Edited 16 Dec 2014 19:23, 8 years ago, edited by awsgc24

Summarised,
Whitton era stations were planned and laid out for double track.
Where initially built with single track only:
- the Main line followed the proposed Down alignment;
- At major locations the station building was provided on either Down or Up side, usually convenient to the town;
- Where the station was on the Down side it was laid out adjacent to the Main line i.e. the future Down track (example Quirindi);
- Where the station was on the Up side it was laid out facing a Platform road i.e. the future Up track, and a “Through” road was provided on the future Down alignment (example Gunnedah).

A disadvantage of the Through and Platform Road arrangement occurred when the layout was signalled as a "key locked loop" and non-stop trains were forced to use the X25 turnouts and crossovers to pass through the Platform Road. This applied to:
* Scone
* Gunnedah
* Riverstone
* and a few other places.

Even with CTC at Scone and Gunnedah, the route through the X25 crossovers remained.

Looking at Gunnedah and its CTC layout dated 2008, several anomalies remained:
* the Through and Platform roads are not actually named on the Circular's diagram.
* what are the unnamed Frame K sidings for?
* are the No1 and No2 Loco sidings still used for that purpose?
* are the No1 and No2 Goods sidings still used for wagonload goods traffic?
* Frame N and the Mobil Oil siding is still there, even though oil traffic has apparently gone?
* Frame L and the Stock siding is still there, awaiting no doubt resumption of cattle and sheep trains?

It was mentioned in another thread, that the Through Road is used for waggon storage, and has catchpoints on Frame H and Frame F, which protect the main lines from runaway stabled wagons.

Summurising, Gunnedah is a clumsy and illogical mess, and could be rationalised if unwanted facilities can be pruned.

The new crossing loop 1km past the station is 1300m long, and replaces the Through (Loop) at the station which is only of a short length, the not-to-scale diagram unhelpfully does not say what.

The X25 turnouts also restrict speeds across three Type F automatic level crossings.

Apparently it is better and easier to let RMS build overbridges than to expect ARTC to eliminate the X25 speeds through the platform road and thus reduce level crossing delays. Eh?