Turbine locomotives succeed

In the 1940s, some railroads experimenting with using turbine-powered locomotives, as an alternative to diesels, in replacing traditional steam. They were designed to run on a variety of fuels, including pulverized or gasified coal. The main problem was that the turbines ran at 100% of capacity all the time, which meant that unless the locomotive were working at full capacity (if it were idling, for example), it was very wasteful of fuel compared with the diesels.

But, what if that engineering hurdle had been overcome, and the railroad system were able to modernize on a fuel system that was not necessarily tied to petroleum?
 
But, what if that engineering hurdle had been overcome...


It was, and diesels still were more efficient.

The low efficiency at low speeds problem with direct-drive turbines you mention was neatly solved by introducing turbo-electric systems. The turbine could thus operate at it's more efficient higher speeds while powering a generator which in turn powers electric motors on the wheels.

With that engineering hurdle cleared, the real problem with turbines proved insurmountable: Efficient turbines require low pressure condensers.

So, building a turbo-electric design meant building a turbine and a generator and a condenser, while building a diesel-electric design "only" meant building a diesel and a generator.

Condensers require quite a bit of space too, meaning diesels were smaller for a given amount of draw weight.
 
just a decade later that the even more powerfull gasturbine came into use, both for ships and trains alike.
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Turbine locomotives work best at high speed. What that means in high speed passenger service or high speed freight. The only problem is pure electric engines beat both and are more efficient for slow speed service also. Out west the Union Pacific used different models of GE powered turbine locomotives to some success on their long haul routes in freight service, but found that only if they were continually moving they worked better than a straight diesel electric. For slow speed service in a congested area, they put some standard diesel engines on the trains so they did not have to run the turbine units at slower speeds, or just took the turbines off and replaced them. The UP was using units that had up to 10,000 horsepower in a single 3 unit locomotive, control unit, turbine unit, fuel tender, on long haul service. Fuel for these units was Bunker C oil that was basically left over from the refining processes off that time. I have read somewhere, IIRC, that Bunker C was costing the RR about 1 to 2 cents a gallon.
 
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Gas Turbine locos do have some significant advantages, especially at higher speeds. They are very light so can make huge power without the huge weight of an equivilent diesel, reducing axle loading which is significant at speed. As you can imagine a 3000hp diesel is friggin massive, but a 3000hp GT is the engine from a regional turboprop airliner, small and light. When using their power at speed they are not much worse than a diesel, especially diesels used for high speed trains like the British INterCity 125 and the Sweedish X2000.

The biggest problem with GTs in trains is their fuel consumption around stations and in towns where, as been noted, they use almost the same fuel consumption per hour as they do running at 100mph+. The answer was arrived at a few years ago with the Canadair Jet Train, whose locos have a 5000hp GT and 500hp diesel. The diesels drive the train at up to 30mph in stations and switchyards, and then turn on the GTs as they get out of town, bypassing the fuel consumption of the GT at low speeds.

So is it technically feasable to have diesels doing the low-speed work back in the 50s and 60s when GTs were starting out as train propulsion.

Heres the Wiki link to the Jet Train.

http://en.wikipedia.org/wiki/JetTrain

BTW it isn't engines and the like which limits train speeds, its track design and condition and signalling systems, and the regs revolving around these things.
 
Turbine locomotives work best at high speed. What that means in high speed passenger service or high speed freight. The only problem is pure electric engines beat both and are more efficient for slow speed service also. Out west the Union Pacific used different models of GE powered turbine locomotives to some success on their long haul routes in freight service, but found that only if they were continually moving they worked better than a straight diesel electric. For slow speed service in a congested area, they put some standard diesel engines on the trains so they did not have to run the turbine units at slower speeds, or just took the turbines off and replaced them. The UP was using units that had up to 10,000 horsepower in a single 3 unit locomotive, control unit, turbine unit, fuel tender, on long haul service. Fuel for these units was Bunker C oil that was basically left over from the refining processes off that time. I have read somewhere, IIRC, that Bunker C was costing the RR about 1 to 2 cents a gallon.

The fuel was cheap and the UP turbines were being used out in the Mountain West, where super-high horsepower from a light engine is really useful (pulling heavy freight trains over mountain passes). In the '70s, apparently some railroads floated plans to electrify those passes so they could put electric locomotives (IIRC, those have a high low-speed torque, and of course don't need fuel at all technically) on those passes. I dunno how much torque a turbine puts out...

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BTW it isn't engines and the like which limits train speeds, its track design and condition and signalling systems, and the regs revolving around these things.

Really, it's both together. I could put Stephenson's Rocket on a TGV line and it would still be very slow (compared to modern locomotives), or I could put a TGV on the Northeast Corridor and it would not be able to go at its design speed. If I don't have an engine capable of the speeds I want, it doesn't matter how great a permanent way I have, and if I have a really bad permanent way it doesn't matter how great an engine I've got.
 
^ In passenger service, you have it pretty much bang on. I think he's thinking of steam engines and gas turbines for freight service. The UP point has been mentioned, and UP only went with the turbines because diesel road engines of the time simply didn't have the beans to handle UP's heavy freight trains on its 'spine', it's like from Omaha to Salt Lake City, which in the steam days was almost entirely handled by the Big Boys, Challengers, 4-12-2s and the like. On that route, moving 8,000-ton freight trains over the Transcontinental route, the turbines were in their element. The other problems other than the fuel consumption were noise (not a problem on the plains but could be in inhabited areas) and reliability.

As far as the steam engines go, I think its possible to make them work using the traction motor idea, actually a combination of both. The idea is that at slow speeds, the steam turbine drivers and electric generator, which them powers electric traction motors on the trailing truck under the firebox or on the tender, thus giving immense push at low speeds and getting the train up to speeds of, say, 30 mph. Electric motors make their most torque at low speeds (in fact right off of idle) but lose power as they spin faster. As they hit the required speed, the engineer switches the engine from the traction motors to the turbine and sets the electric motors to create regenerative power, which can then be used to power a ducted fan to create a vacuum in the turbine, this improving efficiency.

This would be a very large locomotive - but with the right turbines and design, an immensely powerful one, and using a ducted fan and a good condenser design could also dramatically drop water consumption, which would be highly useful for lines though areas with very little water. One could also use the surface condenser as a way of heating water going into the boiler, and using welded boilers could move above the 300psi that was about the limit for steam locomotives to maybe even 500+ psi, which was common in WWII-era warships, thus considerably improving performance.

Use all of those and use electric motors on all the tender axles (The Big Boy, for example, had a seven-axle tender) with electric motors of the immediately post-WWII era, you could probably get 4,500 hp out of the electric motors, enough to get a big train moving (that's about equal to three GP7 or RS3 diesels) and once the turbine was on, the thing would have power to spare, which the Pennsylvania's S2 proved during WWII.
 
Ahhhh, TheMann is talking about a steam turbine engine. The UP units were gas turbine engines. They used the turbines, actually jet engines or turbo shaft engines, to drive a generator to power the engines. They used electric motors to power the wheels. They did not use high pressure steam in these units to turn the wheels.
Wiki article about them:
http://en.wikipedia.org/wiki/Union_Pacific_GTELs

This is a steam turbine engine that the Pennsylvannia RR tried out:
http://en.wikipedia.org/wiki/PRR_S2
It was a steam hog that was only efficient at high speeds.

Union Pacific used their units in the west on the Omaha to Ogden route and on the Los Angeles to Ogden routes. They were done in by the rising costs of fuel and maintinance.
 
Really, it's both together. I could put Stephenson's Rocket on a TGV line and it would still be very slow (compared to modern locomotives), or I could put a TGV on the Northeast Corridor and it would not be able to go at its design speed. If I don't have an engine capable of the speeds I want, it doesn't matter how great a permanent way I have, and if I have a really bad permanent way it doesn't matter how great an engine I've got.

My point was that its easy to get a train to go fast, your average modern diesel loco can pull a passenger train to 100mph+, but difficult to organise a high speed revenue service.
 
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