The EMG Mine. The EMG was a moored, contact, constant-depth mine assembly de-signed for defense against small surface craft such as torpedo boats.

The assembly was designed in 1940 to protect German shipping in the English channel from attack by British torpedo boats and other similar craft. (The original plan contem-plated that this assembly would be employed to protect the flanks of German shipping lanes established in an invasion of England.) The assembly was used operationally until 1943, at which time it was abandoned in favor of the UMA/K and OMA type mines.

The EMG assembly consisted of a ballasted EMC mine case with the lower horns blan-ked off, an EMC anchor, a float, and a weight arranged for constant depth. The assemb-ly was so designed that it maintained a constant depth of eight feet, regardless of the stage of the tide. This assembly could be laid in depths ranging from 30 to 190 feet; but, by lengthening the mooring cable between the anchor and the weight to 820 feet, the assembly could be used in greater depths.

Since the EMG float rode slightly above the water-surface, mine fields utilizing this assembly were easily detected and avoided. To make this apparent disadvantage inure to their own benefit, the German developed a dummy EMG assembly which consisted me-rely of the normal float and anchor, and a 325-foot length of mooring cable. These dum-mies were laid in separate fields or together with EMG's. They were designated "Simulaker für EMG."