500 lb. Smoke Bomb Mk IIntroduction Practice Bombs
U.S.N.B.D. - BRITISH BOMBS AND FUZES; PYROTECHNICS; DETONATORS
AIRCRAFT SMOKE BOMBS

 

 

 

 

 

BRITISH BOMB

FUZING

Tail Fuze No. 885 or

500 LB. SMOKE

 

No. 886

COLOR & MARKINGS

Green overall; red band

 

near nose; black stencill-

 

ing

Mk II

TAIL NO.

No. 81 Mk I

 

OVERALL LENGTH

67"

(Service)

BODY LENGTH

46"

 

MAX. BODX DIAMETER

13"

 

WALL THICKNESS

 

 

TAIL LENGTH

22"

 

TAIL WIDTH

13"  

TOTAL WEIGHT

 

 

CHARGE/WEIGHT RATIO

 

 

BODY CONSTRUCTION:

The bomb consists of a cylindrical bomb body made of thin sheet steel, with a nose plate welded to one end of the body. Three catch brackets, spaced 120° apart are welded to the nose plate, and a nose fairing is secured to the catch brackts by spring clips. Immediately beneath the nose plate is located a loading plate.

An exploder pocket is welded to the nose plate and contains an ejection charge. A nose plug is screwed into the exploder pocket.

An igniter tube with four series of perforations extends down the center axis of the bomb and contains a celluloid tube holding a primed cambric tube. The igniter tube is held in place by the igniter tube holder, located in the center of the tail plate.

The remainder of the bomb body is filled with three banks of smoke generators, each bank consisting of eight wedge-shaped units fitted with drag plates.

A tail plate, to which is welded the fuze adapter, is secured to the inside of the after end of the bomb body by six brass rivets. A tail locating ring is fitted to the inside of the tail plate.

TAIL CONSTRUCTION:

No. 81 Mk I: This tail consists of a cylindrcial strut held in place on the truncated tail cone by four sheet metal fins. The tail is held in place by the usual four spring clips which engage in four similar recesses in the tail ring on the bomb body. A locating pin in the tail ring engages a slot in the bottom edge of the tail cone to position the tail.

SUSPENSION:

This bomb is equipped for suspension in either British or American aircraft, having on one side a single suspension lug and dual lugs 180° removed.

FUNCTIONING:

When the bomb is released from the aircraft, the fuze is armed. At a predetermind height, the fuze functions, and the flash from the fuze magazine ignites the contents of the igniter tube. The perforations in the igniter tube allow the burning celluloid and pri-med cambric to initiate the smoke generators and eventually the ejection charge. The pressure of the gases generated by the ignition of the ejection charge bears against the loading plate and forces the whole inner assembly against the tail plate, which shears the six brass rivets which hold it to the bomb casing. The tail plate and att-ached tail unit are then thrown clear of the bomb, and the bomb contents are ejected through the tail.

REMARKS:

1. Should water, especially sea water, come into contact with the smoke composi-tion used in this bomb, the smoke composition is liable to spontaneous combustion due to chemical action.

500 lb. Smoke Bomb Mk IIntroduction Practice Bombs