Volvo Bus Noise

Meeting: 
Plenary on 2006-12-06
Session date: 
December 6, 2006
Reference: 
2006/0452
Question By: 
Angie Bray
Organisation: 
GLA Conservatives
Asked Of: 
Peter Hendy (Commissioner, Transport for London)

Question

It is encouraging that TfL and Volvo are now addressing the problem of excessive noise, and I am encouraged that the cooling fan has been identified, and action is being taken. However, this is not the whole story, as the local Council and I are still receiving complaints about the low frequency noise of these vehicles, caused by the engine block and exhaust. Can you detail what further tests you are planning to carry out to address these further problems?

Answer

Answer for Volvo Bus Noise

Answer for Volvo Bus Noise

Answered By: 
Peter Hendy (Commissioner, Transport for London)

As previously reported, Volvo are undertaking a vehicle `dynamometer' test of the modified vehicles. The tests will be conducted in the UK by Volvo's research engineers from Sweden. TfL will then undertake an independent drive by test to verify the results. These results are expected to be available in the next few days. As you know, we have also written to Volvo requesting a full timetable for a retrofit programme for all Volvo double deck buses in London.

The engineers believe that low frequency noise is increased by the engine cooling fan `load'. When the first Volvo vehicle used in our original testing is modified, TfL will undertake independent noise and frequency testing on the same vehicle to verify improvements are achieved.

For the future, we have modified our vehicle specifications so that all new vehicles must undertake 3 legal drive by tests and achieve a:

- 3dB(A) reduction over the current legal requirement. In the case of a double deck bus a result of no more than 77 dB(A) is required. - Minimum 79 dB(A) result at full acceleration. - Minimum 84dB(A) result at full acceleration with all auxiliary equipment functioning (including cooling fans).