Metro tanks and 517xx tanks

[rprodgers]

Something I have always wondered about when the remaining metro tanks and 517xx were life expired what were the reasons for Collett choosing the 0-4-2 t configuration over the 2-4-0t for auto trains?

 

I am sure I read years ago, maybe I am mistaken , that the metros (especially the larger ones ) we’re considered more powerful than the 517xx and more stable at speed ?

 

Were the 517xx that originated from a George Armstrong design at Wolverhampton of 1868 more popular in the Northern division than the Southern division which appeared to use the metro tanks more?

I believe the metro ‘s were first built at about the same time by his brother Joseph Armstrong  at Swindon and further ones built later by William Dean.

 

I know that for instance in Cornwall the metro tanks seemed to be more favoured by the GWR. I don’t think there were any 517xx in Cornwall and only ever 1419 of the 48xx class 0-4-2t, whereas metro tanks had been popular there for decades before. I assume gradients and twisty branch lines were a  factor in this.

Edited June 30, 2020 by rprodgers
grammar

[Paul H Vigor]

Didn't the early members of the 517 class start out as saddle tanks? 

[melmoth]

The 517s had a slightly greater route availability (uncoloured, mostly) than the Metro tanks (yellow). That might have made some difference if replacing like for like.

 

1 hour ago, Paul H Vigor said:

Didn't the early members of the 517 class start out as saddle tanks? 

.

Yes, the first 60 or so were built with saddle tanks

[JimC]

The 48s were very much an updated 517 with a very similar boiler. I suppose all else being equal you want the cheapest locomotive that can do a particular job, and arguably the Metro sized niche was filled by the 54s and 64s. The 54s and 64s were straight developments of the Wolverhampton 2021 class, and the 48s had a lot of parts, motion especially I believe, in common, whereas a Metro derivative would presumably have had much less in the way of standard parts.

[rprodgers]

I can see that the 517xx gradually evolved over the years as they had new fire boxes, cabs etc so that in their final form the 48xx resembled them greatly.

 

When I asked the question I was thinking more about the wheel arrangements that why a  2-4-0 t was not chosen for the 48xx as it was more stable* but I guess the benefits of this are negated for push pull operations. 

 

The metro tanks always seemed to be well thought of .

I seem to to recall that metro tanks at sometime  came in small, medium and large but accept the 517xx was lighter.

 

*Also racing express trains with a 48xx auto train was probably not officially encouraged

[Steamport Southport]

I always thought that 0-4-2Ts and 0-4-4Ts were more powerful and steady due to more of the weight being over the driving wheels giving better adhesion. The 14XXs had quite a turn of speed and were noted at over 70 MPH.

 

You also didn't have the rear driving wheel too near the firebox or intruding into the cab.

 

Not many other railways adopted 2-4-0Ts or 4-4-0Ts and most had gone before the grouping whilst 0-4-2Ts and 0-4-4Ts lasted much longer. 

 

Some of the large Metros lasted a bit longer, but they were scheduled to be replaced by more 0-4-2Ts. Cancelled due to the war.

 

 

Jason

[tomparryharry]

64's and 517/48xx do indeed, share a lot of commonality in motion parts. The 64 has the edge, being a smaller sized diving wheel, and the extra set of drivers. 517 & 48xx have a same size of driver, being 5'2". I'm also fairly sure the 517, 48xx, 54,  64xx and Metro share the same cylinder block, in the big world.  

[The Johnster]

On 01/07/2020 at 14:18, rprodgers said:

 

 

*Also racing express trains with a 48xx auto train was probably not officially encouraged

Maybe, but apparently nobody mentioned that to the Gloucester men on the Chalford autos running parallel to the Midland Gloucester-Bristol main line, which were considered fair game.  

[rprodgers]

On 01/07/2020 at 16:08, Steamport Southport said:

I always thought that 0-4-2Ts and 0-4-4Ts were more powerful and steady due to more of the weight being over the driving wheels giving better adhesion. The 14XXs had quite a turn of speed and were noted at over 70 MPH.

 

You also didn't have the rear driving wheel too near the firebox or intruding into the cab.

 

Not many other railways adopted 2-4-0Ts or 4-4-0Ts and most had gone before the grouping whilst 0-4-2Ts and 0-4-4Ts lasted much longer. 

 

Some of the large Metros lasted a bit longer, but they were scheduled to be replaced by more 0-4-2Ts. Cancelled due to the war.

 

 

Jason

 Jason I take your point about the rear driving wheel and its proximity to the fire box

 

I think my idea, now I have thought more about it, came  from reading ages ago about the GWR 3521 class that started off as a 0-4-2t  (1887-1890 both broad and standard gauge)  then because of concerns about being unsteady at speed became 0-4-4t and in then were  rebuilt as 4-4-0 tender locos (1899-1902)*.   Following two accidents in Cornwall in 1895 and 1898.  

 

https://en.wikipedia.org/wiki/GWR_3521_Class

[GWR1890-1908]

RCTS says that some auto fitted 517's were stationed at Truro from the 1920's, but does not say which numbers.

Greg Waldon

[NCB]

On 03/07/2020 at 23:49, The Johnster said:

Maybe, but apparently nobody mentioned that to the Gloucester men on the Chalford autos running parallel to the Midland Gloucester-Bristol main line, which were considered fair game.  

 

I have personal experience of the Chalford autos. The way they were driven can best be described as "lively". Wheel slip on start, wheel skid as they stopped. Collett created a little bomb! The early evening service west out of Stroud was usually packed, which meant clinging for dear life to the straps for those who had to stand.

 

Nigel

[The Johnster]

Auto trains ran pretty fast on such main line services as they were able to everywhere, but the Chalfords were the last and attracted attention from enthusiasts not familiar with this sort of shennanigans, who wrote articles in magazines about it.  The famous St Fagan's Pullman, a Pontypridd-Cardiff working that ran on the SWML between St Fagans and Cardiff General, used to run pretty fast along that section with a 64xx, smaller driving wheels than a 14xx, and the Marshfield Flyer in the other direction between Cardiff and Newport, also a 64xx job, could pop along a bit as well, as I'm sure other examples did, but these were not well known outside their immediate areas or by their regular passengers; enthusiasts generally ignored such humble workings.