Noise demolition

The gate groaned as Gill pushed it back. It was only when I stepped through and heard it clang shut behind me that I realized there was an absence of other noise. Not only had the demolition stopped, but there were none of the usual Selden background sounds of hens and horses or bustle from the kitchens. No smoke rose from the chimneys, but the entrance door stood wide open. 

Francis B. Paca, U.S. Army Engineer R D Labs., Fort Belvoir, Va., Reduction of Noise Arising from Demolition Activities, Rept. I703-TR (20 December 1961). 

List the dBA levels of various equipment and tasks. For example, rock drilling can reach 115 dBA, chain saws 125 dBA, abrasive blasting 112 dBA, heavy equipment 110 dBA, demolition 117 dBA, and needle guns 112 dBA. Show slides of the equipment/tasks that require hearing protectors. Dispell myths about workers getting used to the noise. Have samples of all approved hearing protective devices. Indicate where workers can find hearing protectors. 

Research demonstrates that construction workers are regularly overexposed to noise. The extent of daily exposure to noise in the construction industry depends on the nature and duration of the work. For example, rock drilling—up to 115 dBA, chain saw—up to 125 dBA, abrasive blasting—105 to 112 dBA, heavy equipment operation— 95 to 110 dBA, demolition—up to 117 dBA, and needle guns—up to 112 dBA. Exposure to 115 dBA is permitted for a maximum of 15 minutes for an 8-hour workday. No exposure above 115 dBA is permitted. Traditional dosimetric measurements may substantially underestimate noise exposure levels for construction... 

A defence on contravention of a noise order may be that the best practicable means had been used to reduce or control the noise. Constraints may be placed on construction or demolition work. 

BS 5228 1975, Code of practice for noise control on construction and demolition sites, British Standards Institution, London (1975)... 

The source of noise and vibration on demolition sites will normally be caused by the use of plant and equipment, falling debris and/or explosives. Compressors, pneumatic hand-held tools, front end loaders, excavators and other equipment can create noise levels of more than the lower exposure action level of 80dB(A) and may at times create peak noise levels of more than 137 dB(C) the lower peak sound pressure action value. A noise assessment will be required and workers given ear defenders. 

Supervisors must have received training in COSHH appreciation, principles of demolition and general site safety. Operatives must be trained in the operation of the machinery and equipment used, and in demolition techniques. They will be briefed on the results of relevant assessments, including noise exposure. This also applies to specialist subcontractors. 

BSI (1984) Noise control on construction and open sites Part 2. Guide to noise control legislation for construction and demolition, including road construction and maintenance (BS 5228 part 2) UK BSI. 

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