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.

Want more of this stuff? Follow CityMetric on Twitter or Facebook
 
 
 
 

How can we stop city breaks killing our cities?

This couple may look happy, but they’re destroying Barcelona. Image: Getty.

Can’t wait to pack your bags and head off on holiday again? It used to be that people would look forward to a long break in summer – but now tourists have got used to regular short breaks through the year. We love to jet off to the world’s glittering cities, even if only for a day or two. The trouble is, binge travelling may be killing the places we visit.

You may even have seen some “tourists go home” graffiti on your last trip, and it’s not hard to see why. Barcelona is a good example of how a city can groan under the weight of its popularity. It now has the busiest cruise port, and the second fastest growing airport in Europe. Walking through the Barcelona streets at peak season (which now never seems to end) flings you into a relentless stream of tourists. They fill the city’s hot spots in search of “authentic” tapas and sangria, and a bit of culture under the sun. The mayor has echoed residents’ concerns over the impact of tourism; a strategic plan has been put in place.

It is true though, that cities tend to start managing the impact of tourism only when it is already too late. It creeps up on them. Unlike visitors to purpose-built beach destinations and national parks, city-break tourists use the same infrastructure as the locals: existing systems start slowly to stretch at the seams. Business travellers, stag parties and museum visitors will all use existing leisure facilities.

‘Meet the friendly locals’, they said. Image: Sterling Ely/Flickrcreative commons.

Barcelona may only be the 59th largest city in the world, but it is the 12th most popular with international visitors. Compared to London or Paris, it is small, and tourism has spiked sharply since the 1992 Olympics rather than grown steadily as in other European favourites like Rome.

Growth is relentless. The UN World Tourism Organisation (UNWTO) even speaks about tourism as a right for all citizens, and citizens are increasingly exercising that right: from 1bn international travellers today, we will grow to 1.8bn by 2030, according to UNWTO forecasts.

Faced with this gathering storm, just who is tourism supposed to benefit? Travellers, cities, residents or the tourism industry?

Market forces

Managing the impact of tourism starts by changing the way destinations market themselves: once the tourists arrive, it’s too late. Tourism authorities need to understand that they are accountable to the city, not to the tourism industry. When the city of Barcelona commissioned the University of Surrey to look into how it might best promote sustainable development, we found a series of techniques which have been incorporated, at least in part, into the city’s 2020 Tourism Strategy.

In the simplest terms, the trick is to cajole tourists into city breaks which are far less of a burden on the urban infrastructure. In other words, normalising the consumption of sustainable tourism products and services. In Copenhagen, 70 per cent of the hotels are certified as sustainable and the municipal authority demands sustainability from its suppliers.

Higher than the sun. A primal scream from the world’s cities? Image: Josep Tomàs/Flickr/creative commons.

Destinations must also be accountable for the transport impact of their visitors. The marketing department might prefer a Japanese tourist to Barcelona because on average they will spend €40 more than a French tourist – according to unpublished data from the Barcelona Tourist Board – but the carbon footprint we collectively pay for is not taken into account.

Crucially, for the kind of city breaks we might enjoy in Barcelona, most of the carbon footprint from your holiday is from your transport. Short breaks therefore pollute more per night, and so destinations ought to be fighting tooth and nail to get you to stay longer. It seems like a win for tourists too: a few extra days in the Spanish sun, a more relaxing break, and all accompanied by the warm glow of self-satisfaction and a gold star for sustainability.


Destinations can also target customers that behave the most like locals. Japanese first-time visitors to Barcelona will crowd the Sagrada Familia cathedral, while most French tourists are repeat visitors that will spread out to lesser-known parts of the city. Reducing seasonality by emphasising activities that can be done in winter or at less crowded times, and geographically spreading tourism by improving less popular areas and communicating their particular charms can also help reduce pressure on hot spots, much like Amsterdam is doing.

Turnover is vanity, and profit margins are sanity. No city should smugly crow about the sheer volume of visitors through its gates. If tourism is here to stay, then the least cities can do is to sell products that will have the greatest benefit for society. Whether it’s Barcelona, Berlin, Bologna or Bognor, there should be a focus on locally and ethically produced products and services which residents are proud to sell. Tourist boards should work with small businesses that offer creative and original things to do and places to stay, adding breadth to the city’s offering.

The ConversationWhether Barcelona will introduce these ideas will depend on the bravery of politicians and buy-in from the powerful businesses which are happily making short-term profits at the expense of residents and the planet. It is possible to do things differently, and for everyone to benefit more. It may be that the tipping point lies in the age-old mechanics of supply and demand: bear that in mind next time you’re booking a quick city break that looks like it’s only adding to the problem.

Xavier Font is professor of marketing at the University of Surrey.

This article was originally published on The Conversation. Read the original article.