NESG autos are numbered in hundreds of feet from Melb. The prefix used from
Melbourne to Broadmeadows is MG on Dual Gauge track (Melbourne Goods line)
and MGS on SG only track (Melbourne Goods Standard Gauge). From
Broadmeadows to Wodonga the prefix is ES (Essendon Standard gauge).
Essendon is/was apparently the base station for the signal fitters!! Broad
Gauge autos north of Broadmeadows carry the prefix E.
On the West CTC the numbers are hundreds of METRES from Melbourne via
Ballarat and, thus, are a lot easier to find (take off the last digit to
get the km post). The prefix used is A for Ararat. I guess now that should
be AS but nothing else in Victoria seems to have a hard and fast rule so I
don't expect them to change:-).
At crossing loops on the North East signals are prefixed with a three
letter code for the station (eg LWD for Longwood) over an even number
starting at the up end. The Down Home Arrival is 2, Up Home Departures are
4, Down Home Departures are 6, and Up Home Arrival is 8. Signals out of
number two track (the loop in NSW speak) have a U suffix and signals out of
number three track, if provided, have a V suffix. For example the Down Home
Departure out of number two track at Longwood is LWD over 6U. At Tottenham
Loop there are two Up Home Arrivals, the one ex the NESG is TOT over 8 and
the one ex the West is TOT over 8U.
On the West the crossing loop prefixes are not letters but numbers that
correspond roughly to the kilometreage of the loop. The km posts out west
repeat themselves from 211 km to 265 km. This is due to distance west of
Ararat being calculated via Ballarat. Pyrenees Loop up end is 265km and
down end is 212km. The km posts from Maroona to Pyrenees were altered when
the gauge was converted, they used to read from Ararat in both directions
now they read from Maroona to Pyrenees.
-- Cheers Krel"The Universe is not only stranger than we imagine, it is stranger than we can imagine" - Clarkes second law. Railway rules and regulations are the same.