HANDBOOK OF ENEMY AMMUNITION |
PAMPHLET No. 10 |
GERMAN, ITALIAN AND JAPANESE AMMUNITION |
WOODEN BOX MINE 42 |
German designation: Holzmine 42 |
Data |
Internal dimensions | 290 x 272 x 82 mm (11.4 x 10.7 x 3.2 in.) |
Size of lid | 13 x 12 x 3/4 in. |
Size of aperture in lid | 163 x 65 mm |
Pressure block (without feet) | 6 x 2.4 x 2.4 in. |
Size of compartments: | |
Main charges |
116 x 196 mm |
Priming charges |
45 x 175 mm |
Thickness of partitions | 5 mm |
Size of shearing flange | 195 x 32 x 14 mm |
Size of slot in shearing flange | 7 x 17 mm long. |
Size of wooden blocks | 79 x 20 x 22 mm deep. |
Main explosive | Amatol 50/50 |
Total weight of explosive | 11.9 lb. |
Total weight of mine | 18 lb. |
Note: |
Where appropriate the first dimension is parallel to the length of the pressure block. |
Casing |
The mine is contained in a box (1) of 3/4 inch timber to which the base is nailed. The box is sub-divided internally into four compartments, of which the two at the side contain the main explosive filling (2), while the central compartment (3) contains the primer charges (2-300 gm. Sprengkörper) and the end compartment (4) the operating mecha-nism. The central compartment contains a bottom packing piece 34 x 10 mm. thick, two small wooden blocks, one, 34 x 20 x 8 mm (5), nailed to the bottom packing piece and the other, 34 x 22 mm section (6), nailed to the back; these locate the primer charges firmly in place. The parititons (7) and the partition (13) are removable. The end compart-ment (4) contains a shearing flange (8) secured to the outside wall by two 3/8 inch wooden dowels; this flange is provided with a central slot (9) which allows the end of the striker to pass when arming. Two wooden blocks (10) are nailed to the base on each side of the igniter rest and carry the pressure block when the mine is not armed. The igniter rest (12) consists of a small piece of wood with a U-shaped piece cut-out at the top and screwed to the base from the underside by two large screws to that the "U" is opposite the slot which is out in the partition (13). The lid (14) is secured to the mine at the front and back by metal hooks (15), and is located by wooden dowels (16). At one is a rectangular hole (17) for the pressure block (11), and at the other end a stacking piece (18). On the underside of the lid are two 22 x 9 mm diameter, wooden pegs (19) which prevent the two wooden feet (20), on the underside of the pressure block (11), from moving towards the centre of the box and also prevent the pressure block being put in the wrong way round. When the mine is armed the feet (20) rest on the shear flange (8), in which position the head of the pressure block projects about 2 inches above the lid. During transit the pressure block is reversed so that the feet rest on the blocks (10); in this position the pressure block protrudes about 3/4 inch. |
Filling |
The main filling consists of two charges of Amatol 50/50, each of approximately 2.4 kg (5.3 lb.) in the compartments (2). Specimens captured in Sicily revealed that the char-ges were covered with some bitumastic substance for exclusion of water. The primer charges are situated in the central compartment (3), and consits normally of three 200 gm. charges. An Italian document describes the charge nearest the igniter as a "200 gm. charge No. 28", and the remaining two as "Standard 200 gm. prepared charges". In addi-tion the German marking (see below) mentions "Zwei Füllkörper o. Bohrung". In the ab-sence of further detail the primer charges have all been shown as Sprengkörper 28 (200 gm. charges). |
Igniter |
This is the Z.Z. 42. |
Anti-lifiting Devices |
These can be fitted underneath the central compartment and would most probably con-sists of a Z.Z. 35 igniter is screwed into a 200 gm. charge. To fit an anti-lifting igniter the charge require rearrangement in the central compartment (3). The charge carrying the Z.Z. 42 igniter remains, one additional 200 gm. charge is laid with the hole down-wards; the length of the latter prevents a third 200 gm. charge being inserted. It is be-lieved that the holes for anti-lifting igniters are made when the booby traps are laid. Re-ports from Sicily say that of the mines encountered in one erea, 35 per cent, were fitted with anti-lifting igniters. |
Method of Laying |
An Italian document says the mine is usually laid with the top of the pressure block level with the ground, in which case the aluminium spacing between mines is 6 feet. If the mine has to be laid on the surface this spacing must be increased to 13 feet. The mine is laid with the red strip (21) facing defending troops, i.e. so that the H.E. charge lies more directly under the oncoming load. The mine cannot be laid in water or in damp ground, where it would deteriorate. |
Method of Operation and Laying |
Pressure on the pressure block (11) shears the 2 inch dowels securing the shear flange (8) to the outer wall and forces the shear flange down on to the igniter pin, which is withdrawn and frees the spring-loaded striker. |
Idenfication |
A vertical red band (21) is painted down the centre of one end of the box and is conti-nued on to the lid. When armed, the side of the pressure block (11) facing this band is also painted red. |
The mine marked as follows:– |
I |
HOLZMINE 42 |
bestehend aus |
Zwei Ladungen zu etwa 2.4 kg. Fp. 50/50 |
Zwei Füllkörper o. Bohrung |
gue |
eingehörige Zündungen in besonderem Packgefäss |
Translation |
I |
WOODEN MINE 1942 PATTERN |
consisting of |
two charges each of approximately 2.4 kg 50/50 Amatol |
two "filling" charges without igniter socket |
one 1928 pattern 200 gm. charge with igniter socket |
gue (manufacturers code) |
relevant firing assembly in a special packing container. |
Firing Pressure |
It is reported from Sicily that the mine will fire under a pressure of 200 lb., whereas the firing pressure given in the Italian document is 200-300 kg. (400-660 lb.). From the dia-meter of the shear dowels it appears that the figure of 200 lb. is the more probable. |
To Neutralize |
(i) | Look for and neutralize any anti-handling devices. |
(ii) | Remove lid carefully. |
(iii) | Reverse pressure block so that it sits in the safe position. |
(iv) | Replace lid. |
To Disarm |
(i) | Look for any neutralize any anti-handling devices. |
(ii) | Remove lid carefully. |
(iii) | Remove pressure block. |
(iv) |
Hold the actuating pin in position and remove one of the blocks of the priming char-ge but not the one into which the igniter is screwed. Slide back the block with the igniter until the actuating pin is clear of the shearing flange–lift out charge and ig-niter. |
(v) | Carefully unscrew the igniter, holding the pin in position. |
(vi) | Remove detonator. |
Detectability |
The mine is detected with difficulty by the U.S. detector at a distance of 6- 8 inches under normal conditions. Although the igniter body is bakelite the striker and pin are me-tal and a specimen of the mine when examined was found to contain 32 nails of varying sizes, 2 screws, and 2 fastening clips. |
|