The secret of the Davidka was its 40 kg (88 lb)
bomb, which was much larger than the mortar from which it was fired. In conventional mortars, the bomb is inserted into the tube and the entire
projectile travels through the tube to gain initial guidance at launch time. The Davidka's tail tube is the only part of the shell which fit inside the launch tube. This contributed to the weapon's notorious inaccuracy, as the shell lacked adequate guidance during the launch phase to acquire
aerodynamic stability in the intended direction. It is not a
spigot mortar, either; in a spigot mortar the "barrel" is a guiding rod inserted
inside the shell's propellant chamber. The Davidka's propellant chamber fires inside the mortar tube (barrel) as does a conventional mortar, but the 3 inch (76.2 mm)
caliber of the
barrel is much smaller than the caliber of the
warhead of the bomb. It is therefore an oversized conventional mortar, where most of the bomb, and especially its
center of gravity, remain outside the barrel—an aerodynamically unstable design, which only worked at all because the
center of pressure was still within the barrel. The head of the bomb was essentially a large can filled with nails, rocks, or any other material which could be used for shrapnel. This meant that the blast effects of the weapon were completely random and of dubious efficacy as an
anti-personnel weapon. It was of no practical value for
siege combat or other light artillery purposes, but it made a loud bang. Small pieces of metal and tubes were welded onto the outside of the casing, reducing the weapon's accuracy even further than its already non-aerodynamic design, but contributing greatly to the whistles and shrieks which it made when in flight. The noise was its most important effect, so that anyone attacked by a Davidka mortar would hear the shell seeming to fall very near to them before bursting very loudly, increasing the fear factor. The Arabs abandoned many strongholds during the war as a direct result of this visceral fear: one story relates that, having been told that many of the proponents and designers of America's atomic bomb were Jewish (e.g.,
Einstein and
Oppenheimer), the Arabs thought that they were being attacked with
atomic weapons and subsequently abandoned their homes. This was especially true in the
liberation of Safed. The Davidka was used in the battles for
Haifa,
Ein Zeitun,
Safed and Biddu. According to Palestinian historian
Walid Khalidi, the Davidka carried a bomb that weighed and caused fear and panic when used in built-up areas. ==Syrian rebels' copy ==