GERMAN UNDERWATERS ORDNANCE MINES |
Chapter 7 - SUBMARINE-LAID MINES |
THE TM MINES |
The TMA I Mine. This mine was the only moored mine of the series. Prior to the com-pletion of the M 2 magnetic unit, a contact pistol was designed for the mine. This pistol was a pendulum type styled after the Russian 1906 pistol used in the Russian mines M 12, M 26, and PLT. The evidence as to whether this pistol was used operationally is conflicting, the prisoners of war interrogated having voiced different opinions on the sub-ject. Since no documents were available, a definite answer to this question cannot be given. |
The M 2 magnetic unit which was designed for the TMA proved unsatisfactory. Con-sequently, only a small quantity of TMA mines were laid. Toward the close of the war, the M 3 was adapted for use with this mine, so that existing stocks could be utilized. |
Figure 100 – TMA Mine with Anchor, Ready for Laying |
|
Figure 101 – TMA I Mine |
|
Description of Case |
Shape |
Cylindrical, with hemispherical nose and tapered, finned tail |
Material |
Aluminum (KSS) |
Diameter |
21 in. |
Length |
9 ft. 3-1/2 in. |
Charge |
475 lb. cast hexanite |
External Fittings |
Bowden wire channel |
180° from top center line, extends full length of case |
Positioning lugs |
Five, on nose, 30°, 120°, 210°, 270°, and 300° respect-ively from top center line; 7 in. from center |
Securing lugs |
Two, on nose, 90° and 270° respectively from top center line; 7 in. from center |
Mechanism plate |
11 in. diam., on nose, secured by 15 studs; covered by fairing, 6 in. diam., which is cut away to permit access to the mooring eye and securing lugs |
Safety latch |
On lower fin, in line with bowden wire channel, spring-loa-ded controls bowden wire |
Joning flange |
5 ft. 6 in. abaft the nose, covered by two sections of semicircular sheathing, 2 in. wide |
Fins |
Four, 0°, 90°, 180°, and 270° from top center line, at after end; 2 ft. 4 in. long, 9 in wide |
Operation. When the mine is launched, the safety latch springs out, pulling the bow-den wire. This unlocks the spindle of a hydrostatic clock. Water pressure depresses the clock spindle at a depth of 15 feet, starting the clock. The clock spindle, once depress-ed, is locked in. The clock runs off its delay setting, allowing the detonator to house in the booster, and the firing unit begins its arming cycle. |
No self-disarming devices are fitted. |
Figure 102 – TMA Mine – Cross Section |
|
Figure 106 – TMA Mine Afloat |
|