Safe separation distance determination

Safe separation studies were conducted to achieve increased production and cost effectiveness with improved safety. A typical ammunition production line flow diagram (in this case for the manufacture of 105 mm projectile) consists of several work areas as shown in Fig 8. ( (l) Receiving and storage, (2) Box open and inspect (3) Melt Pour (U) Cool (5) Hold (6) Funnel Pull and (T) Riser Preparation.) Explosive material is transferred by automatic conveyor between these work areas. The requirement was to establish safe separation between explosive boxes, pallets with and without funnels, buckets, and to determine critical height of continuous feed flake Comp B and TNT. The objective of these tests was to establish minimum nonpropagation distances between these items so that an explosion chain reaction will be prevented. 

The results of the above-listed analyses are used to determine the exclusion zone—the area outside of which is considered safe for public access. The results are also used to determine in-plant separation distances. The hazards study must be conducted before finalizing the relative locations of storage tanks, liquefaction facilities, and other power plant facilities. From a capital cost viewpoint, these facilities should be kept as close as possible to each other however, safety considerations mandate minimum safe distances an3 vhere between 200 and 800 m. Enlarging the exclusion zone by 1 to 2 km from any public facility such as a school, a hospital, or a highway may be necessary. 

If separate blast sources are located close to one another, they may be initiated almost simultaneously. Coincidence of their blasts in the far field cannot be raled out, and their respective blasts should be superposed. The safe and most conservative approach to this issue is to assume a maximum initial blast strength of 10 and to sum the combustion energy from each source in question. Further definition of this important issue, for instance the determination of a minimum distance between potential blast sources so that their individual blasts may be considered separately, is a factor in present research. 

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