85. Submarine Identification Flares Mk 10 Mod 0, Mk 10 Mod 1, and Mk 10 Mod 2 differ only as to the color of the signal they provide. All are housed in a seamless steel tube 9.75 inches long and two inches in diameter, closed by a steel cup riveted to one end by a casting at the other end. The casting houses the closure disc and the primer, and is attached to the firing mechanism, which extends along the side of the steel tube. The flare is mounted in a bracket fixed to the conning tower of the submarine. It is fired by a lanyard and burns with a briliant colored flame about nine inches high, which lasts appro-ximately two minutes. The firing mechanism consists of a brass housing two inches long which contains a firing pin, a firing pin spring, and a brass shaft. The brass shaft is inter-locked to the firing pin by a beveled keyway. A pull ring is attached to the lower end of the brass shaft, and a safety cotter pin secures the housing to it. Before firing the flare, remove the safety cotter pin. A strong downward pull on the lanyrads is necessary to allow the firing pin to slip out of the keyway. The firing spring then drives the firing pin upward, firing the primer, which ignites a small charge of black powder. The resultant pressures are sufficient to blow off the steel cup at the top of the tube, exposing the colored flare. See Fig. 35

Figure 35. – Submarine Identification Flares Mks 10, 11, and 12, and Mods

Operation

86. Submarine Identification Flares Mk 10 and Mods are mounted to brackets fixed to the conning tower of the vessel. To fire, first remove the safety pin and then give the lan-yard as sharp pull downward. When mounting, the safety pin should be straightened to facilitate its quick removal when ready to fire.

Packing

87. Twenty submarine identification flares are packed in a wood container. Each flare is marked with a colored band on the steel case to show the color of the signal.

(a) Submarine Identification Flare Mk 10 is marked with a RED band and burns with a RED flame.

(b) Submarine Identification Flare Mk 10 Mod 1 is marked with a GREEN band and burns with a GREEN flame.

(c) Submarine Identification Flare Mk 10 Mod 2 is marked with a YELLOW band and burns with a YELLOW flame.

Stowage

88. The general rules for the stowage of pyrotechnics detailed in paragraphs 9 to 12, in-clusive, apply to Submarine Identification Flares Mk 10 and Mods. Flares which have been exposed to spray should be carefully dried before retunring them to ready service maga-zines for future use.

Safety Precautions

89. In handling and firing Submarine Identification Flares, the following safety precautions should be taken:

(a) Because of the possibilty of detonation, particularly of Submarine Identification Flare Mk 10 Mod 2 (GREEN), all personnel in the vicinity of the flare should take cover immedia-tely before firing. Some submarines of the fleet have been equipped with a shield for shielding the flare on the bracket. This shield should be obtained, is possible.

(b) A few drops of light oil should be supplied in the holes of the firing mechanism just prior to firing. If the flare is explosed to weather or spray for any appreciable time, this oil will be essential to the smooth operation of the firing mechanism.

(c) If they are not to be fired, flares should be removed from the brackets beforer the vesserl is submerged, whenever possible. Flares exposed to submersion below periscope depth should be detached on surfacing and cast overboard.

(d) All flares which have been exposed to weather and spray to such an extent that they show deterioration should be cast overboard. Any evidence of corrosion beneath the bracket clamps, or along the joint of the casting with the steel tube, is sufficient cause for disposal of the flare.