Re: Brief Signalling failure at Camberwell

[Mark Bau <markbau@earthlink.net>]

in article 3ad5c4e6$0$25499$7f31c96c@news01.syd.optusnet.com.au, B. at
b.spammed@four12.net wrote on 4/12/01 9:06 AM:

> "Mark Bau" <markbau@earthlink.net> wrote in message
> B6FA878F.2241%markbau@earthlink.net">news:B6FA878F.2241%markbau@earthlink.net...
>> in article 3ad522e7$0$25508$7f31c96c@news01.syd.optusnet.com.au, Michael
>> Wierzbinski at wizzer1865@NOSPAMoptusnet.com.au wrote on 4/11/01 9:26 PM:
>>> "Sam Eades" <seades@bigpond.net.au> wrote in message
>>> 11cA6.529$wP3.3566@news-server.bigpond.net.au">news:11cA6.529$wP3.3566@news-server.bigpond.net.au...
>>>> "Paul Hambleton" <phambleton@labyrinth.net.au> wrote in message
>>>> fnaA6.12$Z53.2560@vic.nntp.telstra.net">news:fnaA6.12$Z53.2560@vic.nntp.telstra.net...
> 
>>>>> A bit of excitement this morning at Camberwell.
>>>>> As the 1023 UP from Alamein approached platform 2, all the signals
>>>>> went out.  No lights whatsoever. The driver dutifully stopped at the
>>>>> automatic signal guarding entry into platform 2 before proceeding into
>>>>> the platform. All the signals then came back on displaying red before
>>>>> normal operations resumed.  Anyone know what happened.
> 
>>>> Sounds like a power surge or a brief power failure. With a power surge,
>>>> all of the circuit breakers have to reset, then all track circuits
>>>> "drop" causing signals to go to normal (stop). The signaller then needs
>>>> to run the time releases to put them back to proceed (usually 1 to 2
>>>> mins)
> 
>>> Strangely enough, this happens on a very regular basis, at least once a
>>> week.
> 
>> All the signals going "dark" is a pretty strange occurrence as signals
>> actually run off battery power.
> 
> Only in the country.
> 
>> The batteries are kept in a constant state of charge by mains power but
>> if the power were to to go out the batteries should be able to keep
>> everything running for at least 5 hours, usually much longer.
> 
> In the Metro area, all the signalling runs off the AC Signal Power Supply.
> This is 'traditionally' a 2.2kv feed from each traction sub, each section is
> normally fed from each end so if a sub falls over that section can be fed
> from the other end. There are variations, 2 recent installations use 1kv
> (mining?) gear (Cranbourne & Upfield lines).  A slightly earlier
> (perticularly nasty) job was the Epping line, which has 2 Mains feeds into
> each location (from each side of the line iirc), this is fine until the
> Mains supply is subject to a major failure, then you have nothing.
> 
>> point motors, boom gates, signals all can run off batteries for
>> extended periods of time.
> 
> Point motors are almost always AC in the metro area.  Flashing Lights always
> have a battery for the lights and bell, the booms can be either AC or DC.
> AFAIK DC is the current standard.
> 
>> A train shunting a track circuit however will drain batteries relatively
>> quickly compared to the same track circuit being unoccupied.
> 
> The tracks at Camberwell will be plain 25Hz AC tracks.  AFAIK even the High
> Voltage and Jointless tracks run straight off 24v rectifiers off the AC sigs
> supply.  You can't use DC tracks in DC traction territory, otherwise the
> return current would have this habit of picking the tracks under the train.
> :-/
> 
>> Sounds like Camberwell has some serious signal problems if its signals
>> are going dark.
> 
> Sounds like Camberwell has a fubar AC supply.
> 
>> Mark
>> Union Pacific Signal Maintainer
> 
> B.
> Nothing in Particular.
> 
> 


Many thanks for the info. Having never worked with signals in electrified
areas your posting explained quite a lot to me, thank you.

We do use a lot of A.C. but only so we can get different frequencies such as
code transmission through the rails. Is there anything like "Electrocode" in
Australia?

Mark