FAB-5000 bomb

FAB-5000
Sketch of an FAB-5000 bomb
Type	General purpose bomb
Place of origin	Soviet Union
Service history
In service	28 April 1943 - 9 May 1945
Used by	Soviet Air Force
Wars	World War II
Production history
Designer	Nison Illich Gelperin
Specifications
Weight	5,000 kg (11,000 lb)
Length	3107 mm
Diameter	642 mm (25.3 in)
Filling	TNT, RDX and aluminium powder
Filling weight	3,200 kg (7,100 lb)

The FAB 5000NG bomb (Russian: ФАБ-5000НГ, where NG stands for its inventor, Nison Gelperin) was a 5,000 kilograms (11,000 lb) large air-dropped, general-purpose thin cased high explosive demolition bomb used by the Soviet Air Forces during World War II. The device was the most powerful aerial bomb in the Soviet inventory.

The bomb was designed by Soviet chemical engineer Nison Gelperin () (1903-1989) in 1942. Gelperin projected and built bombs with tiny metal casings, in order to reduce the use of iron cast and aluminium. In Gelperin developments, the weight of metal casings represented only the 35 percent of the bomb's weight.

By 1942, the State Defense Committee of the Soviet Union perceived the need of weapons that could hit-hard industrial and military facilities, marshaling yards and fortifications, without the usual scattering of medium-weight bombs. The first attempt came in the form of an explosive unmanned aircraft, a modified version of the TB-3, but the trials of this flying bomb were less than satisfactory.

The Directorate of Logistics of the Air Forces eventually requested to Gelperin the development of a five-ton bomb, capable of being dropped by the Pe-8, the heaviest Soviet bomber of the time. The definitive version of the FAB-5000 was fitted with six contact lateral fuses, and the warhead was filled with 3,200 kg (7,100 lb) of an explosive mixture of TNT, RDX, and aluminium powder. The number of fuses ensured that the force of the blast would disperse laterally, which increases the damage in areas such as industrial compounds and military facilities. In order to load the device, the bomb bay doors had to remain half-open. The tests, however, were successful. Two bombs were dropped, one from an altitude of 4,000 m and the other from 3,300 m. The first bomb fell in open ground, leaving a crater 6 metres (20 ft) in diameter and 3 metres (9.8 ft) in depth. Grass in a radius of 150 m was charred. The second bomb landed in the woods, and left a crater of 8 metres (26 ft) in diameter and 3 metres (9.8 ft) in depth. Some 600 trees were torn out within a 70 m radius, while 30 percent of the trees within 135 m also fell down. Later tests produced craters up to 20 metres (66 ft) in diameter and 9 metres (30 ft) in depth. The project was brought to the assembly line and the bomb was hastily put in service on 15 February 1943. By the end of the war, 98 FAB-5000s had been delivered to the Soviet Air Forces, all of them produced in 1943.