Type V Mine (DE)
The German Type V Mine was made especially for use by submarine minelayers, but it could be sown by any vessel equipped with vertical minelaying tubes. The British found that these weapons were slight variations of the earlier Type IV. By mid-1917, these were the largest German mines found to date, as they featured a 12 inch cylindrical extensive to their charge.
This article is based, initially, on a British report on German mines from July, 1917.[1]
Type V Mine | |
Weight | 835 lbs. |
Casing | 0.2 in. welded steel |
Charge | 361 lbs. T.N.T. |
Trigger | four impact horns |
Primer | unknown |
Detonator | 90 gr. fulminate of mercury |
Buoyancy | 281 lbs. |
Height | 46 in. |
Diameter | 34 in. |
The charge was of cast T.N.T. installed through a loading hole in the bottom of the cylindrical charge chamber. A intermediate primer of compressed T.N.T. was integral to the cast warhead and surrounded the primer proper. The charge chamber was galvanised within.
Action of Laying and Detonation
German mines of Type I through V worked in the same manner. The mine and sinker went to the bottom together. After 10 or 20 minutes, a soluble plug dissolved to release the mine, which rose under its own buoyancy, trailing the tethering cable behind. When the hydrostatic depth gear in the mine determines that its proper depth has been attained, it fired to grip the mooring cable. After this, the depth gear and grip would be locked to prevent ratcheting upward with a rising tide. The British felt the depth gear was reliable and accurate.
When a contact horn was struck and bent, a glass tube of acid would break, and its contents would flow to a bichromate battery to energise it, causing the detonator to fire. This action was instantaneous.
Footnotes
- ↑ German Navy: Part IV, Section 3. Torpedoes, Mines, Etc.. pp. 18-26, Plates 28, 29, 32, 34, 37.
Bibliography
- Admiralty (July, 1917). German Navy: Part IV, Section 3. Torpedoes, Mines, Etc. (C.B. 1182) The National Archives. ADM 186/228.