FYI, the Dail Telegraph today has an article about a possible second airport at Richmond, actually nearer Clarendon station.

A map shows an additional north south runway, at about 80 degrees to the existing East West runway.

This new runway would require the railway and road to be put into tunnels.

Ideally, the new airport terminal would be on the south east corner of the two runways, adjacent to Clarendon station.

To improve the railway service, the remaining single line sections out to be duplicated, except perhaps for the long viaducts on either side of Windsor station. The line is now double track as far as Schofields. There are crossing loops at:
* Riverstone - 2 side platforms
* Mulgrave - 1 island platform
* Clarendon - 2 side platforms
* Richmond has 2 deadend (island) platform.

The Richmond airport would be a temporary affair pending construction of Badgerys/Wilton, which require considerably more infrastructure.

I can bet you bottom dollar nothing will happen at Richmond. The Terrograph's concept of a N-S runway is a pipe-dream that I am sure the residents of Penrith wont accept, hence the same reasons that Badgerys Creek has not happened. Plus they wouldn't build a 12000ft runway for a 'temporary' airport until another was built.

But if they did, I cant see a tunnel being built for the rail, let alone the road. Trains would be terminated before hand.

Fog at Richmond would have a high number of mornings closed down, hence why it hasn't even gone ahead at the moment as a temporary solution.