The UK considered the PBX 9404 too shock sensitive and replaced it by EDC-11.
In 1961 Los Alamos scientists concluded that the primary was not one point safe under all conditions.
A long series of tests was needed to develop a safe version.
[6] This problem was apparently shared by the Python primary designs.
Characteristics of these weapons are: Based on this information it can be assumed that the Tsetse design itself corresponds to the size of the W44 warhead, 349-millimetre (13.75 in) diameter and 640-millimetre (25.3 in) long, with a weight of around 77 kilograms (170 lb).