Rebuilt Patriot and Rebuilt Scot

The only one I can really think of was 111 The Great Bear to a Castle.

There was many classes rebuilt to make other classes but not because their was a problem with them such as the rebuilding of the 4-4-2 Star and Saint classes to 4-6-0 classes when they realised the 4-6-0 were better, also some of the Star class into Castle class, and the 2-6-0 engines into the Manor and Grange class. Many of the 4-4-0 engines were rebuilt with different boilers over the years.

 

This was more of a rebuild to get a use for engines which had no work to do and not due to a problem with the 42xx and the 5205 classes.

 

6959 Class Modified Hall? does that count??

 

Castles from Stars
Halls from Saints
Granges from 43xxs (ok i'm pushing it a bit there)
111 The Great Bear was a bit of a rebuild later in life
and on a slight tangent..
LMS Princess class 4-6-2 from GWR Kings

 

I don't think the previous classes to those mentioned were felt to be so bad as to necessitate rebuilding the whole or most of the class into the new one. development of course, but not rebuilding.

 

The Hall from the Saint was a prototype engine to see if it was of use and then to bring out a new class.

 

Black 5 from Halls,
8F from 2801 class.

 

Kind of interested what is considered a rebuild..
change of boiler ?
change of wheels ?
change of wheel arrangement ?

a 4-4-2 into a 4-6-0 is a pretty substantial change..
a rebuilt Jubilee is a Jubilee with a 2A boiler.. so is a 47xx with a boiler change considered a rebuild or a development ?
I suspect the element of the debate is different language.. in Swindon the word Rebuild is Development .. it was an interesting development that happened to the WC/BBs

of course Swindon "developments" didn't stop with steam... converting a gas turbine into an overhead electric was a pretty ambitious one.. (talking about 18100 into E1000), though as this was done in Manchester I guess it was a rebuild.

 

Without having my books to hand I think the frames of the 4-4-2 were the same as the 4-6-0 so just the outside frame for the trailing wheel to be taken out and the outside bearing section taken off and a driver wheel put into where it belonged and the first 4-4-2 (No 171 Albion (2971)) started out as a 4-6-0 in the first case so this is most likely this was the case.

 

Not especially. The GWR Atlantics were designed to be converted to 4-6-0s from the outset; they were initially built as a 4-4-2 just so as to allow a direct comparison with the French Atlantics on trial.

Whether you call it "rebuild", "renewal" "conversion" etc probably is a bit determined by financial circumstances. I'm reminded of a "rebuild" in the relatively capital-poor LCDR that as I recall started as an outside-cylinder 4-4-0T with 6' drivers and 3' carrying wheels, and was "rebuilt" to an inside-cylinder 2-4-0 tender engine with 5'6" drivers, 3'6" carrying wheels. Possibly the whistle was common to both engines...

Tom

 

I once worked for a bit in the workshop of one of our steam railways which has an excellent reputation for engineering.
A, erm, well-known loco was in for some work, and as a rookie I asked the Engineering Manager what needed doing. He responded "Jack up the whistle and put a new loco underneath..."

 

Far, far worse is written on NP.

 

Well that was a fun can of worms perhaps some of those mentioned are actual rebuilds, but when I meant development, I meant development of the design, not the locos themselves if you see what I mean. When the new class came out, the old based upon class wasn't rebuilt (except maybe a few for prototyping). I only mentioned it to see what would happen

 

It all depends on the Tractive Effort IIRC. After BR's reclassification the Royal Scots at 7P had a TE of 33150 lb; the rebuilt Jubilees a TE of 29570 lb thus 7P whilst the remainder had a TE of 26610 lb thus 6P5F; the rebuilt Patriots had a TE of 29570 lb thus 7P whilst the "unrebuilt" had a TE of 26520 lb thus 6P5F. I must admit that I have never seen the Classification Ranges adopted by BRso don't know how the TEs quoted fitted into the Classification Scheme.

 

It was a bit more complicated than that. The Midland and LMS systems were based on tractive effort but the BR system also included boiler power, i.e. the engine's ability to maintain a train speed. The Southern Region, which, like the others, had the system foisted upon them, extended it to include braking performance with unfitted goods, hence some strange class codes on their engines' cab sides.

By the way, while many of the Kings' vital statistics reappeared on the LMS's Lizzies, there was little in common between the Halls and Black Fives, or 28XX and 8Fs, other than the wheel arrangement, beyond certain Stanier features inherited from the GWR and applied to his other classes.

 

It was tractive effort at speed, wasn't it, rather than starting tractive effort? I seem to recall for passenger classes it was based on the TE at 50mph, and for freight classes the TE at 25mph. Presumably the Midland and LMS carried out trials on the major classes in order to measure those parameters, and presumably estimated for other locos?

Not that complex! There were only two braking classifications, A and B (mnemonically, for "awful" and "better"). They weren't absolute, but instead were based on relative capacity to brake a load that would be typical for the loco's power. For example, a Billinton E4 was 2P2FB and a West Country 7P5FA, but really that meant an E4 on, say, 200 tons unfitted would stop better than a West Country on, say, 500 tons. In absolute terms with the same load and gradient, the West Country would still have more powerful brakes.

The other small difference on BR(S) was that they typically didn't use the "MT" designation for mixed traffic locos of Southern parentage, preferring to have the separate P and F classifications - hence the E4 being 2P2F rather than 2MT.

Tom

 

The BR system was a bit more complicated than just speed & T.E. There's a section in Vol.5 of the RCTS book on the BR Standards that gives more detail of both the LMS & BR system, including graphs and how to calculate boiler tractive effort. Interesting reading.

 

Absolutely. I caused a bit of a stink a few years ago, serving on an older ship which was, well, 'challenging' to operate...

Asked to submit a drydocking list, the Captain & myself replied with "Crop at base of funnel, renew underneath & then renew funnel"

We received, by return, the Company equivalent of a railwayman's "Please explain" form...

 

The design was modified, but it didn't involve any rebuilding of existing Halls.

Bob.