Leg wires

V7. High Voltage Power Transmission Lines Electric Currents. The chief hazard associated with operations near such lines is the possibility of being electrocuted should a cap leg wire or leading wire be thrown by the blast to make contact with the live power line... 

The shot point should never be located closer to a line than a distance equal to the length of both leg wires. Taking the length of both wires is necessary (except when duplex wire is used) he cause the single wires may part and form a single long conductor... 

If " Ledcore units, Primacord1 or Primaline are no-t available, the cap leg wires should be securely anchored at or near the shot point... 

If cap leg wire or a leading wire should happen to be thrown over a power line the blasting crew should not attempt removal of the wire, but request the power company to do this... 

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). 

Elec connection between shell wall leg wire Insulating material Tab... 

Applications of Sapphire Cell-Infrared Spectroscopy Companion to the Diamond Cell in Explosive and Leg Wire Identification , JForensic-Sci, 57-65 (1978) 163) S. Bulusu, Mass... 

Most home builders use 22-gauge insulated copper for their leg wires. This adds to the cost but is vitally important so that the bridge Ignites properly when power is applied. At detonation, only an inch or two of leg wire is chewed off. These slightly shortened wines can be collected and reused after most detonations. 

Keep all leg wires neatly rolled up and tied together as a deterrent against errant radio transmissions that could cause premature detonation. 

U is extremely important that the leg wires be at least two sizes heavier than the bridge wire. 

A short-circuiting device provided on the free ends of the leg wires of electric blasting caps to protect them from accidental initiation by extraneous electricity. 

The inner tube is inserted through a hole in the lid into the substance in the sample tube. A No.O or No.6 detonator is inserted into the inner tube and fixed to the tube by winding the leg wires. 

The test sample assembly is inserted into the bore of the mortar and the projectile is attached to the open end of the mortar. A pen is inserted into the hole in the pen-holder and a reference line is marked on the strip chart paper when the fully-loaded mortar is at rest. The detonator leg wires are connected to the firing circuit and the charge is fired. The pendulum swing length can be read from the results recorded on the strip chart paper. 

Fig.3.122 shows a test sample attached to the frame. Leg wires are connected to leading wires, and the connection is sealed to be water-tight. The sample bottle is sunk to a depth of 1 m and is detonated. The first pulsating bubble is recorded. 

Leg wires from of the detonator are linked with the initiation wire, then connected to the initiator. After verifmg that there is no one in the dangerous region of the test site, the sample is ignited. 

A No.6 electric detonator is inserted into the inner tube, the sample vessel assembly is placed in the ballistic mortar bore, and the 2kg projectile is attached. The leg wire of the detonator is connected to the firing circuit, the charge is fired and the length of swing is measured. 

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