Might the Suburban Rail Loop be two separate rail systems?

Comment

If the voting public are to take the Andrews Government's Suburban Rail Loop proposal on face value, over time, Melbourne will have a train line from Cheltenham to Werribee via the north-east and Melbourne Airport.

But will it be a 'single' train line - for example, the same service, no matter which part of the new rail line you are traveling on? 

Business case development currently underway for the Melbourne Airport Rail Link (MARL) and - should the Andrews Government be re-elected - the Suburban Rail Loop, will determine that outcome however, there may be some benefit to developing what in effect would be two separate rail lines to form the one greater loop line.

In recent days we saw a private proposal dubbed 'AirRail Melbourne' which is concerned with building a new railway from Southern Cross to the Airport via Sunshine and as I mentioned in my commentary, that specific railway is unlikely to cost $15 billion in total and the private investment - to the tune of $5 billion - would give governments the choice to reallocate funds to expanding other rail corridors and introducing new metro and regional services.

AirRail Melbourne, the proposal which will seek to use the market-led infrastructure process set up by the Victorian Treasury, positions itself to take a bet each way on how other projects might work with it. 

For instance, extrapolating the AirRail Melbourne proposal we might foresee a new dedicated line built Southern Cross - Sunshine - Airport and a new track pair from Sunshine - Deer Park - Wyndham Vale to the Geelong/Werribee line junction. Likewise, governments will have a choice to position the MARL/AirRail Melbourne line as a future path for Bendigo and Seymour-Shepparton services just like how the Rail Futures Institute has advocated for in the past.

Governments might even choose to extend the track eastward to form the wider Suburban Rail Loop (SRL) too.

But should they?

When the SRL was unveiled by the Premier, the eastern and northern sections on the map looked somewhat obvious - by simply looking at the map we can see its purpose is to move people around the middle suburbs between the existing radial network of metropolitan and regional services.

The western section looked undercooked, but one suspects that's because of the already announced business case development work occuring for the MARL and look at the situation now - the State Government called for expressions of interest to participate last week and already a well-rounded proposal has had its 15 minutes in the sun.

The passenger movement task to and around the west is different to the northern and eastern sections of the SRL - the west has far more complexity: High-speed rail to Geelong, city to airport services, should MARL be used in future for Bendigo and Seymour-Shepparton?

And so it follows, might - or should - the Suburban Rail Loop as Melbourne's orbital rail line, be two different systems given the two broad passenger movement tasks in different regions of the metropolitan area?

If we assume the western side of the city will proceed with the MARL or something like the AirRail Melbourne proposal which includes rail corridor expansion to the west, the SRL from the Airport to Cheltenham could be a separate rail system akin to what the Sydney Metro is to the wider rail network in Metroplitan Sydney (and regional NSW).

I was recently in Kuala Lumpur, where last year they opened the second and final phase of that city's latest MRT line.  It's a turn-key system, with portions of underground and elevated track broadly connecting through the centre of KL and out to the east and west of the Klang Valley.

We know the Andrews Government has cornered themselves into an underground rail line from Cheltenham to Broadmeadows and some of the most expensive components of underground railway construction are the stations.  The bigger the station, the higher the cost as the rule of thumb goes.

On the Metro Tunnel project, the five stations are enormous - in platform length in particular - to cater for lengthened trains. Upwards of 220 metres.

On KL's Line SBK Line 9 (Sungai Buloh-Kajang 9), trains are just as wide and each four-car train has a similar capacity as our standard metro trains in Melbourne (3-3.1m & 1,200 passengers per train) but with only four cars, the trains are shorter and therefore platform length requirements are shorter as well. The trains are 90 metres in length.

The enormous capacity of the comparatively short trains is achieved with longitudinal seating and wide, open gangways between carriages. The trains are also driverless, centrally controlled with platform screen doors at all stations.

The Andrews Government claims the SRL will enable trips from Cheltenham to the Airport in 45 minutes, and it's likely that the majority of trips on the line (should it be built) will be much shorter and minimal seating in longitudinal configuration - in order to create scalability over time - would likely be acceptable to most people given the line's purpose is to rapidly move people between lines and to the newly served employment, shopping and education precincts.

Food for thought.

Lead image credit: Bukit Bintang station, my-mrt.my