I was always surprised that we never saw a steam locomotive with some sort of gear box system in the middle of the frame. Instead of steam driving the side rods, it would instead power some system where it involves starting in a low gear and goes into the higher gears like a manual transmission. I don’t think this would be that complicated, as you could have one large single piston in the middle of the frame driving a flywheel much like the steam tractors do.
I am also surprised that there was never a steam locomotive towing a auxiliary boiler proving steam to the primary locomotive for steam hungry locomotives.
I think my fantasy locomotive would be a Big boy with saddle tanks and no tender. It would be one giant locomotive! How about a 4-6-8-4 with 4 drivers under the tender powered by a steam turbine?
Thomas 9011’s comment about a gearbox system in the middle of the frame sounds intriguing, but it reminds me of the early years of steam when the locomotives had the cylinders and valve gear mounted within the frame. The Brits kept the system for quite a long time, but here in the US it was given up as a maintainance headache pretty quickly.
As far as the “manual transmission” aspect, that reminds me also of diesel-mechanical locomotives. They worked well for light loads as in switching, but were totally unsuitable for over-the-road work.
I remember riding in the cab of old 20 ton Whitcomb diesel locomotive and I was shocked when the engineer grabbed this huge gear shifter lever and was switching gears and we went along. I don’t remember how many speeds it had but it was very similar to switching a manual transmission in a car.
My knowledge of steam from the era is of stationary electric power plants rather than locomotives.
Power plants from this era are water tube boilers with superheaters. This allows higher temperatures and pressures, with resultant increases in thermal efficiency. I would expect a steam turbine generator driving electric motors similar to those used with diesels
While a locomotive would not achieve the 30% efficiency of power plants, 15% to 20% would seem possible.
actually my question was aimed at what types of conventional or classic steam as I prefer to call it might have been developed in line with the evolution of American steam as it was realized in the three decades of the 1920s to 1940s .
If we consider J-79 steam-converted coal fired gas turbine / electric / condensing / high pressure / power trucks / saddle tank non-tender tender drive / booster middle frame single piston geared and what have you we might also consider possibilities of mainline rack rail and steam ram-jet supersonic propulsion & all …
Ok - since obviously there is a liking to head into unexplored realms of the ‘wild side of engineering’ :
Jawn Henry
While I have no test reports or service reports on that engine , I can easily imagine trouble with side-effects of products of coal combustion and waste water / steam interfering with electrical systems even if - as I presume as given - they had been provided with some sort of protective insulation … of possibly quite optimistic layout not fully taking account for your typical irregular incident and rough handling , generally lacking due hardening against abrasion and the elements . This could have been dealt with , no doubt, if you come to think of several times harder working conditions of electric locomotives in mining railways which do labor on and on as long but vaguely perceivable as locomotives under thick layers of dirt garbs of all sorts of odd elements and without shying water flooded rails , neither .
It could have been done if engineering would have been commited to solve teething troubles with as much financial investment and investigation in design development , testing , building prototypes , improving , re-testing and all that EMD had done to develop their baby to a point where it could be presented to the public , be promoted , marketed and sold on series production ( the lik
But I had suggested some more modest reforms . . . How about the Jawn Henry water tube boiler without the complicated turbine-electric drive – just ol’ (compound expansion of the 600 PSI steam) pistons, rods and drivers?
How about a siderod drive as in the Pennsy S2 turbine, but using a quill drive to one of the driver axles from a high-speed piston steam engine, or maybe the jackshaft arrangement as on the turbine in Sweden? Siderods are not the problem with track pounding as they can be balanced – the problem is the changing force angles of the main rod.
Maybe, we could do some historical research into what the main problems were with railroad steam? If “track pounding” were such a problem, why didn’t we see more of the De Glehn 2-cylinders inside driving the first cranked axle, 2-cylinders outside driving the next axle from the outside, inside and outside cylinders on the same side of the locomotive at 180-deg relative to each other? That had to be a better solution than the Bill Withun Duplex with the back cylinders stuffed under the firebox (didn’t work on the Pennsy) and the inside connecting rod connections to crank axles?
Was the large amount of coal consumed by 6% efficient steam the problem? Some sources say that at their heyday, US steam locomotives were using 30% of the coal mined in the US. Forget about the smoke and the CO2 emissions, that is a lot of coal to carry around, just to run the thing (the locomotive pulled train) that does all of the carrying. In other words, much of your train and track capacity is used just moving the coal around to where you need it to run trains? Would a move to 12 percent efficient steam make this fuel logistics problem more tenable?
You sure added some worthy thoughts to the discussion , I wanted to answer yet didn’t have time and peace of mind to sew up something worth reading . I had long since put various thoughts of my own into the topic and will try and post an abstract on some of them .
Absolutely true , what you write about buying power is not all there is to it , proper organisation of running and maintenance is an indispensable part of making it successful . However this isn’t limited to steam or advanced steam , it applies to any category of traction power - with diesels it was soon found full potential was not to be had by keeping diesels in steam sheds , preferably they wanted facilities of their own taylored to their needs . The same is - or should I say was - true with electric traction . Nowadays , if I see DB’s electrics simply parked on reserved tracks in freight yards instead in engine facilities (which have been torn down) it looks like these don’t need a home anymore and hardly a shops attendance during mileages nearing a million between overhauls , neither . Yet that doesn’t mean it all comes for free : what was spent on running maintenance on earlier power now is spent in high quality design and construction that has to be paid for in acquisition of this power , hat’s why it only pays off when working in very intense daily ton-miles service schedules - which again isn’t necessarily or always the way DB applies them , or so it seems when lately counting like 15 - 22 of various DB classes plus three form Austrian Rys parked in three rows for hours , some of them even for days on end .
More remarks coming up …
As I write this I see the news about New York City : Jesus , that’s the one thing this city for sure didn’t need , ask for
If I am not a stickler for the facts, maybe I make a big deal about getting in the rough ballpark with the numbers?
An H-8 2-6-6-6 locomotive pulling 200 (plus!) coal cars up a 1 percent hill? Empties or loads?
Now I know that a coal car back in the Transition Era is not the same mass as a coal car today. Suppose you had 200 50-gross-ton coal cars in tow behind one locomotive. Just an assumption, but bear with me.
200 cars times 50 tons times .01 (1 % grade – haven’t even accounted for the weight of the locomotive or the Davis formula resistance) equals 200,000 lbs. Are you telling me “they” were getting 200,000 lbs tractive effort out of 6 axles, and yes, I know the H-8 had one of the highest axle loading known to history. Suppose they had 480,000 lbs on the drivers – maybe, just maybe you could get 200,000 lbs tractive effort if you liberally applied sand and if the rails were bone dry and if you held down the safety valves to get an illegal level of boiler pressure.
Something, however, tells me that had a pusher (“banking engine” to our British friends) cut into the train somewhere.
As to the fuel economy of the 844, don’t they usually have trailing Diesels in the consist when they take that locomotive “out for a spin”? And as to going
Never mind , no insult intended if I seemed to take things less serious than I shoud - it’s a flaw that befalls me now and then , really I have to admit it protects me from my head becoming too much entangled in thoughts . I have to throw it off from time to time and say to myself “Look , it’s all a mess , technology as run by humans is an endless show of digressivness and absurdities.” - some hop into a 350 hp 2.2 tons car to get to the shop next block and buy a liitle something while others walk for miles on end or work for hours for but a trifle bit of a wage that is but an insult in itself , yet they have no choice . In this forum we are in blessed positions to be able to discuss such topics relevant but to our mental recreation and reflection while the East Coast is striken by this monster hurricane .
I will write more later on - just a few remarks on the Triplex
I agree , it basically was a potentially progressive idea as for steam of maximum tractive effort . However , the idea was to extend engine unit side of the locomotive in relation to unchanged boiler size and thus avoid depression of power output at low speeds ( as usually inevitable with classic steam ) That said the idea of introducing whatever increase on the boiler side of the locomotive inherently is a contradiction to the idea of the Triplex , you see , since it re-establishes relations found in a ‘conventional’ Mallet - or : you could just use two locos to realize the same . What the Triplex as built suffered from obviously was a severe lack of draughting and - to a minor degree - grate size / air conduct and boiler proportions . That was what prevented the boiler to live up to demands , i e balance evaporation with consumption at low speeds ( it would have been quite another story to make it steam fast enough to feed three engine unit sets at higher speeds - but that wasn’t what the idea focussed on )
A lot of hill climbing was done on train momentum in steam times - yet any railroad with due safety standards loaded locos only to what they could start any point of the line . Probably it was 200 car loads _or_ 1 % grade but not both combined and then not without assistence by a couple of Mikes shoving hard at the rear .
The H-8 were the antithesis of the Triplex : plenty of boiler capacity combined with a comparatively small number of drive wheels or more precisely small percentage # of powered wheels : # of total wheels . In consequence the 2-6-6-6 was a formidable tonnage roller on the level and inevitably a compromised if awesome performer on ramps .
According to dynamometer records, the H-8’s were good for 115,000 lb of drawbar pull, so I would also be surprised if one H-8 could pull 200 cars up a 1% grade. While they had a high axle loading (86,000 lbs), the cylinders and steam pressure was designed for the lower “official” axle loading.
If I am not a stickler for the facts, maybe I make a big deal about getting in the rough ballpark with the numbers?
An H-8 2-6-6-6 locomotive pulling 200 (plus!) coal cars up a 1 percent hill? Empties or loads?
Now I know that a coal car back in the Transition Era is not the same mass as a coal car today. Suppose you had 200 50-gross-ton coal cars in tow behind one locomotive. Just an assumption, but bear with me.
200 cars times 50 tons times .01 (1 % grade – haven’t even accounted for the weight of the locomotive or the Davis formula resistance) equals 200,000 lbs. Are you telling me “they” were getting 200,000 lbs tractive effort out of 6 axles, and yes, I know the H-8 had one of the highest axle loading known to history. Suppose they had 480,000 lbs on the drivers – maybe, just maybe you could get 200,000 lbs tractive effort if you liberally applied sand and if the rails were bone dry and if you held down the safety valves to get an illegal level of boiler pressure.
Something, however, tells me that had a pusher (“banking engine” to our British friends) cut into the train somewhere.
As to the fuel economy of the 844, don’t they usually have trailing Diesels in the consist when they take that locomotive &q
I have the Huddleston and Dixon book. The graph for drawbar pull vs speed shows that at start, the H-8 was capable of 115,000 lbs. As for the H-8 producing 7498 DBHP, that cannot have been achieved at 15 MPH, since 7500 DBHP translates into 187,500 lbs of drawbar pull (and 141,000 lb at 20 MPH).