How did a single computer failure take out the whole of the Melbourne rail network?

Going nowhere fast. Image: Marcus Wong/Wikipedia Commons.

If you don’t live in Australia, then your only experience of Metro Trains Melbourne is probably the ghoulishly jolly Dumb Ways To Die animated clip that went viral in 2012. But, as the clip loosely implies, the group operates one of the southern hemisphere’s largest metro rail networks.

Or, if you were trying to travel Down Under this Thursday, it turned out that they didn’t. A reported computer failure first led to massive delays on the whole system, and eventually to the entire central part of the city’s network being brought to a total halt for several hours.

With thousands of commuters stuck in trains, drivers and guards pleaded with passengers not to force the train doors and escape into the danger of the tunnels (possibly via jolly songs). A desperate Twitter user held a poll on whether he should answer a call of nature through the emergency door; naturally Australia backed him with an 84 per cent Yes vote.

Train failures happen everywhere: signal failures, track failures, accidents, and incidents of all kinds are common annoyances for commuters. But the whole network collapsing due to a computer error seems a bit much: could they not just turn it off and start again…?

Basically, no.

The biggest problem here is that Melbourne has a single underground loop line that links all its suburban tracks together. It’s a bit like London Underground’s Circle/District/Metropolitan/Hammersmith lines, with the crucial difference that almost all Melbourne’s suburban trains go at least partially round the loop – there’s no other route through the city. Even the city’s two terminus stations, Southern Cross and Finders Street, form part of the city loop, and many terminating services share signalling systems with loop trains.

A schematic of the Melbourne city loop. Source: Wikipedia.

Like many rail systems, Melbourne’s was randomly constructed by private companies out for a cheap buck, with no interest in interconnected metro or in buying up expensive city blocks to build through-lines. The city’s flat, swampy land also put everyone off tunnelling.

A lot of mergers and some nationalisation later, the system found itself feeding into two main terminals, both overcrowded. By 1969, transport planners decided that this wouldn’t do, and planned the City Loop.

Planners love joining up suburban lines with a tunnel through the city. You replace two busy, land-scarce, crowded terminals with through stations, serve major city destinations directly, and only have to turn trains around in the sticks. The RER in Paris, London’s Thameslink and Crossrail, and Berlin’s HBF all work on this principle.

But Melbourne’s planners were… braver.

Remember, every train into Melbourne already went into either Southern Cross (then called Spencer Street) or Flinders Street. Building the loop wasn’t like building Crossrail: it was like building a mash-up of Crossrail, Thameslink and the Overground to carry every single train that previously used to go into a London terminus.


The planners rose to the challenge: the number of tracks on the circle varies from two to six (originally planned as four to eight). But the net result was to create a complicated service with a lot of junctions and crossovers, which needs to carry lots of trains.

They had a clever solution to the complexity, too: they built one of the world’s first computerised railways. The City Loop opened in 1980 with fully automated signalling, using a dedicated system called Metrol, which allowed faster, more reliable switching, signaller and passenger information. When it opened, this was a state of the art system.

The trouble is, almost 40 years and some privatisation later, franchise operator Metro Trains Melbourne and government infrastructure owner Public Transport Victoria are still using it.

The brains of the system have been moved from the original ancient PDP-11 mainframes to a network of PC servers, and some modern train control systems have been added; but it’s still based around 40-year-old software, and the interface between the new computers and the tracks and signals still relies on 40-year-old interface boards. Metro Trains has to acquire replacements on the second-hand market as other companies retire their old servers.

Using old equipment isn’t rare in transport. New York’s still running on kit that was 40 years old when Metrol was installed, and the systems being removed in London are even older. Although the dreaded ‘signal failure’ is a common reason for scraping along at snail’s pace, they don’t halt the whole system.

But… well, have you tried watching an analogue versus a digital TV with a bad signal? Old-style train control systems are dumb, often fail, and are designed for the failures to be local and worked around. When newer-style train control systems fail, because the brains are centralised, so is the crash. More recent ones are designed to route around these problems, but Melbourne led the way and paid the price.

The complete system map. Click to expand. Image: Melbourne Metro.

Worse still, in other major cities, if a signal failure takes out one line, then you’ve still got a bunch of other lines to use. The City Loop means you can’t do that in Melbourne: if you lose signalling here, then every train line in the city is stuffed. Although the Metrol system only covers the City Loop and a few neighbouring inner suburban stations, you can’t run trains in the suburbs if they’re stuck on the wrong side of the city.

So what can Melbourne do? Replacing Metrol is often discussed, but would be painfully expensive, especially in terms of the disruption caused – and more recently, modern information systems have been built on top of it, which you’d have to fit in with the replacement.

The government are also starting work on a new tunnelled line through the CBD that's completely independent from the loop, which will help take some of the pressure off services – but even when it’s done, most city lines will still be subject to the same problems.

If I were Public Transport Victoria or Metro Trains, as the old joke says, I wouldn’t want to be starting from here.

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Barcelona’s car-free “superblocks” could extend lives. So will they catch on elsewhere?

Barcelona. Image: Getty.

The world’s biggest cities have larger populations and higher economic outputs than some countries. But as they grow in size and complexity, cities are also facing thorny challenges that threaten the health and happiness of residents. Congestion, pollution and a lack of community spaces have become major drags on people’s aspirations and experiences of urban living.

In response, cities must manage their resources and priorities to create sustainable places for visitors and residents, and foster innovation and growth. Enter Barcelona – the capital of Catalonia, in Spain – where a bold stroke of urban planning first introduced “superblocks” in 2016.

Image: ISGlobal/FAL.

Superblocks are neighbourhoods of nine blocks, where traffic is restricted to major roads around the outside, opening up entire groups of streets to pedestrians and cyclists. The aim is to reduce pollution from vehicles, and give residents much-needed relief from noise pollution. They are designed to create more open space for citizens to meet, talk and do activities.


Health and well-being boost

There are currently only six superblocks in operation, including the first, most prominent one in Eixample. Reports suggest that – despite some early push back – the change has been broadly welcomed by residents, and the long-term benefits could be considerable.

A recent study carried out by the Barcelona Institute for Global Health estimates that if, as planned, 503 potential superblocks are realised across the city, journeys by private vehicle would fall by 230,000 a week, as people switch to public transport, walking or cycling.

The research suggests this would significantly improve air quality and noise levels on the car-free streets: ambient levels of nitrogen dioxide (NO₂) would be reduced by a quarter, bringing levels in line with recommendations from the World Health Organisation (WHO).

The plan is also expected to generate significant health benefits for residents. The study estimates that as many as 667 premature deaths from air pollution, noise and heat could be prevented each year. More green spaces will encourage people to get outdoors and lead a more active lifestyle.

This, in turn, helps to reduce obesity and diabetes and ease pressure on health services. The researchers claim that residents of Barcelona could expect to live an extra 200 days thanks to the cumulative health benefits, if the idea is rolled out across the city.

Space to play. Imag: Mosa Moseneke/Unsplash.

There are expected to be benefits to mental health, as well as physical health. Having access to such spaces can stave off loneliness and isolation – especially among elderly residents – as communities form stronger bonds and become more resilient.

Stumbling blocks

It was Salvador Rueda, director of the Urban Ecology Agency of Barcelona, who first championed the introduction of superblocks – and he argues that the idea could be used in any city. Even so, authorities looking to expand the concept in Barcelona or beyond will need to be mindful of some concerns.

Changes like these require capital investment. Even as the car-free streets are transformed with urban furniture and greenery, the remaining major roads will likely have to accommodate heavier traffic.

Nothing comes for free. Image: Zvileve/Flickr/creative commons.

Further investments in local infrastructure – such as improving surrounding roads to deal with more traffic, or installing smart traffic management system – could be required to prevent serious congestion. Then the question remains, how to finance such investments – a higher tax rate is unlikely to be popular.


What’s more, whenever a location becomes more desirable, it leads to an increase in property demand. Higher prices and rent could create pockets of unaffordable neighbourhoods. This may lead to use of properties for investment purposes and possibly, displacement of local residents.

It’s also worth noting that Barcelona is an old and relatively well-planned European city. Different challenges exist in emerging global cities across Asia, Africa and Latin America – and in younger cities in the US and Australia. There is a great deal of variation in scale, population density, urban shape and form, development patterns and institutional frameworks across the cities. Several large cities in the developing world are heavily congested with uncontrolled, unregulated developments and weak regulatory frameworks.

Replicating what’s been done in Barcelona may prove difficult in such places, and will require much greater transformations. But it’s true that the basic principles of superblocks – that value pedestrians, cyclists and high quality public spaces over motor vehicles – can be applied in any city, with some adjustments.

Leading the way

Over the history of human civilisation, great cities have been at the forefront of innovation and social progress. But cities need a robust structure of governance, which is transparent and accountable, to ensure a fair and efficient use of resources. Imposing innovation from the top down, without consultations and buy-in, can go squarely against the idea of free market capitalism, which has been a predominant force for modern economies and can lead push-back from citizens and local businesses.

Citizens must also be willing to change their perspectives and behaviour, to make such initiatives work. This means that “solutions” to urban living like superblocks need to have buy-in from citizens, through continuous engagement with local government officials.

A man speaks at a public consultation on the Eixample superblock in Barcelona. Image: Ajuntament Barcelona/Flickr/creative commons.

Successful urban planning also needs strong leadership with a clear and consistent vision of the future, and a roadmap of how that vision can be delivered. The vision should be co-developed with the citizens and all other stakeholders such as local businesses, private and public organisations. This can ensure that everybody shares ownership and takes responsibility for the success of local initiatives.

There is little doubt that the principles and objectives of superblocks are sound. The idea has the potential to catch on around the world – though it will likely take a unique and specific form in every city.

The Conversation

Anupam Nanda, Professor of Urban Economics and Real Estate, University of Reading.

This article is republished from The Conversation under a Creative Commons license. Read the original article.