Reducing impact noise from aluminium casks
Noise levels, typically A-weighted levels of 93 dB, were being generated at a brewery by dropping aluminium casks onto the concrete surface of its distribution yard.
The obvious solution was to allow the casks to drop onto a resilient material, but this posed a number of practical problems. Individual movable mats were unsuitable, as 'drops' could take place anywhere in the yard and the mats would be difficult to move around. An entire covering of the yard with this resilient material, while possible, was discounted because the material would not be strong enough to withstand the punishing regime of repeated heavy blows, often with the sharp edges of the cask.
The chosen covering would have to resist being moved by road vehicles and site fork and pallet trucks, and be weather resistant. Fixing the material directly to the concrete with conventional adhesives was therefore impractical.
The solution was found by using a different type of resilient material and fixing it in place to cover the whole distribution yard. The material used was an abrasion-resistant rubber, pre-bonded to steel sheets that could be attached to the concrete using conventional masonry fixings.
About £50 000. (1995)
Peak noise levels were reduced by 10 dB. An additional benefit was improved maintenance and repair costs for the concrete, now protected from mechanical and chemical damage.
The material has been installed successfully in other industries, eg in premises handling gas cylinders and steel drums and in health clubs where weight training takes place.
Information supplied by Trellex Ltd. Photograph courtesy of Bass Mitchells and Butlers