The Mayor's Ambient Noise Strategy - Greater London Authority

The Mayor’s Ambient Noise Strategy Mayor of London 163
4E.12 Industrial noise should be primarily controlled at source, through plant
design, installation, operation, and maintenance. Good operator training is
important. Sources of industrial noise are many and highly varied.
Industrial noise can be challenging to predict at the planning stage.
Diagnosing the source of annoyance, and designing appropriate solutions
can also be difficult. Industrial noise and vibration control is a highly
specialised field. Control technologies are often specific to the particular
industry. Impulsivity, intermittency and tonality can be particularly
disturbing features of industrial noise. Low frequency noise can be
especially problematic. Planning Policy Guidance Note ‘Planning and
Noise’, PPG24 states that the character of the noise should be taken into
account as well as its level, and that ‘sudden impulses, irregular noise or
noise which contains a distinguishable continuous tone’ will require
special consideration. BS 4142 applies a weighting to the measured or
calculated noise level to allow for such characteristics.
4E.13 Issues involved in noise management in industrial development include
quieter processes and equipment; plant insulation and absorption,
enclosure and screening; ventilation and process extracts; hours of
operation; and spatial planning and building insulation. Noise sources
requiring similar measures may also be found in commercial and other
premises (e.g. air conditioning plant, chillers and extract ventilation plant)
- see also Chapter 4F, especially Box 55 and Policy 77.
Quieter processes and equipment
4E.14 Noise is produced in many different ways, such as from vibrating surfaces;
reverberation or aerodynamic processes, such as from a fan, jet or pump; and
impact, which may include first impact and subsequent resonance. Generally,
as a first priority, all reasonably practicable steps need to be taken to secure
use of the quietest processes and specification of the quietest plant and
methods of working, with the aim of designing out noise and vibration at
source. European Union Directives increasingly control industrial noise at
source, through specifying limits for noise produced by many types of
machinery. Noise is particularly difficult to control from open activities, such
as scrap metal handling, and sites used for temporary purposes.
Plant enclosure and screening
4E.15 Generation of noise and vibration cannot always be avoided with available
manufacturing technologies. Transmission of noise and vibration can,
however, be controlled. Issues include siting noisy equipment as far as
possible from noise-sensitive areas; orienting any plant with strong sound
directivity away from noise-sensitive areas; isolation and containment,
e.g. using resilient mountings, insulating ductwork, lagging pipework and
using acoustic claddings and linings; insulating buildings which house