P-385-63 Range Safety Pamphlet Download

Table 15–2 Safe distances for personnel (near bare charges) Charges Missile hazard distance (m) more than 227 kg/more than 500 lbs Minimum 800 12.27 kg/27 lbs to 227 kg/500 lbs Computed 1 less than 12.27 kg/less than 27 lbs Minimum 300 m 2 Notes: 1 Computed missile hazard distance in meters=100 times the cube root of the pounds of explosive: (D=100 X W 1/3 ). 2 When charges less than five pounds are placed on specially prepared or selected sites (para 15–1f(2)(a)) to eliminate a missile hazard, distance may be reduced to not less than 50 m. Table 15–3 Hearing protection distances Weight of explosives Distance to 140 dBP contour (m) kg lb m 0.10 0.25 145 0.23 0.50 183 0.45 1.00 230 0.91 2.00 290 2.27 5.00 394 4.45 10.00 497 9.10 20.00 626 22.70 50.00 849 45.00 100.00 1,070 91.00 200.00 1,348 Table 15–4 Minimum safe distances between radio frequency transmitters and electric blasting operations Transmitter power watts Commercial AM broadcast transmitters (m) HF transmitter other than AM broadcast (m) 100 229 229 500 229 519 1,000 229 732 4,000 229 1,464 5,000 259 1,678 10,000 397 2,318 25,000 610 3,360 50,000 1 854 5,185 100,000 1,190 7,320 500,000 2 2,684 16,755 Notes: 1 Present maximum power of U.S. broadcast transmitters in commercial AM broadcast frequency range (535 to 1,605 kHz). 2 Present maximum for international broadcast. 201 DA PAM 385–63 • 16 April 2014