Prairie Tanks

[Andy Kirkham]

Perhaps because of the success of the Ivatt Mickey Mouse and the inclusion of two types among the BR Standards, It's easy to suppose that the 2-6-2 wheel arrangement was a natural choice for a medium-size  tank engine, However, it struck me the other day, that until the Grouping, the GWR pretty much had a monopoly on them (167 at the Grouping, which I suppose is not that many compared to the total stock) 

 

I find it hard to think of many other pre-group companies that had 2-6-2 tanks - especially standard gauge ones. The Alexandra Docks had a handful. Any others?

[Nick Holliday]

The Lancashire and Yorkshire Railway had some of them. Meant to be an enlarged radial 2-4-2T but nowhere near as successful and with a short life.

The Mersey Railway had some too, but they were made redundant after electrification and seven of them were sold to the ADR, as noted, and the other two went to Whitwood Colliery. Full details and drawings of these can be found in the much-missed Railway Archive magazine, Issue 5.

The LBSCR prepared drawings for what was effectively a tank version of the successful K Class, but due to war time, circumstances meant that they had to stick with the original tender version for new locos.

[Zomboid]

The tank equivalent of a 2-6-0 was more typically a 2-6-4T, presumably because of the larger bunker it allowed.

[Nick Holliday]

Just checked the RCTS volume to see if there were any other examples amongst their absorbed locos, and noticed that the Mersey locos seem to have been the first of that wheel arrangement. What I hadn't appreciated was that the Alexandra Docks and Harbour Board acquired two new locos, of a similar, but updated, design in 1920, and these locos survived well into BR days, a useful counterpoint to all those Welsh 0-6-2 tanks, and the GWR prairies, although we mustn't forget that the GWR had a handful of inside cylinder Prairie tanks as well.

[Andy Kirkham]

Another thought: my impression is that it's only the GWR ones that are referred to as Prairies. Nobody seems to talk about an "Ivatt Prairie".

[Philately]

What about the Gresley V1s and V3s, succeeded by Thompson's L1 2-6-4T.  Seemingly the Gresley 3-cyl locos were less inclined to slip than the 2-cyl L1s.

[34theletterbetweenB&D]

Perhaps because of the success of the Ivatt Mickey Mouse and the inclusion of two types among the BR Standards, It's easy to suppose that the 2-6-2 wheel arrangement was a natural choice for a medium-size  tank engine, However, it struck me the other day, that until the Grouping, the GWR pretty much had a monopoly on them (167 at the Grouping, which I suppose is not that many compared to the total stock) 

 

I find it hard to think of many other pre-group companies that had 2-6-2 tanks - especially standard gauge ones.

 A product of the GWR development into a primarily tank engine traction railway? Churchward's work set the pattern for all that followed, and he designed tailored to the task a set of tank classes that could perform the GWR's relatively large proportion of shorter range turns.

 

Gresley on the GNR would have liked a 2-6-2T arrangement for the inner suburban task of that line, but was constrained by the Metropolitan widened line restrictions to what emerged as the 0-6-2T N2. (Subsequently when in LNER employment the 2-6-2T V1 already mentioned emerged for use on lines with no such restrictions, and this design was directly derived from the experience gained with the 2-6-0 tender classes.)

[Wickham Green]

I see that nobody's thought it worthwhile mentioning the predecessors of the Ivatt 'Mickey Mouse' tanks - the 2-6-2Ts from Fowler and Stanier ............................ probably quite advisable not to mention them, too !

[The Stationmaster]

 A product of the GWR development into a primarily tank engine traction railway? Churchward's work set the pattern for all that followed, and he designed tailored to the task a set of tank classes that could perform the GWR's relatively large proportion of shorter range turns.

 

Gresley on the GNR would have liked a 2-6-2T arrangement for the inner suburban task of that line, but was constrained by the Metropolitan widened line restrictions to what emerged as the 0-6-2T N2. (Subsequently when in LNER employment the 2-6-2T V1 already mentioned emerged for use on lines with no such restrictions, and this design was directly derived from the experience gained with the 2-6-0 tender classes.)

 

Not so much development into a tank engine railway as in many respects continuing to confirm that it was a. tank engine railway.  It's very easy to forget, over a century later, that the large prairies were originally aimed very much at mixed traffic and freight work as at anything else and in many roles were intended to replace both 0-6-0 tank engines which often worked freight and mineral trains over considerable distances as well as replacing 0-6-0 tender engines.  In reality after the Grouping the GWR was predominantly a tank engine railway but in many respects that only confirmed what had already been going on in some areas of the Company's network.

[D9020 Nimbus]

Curiously, the Southern—which also had a lot of short runs—didn't produce a "modern" passenger tank engine (apart from the ill-fated River class). Only in BR days did such types appear (Ivatt and standard 2-6-2Ts, Fairburn then standard 2-6-4Ts).

[The Lurker]

Curiously, the Southern—which also had a lot of short runs—didn't produce a "modern" passenger tank engine (apart from the ill-fated River class). Only in BR days did such types appear (Ivatt and standard 2-6-2Ts, Fairburn then standard 2-6-4Ts).

Presumably this was the combination of a number of factors; the problems with the Rivers militated against fast passenger tank engines, the electrification of the suburban lines and then the Brighton line meant that a lot of serviceable older tank engines were displaced to give many years service in more rural locations (eg R, H, M7 etc) and the larger Brighton tanks were either rebuilt (Remembrance Class became N15x) or spent the rest of their lives on secondary routes until they reached the end of their lives (eg I1,2,3,4 and J1 and J2), when the more modern types arrived.

[The Stationmaster]

Presumably this was the combination of a number of factors; the problems with the Rivers militated against fast passenger tank engines, the electrification of the suburban lines and then the Brighton line meant that a lot of serviceable older tank engines were displaced to give many years service in more rural locations (eg R, H, M7 etc) and the larger Brighton tanks were either rebuilt (Remembrance Class became N15x) or spent the rest of their lives on secondary routes until they reached the end of their lives (eg I1,2,3,4 and J1 and J2), when the more modern types arrived.

 

The main factor was money - it was spent on suburban and mainline electrification and then when Bulleid came along it was also spent of lots of mixed traffic pacifics and a few powerful freight engines.  But as you said the sort of spending that did take place released stuff with a reasonable economic life in front of it so it could be used where there was no new money to spend.

[brianusa]

In the Victorian railway, the GW along with its country constituents, the B & E and the CR was mainly a tank engine  line, even over long distance main lines.  Tenders were a rarity until later in the century.  Probably the same could be said of the SR with its use of tank engines.  It couldn't last though especially after some notable crashes like the M7 speeding on the dual gauge Tavistock branch and later, the River tanks before their conversion to 2-6-0 tender engines.  Interesting stuff!

 

Brian.

[The Johnster]

Curiously, the Southern—which also had a lot of short runs—didn't produce a "modern" passenger tank engine (apart from the ill-fated River class). Only in BR days did such types appear (Ivatt and standard 2-6-2Ts, Fairburn then standard 2-6-4Ts).

 

A question which answers itself; the Sevenoaks accident and the immediate somewhat knee-jerk response to if put the kybosh on any tank engine development on the Southern until the Leader class.  Other railways were less inhibited.  BR immediately realised that big tank engines were just what the Southern's shorter runs on the Central and Eastern section needed and Brighton was set to work building Fairburns in early 1948, followed by the BR 4MT tank which they developed.

[The Johnster]

I see that nobody's thought it worthwhile mentioning the predecessors of the Ivatt 'Mickey Mouse' tanks - the 2-6-2Ts from Fowler and Stanier ............................ probably quite advisable not to mention them, too !

i don't think it is correct to regard the Ivatt  2MT small prairies as successors of the Fowler or Stanier engines, which were much bigger and less connected with branch line work.  The Fowler and Stanier engines are in many ways the forerunners of the BR Standard 3MT tank engine, the 82xxx, which was a sort of Swindonised version of them.  This, too, was only moderately successful.

 

Of course, this is only my opinion, and I do not claim it to be definitively correct!

[The Johnster]

Perhaps the use fo the term 'prairie', an American affectation, on the GW is not surprising when one considers Churchward's use of American design principles in his range of 'standard' engines; 'mogul' was used on the GW as well.  Many people of my generation and perhaps the 2 before it had grown up with the 'whyte' notation for steam locomotive wheel arrangements, which named some of them according to American usage; Whyte was a Yank, and none the worse for that!

 

But this system (incidentally, the Wikipedia entry for it shows names for just about every wheel arrangement, and one wonders how many of these were ever used, even in the US, or were only used on one particular railroad or even depot) only dates from the turn of the 20th century, and UK railwaymen were very small c conservative in attitude; while 'Atlantics' and then 'Pacifics' caughte the public's imagination and were referred to as such in the media, on the railway terminology such as '4 coupled leading bogie engine' or '6 coupled trailing radial tank mineral engine' abounded to confuse all but the knowledgeable and waste everybody's time.

[KeithHC]

Also on the Southern was the W class.

 

Keith

[The Stationmaster]

i don't think it is correct to regard the Ivatt  2MT small prairies as successors of the Fowler or Stanier engines, which were much bigger and less connected with branch line work.  The Fowler and Stanier engines are in many ways the forerunners of the BR Standard 3MT tank engine, the 82xxx, which was a sort of Swindonised version of them.  This, too, was only moderately successful.

 

Of course, this is only my opinion, and I do not claim it to be definitively correct!

 

The 82XX was basically an updated version of the GWR prairies incorporating BR Standard details and using an updated GWR design of boiler with an added dome.

[Zomboid]

But this system (incidentally, the Wikipedia entry for it shows names for just about every wheel arrangement, and one wonders how many of these were ever used, even in the US, or were only used on one particular railroad or even depot) only dates from the turn of the 20th century, and UK railwaymen were very small c conservative in attitude; while 'Atlantics' and then 'Pacifics' caughte the public's imagination and were referred to as such in the media, on the railway terminology such as '4 coupled leading bogie engine' or '6 coupled trailing radial tank mineral engine' abounded to confuse all but the knowledgeable and waste everybody's time.

The Southern Pacific used the names in the sense that their class nomenclature was derived from it, ie their 2-8-0 classes were C1 to C32 for Consolation, 4-6-0 were T1 to T58 for Ten Wheeler, and their very few 2-6-2 (tender) locos were Pr1 for Prairie. Their 2-6-2Ts were s1 class (for suburban Prarie Tanks, S was for switchers). P was used for Pacifics.

[asmay2002]

Perhaps the use fo the term 'prairie', an American affectation, on the GW is not surprising when one considers Churchward's use of American design principles in his range of 'standard' engines; 'mogul' was used on the GW as well.

The name "Mogul" came form the Great Eastern.  Nothing to do with the US.   https://en.wikipedia.org/wiki/GER_Class_527

[rodent279]

The 82XX was basically an updated version of the GWR prairies incorporating BR Standard details and using an updated GWR design of boiler with an added dome.

Weren't the 84xxx BR Standards an updated version of Fowler's 41xxx tanks? Almost carbon copies?

[LMS2968]

No. Only Stanier updated the Fowler 2-6-2Ts, and they were little more successful than the original machines. The lesson was learned after that. They were part of the Ivatt Class 2 2-6-0 and 2-6-2T family, totally new and very good engines.

[D9020 Nimbus]

Anyway the 41xxx were Ivatt tanks anyway.

[The Johnster]

The 82XX was basically an updated version of the GWR prairies incorporating BR Standard details and using an updated GWR design of boiler with an added dome.

 

I agree so far as the boiler is concerned, but the rest of the loco follows very closely on the Fowler/Stanier prairies, dropping a power class from 4 to 3MT in the process.  The boiler was probably the weak point of the LMS locos and the better Swindon no2 must have looked like a good idea.  This was, certainly among South Wales enginemen I knew in the 70s, a retrograde step, and Barry, especially, wanted more 5101s when it got Standard 3MT (this shed has work that required more range than the small wheeled 56xx were comfortable with), but has to be set against the self-cleaning smokebox, hopper bunkers, and other features more up to date than even the last production of 5101s in 1950.  I lack the expertise to comment on the valve gear, though local enginemen complained that it 'knocked', but the Standards required no daily attention between the frames and were easier to prep and dispose.

Edited May 20, 2018 by The Johnster

[The Johnster]

Weren't the 84xxx BR Standards an updated version of Fowler's 41xxx tanks? Almost carbon copies?

As stated by Nimbus, the 84xxx had only very minor cosmetic differences from the recent Ivatt 2MT engines.  You may be a little confused by the numbering; the Ivatts were in the LMS 1200 series to which 4 was prefixed by BR; I am not sure if any were actually turned out in 13xx LMS livery, as production continued for some time under BR to fill orders.  

 

Fowler's 2-6-2T engines, not highly rated by anyone, carried LMS numbers in the 1-79 range, so 40001-40079 under BR.  To be fair to him, he did not actually design them, only signed them off; he was not a mechanical engineer but held the top job.  But if he can't be blamed for these, he should not be praised for the 2-6-4 tank.

 

The Fowler 2-6-4T was a very successful engine, carrying numbers in the 23xx-24xx range, again with the 4 being added by BR.  They were developed, with later examples given hopper bunkers and cab windows, then by Stanier with taper boilers, then with a 3 cylinder version, then by Fairburn with a shorter wheelbase (a series of these were built at Brighton in early BR days for use on the Southern Region), and ultimately developed into the very good BR Standard 8xxxx locos.

 

The 41xxx was a very different thing, the Midland Railway 3 cylinder compound 4-4-0 tender loco adopted by the LMS as a standard express passenger loco.  

Edited May 20, 2018 by The Johnster