Fuzes: Type 3 electric firing device, B-3 (b).

Over-all length: 113 inches.

Length of body: 72 inches.

Diameter of body: 18 inches.

Thickness of wall: 9/16 inch.

Material of wall: Steel.

Type of suspension: Horizontal.

Suspension lug: 2 guide studs on the bomb body position the steel suspension lug.

Color and markings: Gray over all. Green tail struts. No color bands on the nose.

Length of tail: 41 inches.

Width of tail: 25 inches.

Width of tail fins: 10 1/2 inches.

Dimensions of tail struts: Length, 17 1/4 inches; width, 3 3/5 inches; thickness, 1/8 inch.

Material of tail: Steel.

Type of filling: Type 98 explosive cast in paper-wrapped blocks.

Weight of filling: 922 pounds.

Total weight of bomb: 1,584 pounds.

Charge/weight ratio: 58 percent.

Construction of body: The bomb consists of a nose piece, barrel and tail assembly.

The slightly tapered longitudinally welded nose-piece is closed at its forward end by a flat plate which has an 11 3/8-inch diameter. The plate is drilled centrally and this nose pocket can only accommodate a Navy gaine. A metal flange is welded to this plate. It is 5 1/4 inches long, 7/32 inch thick and has an 11 3/8-inch inner diameter. It is pierced by four 1/2-inch holes 3/4-inch aft of the forward end. The nose section is attached to the barrel by a continuous circumferential weld and 17 plug welds. There is a second circum-ferential weld at the point where the nose section begins to taper.

The barrel is of tubular-steel construction.

The tail cone is attached by 30 plug welds to a coupling ring which fits inside the barrel. The coupling ring is held in the barrel by 2 rows of screws numbering 34 in all. There is a standard tail fuze pocket at the apex of the tail cone.

Four Navy type tails fins are welded to the tail cone. The fins are braced by a single set of box-type struts.

Remarks: The type 3 electric firing device is an influence fuze, operated by a photo-electric cell, which is activated by a beam of light projected from the fuze, and reflected from the target. Aerial burst at an altitude of 7 meters or above was desired by the de-signers. Fifty percent accuracy was considered to have been attained.

Figure 69 - Type 3 No. 80 Mk 31 Bomb Model 1.