Cityrail has been simplifying its network ever since the Clearways project was announced in 2005 around the same time as the major timetable changes were introduced that year. The idea behind Clearways was to increase capacity (via additional “turnback” platforms and/or track amplifications) around the network where pinch points caused bottlenecks and to separate the network into 5 separate sectors (which would then converge into 3 sectors in the CBD). This is known as sectorisation, and involves creating sectors that run as independently from each other as possible. As a result, delays in one sector do not spill over into other sectors.
The Cityrail network currently has 3 sectors:
- Sector 1 – made up of the Eastern Suburbs and Illawarra Lines
- Sector 2 – made up of all the lines that use the City Circle, plus the Cumberland Line (Note: the Inner West Line between Strathfield and Homebush shows up faded in error.)
- Sector 3 – made up of all the lines that use the Harbour Bridge
(In practice, sectors 2 and 3 are not entirely separate, with trains on the Western Line and South Line sharing some track between Granville and Homebush, as well as the Western Line and Cumberland Line between Blacktown and Harris Park.)
A Herald report from 2012 revealed that one plan would involve fully separating Sectors 2 and 3. Currently the 2 track pairs between Blacktown and Homebush are used to separate local (all stops) services from express services. This allows express trains to overtake slower local ones. Separating trains on these tracks by sector rather than by stopping pattern then means that an express service could get stuck behind a slower local service. The solution to this would be to also harmonise stopping patterns – with sector 3 running only express services and sector 2 running only local services.
If implemented to the fullest extent, the Richmond and Northern Lines would be separated from the Western Line. Richmond Line trains would become part of the Cumberland Line, running all stations to Campbelltown. This would eliminate a conflict that currently exists at Granville where a flat junction is used by Western Line and South Line trains (by sending Richmond Line trains on the Cumberland Line’s flyover at Merrylands and sending Western Line trains on the Northern track pair not used by the South Line, thus avoiding the flat junction). Northern Line trains would use a third track pair that begins just before Strathfield at Homebush Station and then ends at Sydney Terminal at Central Station, effectively creating a fourth sector. Inner West Line trains would be truncated to Homebush, which relieves some pressure on the heavily used Lidcombe to Homebush portion of the network, allowing South and Western Line trains to pass through there more easily.
This would allow Western Line trains to run faster (by permanently skipping many stations) and more frequently (as they are not sharing any track with Richmond, Northern, or South Lines as is currently the case). Passengers at stations like Toongabbie, Pendle Hill, Wentworthville, and Harris Park would need to catch a Cumberland Line train and change to a Western Line train if they are going into the city. While passengers at stations like Clyde, Auburn, Lidcombe, or Flemington could change to a Western Line train for a faster journey, or stay on a slower all stations South Line train for a direct one. On the network map, this is what it could look like (again, this is purely speculation based on rumour at this point).
Creating these truly independent sectors would also allow for harmonisation of stopping patterns and rolling stock. With high enough frequencies, this will also mostly do away with the need to worry about delays. After all, if a peak hour train comes every 3 minutes and all the trains on that line have the same stopping patterns, then a 3 minute delay effectively puts everything back to normal.
It also makes many commutes easier – with commuters just taking the next train rather than waiting for their train, which will help to reduce station overcrowding on congested CBD stations (by requiring commuters to transfer to another train once they are out of the CBD). Frequencies will also improve, ensuring that commuter wait times are kept to a minimum and allowing many commuters to travel without having to worry about consulting the timetable first.
Higher off-peak frequencies could also mean shorter trips by way of reduced wait times. Parramatta currently has 5 trains an hour into the CBD during the off-peak, meaning a maximum wait of 15 minutes. Increasing this to 8 trains an hour would mean a maximum 8 minute wait, or 4 minutes on average. Similarly, someone taking the train from Pendle Hill currently has to wait 30 minutes for the next train during the off peak, which often means either arriving much earlier than necessary or taking the risk of missing the train and waiting half an hour for the next one. Either way, this means a longer overall journey time. But having 10-15 minute frequencies, and then transfering to a frequent (and express) Western Line train into the CBD, could result in a faster and more reliable journey, despite the removal of direct services. Someone wishing to make a North/South trip, say from Quakers Hill to Merrylands, will now have easy all day access by rail.
The main downside is that it will force many people to transfer to another train. Many commuters on the Richmond and Northern Lines will need to transfer to another train if travelling into the CBD, as they will no longer have direct access.
There do exist alternatives, Simon blogs at Fixing Sydney Transport about how Parramatta can be made the terminus of the Cumberland Line, thus maintaining the second track pair West of Parramatta free for Richmond Line trains. Doing this would allow Richmond and Epping Line trains to keep their CBD access, while still eliminating a conflicting move (by Western and South Line trains) on the flat junction at Granville that currently exists. It would not allow a complete harmonisation of stopping patterns, but does deliver some benefits of the complete sectorisation without most of the disadvantages it would bring. There are merits to this option, and would be an improvement on the status quo.
Ultimately, the government’s decision to run the Northwest Rail Link (NWRL) as a completely independent line (which could become the fifth sector), means that the existing Harbour crossing will need to be run at maximum efficiency during the decade between then NWRL’s completion and when a second Harbour Crossing is built, as this will become one of the biggest bottlenecks on the network. The easiest way to achieve that is to implement the sectorisation outlined above. So if it doesn’t happen in this year’s 2013 timetable, then expect it to happen when the NWRL opens at the end of the decade.