BR Standard Classes on the Western Region

[PenrithBeacon]

Actually the LMS was very much alive to the issue and was in the preliminary stages of planning a mogul replacement for the 4F and replacing the axleboxes on the 7F but planning for the coming war stopped both projects dead.

The issue of the steaming of the Ivatt 4F is very much a separate matter and has a lot to do with Ivatt wanting the engine to have a double chimney. A mistake for such a small locomotive.

[Phil Bullock]

6 minutes ago, PenrithBeacon said:

Actually the LMS was very much alive to the issue and was in the preliminary stages of planning a mogul replacement for the 4F and replacing the axleboxes on the 7F but planning for the coming war stopped both projects dead.

The issue of the steaming of the Ivatt 4F is very much a separate matter and has a lot to do with Ivatt wanting the engine to have a double chimney. A mistake for such a small locomotive.

 

Hmm is it size? I know the Ivatts had a dreadful reputation - Doodlebugs on the S&D. But the Southern men liked their double chimney 4MT 75xxx IIRC and saw them as CLass 5s....

[jim.snowdon]

37 minutes ago, PenrithBeacon said:

Actually the LMS was very much alive to the issue and was in the preliminary stages of planning a mogul replacement for the 4F and replacing the axleboxes on the 7F but planning for the coming war stopped both projects dead.

The issue of the steaming of the Ivatt 4F is very much a separate matter and has a lot to do with Ivatt wanting the engine to have a double chimney. A mistake for such a small locomotive.

What I understood was that the problem was the lack of space on the crank axles of both to get in decent width bearing journals - essentially the design weakness of all large inside cylindered locomotives with Stephenson type valve gears on standard gauge.

 

Jim

Edited April 29, 2020 by jim.snowdon
Added information.

[The Johnster]

As much for my own amusement as for information or to make a point, here's a similar comparison between the 4575 and BR standard 2MT tank.

 

                                                       4575                                              84xxx

 

Driving wheel dia,                       4'7½"                                              5'

Loco weight                                 61 tons                                         66 tons

Adhesive weight                         47 tons                                         41 tons

Cylinders                                      17x24"                                         16½x24"

T.E.                                                21,250 lbs                                    18,515 lbs

GW power                                        C                                                     -

BR power                                      4MT                                                2MT

Overall length                             36'4½"                                            38'9½" 

 

I've not included boiler pressure, 200lbs psi for both locos, because the boilers are quite dissimilar, making the comparison meaningless, unlike the Swindon no.2 common to 5101 and 82xxx.  I imagine the 84xxx would equate to GW power B.  I included overall length to illustrate that the locos are of a muchness for size; the BR loco is also an inch wider than the 4575.  There's not much to choose between the cylinder sizes.  The 84xxx larger driving wheels probably make it a steadier rider and should give it the edge for speed, but this is probably of not much importance given the duties both locos were employed on.  Conversely, the GW loco should accelerate from rest more quickly, which is of some importance on stopping passenger train work if timings are sharp.  4575 is GW RA yellow, and 84xxx BR RA 3, which is probably comparable but in practice I'd say the 84xxx has the edge here.

 

Comments regarding the 84xxx should in theory apply to the Ivatt 2MT tank as well.  There is no equivalent GW tender loco to the 45xx/4575, but the nearest is probably the Collett Goods, 3MT and yellow RA.  It is perhaps fairer to compare this to the 82xxx and 77xxx.  There is an equivalent tender loco to the 84xxx, the 78xxx mogul based closely on the Ivatt 2MT 'Mickey Mouse' mogul and sharing common parts and dimensions with that and the 2MT tanks as well.  

 

Some work was done at Swindon to improve the steaming of the Ivatt Mickey Mouse after Brecon and Moat Lane crews working the Mid Wales line complained that it was inferior to the Dean Goods that the Ivatts replaced as new engines in 1950.  Loads and timings on this route are not exactly onerous, and the incident caused a bit of a spat when the Loco Dept manager at Oswestry passed the complaint to Derby, which responded that perhaps the loco would steam better with a copper capped chimney!  Swindon did some work on the draughting which resulted in a Mickey Mouse tested at 60mph with 20 coaches, which nobody could complain at and many of the Mickey Mice were given this arrangement, not just WR ones.

 

AFAIK, these improvements were never applied to the Ivatt 2MT tanks, or the BR 78xxx or 84xxx, but perhaps they should have been.

[Phil Bullock]

And back in the good days when there was steam on the Cambrian in preservation - SVR sent a Manor and 75069 over to run one summer. 75069 failed so another loco was needed - 46443 was sent so a Class 4 replaced with a Class 2, rather to the trepidation of loco crews. They need not have worried - 46443 acquitted itself well on 6 coach trains.

 

Rather more onerous than the two coach workings on the 3 Cocks to Moat Lane workings although the gradients on that line were fierce in places. Erevry time I am fluff chucking on the Wy south of Builth I imagine an Ivatt hooter sounding up the valley....

[MidlandRed]

7 hours ago, The Johnster said:

Some work was done at Swindon to improve the steaming of the Ivatt Mickey Mouse after Brecon and Moat Lane crews working the Mid Wales line complained that it was inferior to the Dean Goods that the Ivatts replaced as new engines in 1950.  Loads and timings on this route are not exactly onerous, and the incident caused a bit of a spat when the Loco Dept manager at Oswestry passed the complaint to Derby, which responded that perhaps the loco would steam better with a copper capped chimney!  Swindon did some work on the draughting which resulted in a Mickey Mouse tested at 60mph with 20 coaches, which nobody could complain at and many of the Mickey Mice were given this arrangement, not just WR ones.

 

AFAIK, these improvements were never applied to the Ivatt 2MT tanks, or the BR 78xxx or 84xxx, but perhaps they should have been.

 

Do we know what improvements were made? (Although the WR ones received lined green livery they didn't receive copper capped chimneys!!!)

interestingly the larger 43xxx Ivatt Moguls had double chimneys, quoted earlier in this thread as a waste on such a small loco. 

[Phil Bullock]

20 minutes ago, MidlandRed said:

 

Do we know what improvements were made? (Although the WR ones received lined green livery they didn't receive copper capped chimneys!!!)

interestingly the larger 43xxx Ivatt Moguls had double chimneys, quoted earlier in this thread as a waste on such a small loco. 

 

Bit of a clue here

 

https://www.national-preservation.com/threads/locomotive-front-end-designs.722354/page-2

 

Suspect those mods would have increased air flow through the grate, improving combustion

[MidlandRed]

2 hours ago, Phil Bullock said:

 

Bit of a clue here

 

https://www.national-preservation.com/threads/locomotive-front-end-designs.722354/page-2

 

Suspect those mods would have increased air flow through the grate, improving combustion

 

Interesting - re the Mickey Mice on 3 Cocks etc, the engineer in me says great that Swindon could improve them, the commercial in me says did this improve commercial performance? Punctuality, running costs, service improvement, passenger numbers? That the services were ultimately closed as unremunerative anyway is also interesting (and unsurprising given the sparsely populated rural nature of the territory). So the unasked question is what was the point, other than an engineering challenge that Swindon could and did meet, and to answer some crew queries? 

 

Interesting that WRs 9Fs 92203 on (though 30 were built by Crewe) all had double chimneys from new and some of the WR first 8 had them retrofitted. From an enthusiast point of view I think they look better and certainly can contribute to spectacular steam effects in some conditions. However elsewhere in the country the 9Fs were used to their strengths on fast heavy freight over long or longish distances and also heavy freight over shorter distances on steep gradients (eg Consett; Brymbo), and almost exclusively made do without double chimneys - one wonders why this was? 

 

Edited April 30, 2020 by MidlandRed

[Phil Bullock]

Was it an attempt to reduce the number of turns on which bankers were needed up Ebbw Vale? I know the Consett turns were banked - how about Brymbo?

 

 

[PenrithBeacon]

11 hours ago, jim.snowdon said:

What I understood was that the problem was the lack of space on the crank axles of both to get in decent width bearing journals - essentially the design weakness of all large inside cylindered locomotives with Stephenson type valve gears on standard gauge.

 

Jim

Jim,

What you say here is true, but it is also true that this applies to all designs of this type. By the 1920s other railway companies, particularly the GWR, had evolved lubrication systems that mitigated the problem. It isn't the size of the bearing that is the issue but the way that oil was given to it. The LMS introduced the oil pad underneath the bearing at the behest of Stanier when he was instructed to sort out the Scots soon after he was recruited. It was this design that was going to be applied to the 7F (the 4F was considered to be obsolete and not worth it, scrap and build beckoned) but planning for WW2 intervened and it was never done.

The underkeep method of lubrication was introduced pretty well symultaneously in France and the US in the 1890s. Not sure who was first.

Cheers

[MidlandRed]

1 hour ago, Phil Bullock said:

Was it an attempt to reduce the number of turns on which bankers were needed up Ebbw Vale? I know the Consett turns were banked - how about Brymbo?

 

 

 

Consett was to an extent, similar to Ebbw Vale - not sure if Brymbo were banked but they didn't use double chimney 9Fs generally unless odd ones went there on reallocation towards the end of steam (Consett never had them) - the other famous ore working of 9Fs was Shotton (but through flatter territory). 92079 on Lickey was not double chimney either - though it's occassional stand

ins were - largely because the remaining WR 9F contingent were. 

My 9F bible indicates that Swindon carried out trials with 92178 (the first of their main build) at Swindon and on the road between Reading and Stoke Gifford - they were not published but the RCTS book has raw data in tables obtained from NRM  - much of the test data was invalid for various reasons but water evaporation suggested a maximum steam rate of 31000 lb/ft compared with 29000 lb/ft achieved in tests at Rugby with a single chimney example. This is not a large improvement but nevertheless was applied from 92183 on - it was retrofitted to the other WR allocated locos within 92000-7, but not to any LMR, ER or NER locos. 

This Swindon work had been generated, it seems, on the back of greater improvements achieved at Swindon with double blast pipes on the standard class 4 (75xxx) locos. 

Interestingly the 4% horsepower improvement over double blast pipe achieved by the Giesel fitted 92250, and improved efficiency was considered too marginal to be replicated in road conditions so was not applied to other 9Fs. Presumably the cost of adding a double blast pipe to 9Fs already in build was marginal anyway even if the improvement was marginal in reality. 

Edited April 30, 2020 by MidlandRed
More info

[PenrithBeacon]

There is a B&R video which includes footage of the Brymbo branch. IIRC it includes a sequence of a banked train, but I might be wrong.

Cheers

[jim.snowdon]

2 hours ago, MidlandRed said:

 

Consett was to an extent, similar to Ebbw Vale - not sure if Brymbo were banked but they didn't use double chimney 9Fs generally unless odd ones went there on reallocation towards the end of steam (Consett never had them) - the other famous ore working of 9Fs was Shotton (but through flatter territory). 92079 on Lickey was not double chimney either - though it's occassional stand

ins were - largely because the remaining WR 9F contingent were. 

My 9F bible indicates that Swindon carried out trials with 92178 (the first of their main build) at Swindon and on the road between Reading and Stoke Gifford - they were not published but the RCTS book has raw data in tables obtained from NRM  - much of the test data was invalid for various reasons but water evaporation suggested a maximum steam rate of 31000 lb/ft compared with 29000 lb/ft achieved in tests at Rugby with a single chimney example. This is not a large improvement but nevertheless was applied from 92183 on - it was retrofitted to the other WR allocated locos within 92000-7, but not to any LMR, ER or NER locos. 

This Swindon work had been generated, it seems, on the back of greater improvements achieved at Swindon with double blast pipes on the standard class 4 (75xxx) locos. 

Interestingly the 4% horsepower improvement over double blast pipe achieved by the Giesel fitted 92250, and improved efficiency was considered too marginal to be replicated in road conditions so was not applied to other 9Fs. Presumably the cost of adding a double blast pipe to 9Fs already in build was marginal anyway even if the improvement was marginal in reality. 

Wasn't the case for double vs. single chimneys determined more by the usage to which the loco would be put, the double chimney being more suited to duties where high boiler output was required on a sustained basis, whereas the single chimney boilers were better suited to lower susyained output with occasional demands for high output?

 

Jim

[The Stationmaster]

On 28/04/2020 at 20:29, MidlandRed said:

I get all of that Stationmaster.

 

I also understand that the class 45/46 which first went to Bristol were part of the NE/SW dieselisation and fundamentally LMR (with an even older fashioned hat on, Midland Railway). However locos were allocated at Leeds (Holbeck - NER) Derby (LMR) and Bristol (WR) (initially some at Barrow Road)- and possibly some at Gateshead (NER) - so truly inter-regional. The Bristol allocated locos quickly moved to Bath Road (in fact some went straight there). So BR men would have already had the training - other than route knowledge I can't see why these locos couldn't have worked through rather than changing engines at Bristol, other than WR hydraulics were available at Bristol - the route south-westwards was WR (GWR) not LMR (MR) - and the Jubilees were replaced by WR steam at Bristol etc previously. Unless I'm fundamentally missing something here, to an extent, what happened in 1969 (class 43 Warships replaced by class 46) might have been possible from the start if the BR organisation was set up to look more holistically (which happened to an extent after the BRB was implemented in 1963, sometimes more gradually than others) rather than being confined by regional boundaries and practices..... I'm sure this is anathema to some but looking back now seems very odd. 

 

Does anyone know what routes/services those headcodes I posted refer to? 

 

I don't know exactly what happened when depots were combined at Bristol.  But I strongly suspect that some of the links weren't combined for some time due to the vast amount of route learning and traction training which would be needed if links were combined and work reallocated on the basis of overall Seniority.   If that had happened the training requirement would have been enormous with Western men learning former LMR routes and vice versa.  This pattern definitely occurred at other WR depots one example being Margam which when opened maintained separate links based on the original depots which were combined into Margam.  This avoided cross Road Learning although as the depot acquired new work and lost lots of specialised loco work a gradual combining took place. 

 

Thus at Bristol work towards Birmingham would have remained with the original Barrow Road links until retirements and changes of work allowed economic combination while at the same time former Barrow Road senior men wouldn't need to  learn the road to either Paddington or towards the West of England.  Incidentally the LMR diesels definitely went to Barrow Road at some point although no doubt not for servicing as there are photos of them stabled there which indicates they were being worked by Barrow Road men.

 

On 29/04/2020 at 09:12, slilley said:

When were these Hymeks ordered? I have spent hours going through the minutes of the BTC/BR Works & Equipment Committee and Supply Committee meetings and not found anything.  These were the two main bodies within the BTC or from 1963 onwards BR that were responsible for locomotive orders.

I don't think they ever were.

[The Stationmaster]

6 hours ago, MidlandRed said:

 

Do we know what improvements were made? (Although the WR ones received lined green livery they didn't receive copper capped chimneys!!!)

interestingly the larger 43xxx Ivatt Moguls had double chimneys, quoted earlier in this thread as a waste on such a small loco. 

A 2-6-0 went through Sam Ell's hands and received his magic touch which finally enabled it to steam as well as a Dean Goods.  The Flying Pigs had a reputationfor poor steaming and were the subjects of various experiements at Derby to - finally - improve - their draiughting, and Sam Ell probably had a hand in that as well.

[jim.snowdon]

3 minutes ago, The Stationmaster said:

A 2-6-0 went through Sam Ell's hands and received his magic touch which finally enabled it to steam as well as a Dean Goods.  The Flying Pigs had a reputationfor poor steaming and were the subjects of various experiements at Derby to - finally - improve - their draiughting, and Sam Ell probably had a hand in that as well.

Including, in the case of the Ivatt 4s, reverting back to a single chimney.

 

Jim

[The Johnster]

9 hours ago, Phil Bullock said:

Erevry time I am fluff chucking on the Wy south of Builth I imagine an Ivatt hooter sounding up the valley.

Fluff chucking: I'm never going to call anything else again, this is brilliant, but I know what you mean about imagined hooters.  Sometimes I wonder what would happen if just dropped sentences like this in to forums somewhere, out of context... 

 

6 hours ago, MidlandRed said:

Interesting - re the Mickey Mice on 3 Cocks etc, the engineer in me says great that Swindon could improve them, the commercial in me says did this improve commercial performance? Punctuality, running costs, service improvement, passenger numbers? That the services were ultimately closed as unremunerative anyway is also interesting (and unsurprising given the sparsely populated rural nature of the territory). So the unasked question is what was the point, other than an engineering challenge that Swindon could and did meet, and to answer some crew queries? 

It increased the loco's power for a tiny additional cost, and simultaneously reduced coal consumption, thus improving radically the commercial performance.  What effect this had on passenger numbers over the next decade is moot at a time when car ownership was increasing exponentially in a relatively prosperous and wealthy farming community, but it certainly did no harm, and after 1952 when the Mid Wales threw in the towel the improved locos went on to improve commercial performances elsewhere for another 5 years or so.  The service closed because the market vanished, not because it was inefficient.  It had new and improved locos and the latest Hawksworth stock, a better deal than similar rural idylls in East Anglia, or Bishop Aukland, where nobody was using the trains either in 1962 but were up to about 1958 or so.

 

Re double chimneys on Ivatt 4MTs; the original LMS built 30xx had double single chimneys, if that makes sense, angled off to each side presumably to assist with smoke lifting on locos that had a very high set boiler which could thus not use a tall single chimney; I do not know what went on inside the smokebox but the draughting was clearly a problem and needed rethinking.  Under BR, with Ivatt still in the CME seat for the LMR, single chimneys were reverted to and presumably no particular problem with smoke lifting occurred, and steaming was improved.  Further work was done to further improve performance with a double chimney; this I presume was the point at which Stationmaster suggests that Ell became involved.  Beware of taking any of this as fact, there are 3 presumptions in it, but I believe that this is more or less what happened.  

 

The BR standard 4MT moguls, basically Ivatt 4MTs with styling differences, are generally regarded as reasonably successful locos so (another Johnster presumption) presumably whatever improvements had been achieved when the Ivatts were given single chimneys, i.e. the BR build, were incorporated into the 76xxx.  I am not able to figure out why the further improvement to the Ivatt's performance was not applied to the 76xxx in the form of a double chimney, or to the similar 4MT 2-6-4T.  Double chimneys had been successfully applied to the other 4MT, the 75xxx, a Swindon product just to show that the LMR did not have total dibs on producing poorly steaming locos for Sam Ell to improve on, both by Ell at Swindon and on the Southern to a different form; both were successful in improving the loco's performance.

 

I mean overall performance, incidentally, not just the ability to pull heavier trains faster but to do it at lower coal and water consumption and with an improved ability to raise steam.  Mixed traffic locos do not require continuous high boiler output like long distance expresses or heavy freight slogging do, but the improvements were still considerable enough to be worthwhile.  A loco that has been improved in this way can be used to go faster with the same load, improving timekeeping recovery, the same speed with a heavier load, improving income generated, or used the way it was previously in which case it will use less coal and water and require less maintenance as it has been thrashed less.  Or, you can do all of these to a lesser extent simultaneously.  That it was worthwhile on a medium range mixed traffic horse suggests there was significant improvement to be made with the Swindon 75xxx, and even with this 'bad steamer' not all locos were improved.

9 hours ago, MidlandRed said:

 

Do we know what improvements were made? (Although the WR ones received lined green livery they didn't receive copper capped chimneys!!!)

No, they didn't,  though they were improved enough for Swindon to have made the point in that way...

 

Actually, plenty of GW designed locos did not have copper capped chimneys either, going back a long way.  43xx, 42xx and derivates, 28xx/2884, Aberdares, Small Prairies, 57xx and derivates, 54xx and derivates, 48/58xx, to name about half the fleet.  There seems not to have been a consistency of approach in this, which suggests that there was an actual reason for fitting copper caps to chimneys beyond that of appearance and tradition.  I would assume (another presumption, I mean assumption) that a copper cap is less prone to corrosion or splitting from expansion and contraction (it's 'ot by there), but this is not a consideration that seems to have affected the choices made.  It looks initially as if certain boilers were given cast iron chimney caps, but no.4s were copper capped on 4-4-0s they were fitted to, and not tranferred to moguls or 2-8-0/2 tanks as replacements at overhuals, for example, suggesting that there was an actual reason, but I cannot imagine what it might have been.  Things are usually done for a practical or money saving reason on railways, but some defy understanding; I refer you to the debate about ventilators on Collett bowended suburbans as modelled by Hornby.

 

The post 1956 passenger livery was liberally, and incorrectly, applied to mixed traffic locomotives by the WR, the reasoning being that they might be used on passenger trains and should look the part.  I believe all the Halls, Granges, and Manors were given it, and the Hawkworth Counties but these had ceased to be used as mixed traffic locos by then because of piston surge.  The (by that time) 14xx, and 54/64xx were also given the passenger livery, as were auto fitted 4575s; to be fair, these were locos used more or less exclusively on passenger work, and we must include 92220.  Again there is an inconsistency, with some but not all 43xx, Large Prairies, 56xx, 45xx & non auto fitted 4575s, and 2251s, WR allox Ivatt 2MT moguls and 78xxx derivates, 82xxx, 75xxx, and 73xxx receiving the livery.  Some of these classes were given an 'economy' unlined green and some were given lined black, correctly for mixed traffic locos, or unlined freight black.

 

At the time the Mickey Mice were introduced on the WR, the region was mostly correctly painting mixed traffic tender locos in lined black, and some in unlined freight black.  Mixed traffic tank locos were treated in the opposite way, mostly freight black with some lined; this included some 8750s for ecs work at Old Oak despite their 3F rating.  No locos were being painted in lined green livery other than P rated ones on the region, that is, Castles and Kings along with the surviving Stars and Saints, and the shortly to be introduced Britannias.  

 

 

 

 

 

[MidlandRed]

5 hours ago, jim.snowdon said:

Wasn't the case for double vs. single chimneys determined more by the usage to which the loco would be put, the double chimney being more suited to duties where high boiler output was required on a sustained basis, whereas the single chimney boilers were better suited to lower susyained output with occasional demands for high output?

 

Jim

 

The WR tests on 92178 appear marginal at best - the other regions used 9Fs for sustained high boiler output duties (and shorter journeys with sustained high output) without the double chimneys. If a case had actually been made for double chimneys they would surely have been retrofitted more generally than just to WR examples. 

As I said before, the cost of new build locos with double as opposed to single blast pipe chimneys was probably marginal and if that's what the WR wanted, then no problem.

That Swindon had Sam Ell who is renowned as getting the best out of the front end of locos is great - one wonders if the Swindon 9F testing was a good use of resources or perhaps a case of Swindon challenging every loco design they got their hands on whether improvements were needed, likely to be achieved or not.... 

I forgot to mention the mechanical stoker trio 92165-7 delivered out of sequence in 1958, had double chimneys - but the blast pipes were a different diameter from the Swindon design. 

 

 

Edited April 30, 2020 by MidlandRed

[PenrithBeacon]

Sam Ell wasn't always a successful guru; Duke Of Gloucester being a case in point.

[jim.snowdon]

9 minutes ago, PenrithBeacon said:

Sam Ell wasn't always a successful guru; Duke Of Gloucester being a case in point.

Didn't the group that restored find deviations from the drawings in several areas of the boiler, particularly in regard to the ash pan, that impeded air flow through the boiler?

 

Jim

[jim.snowdon]

To quote from Col. Rogers' treatise on Riddles and the 9Fs -

"Draughting had been the subject of tests carried out at Rugby and Swindon, and the pattern adopted was based on these tests. It had been shown that double and other special blast pipe arrangements could give improved results at maximum output, but were inferior in permoance at lesser outputs. Through the whole range of working they were less satisfactory than the single blastpipe. Because the majority of locomotive work demands less than the maximum output, the single blastpipe and chimney were retained on most of the engines. .........  A number of engines were indeed fitted with double chimneys, including 80 of the '9F' class. Locomotives so equipped were those likely to be employed on duties demanding a greater margin of performance. As an example, Class 4 4-6-0s, which had to work ytrains normally within the province of Class 5 4-6-0s, over routes for which the axle weights of the latter were too high, were given double chimneys. The '9F' 2-10-0s, were so extensively in demand for very heavy duties, that the 80 engines with double chimneys included 67 of the last 68 to be built. The late R C Bond told the Author that the double chimneys on these engines proved theirt worth; but that the 'Britannia' class Pacifics did not have to work hard enough to justify their provision."

 

Jim

[MidlandRed]

31 minutes ago, jim.snowdon said:

To quote from Col. Rogers' treatise on Riddles and the 9Fs -

"Draughting had been the subject of tests carried out at Rugby and Swindon, and the pattern adopted was based on these tests. It had been shown that double and other special blast pipe arrangements could give improved results at maximum output, but were inferior in permoance at lesser outputs. Through the whole range of working they were less satisfactory than the single blastpipe. Because the majority of locomotive work demands less than the maximum output, the single blastpipe and chimney were retained on most of the engines. .........  A number of engines were indeed fitted with double chimneys, including 80 of the '9F' class. Locomotives so equipped were those likely to be employed on duties demanding a greater margin of performance. As an example, Class 4 4-6-0s, which had to work ytrains normally within the province of Class 5 4-6-0s, over routes for which the axle weights of the latter were too high, were given double chimneys. The '9F' 2-10-0s, were so extensively in demand for very heavy duties, that the 80 engines with double chimneys included 67 of the last 68 to be built. The late R C Bond told the Author that the double chimneys on these engines proved theirt worth; but that the 'Britannia' class Pacifics did not have to work hard enough to justify their provision."

 

Jim

 

Interesting - double chimneys were fitted to 92165-67, 92183-92249 (Giesel to 92250) and 92178. They were retro fitted to 92000-92002, 5 and 6. Which is 77 locos. It is possible 92163/4 (planned for stokers but not fitted) and 92079 were included in the numbers as they were planned to have double chimneys but didn't receive them.

The matter of inconsistency for me is the WR argued in the early 1950s the extra annual running cost of a 9F was not balanced on the WR owing to its operating characteristics, as the extra power of the locomotive couldn't be used. So, unless things had changed in a couple of years, why try to improve the steam rate when the stock power couldn't be used in the first place? 

[PenrithBeacon]

2 hours ago, jim.snowdon said:

Didn't the group that restored find deviations from the drawings in several areas of the boiler, particularly in regard to the ash pan, that impeded air flow through the boiler?

 

Jim

Yes, but that isn't relevant to a comment on Elle's work. Basically he gave an 8P Pacific two chimneys each intended for a Class 2 0-6-0. Crackers.

His work was predicated on the inherent superiority of a small Victorian locomotive. Not good engineering.

[jim.snowdon]

26 minutes ago, MidlandRed said:

 

Interesting - double chimneys were fitted to 92165-67, 92183-92249 (Giesel to 92250) and 92178. They were retro fitted to 92000-92002, 5 and 6. Which is 77 locos. It is possible 92163/4 (planned for stokers but not fitted) and 92079 were included in the numbers as they were planned to have double chimneys but didn't receive them.

The matter of inconsistency for me is the WR argued in the early 1950s the extra annual running cost of a 9F was not balanced on the WR owing to its operating characteristics, as the extra power of the locomotive couldn't be used. So, unless things had changed in a couple of years, why try to improve the steam rate when the stock power couldn't be used in the first place? 

The WR might have arguing against using them, but BR wasn't just the Western Region. What Swindon was, though, was the centre for boiler design and, without any argument, draughting. It was the other regions that had the duties that merited the capabilities of the double chimneys.

 

Jim

[PenrithBeacon]

I'm astonished that BR(W) couldn't see the value of a double chimney 9F on the Fawley oil trains or the S&DJR summer passenger trains. I think it did and this is just enthusiast talking not professional railwaymen.

Edited April 30, 2020 by PenrithBeacon
Finger trouble