71. These signals are for either day or night use. They are for use exclusively with the submarine signal ejector and are ejected by compressed air. On rising to the surface of the water, Submarine Emergency Identificaion Signals Mk 2 Mod 2 and Mk 3 Mod 0 pro-ject a Single Star Grenade Mk 5 to a height of 250 feet, where a parachute opens and supports the star, which burns for approximately 13 seconds. The complete signal is available in one of three colors, RED, GREEN or YELLOW. See Fig. 32.

Figure 32 – Submarine Emergency Identification Signal, Mk 2 Mod 2
(Similar to Mk 3 Mod 0)

(a) Submarine Emergency Identification Signals Mk 2 Mod 2 and Mk 3 Mod 0 consist of a buonyant tube of aluminum 18.5 inches long and three inches in diameter, which contains the Single-Star Grenade Mk 5 Mod 0. One end is closed with an ogive nose cap. The other end carries the ignition device, which consists of a firing pin, a lock spring and pin, and a safety cotter pin which is of the ring-pull type. Above the firing-pin lever is the primer in its holder, which flashes into the combination delay unit and ejection charge. See Fig. 32.

(b) Early issues of Submarine Emergency Identification Signal Mk 2 Mod 2 contained eit-her Smoke Grenade Mk 3, for day use, or Three-Star Grenade Mk 4, for night operation. Both these signals are now obsolete, and the current issue with the Single-Star Grenade Mk 5 is for both day and night use.

(c) Submarine Emergency Identification Signals Mk 2 Mod 2 and Mk 3 Mod 0 should not be ejected at depths greater than 160 feet as the time required to reach the surface is limited to the 27 seconds allowed by the time fuze.

Operation

72. Complete instructions for firing Submarine Emergency Identification Signal Mk 2 Mod 2 will be found in paragraph 77, 78, and 79, covering the use of submarine signal ejector.

Packing

73. Submarine Emergency Identification Signals Mk 2 Mod 2 and Mk 3 Mod 0 are shipped in wood containers holding 25 signals. The shipping weight of the container is approxima-tely 100 pounds.

Stowage

74. For shipboard stowage Submarine Emergency Identification Signals Mk 2 Mod 2 and Mk 3 Mod 0 should be placed in a gasket sealed metal container, which holds 12 signals and is known as Packing Box Mk 2 for Submarine Emergency Identification Signals. Should this item not be available, a three-inch cartridge tank may be substituted.

Safety Precautions

75. These signals should be inspected frequently. Any corrosion of the safety mechanism is cause for disposal by dumping in deep water as described in paragraph 17.

(a) Should any signal be removed from submarine signal ejector without being fired, the safety cotter pin must be replaced immediately after ascertaining that the firing mecha-nism is undamaged, and that the firing-pin lever is in place.

(b) The signal case should be thorroughly dreid, and the nose cap should be inspected to make sure that its sealing effectiveness is unimpaired.

(c) The Single Star Grenade Mk 5 is installed in Submarine Emergency Identification Sig-nals Mk 2 Mod 2 and Mk 3 Mod 0 by the depot and should not be removed therefrom.

(d) Signals of this type now in service are expected to only 50 per cent performance. For this reason, at least three signals should be fired in actual operations for each star requi-red.