RLBH

Union Pacific also occasionally chuck out one of their steam locomotives in revenue service to avoid a light locomotive positioning move. On one occasion 3985 hauled a 143-car intermodal train, apparently in part because the client who booked most of the train's capacity was known to be a steam enthusiast.

The issue with GM was that they flat out refused to licence production of the engine (and possibly traction equipment), and still do. All GM-powered locomotives have the machinery run off of the same American production line, even if it's fitted in a domestically-built shell. Perfectly understandably, after all GM don't want someone like NBL botching the build and ruining their reputation. But, in Britain in the 1950s, that was economically (dollar shortage) and politically (loss of British jobs) unacceptable.

Not sure where I saw it, but I'm fairly sure I've seen reference to former LNWR management being opposed to further progress of the LYR electrification schemes. There was also hostility from the LMS direction to extension of the Manchester-Sheffield-Wath electrification over the CLC route to Liverpool. Certainly Cox states in Locomotive Panorama that early work at Horwich on a Crewe-Carlisle electrification scheme was abruptly stopped in 1924, O'Brien - the Chief Electrical Engineer and a LYR man - resigned, and the department was moved to Euston and put under control of Cortez-Leigh, an LNWR man. The LMS thereafter confined its' electrification endeavours to suburban operations. The Crewe-Carlisle scheme seems to have been reasonably well progressed and called for a 2-D-2 locomotive along Swiss lines. I have a suspicion, entirely unfounded, that the Weir Commission's case study from 1931 of this section was based on the earlier proposal. The consultants in that case found that the return on capital was poor because the scheme confined itself to the main line, meaning that many steam locomotives had to be retained, and electric locomotives were underutilised. The simultaneous study of the LNER Great Northern section was much more favourable, and it's hard not to wonder whether the attitudes of the two railways to electrification impacted the choice of case studies. Certainly the LNER had wanted to do the Manchester-Sheffield-Wath scheme as early as 1927, but capital wasn't available at the time. The LNER diesels may have been intended to be along American lines (so was Deltic, after all) but were very definitely from British builders - tenders were received from all the usual British suspects. The GWR was primarily interested in spending less on coal west of Newton Abbot, where transport costs made coal much more expensive than the rest of their network. The 1937 electrification study - based on 3 kV DC overhead lines - was done in that vein. The later GWR schemes for oil-fired steam locomotives in this area, and for early dieselisation under BR, had much the same slant on them.

That's a very interesting possibility - Raven at the NER was very keen on electrification, of course, and the NER S3 (LNER B16) 4-6-0s were explicitly intended for secondary routes that wouldn't justify electrification. What the Midland would do would be quite interesting - of course, they and the LBSCR were both using 6.6kV 25 Hz AC electrification, so that would presumably have become fairly widespread. What the locomotives would have looked like is anyone's guess, I think. The LYR was also quite interested in electrification - at one point having three completely different systems on the go. I believe that the 1,200V side-contact third rail system was envisaged as their main line electrification approach, with Manchester-Bury seen as the prototype. The LNWR, meanwhile, was seemingly actively hostile to electric railways. It was LNWR influence that killed off LYR and Midland interest post-grouping.

Looking at unreasonably large locomotives, the Durrant 4-8-4 and 2-12-2 and the LMS 4-6-4 and 4-8-4 make an interesting comparison. The LMS boiler has a 6'10" diameter and (scaling from an unscaled drawing like a naughty boy) a length of 20'3", fired by a 70 square foot grate with no combustion chamber. Durrant has a 7'3" diameter boiler of 19'6" length, fired from a 75 square foot grate with a combustion chamber. The Durrant boiler has a 7% larger grate, 8% larger capacity, but ought to have 12.5% more gas area. It ought therefore to be able to supply somewhere between 7% and 12.5% more steam - though being shorter, the superheater temperature might be lower. Of course, the LMS locomotives have larger cylinders intended to have a maximum of 65% cutoff to reduce tractive effort, whilst still being able to generate power at higher speeds. The claimed goal was 40% more tractive effort than a 4-6-2 Coronation at 60mph - the larger cylinder diameter and increased boiler pressure gives 35%, the other 5% from smaller drivers. The cylinder volume and grate area on the big LMS locomotives are in similar proportion - accounting for increased pressure - to other British locomotives of modern design. The Durrant locomotives, meanwhile, are fairly small-cylindered machines working at 85% cutoff. That gives his locomotives 5.7% more tractive effort for a given driver size. He cheats, of course, by using 6' drivers on his express passenger 4-8-4, which as a result is pretty comparable to the 5'6"-drivered LMS mixed traffic 4-8-4. But the small cylinders mean that at speed his locomotives become limited by the front end - the express 4-8-4 being only 15% more powerful than a Coronation, considerably less capable than the LMS locomotives. In short, I think they probably take the 'big boiler' school of locomotive design a bit too far, and wind up with more boiler than they can use. They'd be perfectly fine, I think, with a 55 to 60 square foot grate, and a more reasonably sized boiler. To actually use the big Durrant boiler to its' full effect, you need a third cylinder - probably three 21"x28" cylinders, compared to his two 21"x30" cylinders. To keep adhesion within reasonable bounds, use the same 65% cutoff as the LMS locomotives. The result is a good match between boiler and cylinder capacity, and (incidentally) perhaps the most sure-footed British express passenger locomotive for a very long time, which is incidentally 64% more powerful than a Duchess. Oh, and the 2-12-2 version offers about twice the power of a 9F 2-10-0, so that ought to take care of your express freight work. Although.... the fact that we're having to limit cutoff probably indicates that we're a little past the practical limits of British railway infrastructure. Tractive effort isn't increasing at the same rate as power, so the trains are getting faster more than they're getting heavier. It ought to be possible to achieve comparable performances with these locomotives - the LMS or Durrant ones - as with diesel locomotives. Matching early electric performance might just be possible, if the boiler and front end design is really good. But they'd do so at vastly greater cost than just buying diesel locomotives, and are clearly at the limit of their growth - whilst electrification is equally clearly just at the beginning of its potential.

Titanium is great for pressure vessels - it's the material of choice for deep diving submarines. It's also incredibly expensive and very difficult to work with. A Aitanium-boilered steam locomotive would be a vanity project of the highest order, and I'm not sure how much practical advantage could be gained. Aluminium would probably be a very poor choice for a boiler, because it has a low melting point and loses strength at fairly low temperatures. The kinds of temperatures you'd expect to find in a boiler. It is, apparently, possible to extrude boiler tubes in such a way that the right structure is created. Metallurgy isn't a strong suit for me so I've no idea how it's done, though! The other issue with an extruded boiler would probably be that it would be difficult to make it tapered. The machinery for extruding a 5' (give or take a foot) boiler would also be fairly expensive and specialised, so you'd need to be confident of building a lot of identical boilers.

It's actually easier to have high pressure in a smaller boiler than a large one. To a reasonable approximation, the boiler wall thickness - and therefore weight - is given by Thickness = Pressure * Boiler Radius / Material Strength This is fundamentally why really high pressures need water tube boilers - the wall thicknesses become prohibitive otherwise.

From Chronicles of Steam (which arrived yesterday!) it was anticipated that an American-style Delta truck would be needed for the largest possible ashpan capacity. Curve radius would be restricted to 10 chains rather than the 6 chains of lesser locomotives to further maximise ashpan capacity - and, I suspect, to prevent them from spreading the tracks too much. A 24-ton axle load was needed, but hammer blow was expected to be near zero since it was a four-cylinder locomotive; the precedent of 23 tons on the Turbomotive was cited. The water consumption of that beast would be quite something - to avoid needing a much bigger tender, you'd need every trough between Euston and Glasgow to be working. And probably a few extra ones north of Carlisle. Interestingly, the idea behind both the 4-6-4 and the 4-8-4 was that both were to be mixed-traffic machines, capable of hauling almost anything - the only exceptions being that the top-link passenger duties needed the speed of the 4-6-4, and heavy mineral work needed the 4-8-4. Implicit in this is an expectation that much more of the freight wagon fleet would be fitted with brakes. The idea of running more, lighter trains with smaller locomotives was dismissed as whenever such things had been tried before the short trains inevitably needed making longer. A lesson that the modern railway could have done with remembering.

Perhaps, although the designers at the time didn't think that way. Certainly the adhesive weight and tractive effort on a WD 2-10-0 is, again, about the same. And with a similarly-sized wide firebox, though I'd be curious about ash pan capacity. Though, if a 4'8" 2-10-0 - why not a larger-wheeled (say 5', or 5'3") 2-8-0 with the same power output and the same weight on the drivers?

Very interesting episode about Thompson, and I have to agree that he's not the villain of the piece. In my experience engineers generally can't be bothered with machiavellian one-upmanship, and just want to make things that work. In fact, I can see a lot of myself in Thompson, both the good and the bad. Perhaps his de novo designs weren't as polished as some other engineers - but then during his time as CME, building new locomotives from scratch wasn't the top priority.

It's a rule of thumb that, by observation, works fairly well for normal trains running to normal schedules. Give or take maybe 10%. That a crack express given a clear run all the way might do better, or a relief getting checked at every signal do rather worse, doesn't overly bother me. It's a quick and dirty way of estimating running times given almost no information. Thinking of 2-6-2s and 2-8-2s – the Gresley V2 and Powell's Britannia-boilered 2-8-2 have pretty similar adhesive weights and tractive efforts. And both proposed for similar fast freight work. Presumably the Coleman 2-6-2 would have been similar again. The main difference is the size of the driving wheels and how heavily they're loaded. So, what's to choose between six 6'2" drivers and eight 5'6" ones on an express freight locomotive?

My rule of thumb, and a surprisingly consistent one, is that end-to-end journey times on rail give an average speed about two-thirds of the maximum speed. Apply that to the Hiawatha, and you get a service that was probably routinely hitting 120mph. Didn't the over-track coaling stations also need facilities to empty the ash pan whilst in service? Or was that the NYC Niagaras?

The N&W was, in some ways, a very 'British' railway for America. It built its' own steam locomotives in its' own works, and was perhaps wedded too long to improving them rather than dieselising because of institutional inertia and a ready supply of cheap coal. Though the Y6b merely had 3'3" LP cylinders. It was the Virginian's Class AE 2-10-10-2 that had 4' LP cylinders - although the Virginian was later acquired by the N&W. As far as speed records go, enthusiasts of American steam in general, and the Pennsylvania Railroad (which reminds me of the GWR in some respects) in particular, claim that the T-1 duplex could do 140mph routinely. Skeptics claim that its' wheels were perfectly capable of slipping at 140mph whilst the rest of the train went nowhere. In order to resolve the dispute, they are attempting to build a new one, although quite where they're going to test it remains to be seen.

And plenty of space for large low-pressure cylinders! The Liberty ships (to take a convenient example) had LP cylinders of 70" bore x 48" stroke; even the HP cylinder was 24.5" bore. While the boiler ran at 220psi, marine engines can also easily use a condenser - which isn't practical for railway applications - which gained another 12.75psi at the bottom end. Having lots of space, practically no weight constraint, and an ample supply of cooling water makes the engine design problem a very different one. In hopes of relating this to railways, the railway steamers would certainly have been fitted with machinery of such a design! I know that Swindon turned the shafts for the GWR's steamers, presumably the railway works must have done a lot of the steam engineering for their own ships as well.

Worth noting that the North American railways generally reached a similar conclusion to the British ones - when first tried, compounding increased efficiency but was more complex. Superheating offered similar gains in efficiency without the increase in complexity. Compounds did continue to be built into the late 1940s for some really big, slow mineral locomotives to haul immense trains, but was generally felt not to be worthwhile.

Which I think is why it keeps coming up. The work existed, it was technically fairly straightforward, and it looks right.

Found a reference: http://www.steamindex.com/people/coleman.htm Cox's Chronicles of Steam is the source, it was a March 1942 suggestion by Coleman to Stanier of 12 possible postwar standard locomotives, also including a 2-8-4T based on the 8F, and an LMS version of the GWR 56xx 0-6-2T. Apparently all worked up in sufficient detail to allow production design to commence if authorised.

A Tom Coleman design, apparently, possibly of similar vintage to the 4-6-4 and 4-8-4 proposals.

In essence, the GWR was very fortunate in having access to exceptionally high quality coal, and a network with comparatively short workings, which meant that it could get away with 4-6-0s up to the point where alternative traction was replacing steam of any kind. Although the repeated references to a GWR Pacific suggest that the writing was on the wall, even if the drawings hadn't been authorised yet. A Standard 2-6-2 might have been an interesting beast, as might be the proposed LMS 2-6-2 - which I believe was to have borne a similar relation to their Pacifics as the V2 did to an A3. On a totally unrelated note - the feverish imaginings of Robert Francis Fairlie in 1868. It's not entirely clear to me whether to class this as a locomotive or not. The description of this... thing is: "The Metropolitan [Railway] should be conducted by stock giving the minimum of dead weight with the maximum of efficiency; this, I think, could be best done by wyat may be termed steam omnibuses, made to carry say 60 passengers, but with power sufficient to haul additional carriages during the busiest hours of the day -- in the middle or slack time the omnibuses could alone carry the mean average of passengers. The weight of the entire machine, together with its load of passengers, would be less than that of the present locomotive engine alone. I have brought here to-night the drawing of a steam carriage, designed expressly for conducting the traffic of the proposed cheap lines in Ireland, which will be useful to show you the character of steam omnibuses (to be modified to suit circumstances) I should recommend for working metropolitan lines. This carriage would work with efficiency and economy the line over Mount Cenis." So there we have it. A lightweight locomotive, capable of carrying 60 passengers plus hauling a number of carriages, and ideally suited to cheaply built rural lines, steeply graded mountain railways, and busy city commuter lines! I can only assume that the passengers were presumed to be of small stature, given the height of the passenger saloons.

There was certainly a policy of the Ordnance Survey not to show military facilities - it was withdrawn perhaps 10 years ago, in recognition of the fact that things like Google Earth made it a totally useless security measure.

I'm not sure that that is a mobile crane, at least not in the sense you mean - it looks a lot like a Liebherr mobile harbour crane, which is prefectly at home wandering the docks but isn't designed to be transportable. A realistic dockside would be very impressive - but also very difficult to do, simply because of space. The largest scale routinely used for model ships is 1:350, and even then the models can get very large indeed - 1:700 and 1:1200 are normal. Then, model harbours have the same problem as model railways - needing space to move the ships around - except that they're not as linear, so they wind up being wide as well as long. A realistic-looking model harbour to take large ships would wind up being comparable in size to a realistic-looking model railway: although the scale is ten times smaller, the vehicles are ten times larger! Even a small harbour is still very large; Burghead is tiny, by harbour standards - a Clyde puffer would be a big ship for it - and is still about 750 feet by 350 feet.

From what I understand, the LB&SCR L class were perfectly satisfactory, once teething issues had been dealt with, and were only converted to 4-6-0s when they were made redundant in their original role by electrification. Not perfect, to be sure, but basically sound machines that did the job that was asked of them well and justified rebuilding once that job went away. That line of thought rather suggests trying the experiment the other way around - put a Raven boiler on a Gresley frame and front end. I'm not sure why you'd bother in practice, but it would be an unusual looking machine anyway.

The only 2-6-4 tender locomotives were, I believe, a South African 2-6-2 class rebuilt to 2-6-4s because of instability, and two classes of Austrian express passenger locomotive. The latter classes seem to have been semi-articulated, with the first pair of drivers mounted on the leading bogie with some clever engineering. I suspect that, in general, it's hard to design a 6-coupled locomotive that can use enough steam to justify a big firebox with two axles supporting it. Trying to get lots of power on a low axle loading is about the only time I can think it might be worthwhile - the Austrian 2-6-4s had a 15 ton axle load.

In the absence of electrification, and given the coal traffic across Woodhead, I could see the 2-10-2 being looked at very closely for the line. Though there would be issues, not least loading gauge. I believe it would have blown the normal loading gauge out of the water, and Conisbrough Tunnel was to have been opened out to a cutting to make space for it. The whole thing was tied up with GCR plans for 40-ton coal wagons, and generally running the pit-to-port operation in the most economical way possible. I've never seen any indication of the 2-10-2's actual characteristics (save that for some reason I thoguht it was to be a 2-10-4), though I believe there's an artist's impression out there somewhere.

That would presumably be Welwyn, where the ECML narrows down from four tracks to two for the viaduct and tunnel (one straight after the other). It does indeed cause capacity problems. Unfortunately, the viaduct is listed, which makes it far more difficult to solve than just building a second one in parallel. Apparently having pretty-looking infrastructure is more important than functional infrastructure. And without addressing the viaduct, there's no point dealing with the tunnel either.