OP 1673A - German Underwater Ordnance; Chapter 11 - Influence Mine Units - SVK and Luftwaffe; Section 1 - Influence Firing Devices - Tables: Influence Mine Units

GERMAN UNDERWATERS ORDNANCE MINES

Chapter 11 - INFLUENCE MINE UNITS - SVK AND LUFTWAFFE

Section 1 - INFLUENCE FIRING DEVICES - TABLES

INFLUENCE MINE UNITS - NAVY

Figure 131 – Table of Influence Mine Units – Navy

Unit	Principle	Originating Firm	Development		Firm	Case	Use	Remarks
Unit	Principle	Originating Firm	Start	1st Sample	Firm	Case	Use	Remarks
M 1	Magnetic	Hartmann & Braun, SVK	1923	1925	H & B SVK	RM, LM, TM	Sub. A/C Sur- face	Magnetic balance for vertical component. Self-setting since 1938. 30-mg until 1941, then 10-mg. 5-mg. for combination.
M 2	Magnetic	Askania	1933	1935	Ask- ania	EMF, SMA, TMA	Sub. Sur- face	Magnetic balance for ver-tical component. Self-set-ting since 1938. Counter-balance against motion. 30-mg.
M 3	Magnetic	SVK	1935	1936- 1937	SVK H & B	EMF, SMA, TMA, LMF, LMB	Sub. Sur- face, A/C	Soft NI-FE antenna system. Self-setting since 1938. 20-mg. Cheaper than M 1.
M 4 (15-mg)	Magnetic	SVK, Eumig, Baermann	1941- 1942	1943	Eumig H & B	EMF, SMA, TMA, LMF	Not laid	Soft NI-FE antenna system. Self-setting 15-mg. Little NI used. Cheaper than M 3.
M 4 (2.5-mg.)	Magnetic	SVK, Eumig, Baermann	1941- 1942	1943	Eumig	EMF, SMA, TMA, LMF	Not laid	Same as above - used in combination capable or re-setting.
M 5	Magnetic	Hagenuk	1942	1943	Eumig	Gnd. mines	Not laid	Same as M 1; 2.5-mg Miniature M 1
A 1	Acoustic	SVK Hell	Sum- mer 1940	In Two Weeks	Hell	LM	A/C	Carbon microphone, Two-relay circuit, 200-cps cut-off after 2 months use, Shock-blocking - 30-sec. period in 1st models; du-ration of shock in later models.
A 1st	Acoustic	SVK Hell	1941	In Three Weeks	Hell	LM	A/C	Same as A 1 but with "stumpf" microphone.
A 2	Acoustic	SVK Hell	Fall 1940	Short Time	Hell	TMB TMC	Sub.	Same as A 1.
A 2st	Acoustic	SVK Hell	1941	Short Time	Hell	TMB TMC	Sub.	Same as A 1st.
A 3	Acoustic	SVK Hell	Fall 1940	Short Time	Hell	EMF SMA	Sub. Sur- face	Same as A 1. Abandoned after large number of EMF/A 3's blew up spontaneously in bad wheather.
A 4	Acoustic	SVK Hell	1942	Four Weeks	Hell	LM TM	Not laid	Same microphone as A 1. Minimum rate-of-change-fixed. Also shock-blocking.
A 4st	Acoustic	SVK Hell	1944	Short Time	Hell	LM TM	A/C Sub.	Same as A 4 but with "stumpf" microphone.
A 7	Acoustic	SVK Hell	1944	Short Time	Hell	EMF SMA	Sub. Sur- face	Same as A 4 but with series condenser for determining mean sound level.
MA 1	Magnetic- Acoustic	SVK Hell	1941- 1942	Four Weeks	Hell	LM	A/C	5-mg M 1 triggers; 1-tube circuit.
MA 1a	Magnetic- Acoustic	SVK Hell	1942	Short Time	Hell	LM	A/C	Same as MA 1 but no shock-blocking.
MA 2	Magnetic- Acoustic	SVK Hell	1942	3 Weeks	Hell	LM TM	Sub. A/C	5-mg. M 1 triggers 3-tube. A circuit with rate-of-change cirucit. 30-40 sec. active period of A.
MA 3	Magnetic- Acoustic	SVK Hell	1944	Short Time	Hell	LM	A/C	Same as MA 2 but 15-sec. active period of A.
AT 1 (AA 1)	Acoustic- Subsonic	SVK	1942	6 Months	Elac	LM	Not laid	Acoustic triggers sub-sonic. Dynamic microphone 25-cps. 3-tube amplifier 60-sec. active period of T.
AT 2 (AA 2)	Acoustic- Subsonic	SVK Elac	1943	3 Months	Elac	LM	A/C	Same as AT 1, but improved protection against detonat-ions. 3-4-sec. active period of T.
AT 3 (AA 3)	Acoustic- Subsonic	SVK Eumig	1943	5 Months	Eumig	TMB TMC	Not laid	Same as AT 2, but with lon-ger life and for TM use.
D 1	Pressure	SVK	1942	6 Months	Hasag	LM TM	---	Pressure component only. Suction contact. Circuit normally set to 8-sec. delay.
D 2	Pressure	Hasag	1944	Short Time	Hasag	LM TM	---	Pressure component only. Smaller than D 1. Pressure contact added and deto-nation protecting valve.
DM 1	Pressure- Magnetic	SVK Hasag	1942	Sum- mer 1942	Haseg	LM TM	A/C Sub.	5-mg M 1 combined with D 1; 8-sec. delay in D 1 circuit at 15-25-mm suction D 1 ready for action 15-40 sec. after M 1.
M 1s	Magnetic	SVK	1943	1944	Hage- nuk	LM	Not laid	Improved M 1 to save bat-tery on pendulum action.
M 1r	Magnetic	SVK	1943	1944	Hage- nuk	LM	Not laid	Sea electrodes detect cur-rent from LL-sweep and block; otherwise normal M 1.
MA 1ar	Magnetic- Acoustic	SVK	1944	Short Time	Hage- nuk	LM	Not laid	MA 1a with sea current blocking device for M 1 component.
S	Low-Fre- quency "Seismik"	SVK	1944- 1945	1945	SVK Hage- nuk	LM	Not laid	Carbon microphone in D 1 unit. Fires on 5-8 cps.
DS 1	Pressure- Seismik	SVK	1945	Short Time	SVK	LM	Not laid	Combination of D 1 or D 2 with S.
AE 1	Acoustik- Echo	ELAC	1943	6 Months	ELAC	EMF SMA	Not laid	Acoustic triggers echo- sounder. Fires when water depth decreases - sensitivity 2 meters.
O	Optic	Ley- boldt	1941- 1942	1942	Ley- boldt	--	Aban- doned in '43	Selenium cell operates relay if light intensity decreases.
WS	Electro- Magnetic	Hell	(1932) 1942	3 Months	Hell	LM	Aban- doned in '43	Two antenna for transmitter and receiver with no mutual induction. Acoustically-trig-gered. Xmtr 5 kc. Distortion of field fires.
AA 4	Acoustic- Supersonic	Siemens	1943- 1944	6 Months	Sie- mens		Aban- doned in '44	Acoustic triggers two sets magnetistrictive receivers 25 kc. Output of two sets compared.
AMT 1	Acoustic- Magnetic- Subsonic	SVK	1944- 1945	1945	SVK	TM	Not laid	Combination of M 4 with AT 3.
AMT 2	Acoustic- Magnetic- Subsonic	SVK	1944- 1945	1945	SVK	LM	Not laid	Combination of M 4 with AT 2.
	Cosmic Ray	SVK	1942	---	Inst. of Prof. Rege- ner	LM	Not laid	24 Geiger counters with 1000-1500 v fed to ampli-fier. Change in cosmic ray back-ground level, when ship passes over, fires mine; rate-of-change cir-cuit.