Chapter 4 - Contact and moored influence Mines: Base PlatesChapter 4 - Contact and moored influence Mines: Base Plates: Table of Contact Mines
GERMAN UNDERWATERS ORDNANCE MINES
Chapter 4 - CONTACT AND MOORED INFLUENCE MINES
TABLE OF BASE PLATES

Base Plate

Where Used

Diameter
(inches)

Material

Mooring
Spindle
Delay

Type of
Booster Tube

SDM
(self-destroying
mechanism)

How Secured

Remarks

Type EMC

EMC EMD

15

Gun metal

Two oil
dash pots

8 ½ in.
long, open
at top

Chemical horn
mounted in top of
mooring spindle
tube

Secured by
20 bolts

Considered obsolete

Type EMC I

EMC EMD

15

Steel

Two oil
dash pots

18 in. long,
closed at
top

Rotary two-posi-
tion switch

Secured by
19 bolts

Considered obsolescent

Type C
EMC II

EMC EMD

15

Steel

Soluble
plug

18 in. long,
closed at
top

Chemical horn
mounted beside
mooring spindle

Secured by
20 bolts

Fitted with lower antenna gland
180° from booster tube; gland
blanked off with a hexagonal cap,
if not, antenna is fitted

Type
UMA

UMA

11 ½

Steel

Two oil
dash pots

15 in. long,
closed at
top

Rotary two-posi-
tion switch

Secured by
19 bolts

Considered obsolete

Type
UMB

UMB

11 ½

Steel

Soluble
plug

15 in. long,
closed at
top

None

Secured by
18 bolts

Fitted with Tombac firing device
gland, 180° from A - E switch and
with mooring spindle locking
detent, 180° from booster tube