Original URL: http://www.theregister.co.uk/2009/12/22/eurostar_eurotunnel_fiasco/

Can anyone explain the chunnel fiasco?

Five trains in, none out

By Chris Mellor

Posted in Science, 22nd December 2009 07:02 GMT

Comment During the weekend channel tunnel fiasco, Eurostar sent five trains into the tunnel and not one came out. Only then did it stop sending trains.

Okay. Imagine you're Eurostar's fat controller in charge of despatching trains. Two have gone into the tunnel and not come out. Do you send in trains number three, four, and five?

Not unless you're a blithering idiot or you simply don't know they're stuck in the tunnel. Let's give Eurostar HR department the benefit of the doubt and assume it doesn't employ blithering idiots. Why then did train number three get a green signal to enter the tunnel?

Next, with three trains stuck in the tunnel, why did train number four get a green light? And if it is beggaring belief that train number four got a green light for tunnel entry, how in the name of the all-seeing being did train number five get one?

There can only be one answer: Eurostar operates blind when trains are in the tunnel. The tunnel operator, Eurotunnel, is in charge of controlling trains in the tunnel, not Eurostar. Either it did not tell Eurostar fast enough, so that Eurostar could hold up trains before they entered the tunnel, or it didn't put up its own red signal at the tunnel entrance.

There are four main questions that need answering. Why did the trains fail? Why did five trains stall in the tunnel instead of just one? Why were passenger communications so bad? and why did it take so long to extract the stalled trains?

Chunnel signalling

The French part of the Eurostar network is operated by the French national railway operator, SNCF. The UK side's infrastructure and stations is operated by Eurostar (UK) Ltd (EUKL), a subsidiary of London and Continental Railways (LCR), which actually owns the high-speed infrastructure and stations on the British side.

It would appear that a Eurostar train from France to London travels on an SNCF infrastructure to the channel tunnel station, Eurotunnel's tunnel, and then on LCR infrastructure to London. That's three separate operators with the first and third actually forming part of Eurostar.

The basic principle of railway operation is that a track is divided into sections by signals. A train travelling on the track enters a section by seeing a green signal light. If it then sees a red signal light at the end of that section, it stops. The track operator detects that it has not passed that signal and sets the preceding signal red so as to stop a second train entering the section and running into the first train.

We know five trains entered the tunnel at Coquelles in France and stopped, with none coming out at Cheriton, near Folkstone, in England. Ergo, there must be at least five signal-delimited sections of track underneath the English Channel. In fact there are lots, as the more blocks there are in a section of track, the more trains can pass along it a given time.

Jonathan Groves, MD of Groves Systems, a railway signalling consultancy, says that the chunnel, with its 31.4 miles of track, could take possibly as many as fifty to sixty trains before all the track blocks had trains on them and do so "in complete safety." He says that there is an RCC (Railway Control Centre) at the Cheriton chunnel station in England which controls all rail movements through the tunnel.

It has a wall-sized display screen, "with about 3m LEDs," and thought to be the world's largest LED control panel, that shows the chunnel track and blocks, and the trains in the chunnel. With this, Groves says: "The RCC operators would have been able to see all the trains in the tunnel."

What is clear then is that unless there was an RCC failure, Eurotunnel knew trains were backing up in the tunnel but only stopped trains entering the tunnel after five had got stuck. Given the length of time it then took to get the stalled trains out of the tunnel - sixteen hours or more - that was a dreadful mistake.

Eurotunnel also could have told stalled train drivers that they were stuck and would be until their trains were extracted from the chunnel - and how long such extractions would take. Judging by passenger reports drivers did not give this information to passengers, and we can assume that Eurotunnel did not give the information to the drivers and other train staff.

The wrong sort of snow

According to a Eurotunnel spokesperson, there was an excessive amount of "fluffy snow" in France and shields installed every winter to prevent snow build-up failed. The trains went from cold and snowy northern France into the relatively warm tunnel and the accumulated snow melted, shorting out the electrical systems. The combined temperature, snow type, and humidity in northern Feance and the tunnel were exceptional - that means untested in system testing terms - and so the trains failed.

Update: The tunnel is pressurised so as to help combat any fire. The positive pressure is designed to push any fire away from the train. The pressured air can be cold or warm and Eurotunnel chose warm air. That meant the cold trains Eurostar trains with their accumulated snow met a warm air breeze as they entered and travelled through the tunnel, which melted the snow.

This was not a unique event; it had happened before in 2003 and also in 1995. Any measures Eurostar took then, if any, were ineffective this time around the block.

Modified shields have now been developed and are being tested to enable Eurostar operation through the tunnel to be restarted. The UK's met office has suggested that the fluffy snow explanation is untenable because its data doesn't indicate fluffier snow was falling in France. PR fluff, in other words

The initial cause of the fiasco was that Eurostar trains were inadequately shielded against snow and melted snow shorted out the electrical systems driving the train. This is a train system design and test error.

Stalled train extraction

Chunnel trains are driven by electricity. Stalled electric trains are extracted by diesel locomotives - Eurotunnel Class 0001 and Class 0031 units.

Our information (thanks Wikipedia) is that the stalled 18:59 Brussels-London (9157) service was towed to St Pancras by one of Eurotunnel's diesel locos. Its St Pancras arrival was 3 hours and 49 minutes late, meaning its diesel rescue locomotive was not able to rescue other stalled trains until it got back to Cheriton.

The 18:43 Paris–London (9053) service had its 700 passengers put on an empty Eurotunnel shuttle train, after being evacuated via a service tunnel, and they were then taken to Ashford International station up the line. The stalled Eurostar train though was still in the tunnel.

The 19:13 Paris–London (9055) service was connected to another Eurostar train behind it and the two were extracted by diesel loco and then continued to London.

The fifth train, a 19:37 Disneyland–London (9057) service, had its 664 passengers also evacuated via service tunnel to an empty Eurotunnel shuttle train and taken back to France.

So we had extraction of three trains by diesel loco and two by electrically-operated Eurotunnel shuttle trains leaving the two stalled Eurostars in the tunnel.

This sequence of events says that Eurotunnel only had two diesel rescue locomotives in operation and one spent four hours or more towing one of the failed Eurostars to London St Pancras and returning to Cheriton. The other towed out two of the stuck Eurostars and their passengers, leaving the remaining passengers needing service tunnel evacuation and Eurotunnel shuttle extraction to Ashford or back to France.

The conclusion is that there aren't enough diesel rescue locomotives. Sending the first off to St Pancras was a huge mistake, as it condemned the remaining trains and their passengers to an even longer wait before rescue. This is a Eurotunnel stalled train extraction process error.

Passenger communications

We know that there is a cab signalling system in the tunnel which is used to give information directly to train drivers on a display. That means the communications route was there for the train staff to be kept informed about what was going on and then tell passengers and start the emergency tunnel train failure process - only there was no emergency process for this situation, and according to passenger reports, the Eurostar train staff were inadequate, with off-duty policemen comforting passengers and devising their own evacuation procedures. Indeed, one driver reportedly locked himself in his cab.

Train operating procedures say emergency doors should not be opened in the tunnel when a train is stalled. There were inadequate toilet facilities. And power turned was off, so that passengers were left in darkness with no air-conditioning to prevent temperatures climbing to uncomfortable levels. There were no emergency food and water supplies either.

Since Eurotunnel are in charge of communications to trains in this situation this looks like a Eurotunnel communications failure as well as a Eurostar staff and operating procedures failure.

This indicates a failure of train staff and operating procedures to cope with the situation, which is another Eurostar responsibility.

Multiple Eurostar and Eurotunnel failures

The weekend fiasco which affected 2,000 or more passengers and knock-on delays affecting more than 100,000 passengers look to be the result of inept Eurostar train shielding, staff training, and train provisioning for multi-hour stays in the tunnel, and inadequate Eurotunnel rescue locomotive resources coupled with an inexplicably bad-seeming decision to send one of them all the way to London. Eurotunnel also did not react fast enough in closing the French entrance to the tunnel, given the delays in extracting stalled trains and passengers.

Lastly, there was a breakdown in communications with passengers on the stuck trains and it is blindingly obvious that the scenario of trains being stuck in the tunnel for many hours has never been adequately tested by Eurotunnel and Eurostar. Both organisations deserve whole heaps of opprobrium for such a gross failure.

Bring on the public enquiries. ®