Acoustics case study

Staffordshire Police 50m Firing Range

Background

SRL Technical Services were appointed by Blue Sky Design Services to support the planning application and acoustic design for a new 50m indoor firing range and training facility at the Staffordshire Police Headquarters in Stafford. The development consisted of a two-storey building with an indoor firing range taking up most of the ground floor and additional classrooms and physical training spaces on the ground and first floors.

Challenge

Due to the high noise levels generated in the firing range, noise break-out was a key consideration of the acoustic design. There was a control room, adjacent to the firing range to regulate entry to and safety within the range where noise levels could potentially exceed the Control of Noise at Work 2005 regulations.

Solution

Using the data obtained during a noise survey and data available for noise generated by gunshots confirmed that the architects’ preferred ballistic walls were capable of controlling noise break-out at the nearest receptors. Walls and floors were specified to minimise the impact that high noise levels in the firing range and physical training suite could have on noise-sensitive spaces such as offices and classrooms. Additionally, SRL specified suitable surface finishes to achieve a desirable acoustic environment in all spaces. This included the range, where we specified localised absorption in the area where firearms officers would stand, to improve speech intelligibility during their training. Using measurements of the noise generated by gunshots at 1m, SRL calculated the expected noise exposure that the range controller would typically experience over a working day. We subsequently advised a suitable glazing specification for the vision panel that would allow the range controller to work without wearing hearing protection whilst not exceeding the exposure limits set out in the Control of Noise at Work 2005 regulations.