Booster Capping

Ui0 Vnivsrsal Destmcior. ihe destructor is used to convert loaded projectUee, missiles, and bombs Into improvised chargee. The destructor has booster caps contaiziing tetryl pel lets. All standard firing devices with the standard base coupler screw into the top. 

Tetiyl. 2,4,6-Trinitrophenylmethylm tramine (tetryl) was used ia pressed form, mostly as a booster explosive and as a base charge ia detonators and blasting caps because of its sensitivity to initiation by primary explosives and its relatively high energy content. Properties are presented ia Table 11 (173). Batch and continuous processes for the production of tetryl have been developed. Tetryl is no longer used ia the United States and has been replaced by RDX (174-178). 

In general terms, PETN can be characterized as a sensitive , brisant, and powerful high expl. Explosive sensitivity is a rather nebulous quantity, but there can be no doubt that PETN is a much more sensitive material than TNT, but rather less sensitive than Lead Azide. In particular, PETN requires very little priming i charge (less than 1 mg LA) to initiate its detonation. This is the characteristic that makes PETN so widely used in blasting cap base charges, in detonating cord and in boosters... 

If no other sources exist, artillery and mortar shells, bombs, land mines, and other munitions may be cannibalized for the high explosives they contain. These munitions usually contain cast explosives, which require extra strong blasting caps or boosters to detonate. However, some of the simpler cannibalization techniques will be discussed. 

If the booster remains in the warhead, the charge can be detonated by attaching a blasting cap or primacord across the red dot. 

If the booster is not used, the warhead may be primed by filling the cavity in the top with plastic explosive, into which is embedded and fastened a blasting cap or a primacord knot. 

Pentaerythritol tetranitrate (PETN) is a colorless crystalline solid that is very sensitive to initiation by a primary explosive. It is a powerful secondary explosive that has a great shattering effect. It is used in commercial blasting caps, detonation cords, and boosters. PETN is not used in its pure form because it is too sensitive to friction and impact. It is usually mixed with plasticized nitrocellulose or with synthetic rubbers to form PBXs. The most common form of explosive composition containing PETN is Pentolite, a mixture of 20 to 50% PETN and TNT. PETN can be incorporated into gelatinous industrial explosives. The military has in most cases replaced PETN with RDX because RDX is more thermally stable and has a longer shelf life. PETN is insoluble in water, sparingly soluble in alcohol, ether, and benzene, and soluble in acetone and methyl acetate. 

Explosives are classed as primary or secondary. Typically, a small quantity of a primary explosive would be used in a detonator (known colloquially as a cap ), whereas larger quantities of secondary explosives are used in the booster and the main charge of a device. This collection of explosives is known as an explosive train in which a signal (mechanical, thermal, or electrical) from the control system is converted first into a small explosive shock from the detonator, which in turn initiates a more powerful explosion in the booster, which amplifies the shock into the main charge. 

These differ from the secondary explosives shown in Figure 1, in that AN-based explosives are generally so insensitive that in addition to a blasting cap , a strong booster is also required for initiation. 

Owing to their intrinsic safety and inexpensive nature, AN/fuel formulations have almost completely replaced dynamites as the mining explosive. As a result, they are by far the most widely used explosive. AN formulations are sold as AN prill or solution, ANFO pre-mixed, AN water—gel (although this is becoming obsolete) AN emulsions, either in cartridges or as bulk material that is brought to the site and loaded directly from the tmck to the borehole and heavy ANFO (ANFO folded into an AN emulsion). AN formulations usually require the use of a high explosive booster, but powerful and cap-sensitive formulations can be prepared. 

For driving the plate, a chge of low density Tetryl was spread on its surface. The initiation was accomplished by the fragmentation of the A1 disk, which occurred when Tetryl booster was ignited by a blasting cap. The... 

Accdg to Urbanski (Ref 1), some smokeless proplnts in the form of scales loaded in an iron tube, at density 0.5 to 0.7 and initiated with a cap 20 g of PA booster detonated with a vel of 1000-1500 m/sec the same proplnts Loaded in the same type of tube but at density above 1.0 detonated at vels betw 7000 8t 7700 m/sec. The vels in both cases proceeded at constant rate thruout the chges which were 10 in long... 

The same chge of flaked TNT initiated with a cap St 12.5 g of Tetryl booster detonated with a vel of 3660m/sec. The length of tube was 10 in and the vel was constant in both cases thruout the length of the tube... 

Booster-Gap Explosive Sensitivity Test of Cole Edwards, described in detail in USP 2832213(1958) (Ref 17). It was claimed to be more reliable and less ex. pensive than the card test (See after "card-gap test") and the three-legged table test, described here after "shock-pass-heat-filter test . The "booster-gap test serves for evaluating shock sensitivity of liquid explosives. It includes a set of snug-fitting telescopic cardboard tubes (ca 1 inch diam) and a cylindrical wooden block for holding the electric blasting cap, Tetryl booster pellet, circular spacer cards, and the cup with liquid explosive (to test) fit compactly in the cardboard tubes when... 

Detonation, Wax-Cap Test in. See Vol 1 of Encycl p VIII, under "Booster Sensitivity Test and also on p A 354, Footnote c, entitled Wax Gap Test ... 

BELAY ELEMENT PRIMER NOSE CAP ANTICREEP SPRING BOOSTER... 

It is identical with the M55 series, except that M55 models have a booster assembled to the fuze. The fuze consists of three major parts 1) A closing cap or head (A) contg the SQ impact element (B, C, E) and the time-action plunger (F) 2) Two time-train rings,... 

Fuzes, MT M43 Series. The original M43 fuze was developed to fulfil the requirement for a single-purpose MT fuze for antiaircraft use with medium caliber shell fitted with the same booster as other standard fuzes. All modifications have the contour which is characteristic of modern design fuzes. They provide for time setting to 30 seconds and are without impact element (See Fig 1-89) The fuze body for the M43 to M43A4 fuzes is in three parts an upper cap, a movable lower cap, and a fixed base (W). 

The mixture was put out in cylinders about 220 mm long by 28 mm in diameter. Due to difficulty with direct cap initiation, a booster was provided. It consisted of compressed, phlegma-tized PETN pellets about 40 mm long by 21 mm diam and equipped with a detonator well 20 mm deep... 

Electric Bomb Gaine, Instantaneous, length 5-3/8 depth 1-3/8 inches. Expl Train The Electric Blasting Cap fitted into hollowed-out cavity in the PA Booster. Leads from the cap ran up to a female plug which was attached by a special adapter to the standard Gaine body (p 199, Fig 148)... 

Type 2 Small Model Bomb Gaine Model 1, Instantaneous. Length 3, depth 13/16 inches. Expl Train MF cap over Tetryl in upper plug PA Booster (p 200, Fig 149)... 

Booster A cap-sensitive high explosive used to initiate other less sensitive high explosives. 

It is suitable for use as booster charges and as base charge in blasting caps and detonadors (Refs 4 6)... 

The device described in USP 2541334(1951) of C.H- Carey D.R. Walton is intended primarily for expls contg a high proportion of AN and little or no NG. In expls of this kind, as the apparent density is increased (as by hard packing), there is reduction in sensitivity to detonation and decrease in sensitivity by influence. Introduction of an auxiliary expl (booster) compressed to a lesser degree than the main charge assures complete detonation. It also permits the use of insensitive expls (as main charges) which could not be detonated by the cap alone... 

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