DATA:

OVERALL LENGTH

BODY LENGTH

BODY DIAMETER

WALL THICKNESS

TAIL LENGTH

TAIL WIDTH

TAIL WEIGHT

WEIGHTS:

Chg/Wt. Ratio

FUZING:

AN-M146, M144

BOMB CONSTRUCTION:

The body is a modified AN-M57 250 lb. G.P. body with a metal closing cup riveted to the base. An intergral booster of four ounces of black powder is placed immediately be-hind the fuze seat liner and serves as an expelling charge. A wooden nose piece fits around this booster and a steel piston in turn is seated in the base of the nose piece. A steel tube or piston stem is welded through a hole in the piston extends from the black powder booster to the plywood ignition disc in the center of the bomb. Six wooden thrust members reach from the piston plate to the tail closing cup and serve to trans-mit stress to this cup without imposing any of the force on the candles. An 1/8 inch thickness of felt lines the entire interior cylindrical surface of the bomb. The 61 candles are in two banks of 30 and 31 and have their ignition ends facing toward the quick-match strands stapled on the ignition disc which separates the two banks.

TAIL CONSTRUCION:

The tail, in appearance, is a standard box type tail. It is attached to the bomb by means of four spring latches fitting into cutouts in the tail closing cup and which can be locked in place by stamped steel strips pivoting over the end of the springs.

SUSPENSION:

Horizontal suspension by standard lugs, 14" apart.

OPERATION:

When the arial burst fuze functions, the fuze booster ignites the black powder boos-ter or expelling charge in the bomb. The force of the expanding gases from the booster acting through the piston and thrust members throws off the fin assembly and expels the candles.

REMARKS:

The bombs are used to form a pattern of red, green, or yellow colored light appoxi-mately 100 yards in diameter around or on a target; the light should be visible from al-titudes of 25,000 to 35,000 ft. day or night. They are used to spot individual targets once the general target area has been marked by flares dropped by Pathfinder planes. The explosive charge in the T6 candle is ignited by the flare composition at the end of burning. These charge serve to prevent any removal of the candles by the enemy once the candles are on the ground.

The M89, M90, and M98 are identical, differing only in the type and number of cand-les:

(1) The M89 contains 61 non-delay T4 candles.

(2) The M90 contains 57 non-delay T4 candles; 2 exploding T6 candles bruning for one minute; and 2 exploding candles burning for two minutes.

(3) The M98 contains 31 non-delay T4 candles; 10 exploding T6 burning for one minute; 10 exploding T6 candles burning for 1.5 minutes; and 10 exploding T6 candles burning for two minutes.