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Subject: Re: Modern Steam Locomotives Author: Dmitri [ Next Thread | Previous Thread | Next Message | Previous Message ] Date Posted: 17:36:48 07/20/12 Fri In reply to: Greg B 's message, "Modern Steam Locomotives" on 16:57:13 07/20/12 Fri What I thought of it was the loss of efficiencies in converting one power source to another (and another, and another) before actually driving the wheels (or propeller). What is the efficiency losses involved in a diesel engine running a generator running an electric motor? There must be a valid reason for it or it wouldn't be done. Hydrogen is "clean" but generating/obtaining, transporting, and storage of hydrogen is dangerous and not cheap. Not that gasoline isn't also (other than to produce). Dmitri >In chapter 18 of Hannegan's Cove, the idea of a modern >steam locomotive is mentioned in passing. The idea >struck me as very interesting for two reasons: 1. >modern diesel locomotives use the diesel engine to >generate electric power, which drives electric motors; >2. the late-generation steamships, especially naval >vessels, used steam turbines to generate electricity >which drove electric motors (basically one step from >current nuclear subs and carriers). > >So it seems that steam-turbine electric locomotives >are technically feasible and might have clear >environmental advantages. Maybe if they burn hydrogen >to produce the steam? > >Did anybody else think along these lines? [ Next Thread | Previous Thread | Next Message | Previous Message ]

Replies:

[> [> Subject: Re: Modern Steam Locomotives Author: Deadly Ernest [ Edit | View ] Date Posted: 18:24:12 07/20/12 Fri Diesel-electric motors are used on a lot of trains and other situations for the ability to more finely control the application of power to the motor and the ability to more easily spread the power delivery out via electric cable to the electric motors on the drive wheels instead of mechanical transfer. I don't know about now, but as late as the 1970s they were still building ships with high pressure superheated steam turbines that used a mechanical transfer of the energy direct to the drive shafts. The steam turned the turbines which turned gears which turned the drive shafts. After the steam ran through the drive turbines it was directed into turbines to generate electricity to drive the on-board electrical systems like radar, radio, lights, tv, etc. >What I thought of it was the loss of efficiencies in >converting one power source to another (and another, >and another) before actually driving the wheels (or >propeller). What is the efficiency losses involved in >a diesel engine running a generator running an >electric motor? There must be a valid reason for it >or it wouldn't be done. Hydrogen is "clean" but >generating/obtaining, transporting, and storage of >hydrogen is dangerous and not cheap. Not that >gasoline isn't also (other than to produce). > >Dmitri > >>In chapter 18 of Hannegan's Cove, the idea of a modern >>steam locomotive is mentioned in passing. The idea >>struck me as very interesting for two reasons: 1. >>modern diesel locomotives use the diesel engine to >>generate electric power, which drives electric motors; >>2. the late-generation steamships, especially naval >>vessels, used steam turbines to generate electricity >>which drove electric motors (basically one step from >>current nuclear subs and carriers). >> >>So it seems that steam-turbine electric locomotives >>are technically feasible and might have clear >>environmental advantages. Maybe if they burn hydrogen >>to produce the steam? >> >>Did anybody else think along these lines?

[> [> Subject: Re: Modern Steam Locomotives Author: Marv [ Edit | View ] Date Posted: 21:44:20 07/22/12 Sun >What I thought of it was the loss of efficiencies in >converting one power source to another (and another, >and another) before actually driving the wheels (or >propeller). What is the efficiency losses involved in >a diesel engine running a generator running an >electric motor? There must be a valid reason for it >or it wouldn't be done. Hydrogen is "clean" but >generating/obtaining, transporting, and storage of >hydrogen is dangerous and not cheap. Not that >gasoline isn't also (other than to produce). > >Dmitri > >>In chapter 18 of Hannegan's Cove, the idea of a modern >>steam locomotive is mentioned in passing. The idea >>struck me as very interesting for two reasons: 1. >>modern diesel locomotives use the diesel engine to >>generate electric power, which drives electric motors; >>2. the late-generation steamships, especially naval >>vessels, used steam turbines to generate electricity >>which drove electric motors (basically one step from >>current nuclear subs and carriers). >> >>So it seems that steam-turbine electric locomotives >>are technically feasible and might have clear >>environmental advantages. Maybe if they burn hydrogen >>to produce the steam? >> >>Did anybody else think along these lines? Probably not cost effective. The Navy has been replacing steam turbines with gas turbines. During Desert Shield is was cheaper to send a gas turbine Destroyer from Norfolk to the Persian Gulf,than to send a steam turbine Destroyer from the Mediterranean. U.S. Nay tugboat YTM 409 had a four cylinder diesel engine driving a generator to power a 900 hp electric main engine. The electric engine was not a powerful as the diesel main engine on a YTB.