Sympathetic explosion

The explosives used for military purposes are different from those used in industry. Not only thermo mechanical power for destruction, but also various other characteristics are required. Experimental tests, such as slow cook-off fast cook-off, bullet impact, and sympathetic explosion tests, must be passed to meet the requirements for insensitive munitions (IM). The aerodynamic heating of warheads on flight projectiles is also an important factor in designing warheads. 

The criteria for insensitive explosives subjected to ha2ard tests permit no reaction more violent than burning in slow and fast cook-off tests and fragment and bullet tests, no propagation in sympathetic detonation tests, no detonation when stmck by a shaped charge jet, no sustained burning when hit by a small fragment, and such special tests as may be required by the use of the explosive. 

In the manufacture of high explosives, the possibility of accidental detonation must always be borne in mind and buildings are constructed and arranged so as to minimise the possible effects of such an explosion. The buildings are placed sufficiently far apart so that an explosion in one building will not cause sympathetic detonation in the other. Practical distances do not make it completely impossible for detonation in one house to leave all other houses unaffected, for two reasons ... 

Burning , etc are listed in Vol 1, p IX Calorimetric Tests for Explosives, Propel- Coefficient de self-excitation (CSE). Fr test for sympathetic detonation. See Vol 3, p C390-L... 

Detonation by Influence or Sympathetic Detonation Tests. Several tests are listed in Vol 1, p X and their description is given in this Section under "Detonation (and Explosion) by Influence ... 

O. Murata, JlndExplSocJapan 17, 102-11 (1956) 8 CA 50, 17454(1956) (Deton by influence) 16) G.R. McVey St V.M. Boyle, "Sympathetic Detonation in Composition B Induced by Air Shock from Pentolite and from Composition B , BRL Rept 1048(1956) 16a) PATR 2510(1958), p Ger 52 (Four-cartridge test) 17) J.B. Cole, G.D. Edwards St T.K. Rice, USP 2832213(1958) (Booster-gap explosive sensitivity test claimed to give more reliable results than the "card and "three-legged table tests) 18) Cook (1958), 189-90 (Designation of "donor St "receptor and "shock-pass-heat-filter method) 194-97 (Deton by influence - testing by air-gap method and a brief discussion on testing thru gap filled with water, mud or solids some theoretical discussion on deton by influence) ... 

Andreev Belyaev (i960), 365-67 (Calcn and exptl detn of distances "safe to deton by influence thru air) 25) M. Sultanoff et al, "Shock Induced Sympathetic Detonations in Solid Explosives , pp 520-32 in Vol 2 of the 3rdONRSympDeton (I960)... 

Detonation (and Explosion), Propagation or Transfer. See "Detonation (and Explosion) by Influence or Sympathetic Detonation and also Detonation (and Explosion), Initiation (Birth) and Propagation (Growth or Spread) in Explosive Substances ... 

Actually the "spontaneous detonation , as understood now, is one taking place when initiated by an agent which is not perceived, such as shock waves from another explosion at some distance [See Detonation (and Explosion) by Influence or Sympathetic Detonation]. In such cases, the term "spontaneous may include an inference that the... 

Detonation, Susceptibility to Sympathetic. See under DETONATION (AND EXPLOSION) BY INFLUENCE... 

Initiation by Influence usually called Sympathetic Initiation, is the initiation of an explosive charge by the detonation of a nearby charge separated from the first charge by an inert medium see Detonation by Influence in Vol 4, pp 395-398 and also Initiation by Hot Fragments Initiation by Shock... 

Type 94M (Explosive) (Navy). A cream-yellow expl compn consisting of Trinitroanisole 60 RDX 40%. Its cast d was 1.64 Brisance by Cu Cylinder Crusher Method 107% PA Expln Temp 216° Friction Sensitivity 40—50 kg (max pressure betw two rubbing surfaces for no explns) Impact Sensitivity 13 cm (max for no explns with 5-kg wt) Power by Ballistic Mortar 112% PA Rate of Deton by Dautriche Method 7700 m/sec. Originated as powerful expl for loading Torpedo Warheads but this use was discontinued due to its sensitivity to Sympathetic Detonation. Later uses included Shaped Charge Grenades and as a Booster Surround (Ref 1, p 32 as Type 94 Ref 5, p 379 as Type 94M)... 

EXPLOSION (OR DETONATION) BY INFLUENCE OR SYMPATHETIC DETONATION AND TESTS. See Vol 4, pp D395-R to D402-L (Numerous refs)... 

Detonation (or Explosion) by Infuluence or Sympathetic Detonation. Its definition and description are given in Vol 1, p X and in Vol 4, pp D395-R to D398-R. Its tests are listed on pp D398-R to D402-L and also under Booster Sensitivity Tests. 

W) C. Belgrano, "Gli Esplosivi , U. Hoepli, Milano (1952), pp 15 to 53 (Physical tests for mining explosives. Included are density, stability, Trauzl test, detonation velocity, Hess test, crusher test, sympathetic detonation test, sensitiveness to initiation, sensitiveness to impact, steel plate test and explosion temperature determination) pp 73 to 75 (Analysis of NG) 76 to 84... 

KL) Anon, "Military Explosives", TM 9-1300-214/TO 11A-1-34 (1967). Chapter 5. Properties and Tests of High Explosives Sensitivity to Frictional Impact (pp 5 1 to 5-3) Sensitivity to Friction (5 3 to 5-6) Sensitivity to Frictional Impact (5-6) Sensitivity to Heat and Spark, which includes Explosion Temperature Test (5-6 to 5-9) Sensitivity to Initiation (5-9) Stability Tests, which include 75° International Test, 100° Heat Test, Vacuum Stability Test and Potassium Iodide—Starch Test (5 9 to 5-15) Brisance Tests which include Sand Test, Plate Dent Test and Fragmentation Test (5 15 to 5-18 and Fig 5 13 on p 5-19) Initiating Value (5-18 5-20) Sympathetic Detonation (5-20 to 5-21) Power which includes Heat of Explosion Test, Ballistic Pendulum Test and Trauzl Lead Block Test (5-21. to 5-24) Blast Effect (5-24 to 5-27) Cratering Effect (5-28 5 29) and Munroe-Neumann Effect (5-29 to 5 35)... 

Gap Tests. Various tests are listed in Vol 4 of Encycl, pp D303-R D304-L and also under DETONATION (AND EXPLOSION) BY INFLUENCE OR SYMPATHETIC DETONATION, where the following tests are described Air-Gap Test (p D397-R) ... 

TATB is well-known for its insensitivity and is currently employed as an IHE for some applications. TATB is however, inferior to RDX and HMX in performance. Therefore, a need exists for the research and development of explosives that are powerful yet resistant to accidental and sympathetic initiation. 

American investigators have reported development of a new IHE called Pica-tinny Arsenal Explosive-2 (PAX-2, a nitramine-based PBX) which possesses reduced sensitivity to sympathetic detonation in cannon caliber ammunition [166] and is considered as a substitute for existing PBXN-5. In this series, PAX-2A which retains all the requisite performance capabilities of PAX-2 but possesses less sensitivity to initiation by outside stimuli, has also been developed. This is regarded as the US Army s first high performing IM explosive. 

Sensitivity to Initiation by Influence (Sensitivity to Sympathetic Detonation). According to Abinder and some other Russian investigators (Ref 60), cartridges or shells loaded with AN or explosives contg large amts of AN transmit deton by influence to other cartridges or shells provided they are laid side-by-side, even with a small air space between them but detonation usually... 

Gap Tes/(Propagation Test or Sympathetic Detonation Test). In order to ascertain the relative ability of the disturbance sent out by the explosion of a shielded detonator charged with pentryi as the base charge to transfer deton over an air gap to a receiving charge of an expIosive(such as dynamite), Clark used the same method as he described fa DDNP in IEC 25,668(1933)... 

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