Ship's Emergency Identification Signals Mks 1 - 4

General: The body of each of these signals varies in length according to its design. Each signal consists of a pressure-retaining disc and disc-locking nut, a primer, a four-gram smoke-less-powder propelling charge, a copper obturating cup, a delay train, an ejection charge of approximately 1.1 grams of black powder, and a signal of pyrotechnic composition. All signal cup except the shower signals have a parachute for mide-air sus-pension.

Operation: The signal is fired from Signal Projector Mk 1 or Mk 1 Mod 1. The signal is placed in the projector primer-first, where it rests against the retaining pin. A pull on the lanyard removes the firing pin and allows wht signal to descend against the firing pin with sufficient force to close the valve and fire the primer. The primer ignites the delay train and propelling charge simultaneously. The gases from the propelling charge expand the obturating cup until it is secured tightly in the bore of the projector. Increased pressure ruptures the pressure-retaining disc, and the gases then escape through the openings in the retaining-disc locking nut into the projector bore. The gases propel the signal ap-proximately 600 feet. The ignited delay train burns until the singal reaches approximately the zenith of its trajectory, and then ignites the ejection charge. The ejection charge ejects and ignites the singal pyrotechnics through a quick match and first fire composi-tion.

Mk 1 (Star)

Length, inches

5.124

Diameter, inches

Color

Burning time, seconds

25 ± 5

The closing cap is embossed for night identification. The star is parachute-suspended.

Mk 2 (Shower)

Length, inches

6.374

Diameter, inches

Color

Burning time, seconds

5

This signal is designed to give two distinct bursts, one with a short delay and one with a long delay. The closing cup is embossed for night identification.

Mk 3 (Smoke)

Length, inches

9.124

Diameter, inches

Color

Burning time, seconds

25 ± 5

The closing cap is painted with same color that is produced by the signal. The signal is parachute suspended.

Mk 4 (Chameleon)

Length, inches

5.124

Diameter, inches

Color combinations

Burning time of each color, seconds

Delay between colors, second

1

The signal is parachute-suspended and designed to change color while burning. Other-wise, the signal is similar to the Signal Mk 1.

Figure 211. Ship's Emergency Identification Signal Mk 2 (Shower)

Figure 212. Ship's Emergency Identification Signal Mk 3 (Smoke)

Figure 213. Ship's Emergency Identification Signal Mk 4 (Chameleon)
and Signal Mk 1 (Star)