Current and Proposed New-Builds

I feel a solution to hand is to build a generic 0-4-0 chassis with interchangeable bodies. We could start with a 'Smokey Joe', get bored with photographing it and then change to to the Dock Shunter diesel before going to the GWR 101 that does 175mph!

https://images.app.goo.gl/LRxQzq3PgJFwtdb48

 

That line often quoted of trying to "utilize existing flanging blocks" always seamed a bit lame to me, true they are big and heavy bits of steel but in the scheme of things way back when with big bits of metal being fashioned in all directions the building new flanging blocks for a new design hardly feels as though it should be in the very difficult pile.

 

It might not have been difficult but it was expensive, and great efforts would be made to avoid having to make new ones, particularly for a very small number of boilers as the unit cost would rise considerably. When Eric Langridge, a draughtsman at Derby, was given the job of designing the boilers for Stanier's new Class 5XP (or converted Claughtons, later Jubilees) he scrapped what he had started when he found that four similar sized boilers (5X, Stanier Crab, black Five and 8F) would be needed and began again so that the flanging blocks could be common to all four. Bearing in mind that the smallest class was the Crabs, and that ran to forty locos.

 

I suspect that GJC foresaw the need for something bigger that the No1 as train loads increased and therefore was not worried that the new no7 was only appearing on a small class. It would soon see wider application. But he then retired on the changed industrial situation post WW1 and the plan fell into abeyance. Collett picked that up again when time came around to design the Castle and initially planned on the No7 - only for the civil engineer to tell him he couldn't. Thus his (Collett's) hand was forced to design something lighter to reduce the overall loco weight and the no7 never saw that wider use.

Once the weight restrictions were relaxed, the no7 was used as the basis (with significant mods to reflect new practice) for that which appeared on the kings.

With respect to the boiler on the 10xx county : Swindon built a large batch of 8Fs during WW2 with much of the tooling probably paid for by the government. This was then re-used to produce much of the boiler for the county. Hence the close similarities between the two boiler designs. Think of the county boiler as a swindonised 8F. How many of those 'tweaks' should be incorporated in that being constructed for the new-build county is a matter of opinion and a topic for much debate both here and elsewhere. The building group presumably fought shy of the expense of a new boiler and were prepared to accept compromises to re-use what was already available. The 47xx group evidently come to a different - and in my view correct - conclusion.

 

I think it clearly was a concern (quite apart from the issue of storing the blocks afterwards for occasional re-use).

As an example from the SR rather than the GWR, Maunsell use date same flanging blocks as the King Arthur / S15 to make the Schools class boiler with a shortened firebox; and Bulleid used the Lord Nelson flanging blocks to make the Q1 firebox. That suggests to me that both designers were aware of the trade off between designing new or using existing patterns, and erred towards using existing (even though there were ultimately forty locos of each design).

As an aside, and I don't know to what extent this affected costs, but the Churchward design of Belpaire firebox is a particularly complicated shape, getting wider from back to front and also the roof sloping up quite markedly from back to front, as well as the subtle curves on the sides. There are good reasons for that shape, but it has always struck me that from a draughtsman's point of view, doing the development of the various plates such that they assumed the right shape when pressed was non-trivial.

Tom

 

To a certain extent I think you are right, one of the GWS main aims is to have as near as possible a complete collection of all types of GWR locomotives. Obviously some types no longer exist and must therefore be recreated if they are to achieve this ambition.
If enough people agree with that, and are willing to put time and/or money into it, then why not.

 

I think though it comes across as an ambition to have as far as possible “a complete collection of Churchward / Collett era GWR locomotives” which is a different thing. Where’s the Metro tank, or Armstrong goods?

Tom

 

Not sure if this has been covered previously, but to quote my newly arrived copy of GWS Echo newsletter.
"The 2 cylinders for 4709 are now ready for casting.
The original GWR design had to be modified in order to:

• Reduce the saddle height to accomodate the current Network Rail loading gauge.
• Reduce the width over the cylinders to increase route availability.
• Slightly reduce the cylinder bore to ensure sufficiency of strength due to the reduce width.

"

They have previously stated they do not currently intend any mainline operations for GWS locomotives, but it would be silly not to keep the option open for the future by making appropriate adjustments to any potentially suitable locomotives at the build stage.

Hope this helps to clarify a few things.

 

Well once, they've finished the current projects, who knows what might be next. . . .
(Although I expect that will be up to the 'new blood' as the current leaders are getting rather long in the tooth now.)

 

Are you aware that studies exist for the Std 7 on Star and Saint and 28xx chassis? These were drawn up on Churchward's instructions in 1919/1920. The thing about the std 7 boiler is that it used the same flanging blocks that had been created for the Bear's boiler. I suggest that by 1921 Churchward had concluded that it wasn't going to be possible to design a boiler using the Bear's flanging blocks, so went ahead and built the Std 7 as we know it. It would be interesting to know when the new flanging blocks for the Castle boiler were approved. Presumably the decision was whether to build the smaller boiler, with the expense of flanging blocks, or wait until enough bridges had been updated to the 22 ton weight limit that had been introduced some years earlier that a reasonable number of Std 7 Stars could be utilised.

 

How could the same flanging blocks be used that were used for the Great Bear? The firebox is a different shape although the front tube plate is the same size.


Sent from my SM-A105FN using Tapatalk

 

Trouble is they existed in such a bewildering variety of options that the chances of getting a project team to agree on what configuration they want to build must approach zero... These are both Metros!

 

Top one please

Tom

 

Fair enough. The barrel diameters for the Bear and the Std 7 are the same, but if that's not relevant I'm happy to be corrected.

 

Not to mention the arguments on NP about the 'correct' configuration and livery . . .

 

Have fun driving in the rain

 

That's why you'd need to build both...

 

With reference to earlier posts, just build one chassis and 2 bodies, simple!

 

Batch build anyone? O

Cabriolet anyone?

 

I know where there's an original tool box from one; just get Steam Railway to sponsor the numberplates* and you'll be halfway there.

*Or in the case of the top one which had painted numbers, a bit of B&Q ply and some cheapo vinyls.