[NSW] Olympic Park/City Railway Signalling Question

["Chris Downs" <cvdowns@ozemail.com.au>]

One of the operational limitations at Olympic Park was the delay between a
service departing either platforms 1/2 or 3/4 and the following train
entering the same platform.  It appears that the signal permitting entry to
the platform did not clear to caution until the preceding train had cleared
the tunnel portal or thereabouts some 200m beyond the station.  The
practical implication of this was that even when trains were queued it was
about 90 seconds usual minimum from the 1st train starting until the 2nd
train stopped, quite a chunk out of 4 minute headways.

When reading David R. Keenan's and Howard R. Clark's "FIRST STOP CENTRAL"
they refer to the later version of speed control signalling used in most of
the City Railway (except the St James - Central leg which uses the earlier
version).  The following statement is made (page 67):
"At peak periods it is possible for a following train to closely approach a
station while the previous train is still in the platform.  In some cases
when this close headway is in operation, the platform entering signal can
clear before a preceding train is completely out of the station in order to
allow the entry of the following train without delay."

The 1st sentence continues to apply today post recent resignalling although
the last signal before the platform is now further away from the platform to
keep the jointless circuit system for that signal completely clear of the
platform.  I have a vague recollection of seeing a following train enter
platform 6 at Wynyard before the preceding train had cleared the platform
(rather slowly).  This was 15 or so years ago and of course there were 3 or
4 intermediate train stops to prevent collision.

Did the original signalling system actually operate in this fashion re
platform entry at Town Hall, Wynyard (and Circular Quay) stations?  If so
does anyone have any details re speeds etc..
(If it did) does the new signalling make the same provision?

Whilst there was little need for this provision at Olympic Park during the
Olympics it would be useful when large events are being cleared to either
increase train frequency or allow extra loading time per train to carry a
higher load and clear OP more quickly.

Chris