Tag Archives: infrastructure

Playing with trains – a North-West rail link

Not content with scrutinising the plan for a National Broadband Network in Australia, guest contributor @pfh007 has now turned his analytical beer coaster to a network of a different sort: a railway network.

There is a Ph.D. for the taking by any researcher who is able to unlock the evolutionary origins of the propensity of young children (and many older people) to be mesmerised by trains, even the generic suburban variety. You can see the rush of endorphins on the faces of weary commuters as an express service roars past within a metre or two of their aching feet. People seem to have a railway gene.

Sydney Train

During the 1970s and early 1980s, the annual model train exhibition held in the Willoughby Town Hall in Chatswood was a highlight for the local kids. It took a full day to observe every detail of the elaborate models complete with green fuzz trees, fields of tiny cows and platforms full of frozen people and Hornby OO gauge recreations of famous rolling stock clattering around and around. Although remarkable as demonstrations of what can be achieved in a backyard shed, those models and their kin were probably responsible for turning large measures of the population into armchair rail network designers.

Consider this a contribution from one such Backyard Bradfield.

One of the striking features of the recent federal election was the ferocious response to the promise to complete the Epping to Parramatta section of the Chatswood to Parramatta line even though new (or finally completed) rail should be of immense appeal to residents of the area. It seems clear that the strength of the reaction was largely due to the failed rail promises of recent NSW political history. In short people were tired of having their railway gene tweaked for short term political advantage.

At one level it is hard to understand why building a new railway in Sydney is so difficult. Unlike the technological challenges facing the early railway builders in Sydney (see the ponies and pick axes in the photos at Museum Station) we have access to marvellous mole-like machines that can bore tunnels right through the Sydney sandstone. We also have advanced administrative systems for compensating people whose houses must give way to new surface track. Shanghai has been laying a new subway at a great rate over the last 15 years, so why can’t Sydney?

Could the problem be cost, even though modern technology and construction methods should have caused construction costs to fall over the last 100 years? Perhaps it is not so much the cost as the complexity of the financing arrangements, which have become too ‘elegant’. The Waratah train deal seems remarkably ‘elegant’ and yet, according to the press, it is poised for implosion.

I think the real problem is that these days we are spending too much time thinking about what we want rather than what a railway needs to be viable. That is we should decide to build a railway and then shape that part of the city to suit the railway. After all, if the majority of Sydney’s suburbs were designed around the car it is highly unlikely that they will be suited to a rail line without substantial modifications.

As the National Broadbank Network (NBN) has established back of the beer coaster calculations as a valid method of policy analysis, I will adopt that technique for some rough calculations of the North-West rail line viewed from the perspective of the needs of the railway.


Using Google Maps, the following route seems reasonable in terms of not going too close to existing rail lines. The precise route is not critical as the demographics and structure of the suburbs will change to suit the new rail line by way of changes to zoning requirements.

Number of Stations: 15

Balmain, Drummoyne, Gladesville, Top Ryde, Denistone East, Eastwood (interchange with Northern Line), Carlingford (interchange with Chatswood-Parramatta Line), North Rocks, West Pennant Hills, Castle Hill, Kellyville, Rousehill, Box Hill, McGrath’s Hill and ending at Windsor.

Train Capacity

Capacity of the new Waratah trains is 896 seated (8 carriages) and, say, another 320 standing (20 in each vestibule) = 1,216 people in total per train

Peak Hour Capacity

The beer coaster is not very big so I will stick with peak hour only and peak “hour” is taken to extend from 6.15 am to 8.45 am, so 2.5 hours. We want a well-signaled, well-designed speedy network that can handle trains at 6 minute intervals. This means we can run 10 trains per hour. Thus the number of peak hour trains is limited to 25 trains.

25 trains in 2.5 hours can carry between 22,400 people (all seated) and 30,400 people (40 standing in each carriage) into the CBD.

I have assumed that during peak hour everyone gets on and travels to the city and everyone comes home by train at the end of the day. I have also assumed that every train going in the opposite direction during peak hour is empty

Station Capacity at Peak Hour

With a capacity at 30,400 people between 6.15 and 8.45 am and assuming that the load is spread equally between all 15 stations, each station will process 2,026 passengers during peak hour. Assuming they all arrive evenly spaced during peak hour, there would be no more than about 80 people on the platform at any one time.

Ticket revenue generated by Peak Hour Capacity

Assuming that everyone works about 46 weeks per year and no one uses the train for any other purpose the revenue generated by the new line (at $50 per week for a weekly ticket) is 30,400 × 46 × 50 = $69,920,000 (roughly $70 million per year)

Certainly people will use the rail line outside of peak hour, but as they will often be concession fares, etc. it is probably safer to do the sums on the basis of the peak hour capacity.

Out of that $70 million you will need to remove operating costs (say $25 million) leaving you with $45 million to pay down the debt used to construct the rail line. As $45 million would only produce a 6% return on $750 million worth of bonds and building the line would cost a lot more than that, there is quite a large shortfall to be found.

To give you an idea of how much that shortfall might be, the price tag for completing the Epping–Parramatta line is estimated at $2 billion.  It seems likely that the cost for the full North-Western rail line would be well in excess of $5 billion.  How do we cover the shortfall?

Remodeling the suburbs along the route

The beer coaster calculations make it quite clear that the finances of our beloved new railway are marginal even if we squeeze 1,200 people on trains running every 6 minutes non-stop between 6.15 am and 8.45 am.

That means we need a nice steady supply of warm bodies arriving at the station.  Where will they come from?  This is what demands the remodeling of the suburbs along the route.  Unless there are  sufficient people who can use the rail line we will not even get to the stage of trying to convince them to use it.

Finding 30,400 people in a Sydney of 4 million during peak hour can’t be that hard, can it?

Well yes it can.

It is worth keeping in mind that, currently, the inner West line in Sydney only runs about 4 services per hour in peak time and you can usually get a seat at Petersham, which is one of the closer stops to the city.  That means that, even in the relatively densely-populated inner Western suburbs of Sydney, it would be a struggle to get anywhere near 30,400 people.

Walkers are unlikely to want to walk more than 15 minutes to the station. It may be that  most people will only be willing to walk a shorter distance. A 15 minute walk at a brisk pace is only 1.5 km.  That means that the walker catchment for each railway station will be a circle of radius 1.5 km.

Bus links and commuter car parks can help extend the catchment for each station, but when you are trying to get an average of 2,026 people to each station during the peak hour, that means a lot of buses or a rather large commuter car park for each station.

The only practical solution is to permit or, better still, encourage medium-high density housing for a 1.5 km radius around each of the 15 stations. Ideally this would be mixed office/housing/retail construction so that the inhabitants of the 1.5 km zone might get away without having a car at all.

On the assumption that only 20% of the people living in the 1.5 km radius will be daily commuters, we will need about 10,000 inhabitants in each 1.5 km radius to generate the 2026 passengers. That is quite a lot of houses or, more likely, apartments (say 5,000–2 people per dwelling).

The re-modeling will not require an army of town planners.  Simply change the zoning rules for the 1.5 km radius around each station to allow medium-to-high density construction of approximately 5,000 dwellings and let the builders and developers of Sydney do the rest.

If this approach was applied to the other rail lines in Sydney we may find that we can deliver an enormous supply of new dwellings (apartments) over the years ahead without any increase in the area occupied by Sydney.  This would allow the preservation of the market gardens on the outskirts, which currently supply much of Sydney’s vegetables.

Needless to say, an increased supply of dwellings where people want to live will go a long way to making housing more affordable in Sydney.

What about the shortfall between construction costs and ticket revenue?

It might be possible to increase the weekly ticket price, but I think $50 is probably a price that will not cause too much “sticker shock”.

It is hard to justify making people outside the railway catchment pay the cost as they will probably have their own rail link developments to fund. It seems reasonable that the shortfall between ticket revenue and paying the construction cost should be recovered from all the property owners in the railway catchment as the rail line will increase the value of their properties.

This could be done by imposing an annual State “infrastructure” tax on houses in the catchment for as long as it takes to retire the bonds issued to raise the construction capital (perhaps 20 years). The rate of the tax could vary depending on the benefit to the taxed property of the rail line.

For example:  the 75,000 dwellings (15 × 5,000) within the 1.5 km radius of each of the 15 stations might pay $3,000 per year for 20 years and the 300,000 dwellings (I have no idea how many there are!) outside the 1.5km radius but still within the railway catchment might pay $750 per year for 20 years.   This ‘infrastructure’ tax would raise $450 million per year.  Add in the $45 million from ticket sales and the annual total of $495 million would pay 6% interest on about $8.2 billion worth of government bonds (or less for a non-government borrower). Taking into account repayment of principal as well over, say, a 20 year period, the debt $450 million could support would be closer to $5 billion.

Not quite there, as the construction cost is probably a lot more than $5 billion but at least in the ball park!

Is it all too hard?

The numbers above are all beer coaster figures, but they do suggest that better public transport has a real cost and involves changes that cannot be imagined away.

Survey after survey reports that Sydney is sick of congestion and wants better public transport, and yet I cannot recall too many attempts by our politicians (of any shades of the political rainbow) to lead the debate as to what better public transport may require of us in terms of contributing to its cost and accepting some changes to the car-flavoured landscape of Sydney.

Perhaps that is the real obstacle to improving public transport in Sydney.


  • If we want new rail lines, we need to think more about what they require of us rather than what we require of them.
  • If we are serious about better public transport, we need to be serious about increasing the density of Sydney’s population (although not necessarily increasing the total population).
  • The main obstacle to building new rail lines in Sydney is low population density.
  • Building a new rail line will require substantial remodelling/re-zoning of the areas within a 1.5 km radius of each station, preferably a mix of medium-high density housing/offices and retail.
  • One way of funding the cost of better public transport is a state infrastructure tax on the properties that benefit from better public transport services.
  • The next time you catch a train in Sydney, take along a beer coaster and count the people on the platform, the density of housing around the station, the frequency of services and the price of the ticket and then start designing your own preferred extension to the City Rail network
  • Some suggestions—Bondi Junction to Cronulla via Kurnell (tunnel under the mouth of Botany Bay), Northern Beaches, Parramatta to Hurstville, Chatswood to Dee Why, Hornsby to Mona Vale.
  • It the context of the above discussion, it is perhaps unsurprising that people are raising questions about the rationale for an expenditure of $43 billion on the NBN.

Photo credit: coverling (copyright Creative Commons)