This bomb consists of a cylindrical, metal container with a hemispherical nose and tail piece welded at either end. Burster containers are located at either end of the bomb, and, in the tail, to one side of the burster tube, is a filling hole closed with a threaded plug. A tail locating ring is welded around the tail portion of the bomb body.
Although provision is made in the bomb for alternate nose or tail fuzing, the nose pocket is always closed with a plug, and only the tail pocket is employed.
The Tail No. 31 Mk I consists of a sheet-metal tail cone to which are riveted four vanes supported by a cylindrical metal strut. The tail is attached to the bomb by four spring clips which engage the tail locating ring on the after end of the bomb body. Inside the tail cone, supporting the lower end of the reach rod, is located a diaphragm with four large holes to allow air passage.
A single suspension lug is provided for carrying in British planes, and two additional lugs for U. S. suspension are 180' removed.
This is a special purpose bomb designed primarily for low-level bombing operations. Its use will be restricted to special missions.
It is recommended that personnel engaged in disposal operations on this bomb be equipped with rubber boots and gloves, and that these be kept damp. All equipment and protective clothing which may have come into contact with the liquid phosphorus should be washed thoroughly immediately after use.
The contents of this bomb will ignite immediately with a highly incendiary effect upon contact with the air. Following the bursting of this bomb, a dense smoke screen will be emitted for at least two hours. Bomb, 500 lb IB, Mk 1 (bulletpicker.com)