cutaway pictures and information courtesy of PzGr40
Cutaway model of a WW2 German B1-EL incendiary cluster bomb.
The B1-EL is the simpelest of a series of light incendiary cluster- and dispenser bombs of which the body is made of Elektron and whom have a thermite filling.
The bomb comes in a variaty of types, other types have a small explosive charge placed to the base (B1-EL ZA) or in the Nose fuze (B1-EL ZB), either modifications in the fuzing system. There are also various types in the 1,3 and 2 kg series that are pending on the same principal design.
Build up of the bomb:
The body of the bomb is an Elektron (92% Magnesium + 5% aluminiun + 3% zinc) piece of pipe, tapered at the base, and internally threaded to receive the base plug. The Top of the body is internally threaded to receive the Fuze AZ.13. Near the top of the body, six holes are drilled as an initial flame escape.
The tail is a three piece (pressed - spotwelded) metal sheet assembly that fits over the tapered base of the bodt. It is held in place by three small rivets.
The fuze used is the AZ 13 (also called AZ.8312). It is a simple impact fuze with no safety features. Before loading the bomb into the Clusterbomb or dispenser, a safety pin is to be removed (hole on right). At impact the inertia block, housing the firing cap (red)overcomes the spring, pushing the firing cap into the firing pin. The body of the fuze is Elektron, the inner parts of the fuze are brass made.
Earlier types of AZ.13 had a steel body.
Above the fuze , a split collar spacer is placed (ring with holes), above it a disc spacer is placed. On top of these two a disc with a small detonator (yellow) is placed that is used to ignite the thermite. The collar spacer enshures the flames can leave the holes through the side of the bomb after ignition. The holes are (off factory) plugged of with wax and a piece of tape goes round the body ??over the holes- to enshure the bombs are moisture proof (thermite is very sensitive to moisture)
Functioning of the bomb:
If the bomb falls to the ground, nose down, the firing cap hits the firing pin. The flame of the firing cap (red) ignites the small detonator (yelow), which on its turn ignites the main charge of thermite. First, the flames will appear from the holes in the side, however soon the whole elektron body and fuze will catch fire.
A fire of Thermite and the elektron body burns very hot, appr. 2000 degr celsius and is difficult to extinguish. Using water to extinguish the bomb will make the bomb burn more fierce.
Weight of the bomb : 1 kg.
Diameter of bomb : 50mm.
Length of bomb : 350mm.
Filling : 680 grams of thermite
A B1-EL dropped from 2000 mtrs height is able to penetrate 5cm of reinforced concrete. However I suppose this data only counts for the older type of B1-El that had a steel nose fuze body.
The bomb was meant to be used in build up areas and industrial areas.
It was used in the bombs and dispensers: AB 42 , AB 70D1, AB 250-2 (224 pcs), BSB 360/700/1000 container (320/570/702 pcs), AB 500-1 (392 pcs), ABB 500 (133 pcs).
During production of the cutaway model it occured to me that the spring that keeps the firing cap away from the firing pin is quite strong. Therefore, an impact of considerable speed is required to enshure ignition. There must have been quite a number of duds.
Cutaway model of a WW2 German B1-EL incendiary cluster bomb.
The B1-EL is the simpelest of a series of light incendiary cluster- and dispenser bombs of which the body is made of Elektron and whom have a thermite filling.
The bomb comes in a variaty of types, other types have a small explosive charge placed to the base (B1-EL ZA) or in the Nose fuze (B1-EL ZB), either modifications in the fuzing system. There are also various types in the 1,3 and 2 kg series that are pending on the same principal design.
Build up of the bomb:
The body of the bomb is an Elektron (92% Magnesium + 5% aluminiun + 3% zinc) piece of pipe, tapered at the base, and internally threaded to receive the base plug. The Top of the body is internally threaded to receive the Fuze AZ.13. Near the top of the body, six holes are drilled as an initial flame escape.
The tail is a three piece (pressed - spotwelded) metal sheet assembly that fits over the tapered base of the bodt. It is held in place by three small rivets.
The fuze used is the AZ 13 (also called AZ.8312). It is a simple impact fuze with no safety features. Before loading the bomb into the Clusterbomb or dispenser, a safety pin is to be removed (hole on right). At impact the inertia block, housing the firing cap (red)overcomes the spring, pushing the firing cap into the firing pin. The body of the fuze is Elektron, the inner parts of the fuze are brass made.
Earlier types of AZ.13 had a steel body.
Above the fuze , a split collar spacer is placed (ring with holes), above it a disc spacer is placed. On top of these two a disc with a small detonator (yellow) is placed that is used to ignite the thermite. The collar spacer enshures the flames can leave the holes through the side of the bomb after ignition. The holes are (off factory) plugged of with wax and a piece of tape goes round the body ??over the holes- to enshure the bombs are moisture proof (thermite is very sensitive to moisture)
Functioning of the bomb:
If the bomb falls to the ground, nose down, the firing cap hits the firing pin. The flame of the firing cap (red) ignites the small detonator (yelow), which on its turn ignites the main charge of thermite. First, the flames will appear from the holes in the side, however soon the whole elektron body and fuze will catch fire.
A fire of Thermite and the elektron body burns very hot, appr. 2000 degr celsius and is difficult to extinguish. Using water to extinguish the bomb will make the bomb burn more fierce.
Weight of the bomb : 1 kg.
Diameter of bomb : 50mm.
Length of bomb : 350mm.
Filling : 680 grams of thermite
A B1-EL dropped from 2000 mtrs height is able to penetrate 5cm of reinforced concrete. However I suppose this data only counts for the older type of B1-El that had a steel nose fuze body.
The bomb was meant to be used in build up areas and industrial areas.
It was used in the bombs and dispensers: AB 42 , AB 70D1, AB 250-2 (224 pcs), BSB 360/700/1000 container (320/570/702 pcs), AB 500-1 (392 pcs), ABB 500 (133 pcs).
During production of the cutaway model it occured to me that the spring that keeps the firing cap away from the firing pin is quite strong. Therefore, an impact of considerable speed is required to enshure ignition. There must have been quite a number of duds.
