Rayleigh Waves and HS2

Several recent news items have discussed the risks to HS2 and the surrounding areas posed by Rayleigh Waves.

These include the Telegraph – High speed rail link ‘at risk of derailment’ because of 225mph trains, the Herald Scotland – High-speed train safety questioned, the Express and Star – Derailment fears over high speed rail scheme and the Oxford Mail Expert warns of HS2 danger.

Rayleigh Waves were first brought up a couple of days after HS2 was originally announced, in 2010, when Peter Woodward, of Herriott-Watt University in Edinburgh, spoke to The Engineer.

According to Woodward, it is most critical to look at the increasing forces and vibrations induced in the track as a train’s speed picks up. ‘A point can be reached whereby a ground wave starts to develop ahead of the train,’ he said. ‘The analogy is that of an aircraft going through the sound barrier.’

These Rayleigh Waves were first predicted in 1885, and have been studied in connection with seismic activity.

In 2000, academics in Nottingham published an article called Rail movement and ground waves caused by high-speed trains approaching track-soil critical velocities in the Journal of Rail and Rapid Transit. The abstract for the paper says

“The obtained theoretical results are illustrated by numerical calculations for TGV and Eurostar high-speed trains travelling along typical tracks built on soft soil.”

As well as the academic articles, David Rayney, submitted evidence to the Transport Select Committee inquiry into High Speed Rail last year – The Application and Effect of the Rayleigh Wave Speed Principle on High Speed Rail travel.

This was followed up by FOI requests, which showed even as late as December 2011 HS2 Ltd were saying

“HS2 Ltd has not at this stage carried out any detailed assessment of possible Rayleigh Wave effects, or any other static or dynamic loading conditions on its potential high speed route sections.

Yesterday, we posted a list of consultant costs which Justine Greening gave as a written answer to Steve Baker MP: these did not include the £500,000 research grant awarded to Prof Woodward and colleagues for research into HS2 and Rayleigh Waves. FOI requests about this research have been refused.

The main HS2 consultation document says on p19

“The focus has been on developing proposals for a safe and reliable railway, using proven European standards, technology and practice.

It’s clear that this statement was misleading, because just as sonic booms are only an issue for the fastest aircraft, rayleigh waves are only an issue when train speeds get above a certain speed (which is different depending on the ground conditions).

HS2 Ltd needs to have HS2 running at speeds faster then most current high speed trains to get the economic case to stack up.

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11 comments on “Rayleigh Waves and HS2
  1. This is nonense. The French have tested the TGV ub to 515kph without difficulty. As speeds get faster adhesion does get more problematic and braking distances are corresponding longer, but the problem could be sorted oyt quite easily with mobile blocks.

    But would be to build HS2 as a maglev line, and in a partially evacuauted tube one would be thinking of speeds for 1000-1000mph or more.

    An evacuated tube from London to Birmingam would not be difficult to dig. It need not be very deep so would go mainly through subsoil or soft rock. An optimised straightened line running underneath the motorways and existing railways would almost do away with the the need for planning permission as no surface land-take would be required.

    Dig 4 pits at 40 mile intervals along the rooute, placing the first one at about Uxbidge. Drop two TBMs in each pit one pointing north and the other south. Set them digging and when they’re going they grind out about half a mile of tunnel a week. Double it as we’ll neeed two tunnels. In less than two years after starting the northen and southern ends of each hole will meet up and you’ve got your tunnel.

    Place a metal plate on the floor of the tunnel, wire it up and put in a maglev train – Birmingham Airport used to have one yonks ago, so its proven technology. Make the train neraly fit the tunnel and the piston effect can be used to evacuate the tunnel as it passes.

    We’ll need to do s bit of working on docking the “train” at the northern and southern termini, but it isn’t really problematic. The train would have to sealed as the tunnels essentially a vacuum.

    And you’ve got your up to date train system for the 24th century and beyond.

    Now no jokes about the wrong sort of snow on the line.

    • im not sure that your claims are based on knowledge of the subject or understanding. You speak of trains operating along underground tunnels at over 1000mph the full length between London-Birmingham-Leeds and Manchester and then up to Scotland? You forget the health and safety requirements of such as silly suggestion and the need for escape points in the event of accident. You suggest that this is proven technology and state that the small short length of people mover that operated at Birmingham as being an example?

      Any thoughts on how substantially more cost this would be in a fantasy world that it was possible?

      At least you seem to agree that there is a need for a new type of fast train technology and that there is a future demand for it.

      • The Zefiro 380 hasn’t be made yet. It comes to China in 2012 at the earliest. This is just the 380a train. It’s lalced the 380a because it can attain a safe maximum operating speed of 380km. It probably can go faster since that is the maximum SAFE operating limit.The 380a is going to put on the Beijing-Shanghai high speed rail. That is the longest high speed rail by far. It is a very challenging engineering project. No high speed train so far can travel nonstop at such distances. How would you power it?

  2. I find it very disturbing that there is no transparency around this issue when the public could be at risk. They should come clean and explain what reasearch is being undertaking and any mitigation being considered. I’m glad it’s appeared in the press this sort of thing should be highlighted.

  3. the media are interested in sensationalism as that sells papers so hardly surprising that they are reporting it. but lets investigate this theory and when it is shown to be just a theory then that will be yet another hs2 myth disproved. why has no-one else mentioned it ? how come sncf havent noticed this, they have had several test trains running at well over 400 kph and the tracks didnt spread or move under the trains ?

  4. It’s everywhere in the media questioning about the safety of HS2. The Government continue to hide facts and not disclose anything to public for anything not in their favour. If Justine Greening and David Cameron both shoe some guts and accountabilitu, they should say “Yep we approve it and if there is any safety issue causing damage to lives, we both will go to jail”. Unless they do that, they ate basically hiding crucial facts and endanger the citizens.

    • @Elaine Luk: “It’s everywhere in the media questioning about the safety of HS2″

      Really – one article has appeared in The Telegraph by Andrew Gilligan, a reporter well known for his visceral hostility to the HS2 project. A synopsis of that article has in turn been syndicated across a number of local titles, virtually all of them in areas close to the route of HS2 – the only other articles are those like this one regurgitated on anti-HS2 campaign websites – so hardly “everywhere in the media” – in fact the entire furore revolves around a single article of dubious validity?

      Telegraph articles of this nature are routinely enabled for reader comments but for some reason the article in question lacked this feature – one wonders why? The Gilligan article is blatant scaremongering of worst possible kind – if the anti-HS2 campaign has now sunk to this level it really is in big trouble.

      High Speed Trains already run at the speeds quoted in the article; 360km/h or 225mph. Any cursory search for information about High Speed Trains operating in Europe will reveal that they are amongst the safest in the world – much safer in comparison to conventional classic line technology trainsets. There hasn’t been a single fatality on any TGV train operating on a purpose built (complying with the exact same standards as that applying to HS2 construction) High Speed Line (LGV) since the first service ran between Lyon and Paris in 1981.

      If you really want evidence to prove how safe these trains are, check out details of the High Speed Derailment on at kilometre post 110.5, LGV Nord (Paris-Lille) high speed line, 21st December 1993.

      At 0706, TGV 7150 was bearing down at 294 km/h (182 mph) on a muddy hole 7 metres long by 4 metres wide and 1.5 metres deep, bridged by a section of unsupported track. The engineer felt a slight bump and made a service brake application. The last four trailers and the rear power unit derailed, and the train came to a rocky stop over a distance of 2.3 kilometres (somewhat less than it takes for a conventional emergency stop). It was fortunate that the train did not jackknife or leave the track bed; this is credited in part to the stiffness that the articulated design lends to the train. Only one passenger was injured, and another treated for shock.

      The Gilligan article takes one piece of information; that research into a theoretically potential design flaw already known to experts in the field is ongoing and blows it up into a story designed with a single purpose in mind; to ignite a flame of panic in the public mindset – this is scurrilous journalism of the lowest possible order and deserves nothing but utter contempt.

      • Peter, it’s a shame you jumped to conclusions about the problems with Rayleigh Waves and HS2 without reading our article and following the links to more information. Like we said, Rayleigh Waves have been brought up in connection with HS2, since a couple of days after the HS2 announcement in 2010. They were brought up during the Transport Select Committee inquiry in 2011, and have been the subject of FOI requests last year.

        If you don’t like the Telegraph article, you might get better results if you complain directly to the Telegraph editorial team.

        With regards to the high speed derailment in 1993, Rayleigh Waves weren’t involved in that.

      • I would pose the question – If the Gov is so confident that this is not an issue why is research not being made freely avaialble?

        • The research is generally applicable and not exclusively for HS2. The ESPRC website gives the details at http://gow.epsrc.ac.uk/NGBOViewGrant.aspx?GrantRef=EP/H027262/1.

          You will see that when the Telegraph stated “Professor Woodward, … and a colleague, Prof Mike Forde of Edinburgh University, have now been awarded almost £500,000 by the Government to investigate the issue” it should read “Professor Woodward, … and a colleague, Prof Mike Forde of Edinburgh University, were awarded almost £500,000 two years ago by the Government to investigate the issue” (£334,485 + £145,325 totalling £479,810 to be precise).

          The research programme does not end until May 2013 so why should work in progress be made freely available – would a painter exhibit a portrait before it was finished? There is overall no real secrecy – this is old news regurgitated by the Telegraph in a sensationalist way and (very sensibly) not wanting to discuss the work with a journalist does not make the work ‘secret’!

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