FOR ARCHIVE USE ONLY: HS2 Ltd Consultation Blog

This blog publicised the public consultation, which ran February to July 2011

HS2 Sound demonstrations

As people are understandably concerned about noise, we wanted to provide the public with scientifically accurate examples of what HS2 trains could sound like, should the proposals go ahead. So we worked with experts to create a range of HS2 sound demonstrations that allow communities to find out what HS2 trains would really sound like in their local area.

The demonstrations were created by an independent company, Arup, who are world-leaders in the development of sound simulations. They are a recognised authority on acoustics and noise modelling. Expert, independent peers verified their HS2 simulations.

Sound booth at a roadshowAs HS2 proposals are still at consultation stage, we needed to balance the cost of producing simulations specific to individual locations with the need for a variety of representative situations. So while we were unable to produce sound demonstrations for every location, we created ten demonstrations that covered a wide variety of different scenarios whether rural, urban or suburban. We think this is the first time that this amount of genuine simulation, independently tested, has ever been done at this early stage in a scheme.

Arup’s SoundLab

Arup have developed their innovative and unique SoundLab technology over 15 years, and used it on a range of projects, from world class concert halls and opera houses, to major transport projects – such as the Florence High Speed Rail station.

The SoundLab technology allows people to hear first-hand what the high speed trains could sound like in different places along the proposed HS2 route.

Arup’s SoundLab technology layers the sound of the latest high speed trains operating in France, ICE3s and TGVs, over recordings of local ambient sounds. These trains were used as the basis for HS2 trains as they provide the closest representation of the types of trains that would be running on HS2 tracks. The train recordings have been scaled to match the speed of the HS2 trains and their distance away from the demonstration location. HS2 trains would be ‘next generation’ high speed trains, and would benefit from developing technology that will make trains increasingly quieter and faster than current designs, such as Eurostar and Pendolinos.

Our demonstrations also include video imaging of HS2, so that people can properly relate the sound to the idea of a high speed train going by. 

Variations in sound levels

Train noise varies with speed. As HS2 trains would not be running at maximum speed in all locations, our demonstrations include a typical urban speed of 155mph (250 km/h) and a typical open countryside speed of 224mph (360 km/h). Sound levels also vary with distance from the railway. Our sound demonstrations provide sound examples at 75m, 150m, 210m, 350m, 440m, 600m and 1km.

Train noise also varies with train length. HS2 sound demonstrations are based on a maximum HS2 train length of 400m, which would run at peak times. HS2 trains would mostly be 200m in length, carrying 500 people. HS2 train services would run at different frequencies during the day, with the peak period seeing the largest number of train passes. The demonstrations are based on trains operating at the maximum capacity of the line.

Where applicable, the demonstrations also represent HS2 train sound with environmental noise barriers in place. Other noise-reducing measures, such as embankments and shallow and deep cuttings, have also been factored in.

Ambient noise

The sound from the proposed railway needs to be heard in context of other surrounding sounds. Arup accurately recorded local ambient sounds (background noise) at different locations to demonstrate different situations in which the train sounds could be experienced by residents. The demonstrations reflect a variety of examples of distance from the line, ambient noise levels, (low, moderate, medium/loud and loud) and noise mitigation.

For Northolt and West Ruislip, Arup made a location-specific recording, since the community lives close to the proposed route and already has existing railway noise to be considered. This scenario was very similar in Birmingham, so the Northolt and West Ruislip simulation was used to represent potential noise levels from the proposed line there.

Sound demonstrations at the roadshows

At the HS2 roadshow sound demonstrations, Arup ‘calibrated’ (accurately set) the sound levels each morning before the roadshow started. The demonstrations reflect the speed the train would run at when passing a particular location, the distance of residential properties from the proposed line, the effect of any proposed sound barriers and the ambient noise level.

Around 30,000 members of the public came to the HS2 roadshows and many listened to sound level demonstrations.

Jeremy Wright, MP for Kenilworth and Southam, listened to the demonstrations in Arup’s SoundLab in their offices in central London:

“The sound I heard was scientifically replicated in a highly sophisticated way and reproduced in a 3D sound laboratory, so it was as accurate a reproduction as it is possible to get.”

Lichfield MP Michael Fabricant, who also listened to HS2 sound simulations, said:

“I went into one of the sound booths [demonstrating high-speed rail noise 1km away] and could hardly hear a thing. I wasn’t sure whether it was a sound booth not working properly, whether it was a fib or whether in fact HS2 really is that quiet… but there are legal obligations on HS2 Ltd not to give misleading information…”

Some local groups opposing HS2 proposals have suggested HS2 trains would sound much louder than in our demonstrations. One group recorded and played the sound of a Eurostar train through a loud speaker at several HS2 roadshow events. Such approaches are an inaccurate representation of train noise and is not professionally recognised as being representative. They are not calibrated and have no technical basis. The Eurostar train uses earlier train technology and is not comparable to HS2 trains.

Inaccurate noise representations with increased sound levels serve no purpose other than to worry people unnecessarily. The HS2 sound demonstrations have been rigorously tested and reviewed by an independent panel of specialists in railway noise.

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Written by HS2 Ltd

July 22, 2011 at 2:28 pm

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