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Subject: 
Re: what is the use of a caboose?
Newsgroups: 
lugnet.trains
Date: 
Wed, 1 Aug 2001 18:58:26 GMT
Viewed: 
1038 times
  
Regarding battery buses, I'm wondering if you hear anything more about these
proposals for flywheel buses? If you just do the maths, the amount of energy
you can store in a flywheel is limited only by the material strength under
tension of the wheel. People keep saying "if we can use graphite or strong
wire radially, build a flywheel and spin it in a vacuum at 30K rpm with
essentially frictionless magnetic bearings we can easily power a bus!" What
a lot of... well, a lot of ifs.

Actually, flywheel is perfectly practical.  Sentinel (once again!) made a loco
that was powered by, IIRC, 2 2 ton flywheels, and it was reasonably capable
(but expensive).  I tend to think that a flywheel drive system is more
practical for bus applications than say a battery system.  (IIRC, the flywheels
were steel, ran in a H or He part pressure atmosphere (about .01 atm pressure),
and provided ~4 hrs of power for the loco (about 100 hp, IIRC)- this was all
mid 60's.

Running a bus for ~1 hr (about the longest bus routes around here, save some
interurban routes like mine), should be manageable with a reasonably weighted
system.  It'd be practical to "flash" charge the flywheel at stops too...if one
could come up with a reasonably safe bus/ground inductive loop, one could
install it at some/all of the stop points, and transfer a fair amount of power
(limited by the motor/generator in the flywheel, rather than the chemical
changes induced in the battery, therefore a much faster recharge is
practical)-even 30 sec of charge at 200-400 hp(kw) would give a good boost to a
bus which probably uses 50-100 hp to get to speed, and 20-50 hp to run at speed
between stops.

I'd like to see some more work done on schemes like this.  I think that we
collectively have to start getting our heads out of the sand with regards to
alternate fuel sources for vehicles.

James P



Message has 1 Reply:
  Re: what is the use of a caboose?
 
(...) Not disputing that. Just not sure that a 30K RPM graphite in an evacuated can with magnetic bearings is, at this moment, "perfectly" practical. Not just yet. But the notion of powering up at stops (think regular electric bus poles that instead (...) (23 years ago, 1-Aug-01, to lugnet.trains)

Message is in Reply To:
  Re: what is the use of a caboose?
 
In lugnet.trains, Simon Bennett writes: <snip some very interesting info> Good info on the reasons why monorails just aren't that practical. The example people always trot out about the Wuppertalbahn kind of highlights the right of way issues! It (...) (23 years ago, 1-Aug-01, to lugnet.trains)

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