X

 

17 minutes ago, melmerby said:

That sounds like a not especially cost effective/engineeringly sound solution.

As there already existed all the blueprints & jigs etc., producing a new A2 boiler would have been fairly straightforward, whereas all the mods needed to fit an alien boiler in the frames needed to be drawn up, pipe runs re-evaluated etc.

You then end up with one non standard loco in a small class, unless HNG did intend that maybe all would receive an A1 boiler as they needed re-boilering at some time in the future.

Look at it the other way around: the Raven design is a 'dead end'; whatever the qualities of the boiler, the engine and frame layout have no further development potential.

 

Doncaster works is steadily rolling out Gresley's pacific boiler, and another spare boiler in hand is always a good plan.

 

Steam engineering is relatively cheap, putting such a spare boiler on an existing loco frame isn't that expensive, and enables assessment of whether this is a worthwhile method for getting the full economic  life out of the frame and engine. If it isn't, then the boiler can be recovered to the pool for use on the standard loco taking it, when the rest of the loco is scrapped.

 

This process was not a one-off, just look at how many of the classes the LNER inherited were reboilered to Doncaster standard: B12, B16, D14-16, J18 - 20, N7, O2, O4 are well known examples.

[AlfaZagato]

Look, too, at what Churchward and Collett both did after grouping.    How many Welsh locos received No. 2s?