DenysW

I've posted below what I see as the British Imperialistic view of Gresley's response to the German early express diesels, even though it was written in 2015. Is the actual truth that the Flying Hamburger (178 miles averaging 77 mph as a 2-coach Diesel Multiple Unit, 200 hp/coach) was too expensive in civil upgrades (curves, block working, freight bypass loops, etc.) for the lines that would have benefitted? On LNER I'm thinking probably Leicester/Nottingham, Harwich/Ipswich, Boston, Norwich, Peterborough: destinations that could have used an under 90 minute service to London for day-return business trips as well as tourism. Choosing Newcastle at 268 miles and showing steam could give a 4-hour service if you pushed it hard with a light load feels like an attention-diverter, not a rational debate about speed or market-suitability. What would Gresley's Flying Bostonian have looked like with 1934 English Electric diesels? A 3-coach DMU with 300 hp/coach? A fiasco? "How the LNER ensured that the Flying Hamburger was dead meat By Mike Amos, Northern Echo Opinion Columnist, 2015 Excerpts: The LNER was determined to resist the allure of diesel traction, particularly the crack German express known – at least over here – as the Flying Hamburger. Papyrus, one of a class designed by Nigel Gresley, but altogether less well remembered than the streamlined and Gresley-inspired Mallard, was chosen to prove that it was possible to cover the 268 miles between Newcastle and Kings Cross in under four hours – the fastest timetabled train took five hours and seven minutes. For 12 continuous (and downhill) miles near Peterborough, the six-carriage train averaged 100.6mph – “by far the longest distance ever travelled at such a speed by a steam engine". The top speed was 108mph, the average 70.4mph; 300 miles were run at 80mph and the journey was completed in three hours 49 minutes despite delays because of an accident near Doncaster. All were world records."

Could the GWR broad gauge loading (as a few pages back) have made this unsuccessful 1855 French design (L'Aigle, but it never soared) have worked by conversion to a 4-4-2, with the trailing axle far enough back to allow a reasonable size grate? I just like the idea of GWR with a split boiler, and entering into a 'My wheels are bigger than your wheels...' contest, and winning due to the extra possibilities of their broad gauge.

From wikipedia's Railway events for 1912: November – The Royal Bavarian State Railways begins the process of standardising the Railway electrification system in German-speaking countries at 15 kV AC, 16.6 Hz No date was given for the process having completed. I have read separately that improvements in insulation materials were the reason that 6.6 kV could later be replaced by 25 kV at the same clearances.

LMS used 40 ton (net) wagons, built at Crewe in the late 1920s inspired by German designs, to get coal to its Stonebridge Park power station. 57 tons total per wagon. They only built 30 however.

I have so far failed to find out what pressure the pre-Grouping and Grouping companies put on the coal and mineral extraction companies to get them to change, or what the common carrier restraints on them were. I can't believe that if the company's pricing was per wagon-mile (not per ton-mile), with a reduction for multiple wagons/same destination that the larger mines wouldn't have changed. With non-tariff pressure as well: braked 40 ton wagons take 2 days before collection. Unbraked wagons take 10-14 days. Etc.

No doubt I'll be corrected with facts on this but my present view is: - By 1906 the French, Bavarians, and Americans all had experience with big-grate (> 40 ft2) boilers put on locomotives. Not always successfully in combination, but experience. Not sure about the Prussians, who appear to have been recovering from a system that had developed as a mess of unconnected branchlines. - The Brits didn't. Very little over 20 ft2, and an industry that liked making progress in small increments - When pacifics became madly fashionable from 1905-ish onwards, the rest of the world had the grates+boilers to make use of the opportunities of the new wider grates the design allows for - Churchward tried to address with the Great Bear and its boiler-development aspects, but the rest were too conservative to try, then got locked into inertia by WW1 - Post WW1 Gresley was the first to go large with a 40 ft2 grate+boiler in 1922, and use the pacific design to closer to its full as the A1 - Result: UK 15-20 years behind the rest of the world

I look at the 5 main French companies, and the Bavarians, all of whom were moving to Pacifics before WW1. Indeed North British built a batch of 40 Pacifics in 1916 for the French Etat because their preferred supplier in Lille had become on the wrong side of the trenches in 1914 with only the first loco delivered. If you have a more powerful locomotive design you can use it for strength or speed (or a bit of both). GCR could have used a better reason to go from the North to London via their line. The Midland could have used them to make the Settle-Carlisle route look less of a waste of shareholder's money for passenger duty. GN and/or LNWR could have shaved time off London-Scotland in response to GWR's claim to have the most powerful locomotive on UK rails (the Bear). None of them chose to, but that doesn't stop the imagination!

Articulateds. Just an 'I wish I'd Known'. If you are looking for an HO articulated model to kit-bash into an imaginary OO UK loco, you'll struggle to find Mallets. Specifically: - the Roco Bavarian BB II 0-4-4-0 is a nice model, but it's a duplex, not a Mallet (no articulation at all) - the Rivarossi Bavarian Gt 2x4/4 0-8-8-0 is a Meyer not a Mallet (double articulation) - the Rivarossi Saxon 0-4-4-0 Meyer is indeed a Meyer I've not looked at Trix/Marklin implementations, or the various Big Boy models (too rich for me). Whatever its other imaginary aspects, the Mantua 2-6-6-2 Uintah RR No 50 is indeed a Mallet with single articulation.

Pacifics. Mixed feelings. I think if there had been a successful UK prototype running on UK loading gauge (the Germans certainly were using 4-cylinder compounds which were pretty wide at UK platform level) then the need for speed would have lead the ECML and the WCML to have started using pacifics pre-WW1. So I think there may be some circular logic in looking at what actual practice was (which was using established designs) rather than the what-if of GCR, GNR or LNWR had run parallel development with Churchward to produce the A1 pacific (and look-alikes) in 1908 instead of 1928. Northern coal poorer than Welsh so GN, GC, LNWR might have been more attracted to the opportunities than GWR. Midland not a contender for this (light engine policy) unless they still had a chip on their shoulder in the 1900s from being excluded from the race to the north in the 1890s.

Pacifics. There a Wikipedia entry dedicated to this. Summary: all around the world 1906-1908. Some evidence (look at Maffei's route to get to the Bavarian S3/6) that you have to build one or two designs to learn how to get them right. UK an exception in that Churchward's Great Bear seems to have discouraged the rest.

I think I may be almost entirely agreeing with Rockershovel, whilst coming at the problem from a different direction ... - Mallets and Meyers are substantially conventional locomotives - but where there are two engine units instead of one under the frame. The front engine unit (only) is articulated in the Mallet; both are articulated in the Meyer. Either can be a tank or a tender engine. Meyer's design and Mallet's patent specified compound, but many of the later US designs ignored this, infuriating purists. The benefits are extra cylinders and reduced driving wheelbase compared to rigids. Tender versions do not use the weight of the tender for traction - Kitson-Meyers, Garratts, du Bousquets, and Engerths have the rear engine units under the tender as well as the cab, and so are all double-articulated 'tank engines', and also use all of the locomotive+tender weight in traction. All can add leading and/or trailing non-driving wheels to improve track wear and for leading into curves. The key difference of the Garratt (probably just to differentiate it from the earlier Kitson-Meyer concept) is to move a substantial amount of the water supply to the front in an extra tank to balance the forces on the front articulation joint - Double Fairlies have a rigid double boiler system on top of two articulated engine units. This severely limits the coal supply as it can only be carried in side panniers. Not really suitable for compounding - The geared locomotives (Shay, Heisler, Climax, Williamette, others) also used all of the weight for traction, but had a single engine unit driving multiple articulated wheelsets. They were slow enough not to need non-driving leading or trailing wheels.

du Bousquets. Yes the only fuel visible at the back area in any of the pictures with enough detail does indeed look like briquettes, neatly stacked, maybe 0.25 m above the top line of the steel work. Some pictures probably show (although clarity is poor) that the rear side tanks have a hinged lid that I'd not associate with water storage. Still confused, but now tending towards Flying Pig's view as most likely to be correct.

Rack locos. I agree with John New, but particularly for the Worsborough Bank. It had mining subsidence as well as its civil design issues, and a rack would have shifted as the ground shifted. Some of the accounts of the Worsborough imply that stalling on the even-steeper section pulling out of subsidence track was a routine cause of failure/problems.

Geared Locomotives. I think the lack of UK interest may simply have been that no-one was selling them to the industrial users who potentially wanted something that had much more power than its boiler implied (thus less out-of-service running costs when you have to keep it stoked just stop the grate from cooling down), could run on poorly laid, often temporary lines, and where speed was a non-factor. Have a look at the 0-4-4-0 Garratts, that had a vendor, and even they were a hard sell with few takers. The key shortage was that none of these had a commercially viable version that allowed the operator to change the gearing ratio. A lack for the steam-turbine locos, but that's another topic.

Back to du Bousquets, I'm afraid. Firstly, I suspect rovershover is confusing the SG of coal (agreed, around 1.26 to 1.4, dimensionless, depending on grade) with the effect of its bulk density, which includes the effect of all the air-gaps. Perfect spheres (I used to have to know this) have a bulk density 67% of their true SG. A liquid has 100% of its SG. Real-world solids are between these numbers, depending on how much the small bits fall into the gaps, and whether the shapes allow better packing than spheres that just-about kiss where they touch, and how much effort the fillers have put into bedding-down the solids. Think of slate. Then think of pouring ground coffee into a jar, then watching it settle if you tap it. The internet suggested value for coal is 750-850 kg/m3, giving 6-6.5 m3 for 5 tonnes of coal. So I should have checked more closely but wasn't that far out. Secondly: French Wikipedia (below) - inasfar as one believes Wikipedia - resolves that the front water tanks travelled with the front sets of driving wheels - as: 'ainsi que les caisses à eau avant'. It also says that the coal bunker was on the main chassis. This could be that Flying Pig's belief was fully right, or that the rear enclosure had some coal, and the rest was in the side-tank that wouldn't impede the driver, or that the rear 'caisses' both had coal in them (as I thought at first). I've only seen one du Bousquet picture that had something heaped up above the hand-rails at the rear, so I'm tending towards two coal stores - one conventionally at the rear of the tank locomotive, and one on one side in a rear tank. The two-store, neither person was right, version of the truth. Some pictures have different filling fittings for the front tanks compared to the rear tanks. I think this just makes me more open to alternative opinions, than it makes me shout 'I woz right!'. French Wkipedia: "Les 031+130 étaient donc articulées selon le principe Meyer-Kitson et se composaient de trois éléments : un châssis constitué d'une poutre centrale portant l'ensemble chaudière-foyer-abri et réserve de charbon, deux trucks portant chacun un ensemble moteur avec cylindres reliés au châssis par des pivots à glissière permettant un débattement suffisant. La locomotive étant de type compound à 4 cylindres, le truck arrière portait les cylindres à haute pression et le truck avant portant les cylindres basse pression ainsi que les caisses à eau avant. Pour assurer des conduites articulées courtes avec rotules, douille et fourreau, les cylindres HP et BP se faisaient face. Les tuyaux d'échappement reliant les cylindres BP à l'échappement étaient en toile caoutchoutée qui se révéla suffisamment résistante. L'échappement était du type « Nord » à cône mobile. En service la machine pouvait s'inscrire dans des courbes de 90 m de rayon et la vitesse limite était fixée à 90 km/h."

du Bousquets: location of the coal bunker. Not sure, not sure at all. I was going by the location of the people in the picture I originally posted, particularly the man stood right at the back, bolstered by the similar lack of obvious enough behind-the-driver storage on other French tank engines (as below: an 0-6-6-0 Tank Mallet, and a 1 m gauge 0-6-0T). Unfortunately I've yet to find a drawing of the du Bousquet that specifies where the coal was stored. The douglas-self page gives the du Bousquet coal capacity as 5 tonnes (say 7 m3), and the water capacity as 12.8 m3. If all four are water tanks, then the space over the rearmost driving wheel seems very small (by eye) to contain about the same volume of coal as the side-tank on one side only. On the other hand, having two bunkers, one on each side of the driver, is not going to be popular when the stoker is shovelling from the same side as the driver when he wants to look for signals. Roughly scaled using the 1.48 m wheels, as below, the space at the back is 1.2m by 1m by (assumed) 2.6 m wide. Comfortably less than 7 m3. I repeat: not sure at all. du Bousquet: Other tanks:

" ... Ermm, where's the coal go?" Looking at the rivets (but not counting them) the French seem to have gone for simple rectangular boxes, the front one for water and the rear one for coal - this is particularly pronounced on the du Bousquet where the water tank was fixed to the front driving wheels and thus pivoted independently of the boiler. I'm a bit surprised by this for the non-articulated tanks as I'd have thought a sloping floor, say 1:10, would have helped move the coal down to the shovelling point, and water doesn't care what shape it's stored in. We Brits did rarely do this - to my knowledge on Fairlies, but there must have been others.

If I may look a gift-horse in the mouth, maybe make the cab on the GWR more spacious? The attached is from an 0-8-0T that ran on La Petite Ceinture, and it does look as if the French wanted enough space for three operatives to more around freely. Plus this enlarged the panniers. The du Bousquet appeared to have enough space on the back for a table and chairs, but he was fitting his rear driving wheels under it.

As recently suggested, French-style GWR 94XX, via a sloppy photoshop of a Hornby model. No coal at the back, much deeper panniers to replace this, and they stretch forwards. Yes, the tanks could do with a taper at the front end to improve visibility, but I didn't have the software skills. The French would probably have left the back open, but I think we may have more tunnels. If the driver had his/her controls duplicated at the back of the cab, I could see this design being preferentially run funnel-backwards, but not enough to call it cab-forwards.

"More on the du Bousquet's, including a very nice model, here: http://www.douglas-self.com/MUSEUM/LOCOLOCO/bousquet/bousquet.htm I like them and wonder if the Lanky or the Great Central might have been tempted to adapt the design." (Almost) everything I know about about du Bousquets I got from that site. Especially everything numeric. I fear their key disadvantage was more water than coal on the loco (only 5 tonnes of the latter), and they didn't comply with the rational British obsession with leading non-driving wheels to reduce track wear. So well suited to slow, heavy-duty trips around La Grande Ceinture at Paris (flat, limited curves, limited distances), less so for UK conditions. Now if London had joined up its sundry goods marshalling yards with a Greater London Belt Joint Railway then goods transfer during wars might have been eased, with potentially two extra Thames crossings. But it didn't.

This picture is from an articulated du Bousquet 0-6-2+2-6-0, but the cab area appears to be only slightly bigger than is typical of pre-WW1 French tank engines. The 'cafe culture' rear end does not appear to be down to loading gauge. The page I got this from had a dimensioned drawing of the 0-8-0 tanks that preceded these on La Grande Ceinture, and they were 2.8 m wide on the side-tanks and 2.9 m wide at the access steps, and did not have the coal behind the cab. So pretty close to the UK gauge, different layout. The difference appears to be the massive side tanks with the water and coal in that free up space behind the cab. So: a GWR pannier design with full-height side tanks and an observation car rear end? Significant rear vision gains, at a cost of shovelling coal, Fairlie-style out of narrow side-tanks. The du Bousquets appear to have been perfectly suited to heavy goods transfers between the fairly close marshalling yards around Paris and that's where all but ten ended up. Build 1908-1910 (ish) lasted to after WW2, despite the collapse of the most of need for La Grande Ceinture in the 1930s.

I've seen it asserted (and I think I half believe it, but only half) that opening the door into the hearth - to shovel the coal in - disrupts the air flow, giving an easier path over the top of the bed of coal - instead of up and through it. Meaning that door-permanently-open operation does not improve the power output as much as you'd hope, even doubling the number of stokers. I've also seen it stated (there was a reference I didn't note down) that the maximum output of the single stoker was 50 hp/ft2 of grate, and the maximum sensible sustained was closer to 32 hp/ft2 of grate. With a side-note that some of the peak numbers recorded might come from stokers highly motivated by attempts on records.

"... It was. They did. The Midland route, via the Settle & Carlisle. It was a LMR (Midland Division) service, hence the use of Saltley engines." I take it this was a combination of avoiding the 1:75 at Shap (I believe the Settle & Carlisle was 1:100 ruling gradient), debottlenecking the northern bits of the WCML of slow-moving freight, and using an under-used asset (Leeds-Carlisle)? The modern layout around Leeds station means it could be bypassed, and I've always been puzzled as to why. This may be (part of) the reason. The 1:75 at Beattock would then have been a Scottish problem, not a Midland one.

So I see a version of this suggestion, liberally paraphrased, as "What if Brunel's parting shot at the Gauge enquiry and the resulting 1846 Act of Parliament had been to instruct Gooch to produce a class of ten locomotives that used the broad gauge possibilities to the full?" Gooch then produces a boiler design appreciably greater in diameter (but the same length) as the best standard gauge competition, and has to re-engineer every detail to make it all work. Is the result an early 2-6-2 powerhouse? Or does he just find the resulting loco won't have a revenue-earning duty (or can't be stoked), and quietly abandons the request? This is independent of what happening to the coaches, although the attitudes of the time do explain why Brunel's loading gauge wasn't 14'.

I actually understood this thought as much more modest, and therefore much more interesting. Brunel's broad gauge was radically bigger between the rails, but only moderately bigger between the tracks. Stephenson started at 4'8" gauge, 4'8" between the tracks, giving a loading gauge just over 9'. JimC's drawing shows that Brunel took this only to 11'6, not the 14' that 7' between the tracks would have given. Also that the mixed-gauge outline is basically Stephenson's loading gauge. So I thought the question was more - if you had an 11'6" width and 15' height in your loading gauge and used all of the extra 2'6" on boiler diameter at the same total length, would you get a loco so much better that it would be worthwhile? And worthwhile includes whether there's a need for it, as well as whether it would have amazing headline numbers. And whether it triggers knock-on costs of civil structures and mechanical stoking.