Really @Lockie91 where did you learn arithmetic . 33 LOL.He said existing tracks, he didn't specify suburban or RRL
On you own figures, MM1 to Sunshine = 14 Sunbury, 6 Melton, 6 MARL = 26.TPH ( MAXIMUM AT PEAK TIME). Well within the abilty of High Capacity Signal being installed.
Bendigo do NOT share these tracks, it's RRL.
Now Sunshine to Albion does need some reconfigure to untangle the spagetti between MARL/Sunbury/Bendigo/Freight. Not a huge task in the scheme of things.
RRL is already at capacity during peaks so there needs to be space found for more planned services there. Easy right? Electrify Melton and run those via MM1 = your 26 TPH. I thought that Wyndham Vale was in the offing for sparking and running via MM1. That frees up a few more paths on the RRL but now you are at 32 TPH on the MM1 pair if the WV frequency is to match Melton.
Then you need to find paths for extra Bendigo, Ballarat and Geelong services that are planned. This will eat up most of the paths on the RRL that you have freed up by moving Melton and WV onto MM1. 3TPH for Bendigo and Ballarat is planned. Is it 6 TPH for Geetroit? If you leave WV on the RRL that takes you up to 18 TPH*
Then lord help us if anything goes wrong, you have pretty much zero padding to divert services onto other lines in case of a failed train or other problem. IMO it is all way too tight between Sunshine and Footscray and is just a recipe for constant delays and problems.
*back of the envelope stuff here so let me know if I have made a mistake
OK Brenton, let's accept that Lockie meant share the 33 TPH between 2 sets of tracks.
That's REALLY GOOD light usage, but of course a bunch of hyperbole.
Down to in tacks, your back of envelope is OK as far as it goes,
BUT this discussion is about MARL (you know, the extra line to Airport)
NOT, let's build and extra pair of sparky lines for Wyndham Vale.
When (if) Melton gets it's own spark line, then those trains come OFF RRL.
Maybe Ballarat will get some of those slots back, MAYBE.
When (if) WV get's it's own spark line, that's another discussion about how to get into the CBD.
Agreed that squeezing the extra 3TPH (grow to 6 ?) into The Sunbury/MM1 track definitely won't work, and the time to think about an extra pair to look after all the growth from the west.
Again takes pressure off RRL, giving scope maybe for more Geetroit trains.
Alas, I don't hold much hope for any sizable increase for Bendigo in the foreseeable future.
Until such time as a dedicated path is found between the rural fringe and Sunshine, no scope - you're going to be stuck behind the 14 TPH Sunbury SAS.
From what I can see, the nasty bottleneck that forces the V/los to wait and wait and wait, is still the half hearted effort done on RRL (how many at grade cross-overs are there ?) , which the re-work for MARL should(must) fix.