Turbine-driven steam locomotives

The Pennsylvania Railroad experimented with a few of these in the years around World War II, but by then it was too late: diesels had already gotten a toehold and were gaining rapidly. Now, steam turbines had been used for propulsion for ships for nearly 35 years previously.

Given that, suppose an engineering wizard had been able to show the Baldwin Locomotive Works and/or the PRR that a turbine-driven locomotive would have been more efficient and would have reduced maintenance costs, both on the locomotives themselves (fewer moving parts, given the removal of the drive rods) and the right-of-way (no pounding of the track due to the motion of the drive rods and the driver counterweights, for example) some time in the early 1920s? Would steam had held off diesels until the 1950s or 1960s--or even later? And suppose there had been a corresponding conversion from coal to #6 fuel oil, similar to ships? Could that have diverted more coal into stationary power plants, making electrification more widespread especially in the northeastern US (say, 11,000 volt catenary from Washington, DC to Boston)?
 
Oh God, how long have you got? The first steam turbine/electric experiments were back in the early 20th century in Britain and Scandinavia. I think there were three or four working designs in the USA around the time you mention. I will look them up, just give me time.
 
The Pennsylvania Railroad made a steam turbine loco but it was a direct drive. They had plans for steam-electric locos but didn't build them. Union Pacific, Chesapeake & Ohio and Norfolk & Western built steam-electric locos.
They all had problems the worst being coal dust and water getting into the electrics. The Union Pacific machine was the most technically advanced and could easily have been developed to outperform internal combustion diesel engines. The Norfolk & Western was probably the most successful of the engines but all were abandoned by the early 1950s.
 
Turbine issues...

Turbines are most efficient at high speeds when the speed stays constant. Thus, they could work for long distance trains that had high priority and few stops. Also, condensers are rather bulky, but important to efficient opperation, so the turbine is exhausting into very low pressure.

One reason the USN stayed with recipricating engines for some ships was that they had longer range at low power (cruising speed) until technology caught up.

A train doesn't need a top speed much higher than cruise, so that's not a consideration, but it does need to be able to accelerate to designed speed and stay there.

You might have diesels for short hauls with turbines for long distance high speed...if it's cost effective to have both steam and deisel infrastructure.

If you make the trains turbo-electric, then batteries can store the excess energy when the train stops, and give a boost when it starts, but turbo-electric is far bulkier and heavier than other methods of power transmission back in the 20's. The USN abandoned it when treaties limited the displacement of warships.
 
Turbines are most efficient at high speeds when the speed stays constant. Thus, they could work for long distance trains that had high priority and few stops. Also, condensers are rather bulky, but important to efficient opperation, so the turbine is exhausting into very low pressure.

...

A train doesn't need a top speed much higher than cruise, so that's not a consideration, but it does need to be able to accelerate to designed speed and stay there.

You might have diesels for short hauls with turbines for long distance high speed...if it's cost effective to have both steam and deisel infrastructure.
So basically, a steam turbine would be good as a long-distance express? OK.

Any problems with torque, i.e. heading up into the Rockies?
 
So basically, a steam turbine would be good as a long-distance express? OK.

Any problems with torque, i.e. heading up into the Rockies?

Yes. I understand that steam piston engines provide far more torque at low revs than turbines. So turbines are not much good at moving off, or getting up hills (not too much of a problem in a ship...).
 
Yes. I understand that steam piston engines provide far more torque at low revs than turbines. So turbines are not much good at moving off, or getting up hills (not too much of a problem in a ship...).

The L.M.S turbine loco "6202 Turbomotive" was a geared drive turbine locomotive built as a joint design by L.M.S and Metropolitan Vickers in 1935 to compare it to its near sisters the Princess Elizabeth class express passenger locos. It had the same boiler, frames and wheels.

It was a semi succesful project that steamed very well but suffered teething mechanical failures. One gearbox failure blocked the main west coast line for 12 hours because it locked the drive wheels. The main advantage Turbomotive had over its sister engines was the lack of hammer blow caused by the reciprocating weight of the pistons, piston rods and valve gear. Turbomotive was allowed to have a ton more on each driving wheel because of this. An unbuilt project was designed to have 2.5 tons above the usual maximum weight per driving wheel.

The tractive effort of a traditional Stephenson type reciprocating steam loco fluctuates particulary at slow speed when it is trying to start a heavy train there is no smooth application of power as you get in a car. A piston steam loco can have a higher tractive effort for part of the rotation of a wheel but this power is not sustained through the whole rotation. Having 3 or 4 cylinders helps reduce the peaks and troughs somewhat but can never remove them. This leads to the spectacular slips you get from a steam loco when the engine wheels race but there is no forward motion.

Turbomotive put its power down smoothly with no peaks and troughs in the power. This meant it could start a 20% heavier train than its sister locos in tests with a dynamometer car. Turbomotive was also more powerful than its sisters with the same boiler because there were no pulses in the blast pipe just a continuous jet of steam a larger blast pipe could be used with no worries about lifting the fire. At speeds above 35 Mph it was up to 35 % more powerful.

Turbomotive was used on the heavy London Euston to Liverpool Lime street trains leaving both stations involves a stiff climb that often needed a banking or helping loco to get up the bank. Turbomotive was able to pull a 515 ton train up these banks when its sisters were limited to 420 tons.

Turbomotive was similar to the Swedish Ljungstrum 2-8-0 turbo-condenser freight engines used on very heavy iron ore trains in the 1930's and 40's but without the large condensing apparatus.

The loco was not a success partly because the war came before the problems could be ironed out and partly because it didnt do what it was meant to do cut fuel consumption. It is usually considered an honourable near miss. The Lungstrum locos were used until they were replaced by diesels.
 
Thanks, I sit corrected!

I vaguely recalled the British steam turbine experiment and knew it hadn't succeeded, but evidently it did better than I realised.
 
I think turbo locos could have been made to work but by the time the technology was maturing it was too late Diesels and electrics had too much of a head start. one of the problems with turbos was not that they didnt work but that they were considered as yesterdays technology. They werent shiny and they didnt have lots of flashing lights. Also steam locos are incredibly dirty (which is one of the reasons I like playing with them:)) and require a lot of hard graft to operate.

Turbo locos might have a future one of the advantages of a steam loco is that it can be made to run on anything that will burn for example there was an experimental turf (peat) burning loco built in Ireland in the 1950's. When the oil and gas run out we might end up with steamers that run on household waste or farm muck.:D
 
I think turbo locos could have been made to work but by the time the technology was maturing it was too late Diesels and electrics had too much of a head start. one of the problems with turbos was not that they didnt work but that they were considered as yesterdays technology. They werent shiny and they didnt have lots of flashing lights. Also steam locos are incredibly dirty (which is one of the reasons I like playing with them:)) and require a lot of hard graft to operate.

Turbo locos might have a future one of the advantages of a steam loco is that it can be made to run on anything that will burn for example there was an experimental turf (peat) burning loco built in Ireland in the 1950's. When the oil and gas run out we might end up with steamers that run on household waste or farm muck.:D
Still better then diesels!
 
In my (admittedly not particularly well-versed) opinion, the Turbomotive would have struggled to succeed on the LMS anyway. Not only did the company move towards standardisation under Stanier, which would put any one-off design at a disadvantage with regard to maintenance time and costs, the directors tended to be conservative when it came to locomotives. Had it been built by the LNER, maybe as a companion to the A4 class, the results may well have been spectacular, even if they would still have been too little too late.

[/train-nerd] Just my £0.02...
 
The LMS was certainly very conservative in the 1920's when the Midland small engine policy was followed by the mainly ex Midland management. However in the period from about 1933 to nationalisation in 1948 the LMS was by british railway standards quite progressive.

The LMS was the only one of the big four companies to build a mainline diesel engine though it never ran under LMS management only being completed a matter of days before nationalisation. It was the only company to have a plan to build large numbers of diesel shunters a plan that was stymied by the war and when production got under way the War Office took them for use by the Army.

Turbomotive was the prototype for a locomotive that would have had a very narrow use that of powering the heavy and getting heavier scottish trains from Euston. This run is split into 2 parts the relatively easy section from london to lancashire then the formidable climbs over Shap and Beattock. The run is about 400 miles.

It was virtually impossible for a conventional loco to do this run on the coal it carried and making the tender longer to carry more coal was impossible because of the restricted 70 foot length of the turntables. The LMS wanted to eliminate the costly and time consuming engine changes that were neccasary by building a loco that could do the first part of the run economically and then have the power to dig in and pull up the banks.

I believe that there would only have been about 12 engines needed. Had these engines been built in time for the war they would have been very useful for the immense troop trains that were run to Liverpool and Glasgow from the south and midlands.
 
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