Page 72 - Marutas of Unit 731

“ Type 50 Uji Bombs—e 25 kg, 10 liters, Type 50 Uji bomb was an

improved model of the Uji series of bombs. e nose contained an impact,

delay fuse and a bursting tube with TNT. A time fuze in the tail set off the 4

meters of primacord exploding the bomb at a height of 200 to 300 meters. In

case the tail fuze and the primacord failed to function, explosion of the

bomb with dispersion of the contents was insured upon impact by the
explosive train in the nose. Approximately 500 rounds of this model were

manufactured in 1940 and 1941, and extensive eld trials were conducted

during the period 1940 to 1942. e bomb was tested by static explosion and

drop tests from aircra. For the initial tests the bomb was lled with dye

solution and suspensions of nonpathogenic organisms. Later trials were
conducted using a suspension of anthrax spores as the payload. e

suspension had a concentration of 50 to 100 milligrams of spores per cubic

centimeter of liquid.”