CZK - Průbojné náložky PN-4 a PN-14

Breakthrough cartridges PN- 4 and PN- 14 belong to special cartridges.


They are intended :- for piercing armour, reinforced concrete walls, building walls, armoured and otherwise reinforced gates and doors, fortified buildings and loopholes, road surfaces, surfaces of airstrips and heliports, railway tops, etc.


- for the establishment of wells in the course of the foundation of underground trenches,
- barricading and de-barricading,
- the destruction of the load-bearing structures of reinforced concrete bridges,
- in the pyrotechnical field, for the mass destruction of large calibre ammunition, aerial bombs and rocket warheads,



The PN-4 and PN-14 charges work on the basis of using the directed effect of the explosive blast to a single point in a part of the cumulative recess, which is made of a thicker steel liner.
PN charges can also be fired sideways against the walls of buildings.
The explosion of PN charges is manifested both by pressure against the object being blasted and in the opposite direction (i.e. in the extension of the longitudinal axis of the charge) and in the plane of the bottom edge of the insert. These are the directions in which most of the shrapnel from the PN liner shell is ejected during the explosion. Therefore, it is necessary that the person firing the cartridge should lie at an angle of 45 degrees to the longitudinal axis of the PN cartridge, if possible. This rule must be observed especially when the PN is fired in the side position against a vertical wall.
There are three folding feet on the bottom edge of the PN cartridge which are folded along the cartridge body during transport. The legs must be unfolded and secured before the PN can be placed on or against an object. The legs have a length which, when unfolded, defines the distance between the cartridge and the object at which the blast effect is most effective.




Both PN 4 and PN 14 pads have the same needle shape without the spike. They differ only in dimensions, weight of the blasting charge and total weight. They are equipped with a carrying strap at the top.



TTD puncture charges PN- 4- height with folded legs: 34 cm
- height with legs folded out: 46 cm
- largest diameter: 20,5 cm
- total weight: 6.4 kg
- explosive weight: 4.8 kg (50/50 mix of tritol and hexogen)
- weight of the trigger body 75 g (explosive pressed pentrite Np 10)

The PN- 4 penetrating charge pierces:
- armour plates up to 35 cm thick,
- reinforced concrete walls up to 100 cm thick,
- in moderately hard rock to a depth of 150 cm, with an upper diameter of 35 cm and a lower diameter of 12 cm,
- brickwork 45 cm thick is driven through from a distance of 9 m, creating an entrance hole 25 x 35 cm and an exit hole 60 x 60 cm,
- a 45 cm thick stone masonry wall is driven through from a distance of 7,5 m, creating an entrance opening of 25 x 25 cm and an exit opening of 25 x 40 cm,
- brickwork 60 cm thick is driven through from a distance of 7,5 m, creating an entrance opening of 35 x 35 cm and an exit opening of 50 x 50 cm,
- a 60 cm thick stone masonry wall is driven through from a distance of 5 m, creating an entrance opening of 20 x 20 cm and an exit opening of 50 x 30 cm,






TTD breakthrough cartridges PN-14
-height with folded legs: 50 cm
- height with legs extended: 75 cm
- largest diameter: 32 cm
- total weight: 22 kg
- explosive weight 17 kg (50/50 mix of tritol and hexogen)
- weight of the trigger body 75 g (explosive pressed pentrite Np 10)

Breakthrough charge PN- 14 pierces:
- armour plates up to 50 cm thick,
- reinforced concrete walls up to 150 cm thick,
- in heavy rock, creating a well up to 190 cm deep, 40 cm to 50 cm in diameter,
- brickwork 45 cm thick is drilled from a distance of 15 m, creating an entrance hole 50 x 50 cm and an exit hole 80 x 80 cm,
- stone masonry 90 cm thick is driven from a distance of 7,5 m, creating an entrance opening of 35 x 35 cm and an exit opening of 100 x 100 cm,





The ignition is carried out with a timed igniter, a flashbang with detonator (BP- 1 flashbang primer) or an electric detonator. In the upper part of the cartridge there is a detonation well with a screw insert and a sealed action body made of pressed pentrite Np 10 (75g). The primer body is used for a more sensitive transfer of detonation between the primer and the cartridge itself.





Sources:
Regulation of Women 2-6 No. 2264 /SŽV/ 1980 issued by the Ministry of Defense of the Czechoslovak Socialist Republic in 1982
Workbook - Crack and Destruction published by VA Vyškov in 2005 under order number 45/2005
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