Which speed and which viable concept for a 4 x 8-coupled proposal ?
Well, as to those old proposals of Henderson’s, you don’t necessarily have to reduce wheel diameter as compared to Mallets if you consider articulated frames and boiler and involve the tender to take part of the drive sets. Principally, this concept of articulated locomotive of which just the ‘simple’ and arguably more ‘realistic’ form was realized – the Triplex with but one drive set under the tender – might be classified as a giant form of articulated tank loco in that the aggregate has become one integrated unit that has lost the basic characteristics of a tender locos, i.e. –
On the subject of condensing steam cycles, how about this story
http://www.wired.com/autopia/2011/01/land-speed-record-attempt-gains-steam/
about a US team trying to beat the steam-powered land speed record recently set by a team from the UK?
The UK effort was pretty much the Stephenson steam cycle – a lot of heat to boil a lot of water at moderate boiler pressure and then the steam goes out the stack – although I thought their car had a turbine. The US effort is an "advanced" steam cycle – flash boiler, 3200 PSI, condensing – but I know their power plant is a 6-cylinder Uniflow engine. Oh, and they are going with "direct drive", relying on the high starting torque of a steam engine, instead of using electric drive.
The entire steam power plant – flash boiler, uniflow piston engine, condensor – is all into one compact stack, which is that thing behind the guy in aviator glasses wearing the red shirt. They are also using waste heat from the condensor cooling air to preheat the combustion air. OK, not a steam engine according to L.D. Porta’s ideas, but interesting.
@ Paul:
So, both of them have it part-traditional / part-avantgarde – yet
vice-versa, for sure, on opposing sides of the .
Relying on the starting torque of a piston steam engine for a speed range
There are a number of factors at work here.
One is that the US Speed Record car uses a condensing steam power plant meant for more prosaic uses – perhaps for a light utility truck or a small city bus that can run on a variety of bio-derived fuels. The Speed Record car, it is claimed, is an effort to draw publicity to the engine, which they hope to use for much more than speed recrods.
Secondly, this is not to say that they won’t use a multi-speed transmission in for the speed record. But the group is claiming high torque with a compact, multi-cylinder radial piston uni-flow steam engine that a production car or truck may be able to utilize direct drive.
Thirdly, with respect to the claim that a (uni-flow) piston engine won’t work with a condensing cycle, I don’t get the impression that their condensor operates much below the atmospheric temperature and pressure of steam. I can see where you need a turbine for the required volumetric efficiency to exhaust into "vacuum", but that is for stationary power plants where the condensor is cooled by lake or river water. That their condensor inlet is not so low pressure is suggested by wanting to use the condensor cooling air outlet as combustion pre-heat.
Thirdly, perhaps the most radical part of what they are claiming is "water lubrication" and the ability to run a piston steam engine on the very high steam pressure and temperature they have in mind without the problems of coking the lubrication oil, removing the lube oil from the condensed water, and so on.
Their uni-flow engine is single-acting (there have also been double-acting uni-flow engines), and I suppose you can always lubricate a single-acting engine from the "back side" of the pistons by oil splash as in a conventional automobile engine, but that would leave a lube film that would get into the condensor water.
That they are claiming 100 HP from a 350 lb package for the complete condensing steam power plant seems pretty impressi
@ Paul
Well, that sure sounds interesting. Mass / power ratio reads respectable – although not exactly Indy Car nor Formula One level (which no one could reasonably expect).
Radial piston engine
Hm – gee, that’s something I had been thinking about when studying engineering; it was a private idea ignited by the long & wide hoods of 1970s / 80s
[quote user="Juniatha"]
@ Paul
Well, that sure sounds interesting. Mass / power ratio reads respectable – although not exactly Indy Car nor Formula One level (which no one could reasonably expect).
Radial piston engine
Hm – gee, that’s something I had been thinking about when studying engineering; it was a private idea ignited by the long & wide hoods of 1970s / 80s US full size sedans and focused on a gasoline radial piston engine, n
[quote user="carnej1"]
Juniatha:
@ Paul
Well, that sure sounds interesting. Mass / power ratio reads respectable – although not exactly Indy Car nor Formula One level (which no one could reasonably expect).
Radial piston engine
Hm – gee, that’s something I had been thinking about when studying engineering; it was a private idea ignited by the long & wide hoods of 1970s / 80s US
This is in addition to what I wrote above. Virtually any automotive piston engine can be run in an external combustion capacity and has been done so many times that the subject does not warrant conjecture.
As to the proposition of a steam powered aircraft that MAY have come to pass in the late 1950’s but the evidence is spotty at best due to the contoversial nature of the aircraft’s power plant. The aircraft in question was the B-36Q flying with a nuclear reactor on board. The government documents released to date suggest that the plane flew with conventional power but with the reactor in a "hot" condition to evaluate the radioactivity in and around the lead lined crew compartment.
Other anecdotal evidence suggests that the reactor did indeed power two Westinghouse steam turbines operating in a Rankine cycle configuration driving line shafts through the wings transferring power to gearbxes to drive the propellers. One of the original crew members on the test flights said the weight of the reactor, drive system and lead shielding necessitated the use of 20 RATO bottles plus the four jet engines to get the craft airborn in 11,000 feet of runway and precluded any useful payload. On conventional power the aircrafrt was known as the NB-36H however this was later changed to the B-36Q with the supposition that this was when it was indeed nuclear powered.
After three weeks of testing the airframe had become radioactive to the point that no further testing was possible and the aircraft was subsequently scrapped. To this day many documents regarding this interesting experiment remain classified and only the passage of time will bring out the entire story.
@ carnej1
@ yardmaster01
Gee, I’m surprised!
Frankly, wasn’t aware of steam powered air planes tested as early as in the 1930s.
Clearly, being able to escape into third dimension is one definite advantage of
‘steam traction&rsquo
[quote user="Juniatha"]
@ carnej1
@ yardmaster01
Gee, I’m surprised!
Frankly, wasn’t aware of steam powered air planes tested as early as in the 1930s.
Clearly, being able to escape into third dimension is one definite advantage of
‘steam traction’ over catenary guided electric traction ...
Actually, a fellow named Stringfellow built a steam powered flying model airplane in the 19th century. It worked very well but never got past the model stage. Around the turn of the 20th century Sir Hiram Maxim built a full size steam powered airplane, but the test flight failed and Sir Hiram was so frightened by the experience he never repeated it!
Faster than old GooneyGoose
Well, al(w)right, that’s progress at last! Still, the Gooneybird would win the gutty sound contest wings down - g Quest for sound or lack of it is when elegy befalls electrics. Seems, on carefully arranged test runs the hasty super railcars have even challenged Connie for speed – when cruising on three engines as she had a soft spot for ...
Electrically fired steam locomotive
Oh, gee – g
During WW-II the Swiss converted a couple of 0-6-0 shunter tank engines to electrical heating, complete with pantograph on top of the cab. It was an emergency effort to fight dire shortage of coal with a minimum of rebuilding.
I enjoyed the picture of the Swiss conversion! There was an early live steam model locomotive sold that was fired with an electric heating element, and Jenson also sold versions of their stationary steam models with electric heating elements. I can understand the Swiss taking the desperate measure of converting a steam loco to electric heating during war, but that patent... even after reading it, I don’t understand what the inventor hopes to accomplish with the new electrically fired steamer. Alternating current, creating steam, driving the wheels, but also spinning an onboard turbine to generate additional HEP and charge batteries? That’s a lot of complexity just to lose efficiency compared to a straight electric...IMHO! [2c]
- James
I’m having a hard time seeing the practical value of this locomotive. Most of the benefits of electric locomotives are due to the use of traction motors. Using electric as "fuel" for what amounts to a rod-driven steam locomotive seems to cancel out those benefits, and create a Rube Goldberg level of needless complication.
At least to model railroaders the electrically run ‘steam locomotive’ is nothing new - g
AltonFan wrote, to quote:
I’m having a hard time seeing the practical value of this locomotive. <<
Well, it says under "Background of the invention", at 0005, quote:
Steam locomotives are old and well known. <<
E-hm – now, while emotionally inclined individuals such as me would tend to object to that claim, proposing that steam locomotives never get ‘old’, they just turn into classics, some into myths even, I agree this might be considered a side track to the issue.
The argument had been made that Chapelon’s best steam locomotives (maybe 10-11% thermal efficiency) were competitive with coal-fired power plants (of the day), especially when transmission losses are taken into account.
The best figures I have seen for single-expansion steam would put efficiency, at best, around 7-8 percent. Modern coal-fired power plants are in the 30 percent efficiency range with the latest supercritical steam cycle plants about 40 percent (with respect to low heat value – LHV – of the coal). My guess is that worst-case transmission loss is 50 percent (full electric power at most remote location from substation), making the electric train at least 3 times more efficient than Super Power steam.
No, but the steam/Diesel question will never be answered on thermodynamics. It is were, we would no longer have coal-fired steam-cycle electric power plants.
The question will be answered on a combination of thermodynamcs, capital, and maintenance combined with the compliance with environmental regulations.
Those guys (the people with the compact automotive steam power plant) are claiming 21 percent efficiency. Yes, that is much less than what Diesels can achieve, but they are claiming a multi-fuel capability (although not yet solid fuel) that Diesels don’t have.
Hi -
What you write is pretty much what I meant, if you come to think of it:
With a higher efficiency and a similarly higher demand of energy at the same time you end up at much the same primary fuel consumption.
For example: using the quoted figure of three times higher efficiency in electric over steam traction; the power applied by these high speed trains is about (approx., for rule of thumb) four times that of steam typical for the 1940s Super Power types, i e it compares like 20000 to 5000 or if you prefer 16000 to 4000 hp at wheel rims. Yep - it takes a lot of power to run about twice as fast (top speed, not start to stop average) than the fastest steam powered trains! Logically, this rule of thumb comparison would tend to indicate electric high speed train rather use more not less primary (coal heat content) energy per train mile, then. You could go on to ma
To Juniatha: Dear lady, you hit the nail right on the head with your last post, specifically the references to the French railroads, to whit: Whether a railroad makes money or not depends on what it’s hauling not what it hauls it with! Steam, diesel, electric, it doesn’t matter. If the freight’s not there neither is the revenue. Going diesel couldn’t save the Pennsy or the New York Central when the shippers dissapeared. But who knows, they might have lived if they went into the rip-roarin’ steam excursion business! Someone once said, "call it transportation and people get bored. Call it a RIDE and you have to fight them off!"