The Germans are constantly bringing out new hollow-charge weapons. Recently, documentary
evidence has come in regarding three new bombs and a
hollow-charge nose-capped device of most unusual interest because it employs a
small hollow charge as an armor-piercing nose cap to open the armor ahead of
the fragmentation bomb itself. The nose device, as reported, appears to open an
entirely new field in armor-piercing projectiles. If it can be applied to artillery
shells, it may conceivably produce a change that might seriously affect the value
of armor. Such a change--both on land and at sea--could be highly significant.
a. 250-kg Bomb
(1) SD (Thick-Cased Fragmentation Bomb) 250*
Figure 1 shows the general arrangement of the HE charge in SD 25C
(550 lbs) bombs having a hollow charge. The charge is amatol 50/50 and
the cavity is semicircular in section.
The HE charge has a metal lining (1) for the cavity which is supported on
a flange (2), and in order to permit the formation of the jet the flange is located
at a distance from the nose of the bomb of approximately 1.5 times the diameter
of the cavity. The opening (3) at the nose of the bomb is
approximately 5 1/4 inches.
(2) Improved 250 HL Bomb
It has been reported that the type of bomb illustrated in figure 1 was disappointing
in performance and modifications were made which resulted in the
production of HL (Hohl Ladung--hollow charge) types of bomb. The 250 HL is
illustrated in figure 2, but there are also the 500 HL and 1,760-pound
800 HL designed on the same lines. The charge is amatol 60/40 and the
bomb is in two parts.
Details of performance of these types from trials "at rest" are given
on the next page:
||Reinforced Concrete Penetration
|250 HL 13.78 inches||not available|
|500 HL 24.6 inches||11.48 ft.|
b. 500-kg Bomb
The cavity in the 1,100-pound SD 500 bomb (no sketch available) is a
truncated cone, the larger diameter being 11.81 inches and the smaller
diameter 4.33 inches.
c. 800-kg Bomb
Details of the performance of the 1,760-pound 800 HL are not available
but its design is similar to the 250 HL and it appears that with an HE charge of
242 pounds it is anticipated it will penetrate 39.37 inches of armor and 19.68 feet of
d. Hollow-Charge Nose Device
A special nose device intended for use with the SD 250 bomb is shown in
figure 3. The purpose of this is to obtain greater penetrating power of the bomb
when dropped from low altitudes.
The device consists of a hollow charge (4) attached to the nose of a standard
type (not hollow-charge), bomb. This charge which weighs about 8.8 pounds is
detonated by its own fuze located at (5), and in order that the detonation of this
hollow charge shall not damage the bomb, the space (6) is filled with a maximum
of sawdust and cement.
The object of the device is to produce a hole in the armor through which
the bomb can pass. The bomb is fitted with a Rheinmetal fuze charged for delay
so that detonation of the bomb shall occur within the target. It is reported that
the nose device can penetrate 2.76 inches of armor plate.
*The 250, 500 etc, refers to weight in kilograms.