Submarine Emergency Identification Flares Mk 10 Mods 0 - 2, Mk 11 Mods 0 - 2, and Mk 12 Mods 0 - 2

Length, inches

9.75

Diameter, inches

Weight, pounds

3.2

Use: These signals are used by surfaced submarines to identify themselves.

Description: The flare case consists of a seamless steel tube, one end of which is closed by a steel closure disc. The firing mechanism, which extends along the side of the flare body, is attached to the base casting, which carries the closure disc and primer. The firing mechanism is enclosed in a brass housing which contains the following: (1) a brass shaft held in place by a cotter pin, (2) a firing pin attached to the brass shaft by a sear joint, (3) a spring surrounding the firing pin, and (4) a lanyard attached to the brass shaft. The flare case contains the following: (1) a black-powder charge, (2) a starter composition, (3) a pyrotechnic charge, and (4) a steel cup riveted to the case, closing one end. Two clamps are welded to the flare body for mounting on the bracket fixed to the submarine bridge.

Colors - Flares Mk 11 Type

Mk 11

Mk 11 Mod 1

Mk 11 Mod 2

Burning
Time
(seconds)

Red

Green

Yellow

10

Blackout

Blackout

Blackout

5

Red

Green

Yellow

10

Blackout

Blackout

Blackout

5

Red

Green

Yellow

10

Blackout

Blackout

Blackout

5

Red

Green

Yellow

10

Colors - Flares Mk 12 Type

Mk 11

Mk 11 Mod 1

Mk 11 Mod 2

Burning
Time
(seconds)

Red

Red

Green

10

Blackout

Blackout

Blackout

5

Green

Yellow

Yellow

10

Blackout

Blackout

Blackout

5

Red

Red

Green

10

Blackout

Blackout

Blackout

5

Green

Yellow

Yellow

10

Operation: Mount the flare so that the firing mechanism points toward the deck. A vertical pull on the lanyard forces the brass shaft up, compressing the firing-pin spring. The sear joint between the shaft and firing pin is broken when the shaft and firing pin is broken when the shaft is pulled approximately 0.5 inches. The firing pin strikes the pri-mer, which ignites a small charge of black powder. The flash from the black powder igni-tes the starter composition, which, in turn, ignites the pyrotechnic candle. The flare burns in four increments of 10 seconds duration and intervening blackout increments of five seconds.

Remarks: Flares that have been submerged below periscope depth should be thrown overboard at the first opportunity.

The possibility of detonation in any of the flares, and particularly in those with green pyrotechnics, should never be lost sight of. For this reason, personnel in the vicinity of the flares should be adequately shielded prior to firing.

Submarine Emergency Indentification Flares Mk 10 and Mods are similar to the Flares Mk 11 and Mods and Mk 12 and Mods, except that these burn with only one uninterrup-ted color - Mod 0, red; Mod 1, green; and Mod 2, yellow.

Figure 219. Submarine Identification Flares Mk 10, 11, and 12 Type