Re: VIC: 1987 Safeworking Systems

[cmgord@ecr.mu.oz.au (Christopher_Martin GORDON)]

: I have recently acquired a 1987 General appendix to the Metrail Working
: Timetable. There are several questions which arise from browsing through
: this:
: - What was the safeworking between Graham and Port Melbourne just before
: its closure?
: - What was the safeworking between Ashburton and Alamein in 1987?

I think it has been station limits since the automation and panel was installed
at Ashburton.  See http://www.ecr.mu.oz.au/~cmgord/trains/signalling/ashburton

: - What was the safeworking between Fairfield Jn and the APM factory
: before its closure?

Either station limits or siding conditions.  I think it was station limits.

: - When was double line block on the Epping line replaced?

: - When was Staff and ticket between Keon Park and Epping Replaced?

Late 1980's.  Three position signalling was provided first to replace
the double line block, and then three position signalling to replace
the TST (train staff and ticket) and now Lalor-Epping is station limits.
Have a look at the date on my Bell signalling page.
http://www.ecr.mu.oz.au/~cmgord/trains/signalling/bell

: An item of interest is that this shows the following signal boxes on the
: Epping line attended for every train:
: - Clifton Hill A
: - Clifton Hill B
: - Merri
: - Northcote
: - Thornbury
: - Bell (not for every train)

I believe switchout was never provided at Bell.  Boom gates replaced the
interlocked gates at Bell street.  The panel at bell was provided very early
in the re-signalling, hence the not for every trains.

Is Bell was switched out then the section would be Thornbury-Reservoir.  This
section is too long for trains during peak hour.

Before the re-signalling there were many gates along the line.  Basically
the line was the same set up as the Upfield line was.  Frankston line was the
same till the early 1980's.  And all the other lines, like Box Hill-Ringwood
was done in sections in the 1950's.

Basically they provided three position signalling when they needed to reduce
the headways on the line for more trains.  Most three position signalling has
a headway of 2 minutes, where four aspect speed signalling is used the headway
is about 90 seconds, designed to get the next train into the station close
behind the previous trains.  The City loop has a headway of 90 seconds.  
: - Reservoir
: - Keon Park
: - Lalor

: Double Line Block working was in force between Merri and Keon Park.
: Staff and ticket operation was in force between Keon Park and Lalor and
: Lalor and Epping
: Thomastown was able to be opened as a Staff Station and had a crossing
: loop.

: Now this may not be interesting to everyone, but I was only 7 years old
: at the time and didn't even know what the word safeworking meant, let
: alone know what a staff was!

That is right.  Double line block basically you send a train if the section
is clear.  (using bell codes between the signal boxes, hence the reason they
had to be staffed).  One of the reasons it was upgraded was to provide better
headways on the line because of the new maintance depot at Epping.

With the double line block say a train is waiting at Clifton Hill, then the
signaller can't get line clear until the previous train has left Merri, now
with three position signalling the train can leave Clifton Hill after the
previous train has cleared Rushall.

There is a little about double line block on my St.Albans and Broadmeadows
pages.  http://www.ecr.mu.oz.au/~cmgord/trains/signalling

--

Chris Gordon
http://www.ecr.mu.oz.au/~cmgord