Mortar, ballistic

Qc 2446 keal/kg, power 148% TNT (Trauzl), 143% TNT (ballistic mortar) (Ref 13). The Ba salt is pptd by addn of Ba chloride soln to solns of MEDINA (it can be regenerated by the addn of HC1 to the Ba salt) this salt is used in isola-... 

It is an expl, more powerful than TNT (about 133% by Ballistic Mortar), and comparable to Tetryl in sensitivity. Its Vel of Deton is 7420 m/sec at d 1.5g/cc, and 5490m/sec at d l.Og/cc. Qc is about 380kcal/mole. It is practically non-hygroscopic and its thermal stability is satisfactory. Has been used by DuPont Co as a base charge for some detonators Refs I) Beil — not found 2) H. Biltz et al, JPraktChem 142, 193-200 (1935) CA 29, 3652 (1935) 3) Anon, Report on Nitro-... 

N 20.29%, OB to C02 -65.65%, white prisms, mp 190°, explodes. Readily sol in organic solvents. Prepn by gently refluxing bis-tri-methylethylenenitrosochloride with coned nitric acid (d 1.42g/cc) (Refs 1 3). 700.46kcal/mole (Ref 4). Impact sensitivity is less than TNT (Ref 2). Power by ballistic mortar is 106% of, TNT (Ref 2)... 

It is an expl which is slightly more powerful than TNT (114% as detd by ballistic mortar at the Res Lab of NDRC at Bruccton, Pa), and slightly less sensitive to impact. Its thermal stability is satisfactory and it is nonhygroscopic Ref L.F. Fieser M. Gates, JACS 68, 2249 (1946) CA 41, 733 (1947)... 

It is an expl which is as powerful as TNT (99% by ballistic mortar), but more sensitive to impact, being comparable to Tetryl. Its 120° Vacuum Stability Test yields 8cc for a 5g sample in 8 hours, as compared with 6.5cc/5g sample in 15 hours for PETN and 3.8cc/5g sample in 48 hours for Tetryl Refs 1) Beil, not listed in General Index 2) L.F. Fieser W.H. Daudt, JACS 68, 2248-9 (1946)... 

At best, expl power i a somewhat nebulous quantity. If we consider relative power as measured in a Ballistic Mortar or Trauzl Block, then OB correlates reasonably well with relative power, provided these comparisons are made for similar expls. This is illustrated in Fig 1, where Ballistic Mortar measurements axe respectively correlated with OB for nitro, nitramine, nitrate ester and aluminized expls. In general Ballistic Mortar measurements are more reproducible than Trauzl Block data. Consequently we have shown these in preference to Trauzl Block measurements. Correlation between Trauzl block data and OB are reported in Refs 1 8... 

AMCP 706-177 (1971) gives the power of PETN as 145% of TNT in the Ballistic Mortar and 173% of TNT in the Trauzl block. It also lists PETN s brisance at 1.5g/cc as 129% of TNT as detd in plate dent test. The Russians use a somewhat different measure of power which they call total efficiency . This involves computing expln product expansion to 1 atm. Andreev Belyaev (Ref 25, p 655) list the total efficiency of 1.6g/cc PETN as 134% of TNT... 

Power. Ballistic Mortar, 9996 TNT Pressure. Max theoretical when exp Id adiabati-cally at Cv, 8956kg/cm2 at d 1.5g/cc and 9553 kg/cm2 at 1.6g/cc. These are 113% of the corresponding values for TNT Rifle Bullet Sensitivity. 10 trials, 7 unaffected, 3 partly burned... 

VIII. Explosive Characteristics. Picric Acid is generally considered to be a relatively insensi tive but brisant expl. On a qualitative sensitivity scale of comparing common expls, PA would be judged to be more sensitive than TNT but appreciably less sensitive than Tetryl. Its power and brisance are also similar to those of TNT (112% TNT in the Ballistic Mortar 101% of TNT in the Trauzl Block and 107% in the plate dent test (Ref 48). In this section we will consider the steady detonation parameters. initiation characteristics and potential hazards of PA... 

Ballistic Mortar 2) Trauzl block 3) Underwater expins and 4) one method - cylinder expansion — that is now used at Lawrence Livermore Laboratories... 

The ballistic mortar method is described briefly in Vol 1, p VII. Basically this test consists of firing a standard weight of expl (usually lOg) in a suspended mortar closed with a tightly fitting steel projectile. The angle of recoil of the mortar is measured and compared to the recoil produced by the same weight of a standard... 

Comparisons between ballistic mortar strengths and heats of detonation relative to TNT are shown in Table 1 (the mortar values were taken from Ref 5 and the heats of detonation from Vol 7, H41-42). Agreement is generally quite good... 

Comparison of Ballistic Mortar Strength with Observed - Heats of Detonation... 

Explosive Ballistic Mortar Heat of Relative to TNT Detonation Relative to TNT ... 

In the ballistic mortar test the explosive is well confined and develops... 

The ballistic mortar and lead block tests use only small amounts of explosive and are not applicable to slurry explosives which are too insensitive to detonate properly under such conditions. For these explosives it is useful to fire larger amounts of several kg under water and measure the period of oscillation of the gas bubble produced. The longer the period the greater the energy of the gas bubble and this part of the total energy of the explosive has been found to correlate well with the blasting effect of the explosive. 

Fig. 6.3. Relationship between ballistic mortar and lead block tests.

In the other type of test, the strength of the detonation (explosive power) is determined. Examples of methods for this type of test are the lead block test [139] and the ballistic mortar test [141]. Only the first type of test, which determines the possibility of a detonation, is discussed here. 

Concerning brisance and impetus, L H (Ref 1, pp 421-22 Ref 2, p 267) suggest that whether the lead block test is a measure of impetus or of an uncertain combination of impetus and brisance, while a subject of contention, is not of great importance in view of the tendency of impetus and brisance to vary concomitantly. They consider, however, that it is probably safer to use the ballistic mortar values in direct comparison of available energy... 

As we do not know which of these values to take, we think that the best way is to average them, which gives 137%. The same reasoning applies to "power" which for RDX is 170 by TT (Trauzl Test) and 150 by BMT (Ballistic Mortar Test), which gives an average value of 160%... 

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