The West Coast Main Line

While the privatised railway network in Britain has made the network rather more complex to run, and also more complex for the passenger (sorry, customer) to navigate, privatisation has undoubtedly brought certain benefits to the network.

For one, I think that, if privatisation had not happened, it would be very unlikely that we would have Pendolinos thrashing up and down the West Coast Main Line (WCML) between London and Birmingham, and between London and Manchester, every 20 minutes. Clearly the clout of Virgin Trains in wanting to get one over on British Airways and BMI has led to a truly excellent service.

At least, an excellent service on paper.

Unfortunately, it's a bit of a squeeze trying to fit all those services in. The Virgin Trains services between London Euston and Rugby consist of three London-Birmingham services per hour, three London-Manchester services per hour, and one service each hour on London-Chester, London-Liverpool and London-Preston (with most of the Preston services extending to Glasgow). That's 9 trains every hour, in both directions, between London and Rugby.

There are also six London Midland services each hour running on various parts of the lines between London and Rugby, one Southern service an hour between East Croydon and Milton Keynes, and up to four freight trains per hour in each direction. That's about 20 trains per hour in each direction.

At this point, you might start to think that 40 trains per hour isn't that much for four tracks to handle. But capacity on railway lines is rather less than you might think it should be.

The basic principle is that trains have to be far enough apart to stop safely should the train in front crash. But when a train is travelling at 125mph, it takes over a mile to stop, which (unless the track is ramrod-straight) means you have no hope of seeing the train in front. So, over two centuries, signalling systems (a bit like traffic lights) have been developed to keep the trains far enough apart.

To cut a long story short, the absolute best you can hope for with trains going at 125mph is to be able to run them about three minutes apart, otherwise they end up seeing yellow signals and eventually red signals and have to stop.

When you build in some slack and allow for some of the trains stopping between London and Rugby, you end up with about 12 trains per hour on a given track if they're all going at roughly the same speed. If you've got slower freight trains to handle as well, you're looking at more like 8 or 9 per hour. So in fact, the 20 trains per hour in each direction between London and Rugby is very close to the theoretical capacity of the line.

So, what happens when you run all those trains and get close to the capacity of the line, day in, day out? What happens when things break? Well, as some of you may have noticed since the WCML was "finished" in December, when things go wrong, they go very, very wrong, because there's no slack.

This was demonstrated, all too publicly, in the first week of January; a light-aircraft crash at Colwich Junction combined with a number of faults in the overhead wires (possibly caused by the cold weather) led to a week of complete misery for passengers on the WCML. (See this BBC article and also those linked to by it.)

Indeed, as reported here by the BBC, the number of trains on time has actually gone down since the WCML upgrades were completed in December and the new timetable came in to force!

Importantly, however, the vast majority of the delays and faults are not the cause of the Train Operating Companies. They are the fault of Network Rail, who are responsible for maintenance. Too much emphasis was placed on upgrades rather than simply replacing old track, signals, and wires, and we are now paying the price for it.

What is to be done?

In the short term, Network Rail has pledged £50 million to improve the reliability of the line. But Network Rail have admitted (RAIL 621, p6) that one "reasonably-sized incident" is enough to knock punctuality for the day from near 100% down to around 70%, such is the number of trains that are affected by one incident. And I don't know how much £50 million will go to fixing that.

In the long term, however, there is almost no capacity for growth on the West Coast Main Line. Within ten or fifteen years the line will be completely full between London and Rugby.

The solution is high-speed rail, the main point of which is more capacity. Unfortunately, it's expensive and takes years to build.

I'll leave the details of high-speed rail for another blog post; to cut a long story short, we could have to put up with the WCML in its present form for decades to come.