> 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.
Believe it or not, you can still buy a special pole for spotting
boxcars by hand. McMaster-Carr part number 2221T8, $200.00
>> 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.
My dad worked on the long gone Milwaukee Road. His division was
electrified with 3000 volts DC. The trolley was sectionalized and the
spaces between the sections were called airgaps.
He said that occasionally they would get orders forbidding them from
bridging the airgap with the engines. They would have to drop the
pantograph and coast across the gap and then raise the pantograph.
>> 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. ...
On the Milwaukee Road, if there was not sufficient air pressure to
raise the pantograph, the fireman would take a long pole with a hook
on the end, hook the pantograph and shove it up against the trolley
and hold it there until the air compressor charged the air system with
enough pressure to hold the pantograph by itself.
My dad said it was scary business in the rain.
> 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.
Well, at least they did it legally, on the face of it. In the San
Francisco Bay Area, General Motors, Standard Oil and Firestone Tire
were convicted of of criminally conspiring to replace electric
transportation with gasoline or diesel powered buses, and to
monopolize the sale of buses and related products to local transit
companies throughout the U.S. They were fined $5,000. That was in
1949. Wikipedia has the whole story.
[TELECOM Digest Editor's Note: At the CTA switch yards in Chicago
using third rail power, when it starts raining heavily, the employees
are instructed to just stand where they are (rain be damned!) lest
they are running or otherwise crossing the tracks to get to a dry
place and the high-voltage third-rails arc and hit them. And yes,
touching the third rail (or the pantograph or catenary to the overhead
wire could be a scary thing; sometimes the wires would flash and arc
when you were doing it. Or, if you ever rode on an electric train
during a storm it was the same way; the overhead wire or the third
rail was always sparking and flashing. However, when handled
correctly, there was no hassle. Example: in Chicago I once saw a track
repairman working on subway tracks. The man *sat down* on the third
rail to eat during his lunch break. People watched him with
amazement. The man got up to leave, but said to his audience, it isn't
the third rail which can kill you, its *where you put your feet that
matters*. And if you ever noticed a tiny bird flying in the sky in a
place like that; they will frequently stop and rest *entirely* on the
third rail. PAT]
Jim Stewart (jstewart@jkmicro.com)