Re: mini/microturbines in the railway?

hhc314@xxxxxxxxx wrote: 
First that the tractive effort that can be provided by a locomotive is
first determined by its weight (as discussed in my earlier posts), and
second by the horsepower developed by its engine. Reduce the weight of
the engine and you will have to increase the dead weight or ballast
carried by a locomotive in the form of a large block of concrete or
stacks of iron weights. Hence if all turbines have to offer is a better
power to rate ratio, this makes them less attractive to locomotive
designers.

Right now, maybe so, but trains, like barges, will be with us from now til doomsday, so we have to think ahead. Given that turbines do well to generate electricity, The main impediment at this instant is the convention of confining propulsion to the generator-locomotive, causing a short-term need to add dead weight to it. The solution is simple: pipe the electricity to all cars which should have their own propulsion motors. I predict these to be the norm within 50 years.

The locomotive throttle designs you describe are termed "cam
controllers". When I was still in the railway business back around 25
years ago, they were still found in use on light rail tracked vehicles
like the legendary PCC Trolley Cars and even some of the "Green Line"
cars used on the MBTA here in Boston. The functioned by switching the
connections to the traction motor in a number of steps. I've long since
forgotten what steps on the cam controllers where which, but they
included "full series, full parallel" and a number of motor taps in
between. (Full series referred to connecting the armature in series
with the field magnet of the motor and of course full parallel
represented running the armature windings in parallel with those of the
field magnet or stator. I'm not sure of how the in-between steps were
implemented, but just guess I would assume that they consisted of a
number of different taps on the stator windings.) This method was, of
course, limited to the control of d.c. powered traction motors. By the
time a.c. powered locomotives like the GG1 arrived, control of the
traction motor(s) was fully electronic.


	All nice to know.

What may be interesting to some readers is the unique braking mechanism
employed by the PCC trolley cars. Old timers may remember that they had
an electro-magnetic powered brake shoe that actually pulled down to the
track and braked these vehicles by magnetically clamping intself onto
the rail. IIRC, I believe it was located between the wheels of each
truck.  Damn system worked very well, but I am at a loss to explain
just how the PCC cars were braked when they lost contact with the
overhead catenaries supplying electical power to them or if they had an
actual braking mechanism on their wheels.


	Works in nicely with my 50-year theory.
	Consider also that when each car has a motor, they can be used
to generate the current to drive the braking magnet,
a win-win situation regarding energy conservation.

More curious still, I understand that the PCC cars are still in use in
some regions of our Nation.  Why not, it it ain't broke, don't try to
fix it!


	Evolution takes time.

Evidently NYC people are really into rail transit judging from the URL
of both of these.

There is ample opportunity for our civilization to fine-tune rapid transit. Here in the midwest, railed transportation, apart from freight trains, is a an ancient relic seen only in text books, old movies and encyclopedia. Only a very few city locations have rapid rails, Cleveland being one. Her in Columbus, though there were here a century ago, there are none now. We have oodles of diesel public transit busses, but they struggle to survive, being dependent on tax money for survival, labor costs via unions being the killer disease. Nonetheless, these (liquid fueled road vehicles) will be the favored public transportation vehicles far, far into the future (e.g. school busses).

,,,And so you now realize that I am an electronics and computer Geek... 

	I think I can say.. "me, too".

		Angelo Campanella

.

Relevant Pages

  • Re: Oil Peaked !
    ... Yep - bet the thing could be 1400 lbs if it wasn't for that crash stuff. ... Fiat 124 coupe I mentioned before at 2000 lbs curb weight. ... and especially the crash safety nonsense has added weight ... cars. ...
    (misc.news.internet.discuss)
  • Re: Support OIl Driilling Off Florida!
    ... The material that goes into making cars stronger is heavy, ... reduced the weight of cars, while making them safer and more efficient. ... "Passenger car fleet average characteristics have changed significantly ... No, it says, "Compared with MY 1998, the average curb weight for MY 1999 ...
    (misc.news.internet.discuss)
  • Re: Lead part - cast or turn?
    ... weight at their periphery will increase the rotational inertial of the wheels, and they will accelerate more SLOWLY than unweighted wheels. ... Being the only engineer father in a troop of kids with mostly doctor and lawyer dads*, it was like shooting ducks in a barrel and the kids' cars always brought home the bacon. ... We weighted the cars with lead to within a quarter of a gram of the legal limit, I made the kids a "calibration weight" out of screws and nuts in a small glass jar adjusted on a lab scale at work. ...
    (rec.crafts.metalworking)
  • Re: Oil Peaked !
    ... Where do you plan to put the pollutants? ... increased the price of cars and the weight of cars along with the ... That's not 1600+ lbs. Try again. ...
    (misc.news.internet.discuss)
  • Re: Wierd Clock Pendulum Period
    ... So do gears. ... the weight lifted for aesthetic reasons so that you have a nice ornament ... | and so without a weight, the motor would need to apply a constant ... By putting a very small motor at the pendulum end of the drive ...
    (sci.physics)
Loading