But it could be (Glenfield a place to terminate trains), and IMHO it makes some sense to do so given the other imbalances in the network.There is no reason at all for it to be. What imbalance is there to be sorted at Glenfield that can't be sorted at leppington? Leppington has 4 platforms and the rossmore facility to store trains which is why it makes perfect sense for all the T2's to go to Leppington.
There used to be 3 facing crossovers Nth of Glenfield. now there are none.
There was no need for those 3 facing crossovers since glenfield was upgraded to 4 platforms. There maybe some trains that terminate at glenfield but they would be late at night and done solely for points operation and cleaning. With the SWRL glenfield was designed to become a cross platform interchange station to seperate T2 and T8 and not a terminating station like it used to be.
My view is the Leppington line is the future, it will make sense (perhaps not now) to have Leppington run direct to the city via East Hills, rather than via Lewisham. Similarly, your (@sims) proposed plan shows how many routes there are from/through/involving Liverpool.
It makes no sense to deliberately run trains via the longest slowest possible route. It's costly, inefficient, and provides a terrible/useless service. On that basis I think it makes sense to have T2 end at Glenfield and Leppington added to T8. A facing crossover (and matching signalling) would enable P2&3 at Glenfield to operate as a turnback.
TfNSW seem intent on sabotaging the SWRL.
I'm with you djf on this score, in spite of sims' objections.
In the longer term, once track capacity through the City Circle is freed up by the Bankstown Line metro conversion, it would be logical to re-direct trains from Leppington and any extension of the SWRL, to the city via the T8 East Hills Line, which would give a much faster journey than the current convoluted route via Granville, or even Regents Park for that matter. This would make sense when you're talking about providing the most direct and fastest route between Western Sydney Airport and the CBD. I'm sceptical of the so-called North/South metro link between St Marys and the Airport getting off the ground, although as I've previously expressed, I can see a future extension of the SWRL from the airport to St Marys to create a continuous Cumberland Line loop via Blacktown, Parramatta and Liverpool.
If as sims suggests that most commuters from Leppington and Edmondson Park change at Glenfield to T8 for a faster journey to the city, then it would make sense, particularly when the SWRL is extended, to re-direct these services via the East Hills Line when the extra track capacity is available. I disagree with Cumberland Line services reverting to Campbelltown and they should continue to and from Leppington, connecting with Liverpool and Parramatta, having regard to future services on an extended SWRL.
There's no need for even current T2 services, whether via Granville or possibly Regents Park, starting from Leppington, when the Cumberland Line service will still provide access to Liverpool and Parramatta. I still maintain, assuming that the Liverpool via Regents Park service is reinstated, that it should start/terminate at Glenfield, which would give all commuters between Casula and Cabramatta a faster semi-express journey to the city. The via Granville service should start/terminate at Liverpool, as the via Regents Park route will free up capacity for stations north of Cabramatta and it will also continue to benefit from the Cumberland Line services, albiet at a higher frequency.
I attach below the latest Route Knowledge Diagrams for Glenfield for both the East Hills Line and the SWRL. The current track configuration with crossovers allows considerable flexibility in switching trains between the East Hills Line, the Main South Line and the SWRL. It also shows that it is feasible, as djf alluded to, to terminate Down T2 services at Platform 2 and return via the facing crossover to the Up Main South. It would not interfere with other services. It's similar to what happens at Revesby for terminating services where there are 4 tracks.
The only reason why I'm suggesting that T2 services should terminate at Glenfield is to allow Casula to continue to have a direct journey to the city without having to change. Otherwise, they might as well terminate at Liverpool.