Additional details have been received concerning the German 50-kg
phosphorus incendiary bomb previously reported in
Tactical and Technical Trends, No. 14, p. 13.
The bomb body appears to be a one-piece steel forging and has no weld
marks. The suspension eyebolt may be in the side or the nose of the bomb, as in
normal 50-kg (110 lbs) HE bombs. The bomb is filled with a very thick, almost
black mixture, which is so viscous that there is no sound of movement of liquid
when the full bomb-case is shaken. This bomb can be distinguished from the
50-kg HE bomb by the following features:
(1) The rear of the bomb from the shoulder to the filling cap is painted red.
(2) The filling cap is also painted red, and is screwed down on a black
rubber washer which is clearly visible.
(3) A sheet metal collar is welded to the case between the filling cap and
the shoulder. The collar, which is painted red, is drilled and tapped to take
screws by which the tail is attached to the bomb.
(4) On one of the bombs seen, a 1-inch red band is painted around the
bomb, 1 inch behind the suspension eyebolt. The body of this bomb is painted
The fuze used has been the normal type. No picric pellets have been
discovered in the fuze pocket, their place being taken by wooden blocks, shaped like
a picric ring, and picric booster pellets.
The fuze functions on impact, and the explosion resulting from the detonation
of the shell casing splits the bomb-case. The subsequent operation is
not known, but it is possible that the flash from the casing detonator ignites the
benzene vapor and, provided sufficient oxygen is present, fires the inflammable
filling. Because of the sticky consistency of the main filling, the latter does not
appear to spread far from the broken pieces of the bomb. Once ignited, the main
filling burns briskly, and has been known to burn for as long as 2 hours, giving
off sooty black smoke.
d. Radius of Effect
Reports have been received of detonation occurring below ground
level. In such cases a small, shallow crater may be formed. These craters
have been measured, and may be up to 6 feet in diameter, and up to 18 inches in
depth. Pieces of turf and earth have been found scattered up to a
radius of 9 feet.
|Length of bomb body|| ||2 ft 6 in|
|Diameter of bomb body||8 in|
|Wall thickness||1/8 in (approx)|
|Nature of filling||Crude benzene, 86% |
| ||Phosphorous, 4%|
| ||Rubber (probably pure), 10%|
|Weight of filling||30 lbs (approx)|
|Total weight||90 lbs (approx)|