Mark 1 / Little Boy
The minimum amout of fissionable material required to sustain a fission chain reaction is called a critical mass. The ffissionable material in the atomic bomb dropped on Hiroshima was uranium 235. This U-235 was kept in two pieces, each smaller than a critical mass. To trigger the bomb, a conventional explosive forced the two pieces together, instantly creating more than a critical mass. This was called a gun-barrel bomb.
| Length: | 320cm |
| Weight: | 4.5t |
| Diameter: | 71cm |
| Yield: |
