Pilum - Results of Experimental Archaeology

Results of Experimental Archaeology

Thanks in part to experimental archaeology, it is generally believed that the pilum's design evolved to be armour-piercing: the pyramidal head would punch a small hole through an enemy shield allowing the thin shank to pass through and penetrate a distance sufficient to hit the man behind it. The thick wooden shaft provided the weight behind the punch.

In one description, one of the two iron nails that held the iron shaft in place was replaced with a weak wooden pin that would break on impact causing the shaft to twist sideways. Gaius Marius is sometimes given credit for this modification. It has been argued that later pila were constructed so that the iron shank would bend on impact. Having penetrated a shield through a small hole and its shank having bent, such a pilum would now be more difficult to remove, and, of course, impossible to throw back.

Further complications and injury could ensue if the understandably-reluctant enemy did not discard his precious shield quickly enough, as there would be a great press from the men behind him.

Opinion among archaeologists once held that the main function of the shank was to disable both shields and the pilum itself by bending, but it is now thought that the pilum was a form of "personal artillery" designed simply to provide a massive counter-shock against any charging foe, and, as necessary, turn any legionary into a spearman.