Advanced steam, operational comparisons

jgallaway81 wrote:I have to say I disagree.

A steam-turbine electric would be the perfect mode of transportation (aside from a direct electric driver from overhead catenary).

As you said, a turbine is most efficient in a very small RPM range. If this turbine was designed so that its most efficient rpm range was perfectly matched to a set multiple of the RPM which produces maximum power in the generator/alternator.

Using modern electronic systems, such a power source could be controlled electronically instead of via standard RPM-voltage manipulation. Either AC-frequency modulation or a DC pulse-width modulation could be used in combination with a steady-speed turbine.

Further, a turbine might not be the most efficient use of the steam. I will admit that this possibility exists and further research in fluid dynamics and hydrothermal mechanics would be required to determine the most efficient means of transforming the heat energy into rotational energy. My thought would be a 2-stage compound 8-12 cylinder diesel-like-block turning the generator... perhaps using 12 total cylinders, four triple-compound engines could be used to turn the generator.

With enough generator capacity, there is no reason that the tender couldn't also provide tractive effort.

As for a hydraulic or a hydrostatic drive, neither of these would have the capability to meet American railroading demands. I believe UP & SP both tried such engine and found them incapable of standing the abuse of our mainline freight operations.

Your constant RPM Turbine setup is going to burn the same amount of fuel no matter what the throttle setting is? I know the idea is too utilize cheaper fuels but that is still very inefficient. I've read of ideas to use multiple turbines of various power settings which can be operated either in compound or simple mode to produce power at multiple settings.
In any case it would seem that the only steam turbine electric locomotives in service will continue to be the type where the turbogenerator is in a power plant and the traction current is sent to the locomotive via catenary...

v8interceptor wrote: In any case it would seem that the only steam turbine electric locomotives in service will continue to be the type where the turbogenerator is in a power plant and the traction current is sent to the locomotive via catenary...

I agree.

I will reiterate that I do not advocate steam powered locomotives except where only coal is available for fuel.
Furthermore I am in favor of more electification, or re-electrification.

just to shed some light on steam turbine drives, steam turbines can have multiple load ranges through the use of multiple nozzles connected to a manifold with valves. eight sections is a common arrangement. openned sequentially by cam shafts I have seen machines with four six and eight seperately controlled inlet nozzles. 10 to 1 turndown is no problem.
I have been very impressed, on occasion, by the loading/unloading rate of GE steam turbines. I mean governor controlling, unloaded to full load in seconds! 25,000hp !:O
boiler controls following that kind of demand is another matter! - but Im learning alot about forced flow steam generators recently, and it can be done.

"Advanced" steam is nuclear power + electric locos.

Sort of like nuclear powered submarines and ships, except you don't have to carry the powerplant around with you everywhere.

Passenger wrote:"Advanced" steam is nuclear power + electric locos.

Sort of like nuclear powered submarines and ships, except you don't have to carry the powerplant around with you everywhere.

modern gas fired stationary electricity is also far in advance of any locomotive steam engine envisioned, or any diesel for that matter.

Then here is wind power. one of the remarkable things about wind power is that alot of it is availible at night, when it has a negative value to the Grid, due to minimum demand. Already happening in Denmark and Germany.
Night trains can consume FREE surplus electric power.

Nuclear locomotive

Wind powered locomotive