Stab initiation

Of a series of 17 compounds examined as stab-initiation sensitisers, the title compound had the lowest ignition temperature of 122°C. 

Performance tests consisted of loading DBX-1 as a transfer charge in U.S. Army M55 stab detonators. Standard M55 detonators consist of three separate explosive layers, pressed sequentially into a metal detonator cup as shown in Figure 6. The first layer is 15 mg of the stab initiation mix (NOL-130) it is a combination of lead azide, lead styphnate, barium nitrate, antimony sulfide, and tetrazene [l-(5-tetrazolyl)-3-guanyltetra-zene hydrate], pressed at 70,000 psi. The second layer is 51 mg of transfer charge, lead azide, pressed at 10,000 psi. Lastly, the third layer is 19 mg of output charge, RDX, pressed at 15,000 psi. 

Given the unreliability of the stab-initiated tests, a second round of testing was performed using a hot nichrome wire to initiate the detonators in place of the NOL-130 stab mix and firing pin. This test was successful and all nine detonators functioned, showing that DBX-1 is more susceptible to this method of initiation. Figure 8 shows the electrical ignition setup. 

All reagents and solvents were used as received (Sigma-Aldrich) if not stated otherwise. NOL-130 stab initiation mix and preformed, 19 mg graphite-blended l,3,5-trinitro-l,3,5-triazacyclohexane (RDX) pellets were purchased from Day Zimmerman (DZI). Samples prepared for LC-MS analysis were dissolved in ammonium hydroxide and run utilizing a Phenomenex Gemini C6-Phenyl column (4.6 mm X 150 mm) and a mobile phase of 20 mM ammonium acetate in water pH 7.02 at 0.75 ml,-min The HPLC analysis is done using... 

Another delay element is shown in Fig 5-45 of Ref 23 (See our Fig 1-58). It is assembled within a single housing as an integral part of Stab Initiated 0.02 Second Delay Detonator. Compositions of primer, igniter, delay, intermediate and base charges are listed in our Fig 1-58. The detonators shown in Figs 1-57 and 1-58 were developed under Army auspices and investigated at Picatinny Arsenal [See PATR 1657 (1947)] (Ref 23, pp 5-59 5-60)... 

Fig 5-44 (Flame initiated 0.10-second flash detonator) 5-60, Fig 5-45 (Stab initiated 0.02-second delay detonator) Chapter 6, pp 6-1 to 6-11, Characteristics of Leads"... 

PATR 1657 J.P. Wardlaw, Investigation of Two Delay Detonators (One Flame Initiated 0.10 Second, and One Stab Initiated 0.02 Second) Developed by Company A (July 1947)... 

PATR 2680 A.C. Forsyth et al, "A Study of Stab Initiation Mechanisms"... 

If the pin punctures the primer case and enters a suitable expl charge, an expin can occur. This is known as stab initiation. 

Flame Initiated 0.10 Second Flash Delay Detonator and Stab Initiated 0.02 Second Delay Detonator. Numerous refs on Delays and Delay Elements are included in this book]... 

Stab Initiation. See under Stab Detonators in Vol 8, P381-R toP385 Instantaneous Stab Fuze Detonators in Vol 4, D844-L to D846-L and Instantaneous Stab Fuze Primers in Vol 4, D850-L to D852-L... 

C.L. Scott H.S. Leopold, Stab-Initiated Explosive Device Containing a Single Explosive Charge , USP 4024818 (1977) CA 87,87254 (1977) [The inventors claim the subject charge output is equal to 3 (ordinary) charge detonators. The charge compn is reported as Tetrazene... 

Stab-Initiated Explosive Device Containing a Single Explosive Charge USP 4024818 (1977) CA 87,87254 (1977) 11) CM, Tarver et... 

Table 23.1 Effect of Loading Pressure on Stab Initiator Sensitivity ...

Stab initiators are used in military systems such as small mechanical fuses where very little mechanical energy is available because of weight limitations and the small dimensions of the springs. Stab detonators use the same ignition mix, or priming composition, as many percussion primers do. Some of these are listed Table 23.2. 

The mechanisms involved in the stab initiation of explosives are still far from clear and, as discussed earlier, it seems possible that various mechanisms could be the cause of initiation under appropriate conditions. There are several experiments still to be made in the areas of electrical and electromagnetic irradiation, particularly as regards laser initiation. 

LA also shows very low sensitivity to stab initiation. This problem is usually solved by adding harder particles or tetrazene to the mixture. 

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