1014 County of Glamorgan

Ideally yes, a complete new boiler would be best BUT the availability of the parts being used were the catalyst that made this project viable. Without that, it may never have been attempted and having stood in the workshop at Didcot surrounded by fabulous projects, not least of them the County and Saint recreations,I can only say Yes Please, lets have more projects like this, and if that means dismembering a derelict 28xx to provide parts to build a Lickey Banker or a Highland Railway 4-8-2, then so be it.

 

I'm still interested to know, and no -one has yet answered the question- what the working pressure of 1014 is intended to be, and how that squares with the 8F being designed for 225psi if the pressure for 1014 is the 250psi of the engines in their later years (which is what I would expect - I don't expect it to be designed for 225psi). Will the 8F firebox need altering for the higher pressure - it's a simple question, can't one of you GWS types find out and answer it? I'm not being critical, just interested as it seems to be something that has been skated over quite consistently.

 

1. Earle Marsh was assistant to Ivatt at Doncaster and left for Brighton with his superior's blessings and a full set of C1 drawings under his arm. That's why the Brighton Atlantics are so close in appearance to their GN counterparts. As we already have an Ivatt C1 there is no real need for the construction of another one so seems quite fitting that history repeats itself in a way with the construction of the Brighton example with GN assistance.
2. Nothing to do with it being a GWR loco. I'd have felt the same if one of the surviving B1s had been sacrificed to provide components for a faux B2 on the grounds that some of the components were similar.

 

me thinks he protesteth too much

 

Hi 61624,

As far as I know, she will be pressed to 250psi as per the later modified version of the 10XX class. I hope you didn't think I was skating over it - I'm just not that observant! As far as how that impacts the boilers previous rating to 225psi I have to say that I (as I look after Castles and 41XXs not 10XXs) don't know but as I said before - the guy doing the feasabillity study and design work on the conversion has a lifetimes experience with boilers ranging up to such complex types that it makes a 'simple' locomotive unit look like a kettle! If he says that it is ok then it is a safe bet that it is... I will ask Keith when I next see him (at the weekend probably) if anyone is interested and then you can have chapter and verse from the equine food ingress hatch.

I hope this helps!

All the best,

Team 4079

 

Whatever.

 

Just out of interest, is the feasibility study on the 8F firebox non destructive?

 

That would be greatly appreciated - and I'd like to stress that I'm asking out of genuine interest, not with the intent of mischief making.

 

Thanks for that reply. It'll be great to see the County complete and running. I hope they can run it at 250lbs. If it has to be set at 225lbs, there would always be the question of how much better a performer it could be.

Cheers.

 

Surely the stay pitchings would have to be altered to cope with the higher pressure? I thought the Countys were rated to 280PSI?

 

They were (as were the Bulleid pacifics) but derated to 250psi fairly early on in their lives.

 

I don't know what date early in their lives is but the 1960 Combined Volume has them still 280psi. Don't know if the CV just quotes original psi though.

 

I'm 90% sure it was early 50s, if not late 40s. Dare I suggest we've found an error in the CB? What does it say for Bulleids?

 

250psi

 

Taken from Wikipedia

Innovations included double chimneys on certain members (the only GWR class ever to have double chimneys fitted by the GWR) and a high boiler pressure of 280psi (though this was later lowered to reduce maintenance costs and for fear of the increased pressure causing damage to the track through hammer blow). Modified double chimneys were fitted to all the class from 1956. They also pulled Hawksworth slab-sided tenders, as fitted to some of his modified Halls and retro-fitted to many earlier designs; however the County tenders had a water tank six inches wider than the tenders built for the Halls and earlier designs.
The running gear of the County was almost exactly the same as Hawksworth's earlier Modified Hall Class. The boiler however was a slightly modified version of the LMS Stanier Class 8F boiler, Hawksworth being able to study this design closely when 8Fs were being built at Swindon as part of the war effort.

 

Not necessarily. Wasn't the Standard no 2 boiler uprated from 200psi (5101 class) to 225psi (61xx class) by using a different stay material but without changing the stay pitch or plate thickness ? Maybe someone could confirm this.

David

 

I seem to remember writing at least some of that...

 

My CB for 1952 (reprint) states 280psi for both 10xxs and the Bulleid Pacifics.
Just reading the County website, it states the first county to be reduced to 250 was 1026 in 1952.

 

Curious concept hammer blow and im not sure i really understand it - Surely Hammer blow is at its worst/ most damaging at speed, by which point piston driven locos are operating at substantial cut offs and the thrust generated by the cylinders is somewhat less than the theoretical maximum regardless of the higher than usual steam pressure ?

 

There are no standards for stay pitch or plate thickness and the different drawing offices would adopt their own standards based on years of experience. If you do the basic stress calcs, you'll find that the 8F boiler is well up to 280 psi on paper. Allowing for the odd broken stay soon drops the margins significantly, though, especially with the plates. Allowing for wastage, which could be as much as 40% on copper firebox plates in BR days, drops it even more. It is things such as these which become governing factors.