Cutaway model of a Ptab 2,5M shaped charge anti tank bomblet / cluster bomb.
Ptab is the abriviation for ‘Protivo Tankovaya Aviatsionnaya Bomba’ which translates as anti tank aircraft bomb.
The bomblet is used in two different types of cluster bombs: 30 bomblets in the RBK 250kg clusterbomb,(pict 04), and 75 pcs in the RBK 500 kg clusterbomb.
The Ptab 2,5M consists of a cylindrical steel body in which a steel cone is placed. An aluminium bushing housing the flame sensitive detonator is glued to the base of the cone. Below this bushing, a bakelite bushing is placed, housing the booster charge (yellow) that ignites the main charge.
The tail is screwed over the base of the bomblet body, and consists of a pressed steel cup to which four fins are spotwelded. A sheet steel ring is welded in the base of the fins.
The fuze used on this bomblet is the AW-524M, a near direct copy of the WW2 German EAZ66 which was used on the SD4-HL and the SD10. The main difference is that the AW-524M has an out of line electric detonator that rotates in line upon arming of the fuze.
Functioning of the fuze:
The impeller is placed on a spindle, but rotates seperate from the spindle. In the impeller (Pict 03 shows the principle functioning, which is the same in this EAZ 66 drawing) a radial hole is drilled in which houses a dumbbel shaped weight, kept pushed inward by a spring, and locked up by a lock up screw on the outer rim of the impeller. When the impeller rotates with 5000 rpm in the aitstream after release from the cluster bomb, the dumbbel shaped weight is thrown outward -riding the spring-, engaging the impeller with the spindle that now screws the impeller forward -out of the fuze body-. When the spindle moves outward the shutter -housing the electric activated detonator- rotates to the armed position above the main detonator in the base of the fuze housing. The spindle is placed in a steel ring, which is placed in a copper wire spool. Upon impact the impeller, the spindle and the steel ring are hammered inward, the steel ring moving through the copper wire spool, generating a current pulse, igniting the electric detonator, the detonatorin the base of the fuze housing, the spitbak detonator, the booster charge and the main charge around the cone. This system is known as either “spitback fuze”, either PIBD “Point Ignited Base Detonated”.
Complete length Ptab 2,5M : 397mm
Length bomb body without tai land fuze : 177mm
Tail length : 170mm
Diameter tail (over fins) : 90mm
Bomb body diameter : 68mm
Regards, DJH
Ptab is the abriviation for ‘Protivo Tankovaya Aviatsionnaya Bomba’ which translates as anti tank aircraft bomb.
The bomblet is used in two different types of cluster bombs: 30 bomblets in the RBK 250kg clusterbomb,(pict 04), and 75 pcs in the RBK 500 kg clusterbomb.
The Ptab 2,5M consists of a cylindrical steel body in which a steel cone is placed. An aluminium bushing housing the flame sensitive detonator is glued to the base of the cone. Below this bushing, a bakelite bushing is placed, housing the booster charge (yellow) that ignites the main charge.
The tail is screwed over the base of the bomblet body, and consists of a pressed steel cup to which four fins are spotwelded. A sheet steel ring is welded in the base of the fins.
The fuze used on this bomblet is the AW-524M, a near direct copy of the WW2 German EAZ66 which was used on the SD4-HL and the SD10. The main difference is that the AW-524M has an out of line electric detonator that rotates in line upon arming of the fuze.
Functioning of the fuze:
The impeller is placed on a spindle, but rotates seperate from the spindle. In the impeller (Pict 03 shows the principle functioning, which is the same in this EAZ 66 drawing) a radial hole is drilled in which houses a dumbbel shaped weight, kept pushed inward by a spring, and locked up by a lock up screw on the outer rim of the impeller. When the impeller rotates with 5000 rpm in the aitstream after release from the cluster bomb, the dumbbel shaped weight is thrown outward -riding the spring-, engaging the impeller with the spindle that now screws the impeller forward -out of the fuze body-. When the spindle moves outward the shutter -housing the electric activated detonator- rotates to the armed position above the main detonator in the base of the fuze housing. The spindle is placed in a steel ring, which is placed in a copper wire spool. Upon impact the impeller, the spindle and the steel ring are hammered inward, the steel ring moving through the copper wire spool, generating a current pulse, igniting the electric detonator, the detonatorin the base of the fuze housing, the spitbak detonator, the booster charge and the main charge around the cone. This system is known as either “spitback fuze”, either PIBD “Point Ignited Base Detonated”.
Complete length Ptab 2,5M : 397mm
Length bomb body without tai land fuze : 177mm
Tail length : 170mm
Diameter tail (over fins) : 90mm
Bomb body diameter : 68mm
Regards, DJH
