Sound and Sound Pressure Level MeasureMents of the Harp-Barbados 16.5-in. Gun with a 51-Ft Muzzle Extension

摘要

The problem of intense sound and sound pressure levels that result from the firing of a 16-in. gun with a 51-ft muzzle extension at Eglin AFB, and the possibility of resulting damage from the blast wave required examination before the installation of such a device at Eglin AFB can be approved. Measurements of the sound and sound pressure levels were made at Barbados, British West Indies, the only known installation of this type. Data were acquired from a sound level measuring system and a sound pressure measuring system on 13 firings. Based on data taken by the Canadian Government in December 1964 without the 51-ft muzzle extension, the effect of the 51-ft muzzle extension was to lower the peak sound and sound pressure levels as follows: (1) At a distance of 8000 ft, the average sound level was 120 db and the average sound pressure level .0029 psi; (2) At a distance of 6000 ft, the average sound level was 127 db and the average sound pressure level .0065 psi; (3) At a distance of 3000 ft, the average sound level was 129 db and the average sound pressure level .0072 psi; (4) At a distance of 750 ft, the average sound level was 147.3 db and the average sound pressure level .067 psi; and (5) The length of the sound pulse is between .5 sec and 1 sec in duration with a quick rise time and a slow decay time. (Author)