The GWR 57XX Pannier Tank

Status
Not open for further replies.

alexl92

Established Member
Joined
12 Oct 2014
Messages
2,047
Hope someone can help!

To my understanding, the 57XX pannier tank is the one numbered in the 57xx and 77xx series with the flatter roof and small, round windows on the front of the cab - such as 5775 on the KWVR or 7714.

However, almost every subsequent design of inside-cylinder pannier tank seems to get referred to as a 57xx. Can anyone explain why this is? Is it just ignorance/inaccuracy?

Thanks!
 
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

Peter C

Established Member
Joined
13 Oct 2018
Messages
4,213
Location
GWR land
Just had a look at Names, Numbers, Types, Classes, Etc. of Great Western Railway Locomotives by W. G. Chapman (1946, reprinted 1971), and it lists four pannier tanks - of which three are inside-cylinder locos, like the 57xx class. There's the 5400s, 5700s, and 1901s, and looking at the measurements listed, the 5400s are only an inch shorter over the buffers than the 5700s, and look to be the same height, give or take a quarter of an inch, to the top of the cab.
My guess, to answer your question, would be that people refer to various panniers as 5700s (or 57xxs) because without going into more detail when looking at them, they're pretty similar in overall shape. The 5700s are different to the 5400s, for example, in various ways, including the coal bunker (on the 5700s, it meets the back of the cab at a right angle, but on the 5400s there's a curve joining the two), and the dome (on the 5700s, the dome looks to be a bit wider in diameter than on the 5400s).

-Peter
 

Irascible

Member
Joined
21 Apr 2020
Messages
925
Location
South-West
It's handy for the Collett ones given they were all slight variations ofi the basic 57xx - the Collett era is the time most people think of as "GWR" but there were a lot of preceding variations on a theme ( as that link above will tell you ). I just think of 'em as "Large Panniers". The Small Panniers are the x4xx classes* which are more or less variations of an Armstrong saddle tank from the 1870s...

There were nearly 900 of the 57xx family, so you'd expect them all to go a bit beyond the 57xx number series even without subclasses.

* edit: except the 94xx, which definitely weren't small!
 
Last edited:

Clarence Yard

Established Member
Joined
18 Dec 2014
Messages
1,517
The GWR had a habit of referring the class by the first number series of the class and the second number is the key to the repeating series. The 57xx are numbered in the 37xx, 57xx, 67xx, 77xx, 87xx and 97xx and then the 36xx, 46xx and 96xx series, having run out of available x7xx series to use.

The 57xx proper are 5700-99, 6700-49, 7700-99 and 8701-49. The 8750 variant describes the later design cab on the rest. Further variations are the condensing tanks, 9700-10. The 67xx series were steam brake only.

There were 913 boilers built for the class and they were completely interchangeable but were only used on the class.
 

Taunton

Established Member
Joined
1 Aug 2013
Messages
6,886
almost every subsequent design of inside-cylinder pannier tank seems to get referred to as a 57xx. Can anyone explain why this is? Is it just ignorance/inaccuracy?
I don't believe so. The large number of 57xx are fully standard mechanically, for boiler, motion, tractive effort, etc. Inevitably for a class built in such numbers over a long period there were enhancements, but things such as the cab window shape are trivia in comparison, and a couple actually got mixed up after repairs.

The likes of the 64xx, etc, which were an adaptation for passenger work with larger wheels, can get described as a 57xx by those who don't have the technical nuances at their fingertips, they certainly look pretty much the same. A 57xx as it stood was a pretty beefy loco, and could readily see off 0-6-0Ts from other companies, and it was a complete maid-of-all-work.

Often forgotten are the older types, mostly gone by the 1950s, which also looked much the same, just with even more spartan cabs etc, which were mostly rebuilds with panniers of onetime saddle tanks. There had once been the best part of 1,000 of these as well, which were by and large replaced over time by the 57xx being built. Other than the frames starting to get weak, which was a common reason for withdrawal, with periodic overhauls at Swindon they too could have lasted to the end of steam.

I've written here before how many on the WR found the 94xx to be a waste of space, especially as they had Red route availability, and would have rather had more 57xx instead.
 

Clarence Yard

Established Member
Joined
18 Dec 2014
Messages
1,517
The 94xx wasn’t designed just to be a larger 57xx - it was also mean’t to be a replacement for such locos as the Pre-grouping South Wales 0-6-2T.

As a pure yard shunter and light trip freight/passenger loco, the 57xx took some beating. They went about four years between overhauls (a nominal 80k miles) and were very economical locos.
 

alexl92

Established Member
Joined
12 Oct 2014
Messages
2,047
The GWR had a habit of referring the class by the first number series of the class and the second number is the key to the repeating series. The 57xx are numbered in the 37xx, 57xx, 67xx, 77xx, 87xx and 97xx and then the 36xx, 46xx and 96xx series, having run out of available x7xx series to use.

The 57xx proper are 5700-99, 6700-49, 7700-99 and 8701-49. The 8750 variant describes the later design cab on the rest. Further variations are the condensing tanks, 9700-10. The 67xx series were steam brake only.

There were 913 boilers built for the class and they were completely interchangeable but were only used on the class.
Interesting, thanks everyone!

This quote best summed up my confusion - to me, the 87xx, 97xx and 46xx for example look like different locomotives altogether - albeit still panniers. Are they effectively still the same loco underneath then?
 

Irascible

Member
Joined
21 Apr 2020
Messages
925
Location
South-West
This quote best summed up my confusion - to me, the 87xx, 97xx and 46xx for example look like different locomotives altogether - albeit still panniers. Are they effectively still the same loco underneath then?

Yes - 57xx subclasses were just different in details ( like particulars of the cab, or braking, or auto fitting, or condensing gear ) and I suspect were probably mechanically compatible with their predecessors, although don't quote me on that; boiler pressure & details are what tended to change. The "Small" panniers, the 6400 & similar, had different cylinders & came from a different lineage.
 

Taunton

Established Member
Joined
1 Aug 2013
Messages
6,886
The main thing about the 54/64/74xx Panniers is they were intended for branch passenger service, with various divergences such as larger wheels, lighter weight, or auto-train controls. This reflected their 19th century predecessors, where there were also some similar sub-classes with these differences.

The different cab detail within the 57xx is really just a case of different sheet metal, no mechanical difference.

The condensing locos at Old Oak, which rarely actually ran condensing, only one (sometimes two on busy days) being on the Smithfield freights at once, were again a replacement of previous comparable locos. The tanks had to be cut back at the front to keep the weight within limits. Apparently the condensing gear sapped power when in use, so drivers would use it as little as possible. They most commonly spent the rest of their time shunting at Old Oak, or on ecs to Paddington.
 

Gloster

Established Member
Joined
4 Sep 2020
Messages
2,983
Location
Up the creek
The condensing locos at Old Oak, which rarely actually ran condensing, only one (sometimes two on busy days) being on the Smithfield freights at once, were again a replacement of previous comparable locos. The tanks had to be cut back at the front to keep the weight within limits. Apparently the condensing gear sapped power when in use, so drivers would use it as little as possible. They most commonly spent the rest of their time shunting at Old Oak, or on ecs to Paddington.
The Smithfield services could often require three or even four locos in steam, but only in the early hours of the morning. The problem was that much of the traffic had to be taken from Acton, where it had (I presume) arrived on overnight goods services, to Smithfield as soon as possible. For the rest of the day one, or maybe two, locos would suffice.
 

Harvester

Member
Joined
9 Nov 2020
Messages
189
Location
Notts
The 94xx wasn’t designed just to be a larger 57xx - it was also mean’t to be a replacement for such locos as the Pre-grouping South Wales 0-6-2T.

The 94xx wasn’t designed just to be a larger 57xx - it was also mean’t to be a replacement for such locos as the Pre-grouping South Wales 0-6-2T.

I can remember these Hawksworth engines at Paddington during visits (1962-1964). They always seemed to be doing the bulk of the empty stock workings into and out of the station. It is surprising that over 200 were built, the last batch (3400-3409) entering serviice as late as 1956, when diesel shunter construction was well under way. In fact 9499, new in July 1955 had a working life of only 4years 2 months with BR.
 
Last edited:

Dr_Paul

Member
Joined
3 Sep 2013
Messages
1,059
One thing that puzzles me about pannier tanks is whether the tank is one piece sitting over the boiler or two separate tanks that join in the middle, and how the tank/tanks are bolted to the locomotive. Can anyone here enlighten me?
 

Clarence Yard

Established Member
Joined
18 Dec 2014
Messages
1,517
There are two tanks on a Pannier, one on each side of the boiler. They are fixed from the boiler/smoke box top as well as sitting on one or more support stools.

The two tanks are connected by an underslung equalising pipe that ensures that the two tank levels are always identical.
 

Dr_Paul

Member
Joined
3 Sep 2013
Messages
1,059
There are two tanks on a Pannier, one on each side of the boiler. They are fixed from the boiler/smoke box top as well as sitting on one or more support stools.

The two tanks are connected by an underslung equalising pipe that ensures that the two tank levels are always identical.
Thanks for that! It's not clear from photographs, and I couldn't tell even when I had a close look at one at Sheffield Park a few years back, including looking down on it from the footbridge. I've not seen a photograph of one with its tanks removed.
 

DelW

Established Member
Joined
15 Jan 2015
Messages
2,089
I've always been mildly puzzled why the GWR chose to build a large fleet of pannier tanks, which was more or less unique in Britain as other railways mostly chose side tanks or saddle tanks.

Were there particular advantages in the arrangement, or was it just the Great Western wanting to do things differently? ;)
 

kje7812

Member
Joined
1 May 2018
Messages
291
Location
Cardiff or Kidderminster
I've always been mildly puzzled why the GWR chose to build a large fleet of pannier tanks, which was more or less unique in Britain as other railways mostly chose side tanks or saddle tanks.

Were there particular advantages in the arrangement, or was it just the Great Western wanting to do things differently? ;)
Sort of both, having them as pannier tanks allows access to between the frames from the running plate (compared to side tanks). As all but the 15xx were inside cylinder, being able to peer in at the motion is useful. Pannier tanks also have a low centre of gravity compared to saddle tanks, which help running at speed. But other railways managed, so probably more that every railway liked to do things their own way.

An example of variation in the class is that 5764 has top feed and 7714 has bottom feed but blanking plates allow the boilers to be interchangeable. The SVR have a spare boiler allowing them to be swapped about.
 

Taunton

Established Member
Joined
1 Aug 2013
Messages
6,886
Sometimes nicknamed a "matchbox tank". It does indeed allow easier access to the inside cylinders and motion compared to a side tank, and lower centre of gravity and also easier access to the tank filler compared to a saddle tank, which for obvious reasons has to be at the topmost point of the tank. Once Belpaire fireboxes came along fitting a saddle tank over the shape was a difficulty, which other railways handled by not using Belpaires. Inside cylinders minimise "boxing", or "beetle-ing" of a 2-cylinder loco nosing from side to side, further aiding stability. The GWR had lots of these other tank types of course, in the 19th Century saddle tanks were their most common type, but a large number of these were progressively converted to panniers.

Churchward started it off, about 1910, but by rebuilding saddle tanks on a somewhat ad-hoc basis. It was Collett who seized on the approach and started building large numbers of new locos, plus continuing the saddle tank conversions. Churchward hadn't done many new saddle tanks either, so Collett was dealing with a big Victorian-era replacement programme. There were still a few old saddle tanks left 40 years after the pannier conversions started, and along the way a few actually got changed back..
 

Irascible

Member
Joined
21 Apr 2020
Messages
925
Location
South-West
They originally built saddle tanks, but iirc just wanted to lose weight & fit a flat top firebox, so basically cut the top off. Panniers are a little flatter sided anyway so the reduction in water cap isn't quite as much as a glance would suggest. They built plenty of side tanks too, the Metro & 48xx & small Prairies are all near various pannier classes.
 

D6130

Established Member
Joined
12 Jan 2021
Messages
1,781
Location
West Yorkshire/Tuscany
As all but the 15xx were inside cylinder, being able to peer in at the motion is useful.
Apologies for seeming to be pedantic, but the 1366 class pannier tanks (Weymouth Quay, Wenford Bridge, etc.) also had outside cylinders, being a Collett update of Churchward's 1361 class saddle tanks.
 

Irascible

Member
Joined
21 Apr 2020
Messages
925
Location
South-West
Apologies for seeming to be pedantic, but the 1366 class pannier tanks (Weymouth Quay, Wenford Bridge, etc.) also had outside cylinders, being a Collett update of Churchward's 1361 class saddle tanks.

Still had inside valvegear though - I'm struggling to think of a GWR class that didn't have inside gear if you don't count the 1500s, which didn't actually get built by the GWR ( still a Hawksworth design though ).

OK ok, the VoR tanks... and the railmotors.
 

Bevan Price

Established Member
Joined
22 Apr 2010
Messages
5,966
I understand that one reason that Saddle tanks were rebuilt to / replaced by Pannier tanks was partly connected to the movement of water within the tanks at speed. Apparently, the Pannier tanks gave a much smoother ride than saddle tanks, due to the way water could swirl about inside the saddle tanks, but the design of pannier tanks reduced that effect.

Although not unknown, it seems uncommon to find photos of saddle tanks operating passenger services (anywhere on BR), whilst pannier tanks were common on GWR secondary / branch passenger services.

The RCTS History series of GWR locos notes that the 57xx tanks were a slightly modified version of the 2721 Class dating from 1897, whilst the 16xx Pannier tanks met a need for lighter shunting locos than the 57xx Class - and were an update of the 2021 Class, also dating from 1897.
 

Taunton

Established Member
Joined
1 Aug 2013
Messages
6,886
The RCTS History series of GWR locos notes that the 57xx tanks were a slightly modified version of the 2721 Class dating from 1897, whilst the 16xx Pannier tanks met a need for lighter shunting locos than the 57xx Class - and were an update of the 2021 Class, also dating from 1897.
These older locos were built as saddle tanks but converted to panniers, starting in Churchward's time about 1910. Churchward built few if any of these tank locos new, but his predecessor Dean had built several hundreds of them at the end of the 19th century. A GWR curiosity was that equivalent designs, including the two types mentioned above, were designed and built simultaneously by both Swindon and Wolverhampton works, although both then spread out across the system. There were some differences between them such as wheel size, but it was almost as if they were from separate companies.

These locos, and indeed those built earlier in the 1800s, had backless cabs and other Victorian-era features, but once rebuilt with pannier tanks, and then some which had full cabs added, many are hard pushed to distinguish them from the last of the 57xx built in BR times
 
Status
Not open for further replies.

Top