Electric squibs

The DuPont Co makes also electric igniting devices, called electric squibs (Ref 50, pp 94-5). Three types of US electric squibs patented by Burrows et al, are described in Ref 44, pp B212 to B214... 

No description of British devices corresponding to US electric squibs is found in Brit books on explosives in our possession, such as Refs 36, 38 51. In Ref 38, p 59 is, however, a description of an electric device which probably serves the same purpose. It is an electric powder fuse, which consists of a thick paper tube contg a small chge of Blasting Powder (Brit for Black Powder or Gunpowder), with an ordinary low-tension fusehead fixed at one end. On passing electric current thru the fusehead it flashes and sets off the BkPdr in the tube, which can... 

In the DuPont s Hdb (Ref 50, p 187), the device consisting of a paper cartridge of BkPdr in which a safety fuse is inserted is called black powder primer with safety fuse, and the device Combining a BkPdr cartridge with an electric squib or cap is called black powder primer with electric squib or cap. 

Squib. 1) (General). Any of various small size pyrotechnic or explosive devices 2) (Specific). A small explosive device similar in appearance to a detonator, but loaded with low explosive, so that its output is primarily heat (flash). Usually electrically initiated, and provided to initiate action of burning type munitions, pyrotechnic devices and rocket propellants. An electrical squib consists essentially of a tube containing a flammable material, and a small charge of powder compressed around a fine resistance wire connected to electrical leads or terminals (Ref 40a, p 135)... 

It is a Iso good practice to ha ve a grea ter gap so that the safety factor can be established. Depending on the type of fuzes being tested they are fired by applying a load or using electric squibs, etc (p IIB-32 of Ref 39)... 

Electric squibs may also be of the delay type, varying in length from 3-1/8 to 5-1/8", depending on the delay time (Ref 1)... 

Te, Mg, Se or Zr, or a mixture of smokeless powders. It is suitable for electric squibs. Tire mixture is heated by means of a bridge wire of Ni-Cr alloy with a diam of at least 0.00225 , whereby certainty of firing is assured under conditions prevailing in series firing USP 2228339... 

These devices are described in Ref 2, pp 120—21, Fig 91), under the title Type 3 and Model 10 Bomb Launching Devices . The description includes the compn of proplnt used in Rocket Mortar as NC 65, NG 30, Et Centralite 3.0 NaCl 2.0%. It was code-designated by the Japanese as 343 DT2 and was ignited by an electric squib... 

Primers, Military (US) (Table E9 on p E57 gives electrical characteristics and compos of explosive trains of Electric Primers XM85, 87, 88 and 89) Electric Squib, MK1, All-Purposes (Vol 5, p E59-L) Electro-Explosive Devices (Vol 5, pp E63 L to E64-L)l Electro-Explosive Devices, Pulse Firing (Vol 5, p E65) Electro-Explosive Device, Thin Film for (Vol 5, p E68-L)... 

Flash Charge of Electric Squib. Its compn is DADNPh (JAN-D-552) 20 2%, KC10g (MIL-P. 150C Grade I, Class C) 60 5%, powdered wood charcoal (JAN-C-178A) 15 2%, Nitro-starch (N 12.75% min) 5i0.5%. Another oompn... 

Electrical Firing Properties of Some Lead Compounds of Nitrated Resorcinol. Lead Mononitroresorcinol (LMNR), PbC CgH NO ) (See p D1271-L in this Vol), used in electric squibs has a lead content betw 68 77%. 

See Electric Squibs in this Vol and also under " Nonmilitary Ignirers in Vol 4, pp D733 Sc D734-L and "Nonmilitary Primers", pp D734-L to D737-L... 

Electric Squibs (Also known as Electric Igniters, or Electric Actuators). These devices are intended to fire deflagrating expls, such. as a pellet or blasting Bk Pdr (Black Powder), NC (Nitrocellulose), or loose smokeless propellant. 

There are also electric squibs which.are used for military purpose. One such device is the US Navy All-Purpose Mkl Electric Squib", shown as Fig E21. It comprises a gilding metal or A1 case (3), contg Pt-Ir bridge wire (4), surrounded by the ignition bead (5), winch may be LSt(Lead Styphnate), LA(Lead Azide) or LMNR(Lead Mononitroresorcinate) + KC103 (95/5). The bridge is connected to two leg wires (l), which pass thru a phenolic plug (2). 

In the pamphlet of Odierno ( Ref 6, p XVA, Table) are listed three US Military Electric Squibs. The Table is reproduced here as Table E10... 

Refs 1) F.S.hort, Raymond Engineering Laboratory Rept No 271(1950), Electrical Squibs BS-14b, BS—19b, Dimple Type Middletown, Conn 2) J.J. Berliner Staff, Explosives, Pamphlet (1953J, p 37 3) Robert Betts, Ordnance... 

Missile Laboratory Rept 4, No 3J14N1, M Compilation of Data on Army, Navy. and Commercial Standard Electric.Squibs , Redstone Arsenal, Huntsville, Alabama (1956) 4) C.E.Baugh,... 

NAVORD Rept 6628 (1959), Evaluation of Explosive Switches MK66 Mod O, and Mk 67 Mod O, White Oak, Maryland 5) J.C.Kenyon, Ordnance Mission Data Rept 4, DA Project 512-1 5-009 (1962), No- Fire Level Test of TADM Electro-Explosive Devices, White Sands Missile Range, New Mexico 6) S Odierno, Information Pertaining to Fuzes , Pamphlet, pub-lished by Picatinny Arsenal in 1964, Vol 4, pp XVA XVB 7) DuPont Blasters Hdb (1966), 94—5 (Electric Squibs)... 

Burrows Inventions L.A.Burrows, during his work with the DuPont Co, obt many patents on explosives, igniters, initiators, fuses, explosive rivets, electric squibs, etc... 

Rion and Dupont (Ref 44) examined the mode of detonating expl trains which can incorporate several std W-contg delays of either 0.6 or 2.8 sec duration. The techniques considered were electrical squib and percussion fuse. The relative merits.of each system are discussed. They also present an exptl device for electrical ign delay time measurement. Charsley and Tolhurst (Ref 46) in their study of the 50/50 W-K dichromate delay system note that reaction between these constituents starts at 400° when the dichromate melts and contacts the W, producing yellow flames. They also found that when this mixt is heated rapidly to 380—400°, ignition occurs with a bright flash... 

It can be used as an active component in initiating mixtures, e.g. for electrical squibs in bridgewire detonators. It is more powerful and more sensitive than -+ Lead Styphnate reaction. 

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