Sydney: why have one metro system when you can have two (or more)? Part 1

The second week of January 2023 featured extensive media coverage in the Sydney Morning Herald about the Sydney Metro. It’s unclear what triggered this, apart from the opening of the next stage of Metro City and Southwest from Chatswood to Sydenham in 12 to 18 months’ time, and of course the fact that the NSW state election is imminent.

Although the SMH articles were generally positive, they touched on the project’s controversial past, and how the fully automated and imported single-deck trains of Sydney’s first metro broke with the tradition of Sydney’s established double-deck rail network. They have also mentioned the project’s somewhat uncertain post-Covid present, and how the pandemic and a protracted industrial dispute have contributed to the delay in completing the final stage from Sydenham to Bankstown to 2025.

While the media highlight was on Metro City and Southwest, the NSW Government has also commenced the construction of two more lines and released long-term plans for future metros. This underscores the NSW government’s ambition that all future expansion of Sydney’s rail network will be achieved through the extension of these lines and eventually the construction of additional metros. 

It is easy to jump from this to a second conclusion – that the government will turn the current disconnected projects into an single seamless metro system as an alternative to the current suburban rail network. However, the notion that the government wants full integration of the metro lines may be an oversimplification. It seems that instead of getting one metro, we will end up with two – and possibly three or even more – distinct and, to varying degrees, incompatible systems.

This is becoming clearer as construction of the Sydney Metro Western Sydney Airport (Metro WSA) line gets underway and the differences between it and the combined Sydney Metro Northwest and Metro City and Southwest (Metro NW/City/SW) emerge. I’ll take a look at these differences and their implications in this article, while in the second part I’ll look at how the third line under construction, Sydney Metro West, fits into this picture and canvass some possible scenarios for the long-term development of Sydney’s metro lines.

Metro Map Appendix E- Design Guidelines (1)

Sydney Metro lines in operation or under construction, and selected proposed extensions and lines (source: Sydney Metro)


Are the Metros really that different?

I don’t think many people understand how incompatible how Sydney’s first two metros will be. I’ve summarised the main points of contrast in the table below (this also includes Sydney Metro West), but a few things stand out (click on the table to download a more readable version).


Two differences are apparent straight away. The first is that Metro WSA will be operated by Parklife Metro, a completely different consortium to the Metro Trains Sydney group of companies that is operating Metro NW/City/SW. The second is that the airport line will use 25 kV AC electrification, unlike the combined Metro NW/City/SW and the suburban and interurban rail networks, which all run on 1,500 V DC.

While there are sound practical reasons for the different power systems, it sets up a major incompatibility between the two metros. In theory, this could be overcome through the installation of of bi-mode equipment on the trains which would allow them to use either system, a common feature of international trains in Europe. However, this is rarely done on metro rolling stock, and there are further differences which will probably rule this out.

For example, Metro WSA will start by running three-car trains, which will likely be provided by Parklife Metro member Siemens, a rolling stock manufacturer, rather than Alstom, the supplier for the current metro. The stations will also be designed for sets this size, but provision is being made for them to be expanded in future to accommodate longer trains – but, it appears, only to be big enough for four-car ones.

St Marys metro station cutaway

St Marys Metro Station indicative elevation showing provision for a maximum four cars (source: Sydney Metro WSA EIS)

This makes the trains only half the length of their Metro NW/City/SW counterparts which are currently six cars and which can be extended to eight. Finally, there is some suggestion that the Metro WSA trains will have wider bodies than the Metro NW/City/SW rolling stock to accommodate passengers with luggage travelling to and from Western Sydney Airport.

These specifications are designed for the initial role of Metro WSA and the relatively low anticipated demand. The 23-kilometre line will run from St Marys station on the western rail line to the new airport and the Aerotropolis (now called Bradfield). There will be only six stations an average of over 4.5 km apart, most serving what are now greenfield sites. 

Chapter 7- Project description - operation (2)

Sydney Metro Western Sydney Airport: Project Overview (source: Sydney Metro WSA EIS)

For many years to come the line will sit in relative isolation, its primary role to provide a shuttle service to and from the new airport and Bradfield. However, there are plans to expand Metro WSA both north and south to create an outer orbital rail line. This means Metro WSA could eventually become a significant piece of infrastructure for the region, especially if all the predictions for the growth of the airport and Bradfield are fulfilled – yet the line will be constrained to little over half the maximum capacity of the other metro link.

Extending Metro WSA also means that it will have to interchange with other railways and metro lines. Heading northwards the line will connect to the Richmond rail line and eventually to Metro NW/City/SW, but for the reasons outlined above there is little possibility of through running (more on the practical consequences of this decision in a moment). 

What is the Government’s strategy?

Taken in isolation and from a strictly operational perspective, the high level of incompatibility between these lines is not quite as big an issue as it may seem. Metro systems in other countries often comprise many standalone lines with passenger interchanges but no direct physical links between them, which means a technical problem or maintenance shutdown on one line does not affect the whole system. This approach is less common when lines meet end-to-end, but it is not unheard of if the lines involved are very long.

It’s also not that unusual for different lines within the one system to be technically incompatible with each other. However, this usually occurs when metro systems have developed over long periods of time and can reflect improvements in railway technologies, changes in priorities or design philosophies, or in some cases, the unique needs of specific lines.

But none of this applies here. It is highly unusual for a government to deliberately plan two metro lines in the same city which will will open only a few years apart to be as different as these two lines are. In this case, explicit decisions have been taken to make them incompatible, in much the same way as Sydney’s first metro was designed to be completely different to the suburban rail network, and to keep them that way.

There were political as well as practical reasons for the government’s first decision, in that part of the rationale was a desire to engineer a deliberate and permanent separation between the systems. Why exactly this is being done a second time is harder to discern, but there are some partial explanations. For example, the choice of a different consortium to supply the stations, systems and trains for the airport line and then to operate it was the result of the decision to apply a PPP model to the metros in the first place.

Given its decision to bundle construction, rolling stock, operations and maintenance into single bundles for each metro, the government was never going to lock in a single private consortium as the sole provider and operator of all future metro lines simply because they were contracted to build the first metro link, even if this could have provided uniform specifications and rolling stock resulting in reduced costs. Of course, development of two separate systems also makes it much more convenient for a future government to privatise the metro lines (something the current government has denied it wants to do).

However, this still does not fully explain the degree of technical incompatibility between the Metro WSA and Metro NW/City/SW lines. One possible reason for this is cost; the capacity built into the specification for Metro NW/City/SW would have substantially increased the initial price of building Metro WSA, even though the latter won’t need it for a very long time. It is still unclear, however, why the specification for the latter’s stations seems to make expansion beyond four-car trains impossible.

When metros meet…

As I noted earlier an extension north from St Marys means that Metro WSA will eventually meet Metro NW/City/SW – the question is where. The issue is compounded by the government’s curious decision to terminate Metro NW/City/SW at Tallawong, just three kilometres short of Schofields railway station. If the two metros were to meet at Tallawong, this would have some unfortunate consequences, particularly for people using the Richmond line wishing to change to or from the metro. Any of these passengers wanting to travel east on the Metro NW/City/SW would have to change first at Schofields to Metro WSA and then again at Tallawong. 

At least there is a simple solution to this – extend Metro NW/City/SW to meet Metro WSA at Schofields, and build a three-way interchange there between the two metros and the rail line. The situation to the south of the planned Metro MW/City/SW terminus at Bradfield is more complicated.

Here there are two options; a connection south through Narellan and Campbelltown to Macarthur station which is the terminus for suburban services on the main south rail line, and a much shorter link southeast to Leppington station, the terminus of the South West Rail Link (SWRL). Initially it seemed that the Macarthur link was the priority, but recently the Federal and NSW governments have announced $155 million in joint funding to prepare a business case for “Stage 2” of Metro WSA which would be a link to Leppington.

north south rail line

Earlier indicative plan for a north-south line incorporating a potential link to Macarthur and SWRL extension (source: transport for NSW)

The stage 2 option would not end there. The proposal to be assessed in the business case also involves the conversion and incorporation of the SWRL between Glenfield and Leppington into the Metro WSA. This replaces an earlier proposal which would have seen the SWRL extended to an interchange with Metro WSA at either the airport or Bradfield.

The attractions are obvious – a metro extension to Glenfield via Leppington would be about 18 km but would involve only about 6 or 7 km of new surface line to be built largely outside built-up areas. The existing 11 km line from Leppington to Glenfield which would require metro conversion is only eight years old.

2022-23-factsheet-nsw-business-case-for-the-extension-of-the-sydney-metro-western-sydney-airport (3)

Indicative route for Stage 2 of Sydney Metro Western Sydney Airport (source: Australian Government)

This compares favourably to the alternative proposal for a metro line to Macarthur. This would be only slightly longer (around 20 km) but would be an entirely new build requiring tunnelling through the established suburbs of Narellan and Campbelltown. Another advantage is that Glenfield is already a rail junction, and access to the airport would be provided from these lines and in particular from Liverpool and Campbelltown. Incorporating the existing SWRL would also improve Metro WSA’s viability by increasing its patronage.

The disadvantages are equally obvious, and echo those of the similar conversion of the Epping-Chatswood Rail Link to be incorporated into Metro Northwest. The people most inconvenienced would be current passengers on the SWRL who mainly commute to the CBD or Liverpool using the T2 rail line, or those travelling to Parramatta on the T5. These passengers would have to change at Glenfield (there would be less of a problem for people travelling from Leppington or Edmondson Park to Sydney Airport or the city on the T8 line, as they have to change at Glenfield anyway).

At first glance this raises the possibility that the government is setting up a long-term option to partially convert the T8 line between Glenfield and Central station via the airport to become part of an extended Metro WSA. This would be a longer but in some respects simpler conversion than the Bankstown line. The T8 line has been quadruplicated from Revesby to the junction near Wolli Creek allowing some services to run express, and there is space for the quadruplication to be continued to Glenfield. This would allow two tracks to be converted to metro while leaving the other two as suburban rail lines, providing a roughly 45-minute ride between the two airports, with another 12 to 15 minutes to reach the city.

T8 line

T8 Line (green) – potential for conversion? (source: Sydney Trains)

Being a simpler conversion than Bankstown does not mean that any such proposal would be any less controversial. Even if suburban services were to be maintained, any metro conversion would inevitably take over the current express tracks as well as the line to Sydney Airport, and T8 passengers wishing to avoid all-stop services would have to change at Glenfield.

However, this may all well be moot. If Metro WSA is limited to only four car sets, then capacity on an extended line would be only around 26,000 passengers per hour per direction (as compared to Metro NW/City/SW which would be able to carry over 45,000 per hour with eight-car sets). This does not seem adequate to carry both airport and commuter peak-hour traffic in, say, 20 years time.

Multiple metros and suburban rail – an uncertain relationship

Some aspects of the state government’s strategy are clear, others much less so. Obviously it wants all future rail expansion to be done through metro construction, but also equally obviously it does not want to create a single-operator metro monopoly. There will be at least two metro consortia operating separate metro systems, and as I’ll discuss in the next part, in future there will quite possibly be more.

While provision has been made for expansion, the first two metro lines have been designed around their primary purposes, to the point that they will be almost completely incompatible. This will cause issues when these metros eventually meet, but these can be managed. However the limited design capacity of Metro WSA will have more serious implications, constraining the line’s longer-term future as outer Western Sydney’s key north-south public transport corridor.

It also limits the likelihood that there will be a Bankstown-like conversion of the T8 line from Glenfield to the city, even though the SWRL from Leppington to Glenfield is earmarked for conversion as part of stage 2 of Metro WSA. The government may have decided that the T8 is a conversion too far, and that apart from the metro takeovers of the Epping-Chatswood rail link, the Bankstown line and potentially the SWRL, Sydney’s remaining suburban rail network could be left intact, even if it is to be surrounded by multiple metro systems. If this is the case, will future governments give the suburban system the same level of attention as the shiny new metro lines, along with the continued investment required to support its long-term future?

In part 2 I look at how Sydney Metro West confirms the Government’s desire to create three separate Metro systems rather than one, and explore the long-term implications for the expansion of Sydney’s rail network.

Edited for typos and clarity 15/01/2023
Table corrected 27/01/2023


This entry was posted in Airport, Bradfield, metro, Planning, Public Transport, Rail, Sydney Metro, Sydney metro area, Transport, Western Sydney and tagged , , , , , , . Bookmark the permalink.

3 Responses to Sydney: why have one metro system when you can have two (or more)? Part 1

  1. Peter Warrington says:

    Thanks Alex, great work. I think the big challenge for the East Hills etc line is the lack of jobs to date and thus the lack of probably churn on such a long line (compared to the North West or West). But still nobody sees the problem. I guess it’s personal for me being a child of that line. Cheers, Peter


  2. Pingback: Sydney: why have one metro system when you can have two (or more)? Part 2 | StrategicMatters

  3. Pingback: Whatever the NSW election result, metros are the winner | StrategicMatters

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