T1 has 13 trains an hour across the bridge at the moment and you want to limit that to 6 trains an hour Transtopic. Good luck with that. Adding extra BM and CCN services is a better solution especially if amplification on the northern line happens as well.You're taking my comments out of context sims. That's not exactly what I was implying. Perhaps I didn't explain myself clearly enough, so apologies.
There are currently 16tph T1 services across the bridge plus 4tph T9 services in the morning peak. I was suggesting that the 4tph T2 services starting from Parramatta be extended as an all-stations service from Blacktown and increased to 6tph, continuing on the Suburban tracks from Homebush across the Harbour Bridge, rather than on the Locals to the City Circle. These services effectively become part of T1. They would share the Suburban tracks with Liverpool via Granville services @ 6tph from Granville and T9 Northern Line services @ 8tph from Strathfield - a total of 20tph with the current signalling. The Suburban tracks between Lidcombe and Homebush would run at a total of 20tph, with 8tph from Leppington/Liverpool via Regents Park, 6tph from Liverpool via Granville and 6tph from Blacktown, until sextuplication is completed allowing more services.
With the extension of the current T2 starters from Parramatta to Blacktown (all-stations) and an increase to 6tph, the T1 Penrith and Richmond services could be reduced to 12tph, all of which would be express services using the Main tracks and terminating at Central. This would be an interim measure as a precursor to extension to a future City Relief Line from Eveleigh from the Mains and ultimately a separate express tunnel from Parramatta to cater for future growth, independent of the metro.
BM and CCN Intercity services @ 4tph each could still be accommodated on the Mains to Sydney Terminal until such time as further amplification works are undertaken.
All of this highlights how the government has been trying to screw every last drop out of the existing network to meet the increasing demand, without facing up to the fact that significantly greater investment should be directed towards upgrading it in preference to the metro expansion, which is still warranted in the longer term.
Before I make my next statement can I get your confirmation on these numbers you put out. I think you are forgetting about including the south coast line numbers in to your mains numbers which makes your numbers impossible to reach as they share the mains corridor between redfern and central terminal.
Mains - 4 x BM, 4 x CCN and 12 x T1.
Suburbans - 6 x T1 Blacktown, 8 x T9 and 6 x T2 via granville.
Locals - 8 x via regents park, 6 x via granville and 6 x T2 to blacktown?
You've double counted the 6 x T1 Blacktown services (formerly 4 x T2 Parramatta) and the 6 x T2 via Granville services under both the Suburbans and Locals.
It should be -
Mains - 4 x BM, 4 x CCN and 12 x T1.
Suburbans - 6 x T1 Blacktown, 8 x T9 and 6 x T2 via Granville.
Locals - 8 x T2 via Regents Park and 8 x T2 Homebush/Ashfield (truncated until sextup completed between Homebush and Lidcombe to allow the all-stations service to be extended to and from Bankstown via Regents Park).
With regard to South Coast Intercity services using the Mains between Redfern and Central to access the terminal platforms, that would add say an additional 4tph for the short length of track between the Illawarra Dive and the entrance of Central Yard in the vicinity of the Cleveland St overbridge.
I have never been able to get a definitive maximum number of trains that Sydney Terminal could handle, but with 14 terminating platforms being available after completion of the metro underground platforms, then surely it could handle 24tph or more, when Bondi Junction on the ESR with its recent upgrade was designed to handle 20tph terminating services with just 2 platforms and diamond crossovers.
As I stated, the termination of T1 services at Central would only be an interim measure until the City Relief Line was built. If Sydney Terminal became too congested, the South Coast Intercity services could be redirected to and from Bondi Junction as some currently are.
Putting future metro lines aside, I visualise an ultimate plan for the existing Sydney Trains network on the Western Line corridor, as being 3 track pairs from Parramatta/Granville to Lidcombe and 4 track pairs from Lidcombe to the CBD.
The track pairs would feed into the CBD as follows -
1. New express tunnel from Parramatta to City Relief Line terminating at Wynyard
2. Existing Western Main Line to Sydney Terminal with grade separated crossovers with City Relief Line
3. Existing Suburban Line, with T2 via Granville and T9 services as branches, through the CBD across the Harbour Bridge
4. Locals to and from Bankstown and Leppington/Liverpool via Regents Park including completion of sextup between Homebush and Lidcombe.
The City Relief Line, which is only over a relatively short distance and with 4 new underground stations, could be built much sooner than Metro West, which is at least a decade or more away. It would provide far greater and more immediate relief to the Western Line congestion and to the broader rail network generally. The express tunnel would be a longer term option to cater for future growth, which Metro West won't provide for outer Western and Richmond Line commuters. The tunnel would also free up capacity on the Mains for an increase in BM and CCN Intercity services to Sydney Terminal.
I haven't touched on upgrades to T4 and T8 as that's another story in itself, but for starters the Airport Line should ultimately be diverted from the City Circle to a new mid-city terminus.