On May 16, 2:22 pm, Reuters News Wire <reut...@telecom-digest.org>
wrote:
> Hundreds of Indian rail passengers got more than they had bargained
> for when the driver of their train asked them to get out and push.
In Japan immediately after WW II, the infrastructure was so badly
destroyed that single freight cars had to be positioned for loading by
hand labor. Passengers waiting nearby applauded the workers when the
car was sited.
> The incident occurred in the eastern state of Bihar on Tuesday after a
> passenger pulled the train's emergency chain and it halted in a
> "neutral zone," a short length of track where there is no power in the
> overhead wires.
That is actually not uncommon. Electric supply, whether by overhead
wire or trackside 3rd rail, has numerous dead spots for a variety of
reasons. Usually a train is long enough so that one part of it is
still making contact, or a connector pole is used as Pat described
below.
> The train's conductor gets off the train with a long metal rod which
> he touches to a certain place under the train, and the other end of
> the rod to a place on the third rail, causing the power to
> resume. ...
This is commonly done in yards and shops where there is no 3rd rail.
I wouldn't want to hold such a rod since the power supply -- enough to
power a heavy train -- is enormous, plus there are nasty arcs. But it
is done regularly and safely.
On subway trains, there is a "shoe" sticking out of the wheel assembly
(the trucks) that makes contact with the 3rd rail. It slides along it
and that powers the train. The Long Island and Metro North RRs also
use this system. The power is about 600-750 V DC with very high
amperage. Other systems use overhead wire of higher voltage, such as
11,000 or 25,000 V AC which is more efficient to transmit. Amtrak's
NEC (with SEPTA and NJT and MARC) still runs on 25 Hz AC.
> children, a favorite game we played (I was nine or ten years old) was
> entitled 'Stall the trolley bus' ...
Unfortunately, such technique was used for less benign purposes in
troubled urban areas. Kids would pole down the poles of a trolleybus
then board it and beat up the passengers who were from different
neighborhoods or gang turfs.
The trolleybus was a nice compromise between the street flexibility of
a diesel bus and the power efficiency and cleaness of electricity.
Unfortunately, only a few cities still have them.
[TELECOM Digest Editor's Note: Well, Chicago got to be such a 'troubled
urban area' by sometime in the 1960's. Subways were no longer safe to
ride, with passengers getting robbed and raped on many occassions. They
did away completely with street car and trolley busses in the late 1950's.
Their claim was streetcars were too 'inflexible'; busses with rubber
tires could go anywhere and trolley busses (rubber tires but with
overhead wires) were too expensive to maintain. At least that's what
the bigwigs in *Detroit* convinced the bigwigs at CTA to say to the
public. What you need is gasoline powered motors, Detroit told CTA and
other transit companies.
hancock4@bbs.cpcn.com