6023 King Edward 11

I don't think that you can dispute that a King was a more powerful loco than a Castle although the figures quoted by JTX are obviously a salesman talking! In terms of theoretical tractive effort, a King is 27% 'stronger' than a Castle. However, you only need that extra pull if your trains warrant it, and I suspect that the GWR's trains generally didn't. I'm no expert on GWR, far from it, but I understand that the GWR philosophy was more aligned towards the Midlands little and often train service rather than the LNW's hang 'em on till the coupling breaks. The LMS, out of Euston and on to Glasgow traditionally had heavy trains and taxing gradients and needed the power of the Duchesses, but nowhere else. The LNER, arguably, and the Southern, definitely, didn't need the number of class 8 locos that they had. If there had been a need for more such locos across the country, BR would surely have built more 8P pacifics, instead of the solitary 71000, built more on an excuse than as a necessity. Class 7 locos would handle virtually all the express passenger work required right up to the end of steam and they are always going to be a cheaper option to use than a class 8, all other things being equal.

 

Yes, if you read what i said i dont disagree... But like i also said, if the fireman can keep the boiler up at 250psi, which has been the thing on several occasions.... The last king that tried going up shap (through no fault of the loco) certainly didn't 'eat' a castle, whichever way you slice it!!

 

A King going up Shap wouldn't "eat" a Castle, it's not that much more powerful. I think we can forget about tractive effort as a real measure of power. However, I still think that if the footplate conditions and the fireman's technique were absolutely right for a King, as we assume they were on Castle 5043 over Shap, a King would sustain a higher output than any Castle.

Those epic test runs with 6001 in sleeved single-chimney form in the early 50's, with a 27 coach train, produced a sustained level of steaming that I doubt even a four-row superheater, double-chimney Castle like 5043 could match.

On the other hand, on the May '64 Plymouth-Bristol record run with 7029, I believe she ran at 91mph around Yatton on the final blast towards Bristol. That was with (I think) seven coaches on dead level track. I've read that she is thought to possibly have been producing the class record power output of around 2000ihp. Any King would have to be working very well to equal that and I think that it would maybe be only a double-chimney version that could match it. The back pressure issue might be a problem with the sleeved single-chimney King at that speed.

Just my opinion.

 

The reason that the Western put Castles back on the job was because the Kings were actually getting to be fatigued and unreliable by the mid to late 50's. They were really too big to be reliable 4-6-0's and suffered far more hot boxes and other mechanical failures than are generally credited to them, and all in all the Castle is a better machine. Almost certainly they will out power a Castle in the short term but the problem is that a really good fireman will be master of a Castle even driven hard, just, but try driving a King as hard and its appetite for coal at the front of the grate becomes voracious, and trying to fire one of them continually down the front of the grate is a fireman killer. I recall talking to Alastair Meanley after he and Ray Churchill put up what Mike Notley claimed at the time as a record output with 6024 up Hatton in 2002. They left Leamington from a stand with around 480 tons (about 80 tons over the normal Bham 2 hour loads) and went over the top of Hatton at about 58 mph if memory serves me correctly. Alastair said that he had the support crew man shovelling coal down the tender and that you could not keep the coal on the grate and that there was no way that the steam rate could have been kept up for much longer. Much of this is to do with the fact that they should have been what Stanier ultimately made them, a Pacific. there is no substitute for grate area. 6024 has all but disappeared from the main line, and it seems as though it is going to require a lot of work before it turns out another performance like that. With hindsight it would have been very interesting if the western region had followed the LMR's lead on the Royal Scots, and fitted the Castles with 250 psi boilers when the new 4 row boilers were made in the mid to late 50's. There would not have been anything to choose, apart from the fact that the Castles were acknowledged as being the faster engine.

 

Very interesting. I was aware that the long firebox on a King made firing more difficult than a Castle.

 

Contemporary sources, Holcroft for instance, suggest that the GWR believed that the Castles were superior to the Kings *if* the work was within reach of the Castle. After all 130ish Castles built or rebuilt against 30 Kings tells its own story, although unlike the Kings the Castles were used as mixed traffic - Cook tells us that Collett eventually decided to build a batch of Castles when the running department asked for more 47s because the Castles would be more versatile.

 

The 240.701-12 class had a narrow box with a grate area of 40.5 square feet and were hand fired. They were far more powerful than a King, had to be for the work they were expected to perform, yet were manageable for the fireman. You have to take a serious look at the front end of the design of the King, the job of an exhaust system is not to pull the fire to pieces at what are by international standards moderate outputs for the boiler size. If Churchward had not made serious errors in his rebuilding of the French compound the King design might well have been a Du Bousquet based compound. GW locomotives would have looked rather different but Collet would never have broken Churchward's mould. If only GJ hadn't got things wrong in this area (and it is strange that he did so) there would be less that was negative about the GWR's largest express passenger design. It wouldn't be a King as we know it though.

 

I have read that the reason BR didn't build any Class 8 passenger locos was that they considered the 8P products of the Big Four were sufficient for their needs and the reason behind the building of 71000 was the destruction of 46202 in the Harrow smash created a "vacancy" in the 8P ranks and Riddles took advantage of this to experiment
with "The Duke."

 

I don't believe Riddles had much to do with 71000. Harrison is generally considered to be the principle responsible body. (And if the thing had been built at Doncaster there would have been fewer problems for the DofG people to deal with - the exhaust would have been right as a start).

 

Evening everyone,

Any news on how the steam test went?

 

Good question - note on the project website says that a fire was lit with a view to steaming at 17:00 on 28th (Sunday). I'm probably heading up on Friday so if no news is out by then I'll see if anyone is around to ask. I would imagine if they've lit a fire they would be looking to steam test this week unless anything became apparent - but then I'm not that up on how these things work!

 

So what did Churchward rebuild on the French compound apart from putting a more reliable GW taper boiler on it? Not much of a serious error in that. the plain fact was that at the time in question the French compound was no better than Churchward's simple expansion loco's, and it took quite a while before Chapelon managed to sort out some of the abysmal compounds that the French possessed.

 

I would agree with that. Churchward found that the French Compounds made no significant saving of coal,water, and Oil to justify the expense of building compund locos for the GWR. The omly design he adopted was the bogie

 

There were 171 Castles built and rebuilt from Star Class locos, but only 170 in service, as I think 100 A1 Loyds was withdrawn just before 7037 Swindon was in Service

 

The first fire since 1962 was indeed lit on Sunday evening.
Pressure was allowed to rise a steady pace until 210 psi was reached on Tuesday afternoon. It has highlighted a couple of minor niggles which will be addressed over the next few days.
It is planned to have the society insurance examiner and a reprasentative from the VAB at the next steaming which is anticipated for a couple of weeks time.

Hope this keeps you all informed?

 

Thanks Jake - hope you have a successful weekend. May be up tommorow depending on what the family want to do, and what the weather is looking like.

 

I believe they had to change the chimney and thus draughting slightly to fit the loading gauge. You're perhaps a bit unfair about the boiler: I don't believe they scrapped the French ones, just built a standard boiler to fit so there was a spare boiler for shopping. Both that and the fact that they lasted twenty odd years before going to scrap suggests they were regarded as useful bits of kit, but ISTR reading somewhere that Chapelon eventually demonstrated that the LP cylinders were doing very little work at high speed.

 

Stewart Cox in his Locomotive Panorama book (I think - I'm away at the moment so can't check) records, with a general arrangement diagram, that Harrison's first design included a Bulleid type boiler (tapered underneath to allow the middle cylinder to drive the middle driving wheel), Witt type (elephant's ears) smoke deflectors and a very high running plate. Harrison was working with C.S. Cocks at Derby at the time. Cocks had previously worked for Bulleid at Brighton so I can see how this could have happened. It was turned down flat by Riddles when it arrived at Marylebone. I don't know how much of Harrison's work was left after Riddles and Bond overruled him. Certainly the boiler was changed for Britannia boiler, presumably on cost grounds. I've read elsewhere that Harrison takes credit for the design of the middle big end. A bugbear on the Gresley Pacifics especially when subjected to poor maintenance during and after the war. Harrison's term as second in command to Peppercorn at Doncaster and his experiences there made him determined to avoid a repeat of these issues with 71000. As for the Caprotti gear, the original Harrison general arrangement diagram does not make this clear. I like to think though that this was an innovation introduced by Harrison and Cocks. Can anyone else shed some light?

 

When "La France" was rebuilt with superheater Churchward fitted main steampipes that were far too small for the volumes of steam they had to convey. It is highly unlikely that the rebuilt engine could equal the performance of the locomotive in its original form.

This is strange, because in 1898 Barbier, under Du Bousquet, investigated steam flow in 4 cylinder compounds. In 1908 a batch of 25 4-6-0 mixed traffic locomotives were built, based on the atlantic design. From 1910 the design was superheated and in the 1930s a Lemaitre exhast system was fitted. These engines, weighing no more than 70 tons could produce 2000ihp on a sustained basis, say 1700ihp before the exhaust change (based on figures taken from the improvement such a fitting gave to the atlantics). Churchward was supposed to have a fair grasp of steam flow, so who made the mistake? Also, what was the maximum sustained ihp of the "Star" class? Chapelon did not qualify until after he had served in WW1, Du Bousquet was his spiritual predecessor.

 

Holcroft, in "GW locomotive practice", states clearly that the highest drawbar horsepower he noted in the records was from a French compound with a No1 superheated boiler in the 40-45mph region.