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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Was the decline in Liverpool’s historic population really that unusual?

A view of Liverpool from Birkenhead. Image: Getty.

It is often reported that Liverpool’s population halved after the 1930s. But is this true? Or is it a myth?

Often, it’s simply assumed that it’s true. The end. Indeed, proud Londoner Lord Adonis – a leading proponent of the Liverpool-bypassing High Speed 2 railway, current chair of the National Infrastructure Commission, and generally a very influential person – stood on the stairs in Liverpool Town Hall in 2011 and said:

“The population of Liverpool has nearly halved in the last 50 years.”

This raises two questions. Firstly, did the population of the City of Liverpool really nearly halve in the 50 year period to 2011? That’s easy to check using this University of Portsmouth website – so I did just that (even though I knew he was wrong anyway). In 2011, the population of the City of Liverpool was 466,415. Fifty years earlier, in 1961, it was 737,637, which equates to a 37 per cent drop. Oops!

In fact, the City of Liverpool’s peak population was recorded in the 1931 Census as 846,302. Its lowest subsequent figure was recorded in the 2001 Census as 439,428 – which represents a 48 per cent decline from the peak population, over a 70 year period.

Compare this to the population figures for the similarly sized City of Manchester. Its peak population also recorded in the 1931 Census as 748,729, and its lowest subsequent figure was also recorded in the 2001 Census, as 392,830. This also represents a 48 per cent decline from the peak population, over the same 70 year period.

So, as can be seen here, Liverpool is not a special case at all. Which makes me wonder why it is often singled out or portrayed as exceptional in this regard, in the media and, indeed, by some badly briefed politicians. Even London has a similar story to tell, and it is told rather well in this recent article by a Londoner, for the Museum of London. (Editor’s note: It’s one of mine.)

This leads me onto the second question: where have all those people gone: London? The Moon? Mars?

Well, it turns out that the answer is bit boring and obvious actually: after World War 2, lots of people moved to the suburbs. You know: cars, commuter trains, slum clearance, the Blitz, all that stuff. In other words, Liverpool is just like many other places: after the war, this country experienced a depopulation bonanza.


So what form did this movement to the suburbs take, as far as Liverpool was concerned? Well, people moved and were moved to the suburbs of Greater Liverpool, in what are now the outer boroughs of the city region: Halton, Knowsley, St Helens, Sefton, Wirral. Others moved further, to Cheshire West & Chester, West Lancashire, Warrington, even nearby North Wales, as previously discussed here.

In common with many cities, indeed, Liverpool City Council actually built and owned large several ‘New Town’ council estates, to which they moved tens of thousands of people to from Liverpool’s inner districts: Winsford in Cheshire West (where comedian John Bishop grew up), Runcorn in Halton (where comedian John Bishop also grew up), Skelmersdale in West Lancashire, Kirkby in Knowsley. There is nothing unique or sinister here about Liverpool (apart from comedian John Bishop). This was common practice across the country – Indeed, it was central government policy – and resulted in about 160,000 people being ‘removed’ from the Liverpool local authority area.

Many other people also moved to the nearby suburbs of Greater Liverpool to private housing – another trend reflected across the country. It’s worth acknowledging, however, that cities across the world are subject to a level of ‘churn’ in population, whereby many people move out and many people move in, over time, too.

So how did those prominent images of derelict streets in the inner-city part of the City of Liverpool local authority area come about? For that, you have to blame the last Labour government’s over-zealous ‘Housing Market Renewal Initiative’ (HMRI) disaster – and the over enthusiastic participation of the then-Lib Dem controlled city council. On the promise of ‘free’ money from central government, the latter removed hundreds of people from their homes with a view to demolishing the Victorian terraces, and building new replacements. Many of these houses, in truth, were already fully modernised, owner-occupied houses within viable and longstanding communities, as can be seen here in Voelas Street, one of the famous Welsh Streets of Liverpool:

Voelas Street before HMRI implementation. Image: WelshStreets.co.uk.

The same picture after HMRI implementation Image: WelshStreets.co.uk. 

Nonetheless: the council bought the houses and ‘tinned them up’ ready for demolition. Then the coalition Conservative/Lib Dem government, elected in 2010, pulled the plug on the scheme. 

Fast forward to 2017 and many of the condemned houses have been renovated, in a process which is still ongoing. These are over-subscribed when they come to market, suggesting that the idea was never appropriate for Liverpool on that scale. 

At any rate, it turns out that the Liverpool metropolitan population is pretty much the same as it was at its peak in 1931 (depending where the local borough boundaries are arbitrarily drawn). It just begs the question: why are well educated and supposedly clever people misrepresenting the Liverpool metropolis, in particular, in this way so often? Surely they aren’t stupid are they?


And why are some people so determined to always isolate the City of Liverpool from its hinterland, while London is always described in terms of its whole urban area? It just confuses and undermines what would otherwise often be worthwhile comparisons and discussions. Or, to put it another way: “never, ever, compare apples with larger urban zones”.

In a recent Channel 4 documentary, for example, the well-known and respected journalist Michael Burke directly compared the forecast population growths, by 2039, of the City of Liverpool single local authority area against that of the combined 33 local authority areas of Greater London: 42,722 versus 2.187,708. I mean, what bizarre point is such an inappropriate comparison even trying to make? It is like comparing the projected growth of a normal sized-person’s head with the projected growth of the whole of an obese person, over a protracted period.

Having said all that, there is an important sensible conversation to be had as to why the populations of the Greater Liverpool metropolis and others haven’t grown as fast as maybe should have been the case, whilst, in recent times, the Greater London population has been burgeoning. But constantly pitching it as some sort of rare local apocalypse helps no one.

Dave Mail has declared himself CityMetric’s Liverpool City Region correspondent. He will be updating us on the brave new world of Liverpool City Region, mostly monthly, in ‘E-mail from Liverpool City Region’ and he is on twitter @davemail2017.