Underwater detonation test

The principle of the underwater detonation test is illustrated in Figure 5.10. The size of the water-filled tank in Figure 5. 10 is after Satyavratan and Vedam (1980). 

Figure 5.10. Underwater detonation test (After Satyavratan and Vedam, 1980)...

It should be mentioned that several fectors may influence the test data primarily, it is the mass of the explosive charge (Figure 5.11), the charge depth, and the manner of charge initiation. The energy value obtained the underwater detonation test is comparable with the energy value obtained the theoretical thermodynamic calculations. 

New perchlorate salts [Cr( 104)3](N2H4)3 and [Cd(C104)2](N2H4)3 have been synthesized and their energetic characteristics evaluated by applying underwater detonation tests [35]. 

Underwater Detonation Propagation Test Using VP-50 Pipe... 

The test results for emulsion commercial explosives have shown that there is a correlation between the depth of the wetness pipe dent and the relative energy calculated theoretically. The test results are very usefiil, esj cially when used together with results obtained by underwater detonation and by ballistic mortar tests. 

Bjamholt, G. Str gth testing of explosives by underwater detonation, Propellants and Explosives 3, 70-71 (1978). 

TNT Al wax 47 31 22 5). Three MEDINA-contg formulations were compared with std expls in plate dent, air blast, underwater blast, and fragn tests. MEDINA showed a 4% improvement over RDX in shaped charge penetration (Ref 14). MEDINA was tested as a detonator fill, but was unsatisfactory due to poor stability (Ref 14)... 

Novit (Swed). An underwater expl consisting of TNT 50 and Hexanitrodiphenylamine (HNDPhA) 50%, invented prior to WWI. Its properties were loading d, 1.65—1.68g/cc relative brisance, 103% (TNT 100%) Qe f iOOOcai/g (TNT 950) power by Trauzl Pb biock test, 315cc (TNT 290cc) and vel of deton 7200m/sec (TNT 6800)... 

The tests have shown that initiation of cast Pentolite receptors underwater by shock wave was facilitated by combined frontal and lateral influences. Initiation did not occur exclusively at the front end of the receptors. When the receptors were beyond about 3.5 radii from the center of the spherical cast Pentolite primer, the initial low-velocity propagation in the receptors proceeded longer than 15 or 20/xsec and seldom developed into high-velocity detonations. Abnormally dense receptors tended to react longer in a low-velocity propagation even when fairly near a primer... 

Later they proved to be very effective for underwater explns. Two Penthrinits, 1 2 of Table 17 were, accdg to Stettbacher (Ref 6), loaded in 1929—1930 in 2cm shells and tested at Oerlikon Fabrik at muzzle velocity (vQ) 840m/sec. No prematures occurred. The addition of about 15% A1 powder increases the efficiencies of Penthrinits, while high amounts seem to decrease it. For example, addition of 30% A1 to formulation 1 of Gelatine Penthrinits decreased detonation velocity from 8000m/sec to 7200... 

In the under—sand and underwater tests, for which 50mm-diameter propellants were used, sample C detonated completety. This indicates that 20mm diameter samples cannot adequately prove if the propellant will cause induced explosion if they have larger diameters. 

In order to report the energetics of these tests in a format better suited for comparison against underwater explosions, the PAV work of the Reynolds Industries RP-1 detonator was used as a standard on an equal volume basis. This comparison, the relative potential bubble energy (RPBE), can be written in the form 5... 

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