Slick Marker Cartridge AN-Mk 1

Length, inches

Diameter, inches

Muzzle velocity, ft./sec.

Weight of dye, grams

28

Use: This marker is used primarily to provide reference points for aircraft engaged in antisubmarine warfare.

Description: The cartridge is composed of a shotgun-type case containing a primer, a black-powder propelling charge, and the projectile. The projectile has a thin aluminum case and contains 28 grams of fluorescein dye and a black-powder bursting charge initia-ted by a Bickford type fuse.

Launching: The marker cartridge is fired in the Pyrotechnic Pistol AN-Mk 8, which may be held in the hand or mounted in the Mount M1.

Operation: When the cartridge is fired, the black powder in the head of the case pro-pels the projectile from the pistol and at the same time ignites the Bickford fuse. The fuse burns for about eleven seconds before igniting the bursting charge which expels the fluorescein dye out into the water. The projectile has a positive buoyancy and will remain near or at the surface until a small, bright green slick is created.

Remarks: This cartridge should not be fired from altitudes greater than 500 feet, be-cause the cartridge must be in the water when it bursts.