Design of the Roman pilum

[BrainGlutton]

I’ve read two different descriptions of the Roman pilum, the throwing-spear of the legionaries:

1. The head was joined to the shaft by a pin which broke on impact, making it impossible for an enemy to grab a thrown pilum and hurl it back at the Roman ranks. After the battle (if the Romans won it), Roman legionaries or auxiliaries would gather up all the shafts and heads; they were easily repaired.

2. The head was joined to the shaft with a soft metal which bent on impact, so an enemy who caught a pilum on his shield would find himself encumbered with a useless, bent, whole pilum, shaft and all, making his shield unwieldy and useless.

Which is correct?

[kellner]

In book I of his Gallic War Ceasar writes the following:

Gallis magno ad pugnam erat impedimento quod pluribus eorum scutis uno ictu pilorum transfixis et conligatis, cum ferrum se inflexisset, neque evellere neque sinistra impedita satis commode pugnare poterant, multi ut diu iactato bracchio praeoptarent scutum manu emittere et nudo corpore pugnare.

It has been years since I took any Latin and I’ll leave a literal translation to someone else.
The general idea is the following:

That each of the thrown pila pierced and connected multiple shields greatly impeded the Gauls in their fighting. Because the iron bent they could neither rip it out nor fight adequately with an impeded left hand. After much and long shaking (?) they preferred to let the shield go and fight with a naked body.

My translation is certainly full of errors but there is a clear reference to bent pila.

[Valgard]

I’ve always heard explanation #2 and the photos I’ve seen of pilum (at least modern recreations of them) have a long thin shaft that looks like it’d bend upon impact (the head and base - for attachment to a wooden shaft - are shorter and larger).

[Gorsnak]

Remember that the legions threw pila for centuries, and that their equipment didn’t remain static. It’s quite possible that both breaking pins and bending shafts were used at different times.

[Can_Handle_the_Truth]

@Gorsnak

Remember that the legions threw pila for centuries, and that their equipment didn’t remain static. It’s quite possible that both breaking pins and bending shafts were used at different times.

Correct. The pilum was redesigned many times over several centuries. Asking “What was the design of the pilum?” is a bit like asking “What rifle did the U.S. Army use?” without specifying a date.

[tomndebb]

From The Complete Encyclopedia of Arms & Weapons, ed. Leonid Tarassuk & Claude Blair:

During the long period in which this type of javelin was used, it underwent two specific modifications designed to prevent the enemy from using the weapon once it had been launched. The first was introduced during the time of Gaius Marius (158 - 86 B.C.), who had the forward nail used for attaching the head to the shaft replaced by a wooden rivet. When the enemy’s shield was struck, the rivet broke; the haft turned on the remaining nail, rendering the javelin useless and at the same time throwing the enemy off balance. The other modification was made at the time of Julius Caesar (100 - 44 B.C.). The change involved the head, the central part of which was made considerably narrower and of soft metal, thus weakening it and making it easy to bend. So the pilum retained its strong metal tip, joined to the rest of the head by a deliberately weaker section, which even seems to have been made of a different metal in some cases. In the time of Marcus Aurelius (A.D. 160 - 180), the head was lengthened considerably.