When an Amtrak train careened off the tracks in Philadelphia this week, it raised a host of questions over railroad safety.
As U.S. politicians trade blows over issues of funding and accountability, they could also look at what they can learn from railway safety systems in Europe.
What systems are in place in Europe?
Most countries across Europe have their own rail safety measures, according to Chris Jackson, editor of Railway Gazette International, but there are three basic systems in place.
• Automatic warning system (AWS): In this case, a ramp or magnet on the track sounds an alarm in the driver’s cabin if it calculates that the driver is going too fast. If the driver doesn’t acknowledge the alarm, it triggers an emergency brake. This is primarily used for signals — for example, red lights ahead — and for speed restrictions.
• Automatic train protection (ATP): This works out what the safe speed of a train should be at any time. If the train is going too fast, it will intervene and trigger a brake. On high-speed lines in Europe — anyplace above 125 mph — the ATP system is monitoring the train all the time through radio or cable. If the train is not on a high-speed line, it can be monitored intermittently or continuously. This system is more sophisticated than the automatic warning system.
• The European Train Control System (ETCS): Work is well underway to introduce a pan-European standard across the continent. This system is essentially a more sophisticated form of the ATP.
How does ETCS work?
The ETCS project was launched 20 years ago because sending trains over European borders was difficult due to the different signaling systems in place in different countries. The system has been used on some lines for 10 years, in other countries it’s still in a test phase.
What makes it stand out is that it doesn’t just repeat what the signals are saying, as the ATP does, but gives the driver the geometry and the line conditions for the next 4 or 5 miles of track on his or her display system, said Jackson.
How is the transition going?
Spain suffered its deadliest rail accident in years July 24, 2013, when a passenger train derailed on a curve near the northwest city of Santiago de Compostela. In addition to 79 fatalities, some 170 passengers were injured.
The train was traveling at nearly twice the speed limit when it came off the tracks.
Investigations pointed to driver error, which observers suggest was compounded by the fact that Spain was operating two rail safety systems.
The route the train was following, from Madrid to Ferrol, had a mix of conventional and high-speed track, with the latter allowing high-speed trains to travel at over 200 kilometers per hour (124 mph.) The section on which the accident occurred was not configured as high-speed track.
According to Jackson, Spain hadn’t finished building the line for high speed, apparently because it had run out of money. So the conventional track was temporary, with a temporary sharp curve in it. Moreover, while the high speed section had ETCS, the Spanish rail operators hadn’t worked out how to put that system on this temporary stretch of the track, so it was operating on an older system known as ASFA.
“So: You have a high-speed train, operating on a track which is not purposed for high-speed trains, with no high-speed train signaling/warning system in place, and then you add a sharp curve into the equation. Thus the crash,” Jackson said.
Since the crash, Spain has set up a working group to identify other potential hot spots in order to rectify this problem, he added.
How does the Santiago disaster compare with the Amtrak crash?
There are certainly striking similarities.
Investigations into the Philadelphia crash are still in their early stages, but in each case, a train derailed with a tragic loss of life after going far too fast into a bend.
The United States also is going through a process similar to Europe’s, in that it is moving from traditional signaling to a continuous communications-based train protection system, said Jackson.
Many questions in the aftermath of the Amtrak crash have focused on why that newer, automated speed-control system, called positive train control, was not already in place on that northbound section of the line that runs between Washington and New York.
Positive train control has been in place for years for southbound trains entering that curve because they are coming from a higher-speed section of track, an Amtrak official said. But the speed limit on the northbound stretch approaching the bend is 80 mph, so it wasn’t judged necessary to install the system there.
Investigators don’t know yet what caused the train that crashed to accelerate to more than 100 mph as it approached the curve heading north, with no automated system to prevent it.
But Robert Sumwalt, a board member of the U.S. National Transportation Safety Board, told reporters: “We feel that had such a system been installed in this section of track, this accident would not have occurred.”
How does Britain keep rail travelers safe?
The United Kingdom only has ETCS in parts of Wales but it is being trialed between Hitchin and Hertford, north of London, on a test track, said Jackson.
In any case, Britain already has quite an advanced safety system in place, called the Train Protection and Warning System — TPWS.
This was introduced after a deadly rail crash in 1999, said Sim Harris, managing editor of UK-based website Railnews, and is “pretty universal” in Britain.
How the system works: there is a grid in the track between the rails, which contacts receptors wirelessly on the train above. If it detects the train is going too fast on an approach to a curve, red signal or platform, it warns the driver. After a few seconds if the driver doesn’t brake, “it brakes it for him, taking the train down to a safe speed,” he said.
The Amtrak train was traveling at 106 mph as it entered a curve with a speed limit of 50 mph, according to preliminary information from the NTSB. The TPWS system means that “in Britain you couldn’t do that,” said Harris.