## Metro in power failure

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• Thinking recently about emergency planning, it came to my mind: what happens to a metro in a power failure? A few thoughts come to mind: - In Joel s carfree
Message 1 of 3 , Apr 4, 2007
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Thinking recently about emergency planning, it came to my mind: what
happens to a metro in a power failure? A few thoughts come to mind:

- In Joel's carfree city prototype, what's the maximum number of metro
and metro-freight trains that would be in operation at any given
moment? What would the maximum power consumption be?

- In the event of a municipal utility failure, what happens with the
metro? Are the trains able to glide without power to the next station
to allow a total evacuation without making passengers walk through
tunnels?

- Is an emergency diesel or NG generation system out of the question
for a metro to keep it running? My school has a roughly 80 kW propane
generator to run the elevator, fire pump, emergency lighting, phone
system, and intercom. I assume a metro would need _slightly_ more. *grin*

I'm assuming, though, that Joel's carfree city probably has all the
electric lines underground, reducing storm-related failures. By the
way, where would the metro's maintenance area be? In edge utility
districts?

BTW, for a city the size of Joel's prototype, would a dedicated city
power plant be called for?
• ... say about 50 trains, 10 cars = 500 cars 600 kW per car (max), say 150 kW average = 75,000 kW this assumes the high rates of acceleration proposed in the
Message 2 of 3 , Apr 5, 2007
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>Thinking recently about emergency planning, it came to my mind: what
>happens to a metro in a power failure? A few thoughts come to mind:
>
>- In Joel's carfree city prototype, what's the maximum number of metro
>and metro-freight trains that would be in operation at any given
>moment? What would the maximum power consumption be?

say about 50 trains, 10 cars = 500 cars
600 kW per car (max), say 150 kW average = 75,000 kW
this assumes the high rates of acceleration proposed in the book

>- In the event of a municipal utility failure, what happens with the
>metro? Are the trains able to glide without power to the next station
>to allow a total evacuation without making passengers walk through
>tunnels?

supercapacitors should probably be installed; these can store
enough power to move trains into stations; they also help with
regeneration

>- Is an emergency diesel or NG generation system out of the question
>for a metro to keep it running? My school has a roughly 80 kW propane
>generator to run the elevator, fire pump, emergency lighting, phone
>system, and intercom. I assume a metro would need _slightly_ more. *grin*

Well, only about 1000 times more ;-)
Actually, to keep the system operating in limp-along,
probably 20,000 kW would do it.
To put this in perspective, the largest diesel engines,
used to power ships, are something like 75,000 kW each.

>I'm assuming, though, that Joel's carfree city probably has all the
>electric lines underground, reducing storm-related failures.

absolutely!

>By the
>way, where would the metro's maintenance area be? In edge utility
>districts?

yup

>BTW, for a city the size of Joel's prototype, would a dedicated city
>power plant be called for?

can't give a definitive answer; it depends on the power
sources and where the energy supply is

----- ### -----
J.H. Crawford Carfree Cities
mailbox@... http://www.carfree.com
• ... tunnels? In Prague one or two of the metro lines can go under its own power to the next station, slowly... I assume using some kind of small battery... for
Message 3 of 3 , Apr 5, 2007
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Matt Hohmeister wrote:

>In the event of a municipal utility failure, what happens with the
>metro? Are the trains able to glide without power to the next station
> to allow a total evacuation without making passengers walk through
tunnels?

In Prague one or two of the metro lines can go under its own power to
the next station, slowly... I assume using some kind of small battery...
for where it is level or a slight incline. For going down you at least
need brakes, plus in either situation door opening would be nice. I am
not sure if there is an advantage to ultracapacitors for a situation
like this.

A system which generates emissions or needs to store liquid for fuel in
a tunnel is not a good idea.

-T
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