A month or so ago, I have been forwarded by residents in the Clayland Road area a leaflet from the NLE team explaining their noise standards (here). The information I have found over the last months show that a number of their statements on this document are inaccurate or at least debatable.
I have written to ask for a meeting to review these and ascertain the facts. Here is the letter.
A post will follow with the minutes of the meeting.
Friday, 2 September 2011
Tuesday, 14 June 2011
The NLE noise standard is virtually 100% louder than standards abroad
The proposed Northern Line Extension maximum noise standard for residential properties does not compare well to other countries in the developed world or other projects in England.
The best standard is 32 dB in Norway. The Northern Line Extension proposed level of 40dB is almost 100% louder (10dB over is a doubling in perceived loudness)
I have listed here the ones I have found in reverse chronological order of their use (all values are Lamax for ground-borne noise):
Northern Line Extension: 40dB (June-2011)
Dublin: 35dB (Application Oct. 2010) document
Australia: 35dB (June 2010) document p. 8 (35dB night and 40 dB day)
Crossrail: 35dB (April 2008) document
Norway: 32 dB (prior to 2005) document
USA: 35dB (since April 1995) document (day and night)
The picture that is emerging is an international alignment towards a value between 32 and 35dB Lamax for ground borne noise lead by the USA from 1995.
I am starting to wonder whether we should ask for a 32dB Lamax.
The best standard is 32 dB in Norway. The Northern Line Extension proposed level of 40dB is almost 100% louder (10dB over is a doubling in perceived loudness)
I have listed here the ones I have found in reverse chronological order of their use (all values are Lamax for ground-borne noise):
Northern Line Extension: 40dB (June-2011)
Dublin: 35dB (Application Oct. 2010) document
Australia: 35dB (June 2010) document p. 8 (35dB night and 40 dB day)
Crossrail: 35dB (April 2008) document
Norway: 32 dB (prior to 2005) document
USA: 35dB (since April 1995) document (day and night)
The picture that is emerging is an international alignment towards a value between 32 and 35dB Lamax for ground borne noise lead by the USA from 1995.
I am starting to wonder whether we should ask for a 32dB Lamax.
Thursday, 9 June 2011
Heart of Kennington Association presentation
The NLE team didn't bring any more information than what has been available for 3 years at last night's presentation meeting for the Heart of Kennington Association. We should be concerned about this and carry on putting pressure on them for lower maximum noise level standards such as those used for Crossrail.
A- They are not proposing a clear strategy to mitigate the noise for people living around the loop and the new tunnel
B- They are not committing to match the Crossrail noise standards
C- They are not issuing the information that will show how our homes will be affected
They had been issued with 4 questions relating to noise a week in advance (see below), they only answered one and gave no clear information that wasn't already in the 3 years old Preliminary Environmental Assessment of 2008.
The first two dealt with mitigation measures to be used in the existing loop and in the rest of the line. They are not proposing anything at present. As they had already said at the last meeting, they are looking at and costing a floating track bed option for some areas but are not prepared to say whether they will use it or where they might.
The third query was a bout the Maximum noise level of a train inside our homes that they were designing towards. They are still only committing to 40dB (Lamax) inside residential properties - this is a noise 50% louder than the standard used for Crossrail of 35dB (Lamax). They explained that Crossrail had been forced to use this through the Public Enquiry implying that the NLE team will take the same approach as Crossrail and will only use this if obliged.
The fourth question was about predicted noise levels in our area. No precise information was provided, neither a contour map or other data. Some of this information must available at this stage to allow them to design and cost; we should be concerned that they are not releasing it as this is they only way to know who will be affected and how.
They repeated the idea that noise levels are likely to be less for people living around the loop but no statement that they will ensure that it will be so. Baring in mind that the number of trains is going to soar, this is a serious issue for those who live near the loop.
The only new piece of information is that they are going to monitor the noise in properties on the loop and in similar situations to show how their proposed standard compares to the existing levels above the loop. One outcome of this is to discover if the existing noise levels are above - or below - their standards. The second possible outcome is that they use this data to demonstrate a case for not achieving their own standard in locations where the noise is already above it. This has been used by London Underground elsewhere. For those already on the loop, it means that they might design the line so that the noise level stays the same - or marginally above - instead of an improvement which is easily achievable with modern technology.
It is clear from their evasive answers that noise is the issue they will not discuss openly in detail until their application at the end of the year. I have since the meeting asked the NLE team for a date when they are planning to answer our questions. Their reply was again evasive, they referred back to the monitoring exercise.
This exercise does not give us any further reassurance that our quality of sleep is being cared for. It is there to convince those currently above the loop that their situation will improve or not get worse and monitor that it does. The reality is that their standard disturbs sleep (see here for more info).
As did the Crossrail team, they are preparing a case to do as little as they possibly can get away with to win the Public Enquiry. We must keep putting pressure on them so that the interests of those around the line are protected.
In the Crossrail story, it was the Councils, lead by Camden, who represented the local residents and employed noise specialists to make the case and won the 35dB for residential properties. Will Lambeth represent us as well?
Questions issued prior to meeting:
A- They are not proposing a clear strategy to mitigate the noise for people living around the loop and the new tunnel
B- They are not committing to match the Crossrail noise standards
C- They are not issuing the information that will show how our homes will be affected
They had been issued with 4 questions relating to noise a week in advance (see below), they only answered one and gave no clear information that wasn't already in the 3 years old Preliminary Environmental Assessment of 2008.
The first two dealt with mitigation measures to be used in the existing loop and in the rest of the line. They are not proposing anything at present. As they had already said at the last meeting, they are looking at and costing a floating track bed option for some areas but are not prepared to say whether they will use it or where they might.
The third query was a bout the Maximum noise level of a train inside our homes that they were designing towards. They are still only committing to 40dB (Lamax) inside residential properties - this is a noise 50% louder than the standard used for Crossrail of 35dB (Lamax). They explained that Crossrail had been forced to use this through the Public Enquiry implying that the NLE team will take the same approach as Crossrail and will only use this if obliged.
The fourth question was about predicted noise levels in our area. No precise information was provided, neither a contour map or other data. Some of this information must available at this stage to allow them to design and cost; we should be concerned that they are not releasing it as this is they only way to know who will be affected and how.
They repeated the idea that noise levels are likely to be less for people living around the loop but no statement that they will ensure that it will be so. Baring in mind that the number of trains is going to soar, this is a serious issue for those who live near the loop.
The only new piece of information is that they are going to monitor the noise in properties on the loop and in similar situations to show how their proposed standard compares to the existing levels above the loop. One outcome of this is to discover if the existing noise levels are above - or below - their standards. The second possible outcome is that they use this data to demonstrate a case for not achieving their own standard in locations where the noise is already above it. This has been used by London Underground elsewhere. For those already on the loop, it means that they might design the line so that the noise level stays the same - or marginally above - instead of an improvement which is easily achievable with modern technology.
It is clear from their evasive answers that noise is the issue they will not discuss openly in detail until their application at the end of the year. I have since the meeting asked the NLE team for a date when they are planning to answer our questions. Their reply was again evasive, they referred back to the monitoring exercise.
This exercise does not give us any further reassurance that our quality of sleep is being cared for. It is there to convince those currently above the loop that their situation will improve or not get worse and monitor that it does. The reality is that their standard disturbs sleep (see here for more info).
As did the Crossrail team, they are preparing a case to do as little as they possibly can get away with to win the Public Enquiry. We must keep putting pressure on them so that the interests of those around the line are protected.
In the Crossrail story, it was the Councils, lead by Camden, who represented the local residents and employed noise specialists to make the case and won the 35dB for residential properties. Will Lambeth represent us as well?
Questions issued prior to meeting:
- As many houses in the area are already subject to noise from the existing Northern Line, can tell us what steps you would plan to take in the construction phase to ensure that there is no increase in noise levels from the more frequent, faster running trains which will use the extension tunnels when they are in operation?
- What measures are you proposing to use to reduce sound levels, what is their effect likely to be, and can you show on a detailed map of the area where you are planning to use such measures?
- We understand that CrossRail have undertaken to reduce maximum noise levels for those affected when it comes into operation to no more than 35dB Lamax inside residential properties. Will you give a similar undertaking?
- Would you let us have your latest noise assessments (Lamax inside Lower ground floors) to replace those which were made available in the Preliminary Environmental Assessment of December 2008; and could you also show these in ‘contour’ form in relation to a detailed map of the area showing zones above 20dB, 25dB, 30dB, 35dB, 40dB and 45dB Lamax inside Lower ground floors?
Tuesday, 31 May 2011
Presentation of the NLE at the Tunnels and Tunnelling Conference 2010
This presentation by David MaCann from Halcrow, the engineer for the NLE, speaks for itself but it is worth noting that there will be a train every 2 minutes at peak time (32 trains per hour). (There is an interesting part more specifically about Kennington after 20 & 32minutes).
It is also mentioned that the updated Environmental Assessment should be available now. (it will be completed a few months after the talk which was in September 2010). Considering that detailed information is available, it is difficult not to be paranoid of the virtual absence of information that has been issued on noise to date; at all recent consultation events and on their website the NLE team only mention the 2008 Environmental Report.
On the positive note, they state that they are designing the tunnels to be big enough for the tunnels to "accommodate a floating track bed" as they "anticipate noise and vibrations is likely to be an issue along the route" and considering the recent experience on other projects of London Underground and Crossrail (after 17 minutes). They don't confirm where this measure will be used, or if it will be used either. I am not yet clear if "floating track bed" is the same as "floating slab track" ; the later is the one used at Crossrail in sensitive areas.
Also worth of note is that the reason for the tunnel route avoiding the Oval grounds is that it is feared that the vibration will impact the Cricket games (not an issue with piled foundations as has been previously presented). The route has been curved more and lengthened to achieve this re-routing - and therefore made costlier. If it impacts cricket games, shouldn't we be worried that it impacts our homes?
Thursday, 26 May 2011
Consultation meeting - Wednesday 25 May 2011
The subject of noise impact on the properties around the planned Northern Line Extension was approached by the team at yesterday's consultation meeting.
Their presentation lacked clarity in terms of noise impact, the slide only mentioned a "quiet library" description of the expected sound level inside properties. The measurement they first declared as maximum was the average, called Laeq, instead of the measurement that matters most to our community which is the strict maximum noise level created by each train, called Lamax, ie the one that we will hear inside our homes. It is surprising that they used the average, Laeq, as the maximum, Lamax, is the standard for punctual sounds such as the tube and the one refered to most in previosu similar projects such as Crossrail. The Laeq they are committing to at present is 30dB.
Once directly asked, they confirmed that the true maximum they are committing to at present is Lamax of 40dB. This is the level of a quiet normal human voice in your bedroom (20dB is a whisper, more information on sound can be found here).
They presented these parameters as those used by Crossrail, as does their environmental report of 2008. It is only once they were corrected that they accepted that crossrail is working towards a maximum of Lamax = 35dB for residential properties that will be strictly applied in large parts of central London. Crossrail is using a combination of resilient track support system AND floating slab technology to achieve this. (More information about crossrail can be found here).
Once asked further, they explained that the design team was working on an option following the "Crossrail" parametres and attenuation measures but they would not commit to these standards. They conceded that these parameters were achievable and might be used in the worse areas.
We asked them twice to release the new information that has been developped for their team to develop the design and costing ; they replied that it will be part of the overall application that will be completed in 9 months time.
Their reluctance at releasing now up to date and precise data on the noise impact showed clearly how fundamental it is to put pressure on them to use decent sound levels for all residential properties. We should also ask further for the release of the draft noise and other environmental impact documents that already exist and which ought to form part of a true consultation exercise. This will help everyone in the area to get a clear picture of how they will be affected, in particular those who are trying to sell their home and are faced with concerned buyers.
Their presentation lacked clarity in terms of noise impact, the slide only mentioned a "quiet library" description of the expected sound level inside properties. The measurement they first declared as maximum was the average, called Laeq, instead of the measurement that matters most to our community which is the strict maximum noise level created by each train, called Lamax, ie the one that we will hear inside our homes. It is surprising that they used the average, Laeq, as the maximum, Lamax, is the standard for punctual sounds such as the tube and the one refered to most in previosu similar projects such as Crossrail. The Laeq they are committing to at present is 30dB.
Once directly asked, they confirmed that the true maximum they are committing to at present is Lamax of 40dB. This is the level of a quiet normal human voice in your bedroom (20dB is a whisper, more information on sound can be found here).
They presented these parameters as those used by Crossrail, as does their environmental report of 2008. It is only once they were corrected that they accepted that crossrail is working towards a maximum of Lamax = 35dB for residential properties that will be strictly applied in large parts of central London. Crossrail is using a combination of resilient track support system AND floating slab technology to achieve this. (More information about crossrail can be found here).
Once asked further, they explained that the design team was working on an option following the "Crossrail" parametres and attenuation measures but they would not commit to these standards. They conceded that these parameters were achievable and might be used in the worse areas.
We asked them twice to release the new information that has been developped for their team to develop the design and costing ; they replied that it will be part of the overall application that will be completed in 9 months time.
Their reluctance at releasing now up to date and precise data on the noise impact showed clearly how fundamental it is to put pressure on them to use decent sound levels for all residential properties. We should also ask further for the release of the draft noise and other environmental impact documents that already exist and which ought to form part of a true consultation exercise. This will help everyone in the area to get a clear picture of how they will be affected, in particular those who are trying to sell their home and are faced with concerned buyers.
Subscribe to:
Posts (Atom)