Gladiatorial games, part 23

(… continued from Gladiatorial games, part 22, posted on 18 Apr 2016).

Rick Methold, the expert acoustics witness appearing before the HS2 Select Committee for Chiltern District Council (CDC), summarised the data in the table that he presented as his exhibit A1571(37) by taking the “net change” total for each of the three rows – that is the total of dwellings suffering an increase in noise of more than 3dB, less the number of dwellings enjoying a noise decrease of more than 3dB. These totals reveal that the Environmental Statement (ES) for HS2 has a net change total of 1407 dwellings, significantly more than the 312 identified in the ES for HS1, which was reduced to 75 after further mitigation had been secured (see footnote 1).

I have to say that I’m not entirely happy with the concept of taking the net increase total; it seems to me that you can’t cancel out one person’s noise increase by another’s noise decrease. I would rather see the increases and decreases totalled separately. Whilst this reduces the disparity between HS1 and HS2 in terms of those suffering a noise increase, it seems a fairer comparison to my mind.

What Mr Methold pointed out to the Committee, however, was that, comparing the assessments in the Environmental Statements on his “net change” basis, HS2 has twice the noise change impacts per route kilometre than HS1 – if you consider just those dwellings suffering a noise increase of more than 3dB, this ratio comes down to one and a third times. He also made the, to my mind somewhat unfair, comparison that the ES HS2 assessment has seven times the noise change impacts per route kilometre than the fully-mitigated HS1.

It is usually good advice if you want to pep up a presentation, to show your audience a multi-coloured pie chart, and Mr Methold did not disappoint by revealing A1571(39) at this stage. This exhibit merely presents the data in the A1571(37) table graphically, but does allow the relative severity of the noise impacts to be appreciated.

Mr Methold pointed out to the Committee that “41% of the noise change impacts on High Speed 1 were reductions” – again he is referring to the fully-mitigated version of HS1 here, the ES figure is 24 per cent. However, whichever of these two figures you take for comparison purposes, HS2 is not in the same league, with only 1 per cent of dwellings expected to see a significant noise reduction. This reflects the extensive use made of existing transportation corridors for the HS1 route – hardly a feature of the HS2 design – and I doubt that further mitigation of HS2, as currently planned, will do much to change this unfavourable comparison.

Exhibit A1571(39) also demonstrates that the noise increases suffered along the HS2 route are expected to be much more severe than HS1 residents encountered. Mr Methold pointed out that “10% of High Speed 2’s impacts are greater than 10 dB increases being compared to 1% for High Speed 1”. He also claimed that “46% of High Speed 2 impacts are greater than 5 dB increases, whereas only 5% was for High Speed 1”. Whilst I have some minor quibbles with Mr Methold’s numbers – I make it 9 per cent greater than 10dB and 45 per cent greater than 5dB for HS2, and would use the ES figures for HS1, increasing the HS1 total above 5dB increase to 8 per cent – I cannot disagree with Mr Methold’s conclusion that there is “a very, very different distribution in the severity of … noise impacts” between HS1 and HS2 (see footnote 2).

Neither would I disagree with the way he summarised his case (see footnote 3):

“… overall the scheme wide predictive effects [for HS2] are considerably worse than HS1, on this analysis, and that is despite HS2 being required to adhere, under national policy, to [mitigate] non-significant adverse effects. We can see that there is considerably lower proportions of noise reductions on High Speed 2, and this we set against other high risk unknowns that we know about High Speed 2.”

Committee Member, Mark Hendrick MP, commented to Mr Methold that it seemed “obvious that a high speed train, like HS2 is going to be noisier than HS1”, and this meant that “the mitigation will need to be that much stronger”. He is, of course, correct on both counts; the problem is that the evidence that we have seen during the Select Committee hearings is that HS2 Ltd is not inclined to offer “strong” mitigation, and, by ignoring all noise increases where the HS2 noise contribution is below LOAEL, is also understating the severity of the problem. It is disappointing that Mr Hendrick appears to have forgotten his observation when it came to writing the Select Committee’s final report (see footnote 4).

Before finally putting this issue of the differences between HS1 and HS2 to bed, Mr Methold tackled the twin arguments that had been advanced by HS2 Ltd, based upon experience of HS1, that noise from HS1 trains has not been seen as a problem:

  • That there had been no complaints from residents near the route of HS1. According to Mr Methold “complaints aren’t the only indicator of the existence of a noise, many people won’t complain, but they will still be annoyed”. He identified three possible views that might lie behind a resident’s reluctance to complain: a feeling that nothing can be done, a fear that a complaint may reduce the value of their property, and the hope that someone else will complain for them (see footnote 5).
  • That there are no successful Land Compensation Act Part 1 claims from High Speed 1. Mr Methold said that he didn’t regard this as “a very good indicator” as “a lot of them get settled before they are moved to formal lands tribunals” (see footnote 6).

Finally, just in case you are wondering what the views on this topic are of the Promoter’s noise expert, Rupert Thornely-Taylor, it would appear, from the evidence that he gave on the same day as Mr Methold’s appearance, that he recognises the differences that the CDC witness had identified. When invited to consider whether research into the effects of HS1 noise would be relevant to the HS2 case, he responded that he thought that this would involve “so many caveats, as to leave us with as much uncertainty as there is” (see footnote 7).

(To be continued …)


  1. See paragraph 255 of the transcript of the morning session of the HS2 Select Committee held on Wednesday 4thNovember 2015. Mr Methold noted that there was a discrepancy between the net change total of 1407 that he had quoted for HS2 and the corresponding total of 1,850 that is identified in the Health Impact Assessment (HIA) for HS2. He said that his work had “not been able to replicate that number”, but that, at least, his figure was “erring on the side of caution”. The paragraphs in the HIA that quote the higher total are 2.2.3 and 5.6.16.
  2. Mr Methold’s observations on exhibit A1571(39) are recorded in paragraph 259 of the transcript of the morning session of the HS2 Select Committee held on Wednesday 4thNovember 2015.
  3. See paragraph 260 of the transcript of the morning session of the HS2 Select Committee held on Wednesday 4thNovember 2015.
  4. See paragraphs 262 to 264 of the transcript of the morning session of the HS2 Select Committee held on Wednesday 4thNovember 2015. See also paragraph 326 of the HS2 Select Committee’s Second Special Report of Session 2015–16.
  5. See paragraph 270 of the transcript of the morning session of the HS2 Select Committee held on Wednesday 4thNovember 2015.
  6. See paragraph 271 of the transcript of the morning session of the HS2 Select Committee held on Wednesday 4thNovember 2015.
  7. See the discussion reported in paragraphs 144 to 151 of the transcript of the afternoon session of the HS2 Select Committee held on Wednesday 4th November 2015.


I wish to thank Michael Woodhouse for his suggestions and comments, which I have found invaluable in preparing this series of blogs.

Exhibits A1571(37) and A1571(39) have been extracted from the bundle of evidence submitted to the HS2 Select Committee by Rick Methold and published on the website of the HS2 Select Committee.

Important Note: The record of the proceedings of the HS2 Select Committee from which the quotes reproduced in this blog have been taken are uncorrected transcripts of evidence, which are not yet an approved formal record. Neither witnesses nor Members have had the opportunity to correct the record in such instances, and it may therefore be subject to changes being made in the light of any such corrections being requested.




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