City of Truro - The truth

[richard]

Garratt discussion has been moved to its own thread, here:

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Richard

[StGatien777]

GWR= Gresley Was Right lol.

Gresley was indeed right.

I believe it was Gresley who said something like: "..This country owes a lot to the genius of George Jackson Churchward..".

It was something like that anyway. The GWR was fantastic under Churchward. It was Collett who removed the whole 'experimentation' process from Swindon. Thats why the likes of Stanier and Gresley prospered during the thirties, if Stanier were at the GWR who knows?!? Hawksworth tried to bring it back, but was just a little too late and didnt have the money that GJC had at his disposal. His tanks (1500 and 9400) were excellent, he even designed a real pacific for the GWR which never materialised (unfortunately).

Its not easy to say that Truro did break the 100mph barrier for the fist time. Whoever said that it did, the driver? I believe a driver decided to push a GW County towards the end of her days. The clock read 102mph, the mathematician in the front coach read 99mph (no saft dynamometer car, just pencil and paper and possibly a sarnie or two). GW County's were never recorded as breaking this barrier, however the speedometer on the County in question (i'm afraid I forget which one) technically said that they did. So I dont think that Truro's efforts can really be considered serious, unless of course there happened to be someone with a decent understanding of the equations of motion in the front coach in 1904?!?

Regarding 4468, a Coronation pacific would have blown Mallard away if it had run the same route as Mallard. The WCML is too twisty and bendy, the ECML is better for attack. I'd say that a Coronation could have reached 150MPH on the ECML, given enough encouragement and the resident nutter for a driver.

A3 people, I wouldn't be crowing. 1923 ring any bells?!? or any whistles from a Castle?!?

[73D]

StGatien777; regarding City of Truro’s 100mph you don’t seem to have read my post on the previous page.

Regarding the so called stagnation on the GWR in the 20s and 30s the GWR was so far ahead of need that there was no point in spending more money in development when just evolution of existing designs could do what was needed.

Was even the lack of outside valve gear really a problem? Swindon set-up their locomotives with a lot more accuracy than anybody else and inside motion has a lot less problem with stresses, so did it need to be taken down as often as outside valve gear? It would be interesting to see maintenance figures and costs of say a Black 5 and Hall in the 30s. Oiling round is the main disadvantage of inside gear, but once outside the works it's someone else’s problem!

[60800]

Going back to Hawksworth's pacific, I have been fortunate enough to see the minature Hawkworth pacific Great Bear in steam at Normamby Hall which I believe to be the proof of concept model for the real thing if it were produced. Unfortunately, from the only photos I can find, it seems she's now stuck in a glass case at a museum somewhere, my guess being Swindon Steam museum.

[Blink Bonny]

Ay up!

The lack of outside valve gear is not a problem at all, unless you happen to be the poor sod who has to set it up in the first place or oil it on shed but it must be said that the GWR were not alone in having inside gear. Thompson Pacific, anyone? Or the Pricess Royals with TWO sets of inside motion and two outside? The fact is that the Castle righteously smote the A1 entirely because of the much better, long travel, long lap valve gear.

As to boilers, here's where the real stagnation occurred. Pre WW1, the GWR had it right with moderate superheat because this was all the oils of the time could deal with. The LNWR got it very wrong with their Claughtons which had a high degree of superheat. Theoretically, the higher the degree of superheat, the more efficient the locomotive but only if the valves are lubricated with an oil able to withstand the high temperatures involved. In the Claughtons, they weren't and it was only after WW1 that suitable oils became available. Before then, the oil tended to carbonize in the steam chests and cause the valves to seize solid, wrecking the valve gear and not doing the cylinders much good either.

Look what happened to the Castles and Kings when they were fitted with decent superheaters and double chimneys in BR days. Suddenly they were able to prove what a student of design could see - that they were hobbled by an adherence to an outdated principle. Would Stanier have been different? Unlikely. The 5MT 2-6-0s, Princess Royals, Black 5s 8Fs and Jubilees all had small superheaters when new and Stanier was baffled as to why the latter in particular should be so disappointing. Ironically the man who cured all these classes and shaped future design on the LMS was Robin Riddles - an ex-LNWR man.

[kudu]

Ay up!

The lack of outside valve gear is not a problem at all, unless you happen to be the poor sod who has to set it up in the first place or oil it on shed but it must be said that the GWR were not alone in having inside gear. Thompson Pacific, anyone? Or the Pricess Royals with TWO sets of inside motion and two outside? The fact is that the Castle righteously smote the A1 entirely because of the much better, long travel, long lap valve gear.

I'm going on memory, but didn't Holcroft show Gresley how to do derived motion the simple way?

But we should remember Picasso's dictum that good artists borrow, great artists steal. And arguably Churchward's genius was not in being original like some latterday Brunel but precisely in knowing which ideas to steal and which to ignore. Maybe his truly original contribution was his belief that the birthplace of steam had something to learn from foreigners.

Kudu

[Blink Bonny]

Well put, kudu. However, my point is this:

Having got a technical lead of about 20 years on the rest (apart from the NER who were also experimenting with new valve gears but not particularly with boiler design) then development stopped and dogma took over, even when better ideas were demonstrated. If Riddles' modifications to the Swindon boiler didn't act as a wake-up call then there was an engineering problem.

[60800]

Whoops, I'd like to correct myself on the statement about Great Bear, I didn't realise the full size pacific had actually been built

[manna]

G'Day Gents

Thats alright, 'Blackout60800' Nobody picked up on it, shows how interested we are on all thing.......GWR......Ugh !! When you sit on your laurels to long you get an itchy a***

manna

[kudu]

Whoops, I'd like to correct myself on the statement about Great Bear, I didn't realise the full size pacific had actually been built

Don't tell me you thought "Great Northern" was Britain's first Pacific? The Great Western had already been there, done that - and within 2 years had undone that by taking its rear wheels off.

Though you could say the Gresley version was the first Pacific its designer actually wanted to build - hence Churchward's alleged comment "What did that young man want to build it for? We could have sold him ours!"

Kudu

[Blink Bonny]

Ay up!

I read somewhere that The Great Bear had been built mainly as an exercise in boiler design? If that is the case, then that's one hell of an exercise!

However, what is certain is that the engine didn't come up to expectations. Maybe with a decent superheater and combustion chamber?

[manna]

G'Day Gents

I suppose it's a bit like the GER building 'Decapod' then, did they really imagine they would end up with a fleet of them pounding the rails out of Liverpool St.

We seem to have moved away from the City of Truro (luckily)

manna

[60800]

I must say I think the decapod is the ugliest steam loco I have ever seen, the firebox sides are awful and the smokebox looks like it's been squished Any uglier? post away!

[richard]

I don't think the original Decapod was that bad - the 2-8-0 rebuild was pretty ugly though!


Richard

[60800]

The 2-8-0 rebuild is worse, as I've just seen, the cylinders are a right hash and the wheel spacings make me cringe . The only reprieve is that the awful firebox cladding has gone.