Re: Three CityRail questions

[David Johnson <trainman@ozemail.com.au>]

Bradley Torr wrote:

> (1) Why are many down trains on the Bankstown line that are scheduled to
> proceed to the City Circle via Lidcombe timetabled to stand at Bankstown
> station for around twelve minutes, while trains scheduled to proceed to
> Liverpool don't have such a lengthy standing time?

Trains doing Banko circles do not terminate anywhere.  This means that if it
loses some time, it can't be regained at a terminus (Waterfall terminators get
34 minutes to change ends).  By putting the extended stop at Bankstown (and
also sometimes at Strathfield), late trains can regain lost time.

> (2) At Parramatta station, is there a pattern to which train uses which
> platforms, e.g. which down trains use Platform 2 and which use Platform 4;
> and which up trains use Platform 1 and which use Platform 3? Or is it
> random?

They operate to the timetable (usually).   Generally, during off peak they try
and keep the intercity trains on the Suburban lines (1 & 2).  They try to keep
suburban trains on the Main Lines (3 & 4).  During peak hour(s), a number of
suburban trains spill over to the Suburban lines, but these are usually the
express ones.

> (3) Why is it that, while travelling along in a train (particularly the
> pre-Tangara sets), ocasionally most of the lights and the air conditioning
> will cut out for a short period, and then suddenly start back up again?

There are two reasons why the main lights and fans will go off:
1)
There is a brief interruption to the 1500V supply, usually caused by
pantograph bounce.  The Auxiliary Power Supply (S/R/L sets = Supply Set.  K/C
sets = Motor Alternator) shuts down briefly, then re-starts automatically.

2)
When the pantograph goes from one power section to another, the voltage
changes.  At some locations, the voltage differential is quite large (in the
order of hundreds of volts).  At this point, there is a large current surge to
the input of the Auxiliary Power Supply.  This causes a device called the Over
Current Relay to disconnect the power.  The driver then needs to reset the
over current relay by pressing the Lights On pushbutton, which starts the
Auxiliary Power Supply.

--
David Johnson
trainman@ozemail.com.au
http://www.ozemail.com.au/~trainman/
------------------------------------
These comments are made in a private
capacity and do not represent the
official view of State Rail.
C.O.W.S. Page 11.