FYI, I just spoke to someone I know that is an engineer and we talked about Marius' Pilum:
"And it is said that it was in preparation for this battle that Marius introduced an innovation in the structure of the javelin. Up to this time, it seems, that part of the shaft which was let into the iron head was fastened there by two iron nails; but now, leaving one of these as it was, Marius removed the other, and put in its place a wooden pin that could easily p531be broken. 2 His design was that the javelin, after striking the enemy's shield, should not stand straight out, but that the wooden peg should break, thus allowing the shaft to bend in the iron head and trail along the ground, being held fast by the twist at the point of the weapon." (Plutarch, Life of Marius)
What was bugging me about this passage was that I couldn't wrap my head on how it worked. If the wooden pin/peg would be stressed enough to snap, what about the iron pin? Wouldn't that be protecting the wooden peg? Because that's the whole point of having two or more pins to join the shank's tang and the shaft. And in that regards I was right, if they were both tightly fit, it wouldn't work. But we did find an easy way to make this work.
The pilum shank's tang would have two hole's drilled through it of equal diameter. The wooden joint block would then have a slit in the center, to receive the shank's tang, and then would have two holes drilled through it for the pins. Nothing crazy yet. Still a basic heavy pilum.
The wooden peg would get go into a hole in the joint block equal in size of the hole in the tang, with the wooden peg being big enough that its a tight fit, while being of a type of wood that isn't overly hard (maybe pine). Meanwhile, the iron pin hole in the joint block would be smaller than the hole in the tang, and driven in centered in the tang mating hole, giving it some "wiggle room." With the wooden peg being the only one of the two actually touching the shaft's tang, it would be primarily responsible for stability until the throw is made.
When the pilum is thrown, and the shank hits an immovable object, the mass of the pilum's heavier wood shaft would continue forward with the room to maneuver by the iron pin being smaller than the diameter of the tang's hole (giving about 1/8"-1/4" of movement). That gives enough room for the entirety of the force to be delivered against that single wooden peg. Helping cause the shearing affect could be using a small file to sharpen the insides of the tang hole meant for the wooden peg, this would assist in cutting it. By the time the iron pin connects with the tang hole edge the wooden peg would have already sheared.
This would then render the pilum unusable, with the shank held on only by the single loose iron pin, which would then cause the shank to swivel at the joint block. Making it impossible to throw back accurately or effectively, and if it were stuck in a shield, then the shaft would droop, maybe even dragging on the ground.
To repair, super simple. Someone takes a hammer and metal pin, knocks out whatever remnants of the old wooden peg remain, straightens everything, and then hammer in a new wooden peg. Done...
I know there is little evidence that Marius' Pilum was actually used, the archaeological evidence of the Late Republic that I'm aware of indicates the Romans and Italians were actually going for a sturdier method of attaching shank to shaft, adding a third pin, adding flanges and collets, with the shank being of unhardened iron (only the tip being hardened).
But at least I finally figured this out.
"And it is said that it was in preparation for this battle that Marius introduced an innovation in the structure of the javelin. Up to this time, it seems, that part of the shaft which was let into the iron head was fastened there by two iron nails; but now, leaving one of these as it was, Marius removed the other, and put in its place a wooden pin that could easily p531be broken. 2 His design was that the javelin, after striking the enemy's shield, should not stand straight out, but that the wooden peg should break, thus allowing the shaft to bend in the iron head and trail along the ground, being held fast by the twist at the point of the weapon." (Plutarch, Life of Marius)
What was bugging me about this passage was that I couldn't wrap my head on how it worked. If the wooden pin/peg would be stressed enough to snap, what about the iron pin? Wouldn't that be protecting the wooden peg? Because that's the whole point of having two or more pins to join the shank's tang and the shaft. And in that regards I was right, if they were both tightly fit, it wouldn't work. But we did find an easy way to make this work.
The pilum shank's tang would have two hole's drilled through it of equal diameter. The wooden joint block would then have a slit in the center, to receive the shank's tang, and then would have two holes drilled through it for the pins. Nothing crazy yet. Still a basic heavy pilum.
The wooden peg would get go into a hole in the joint block equal in size of the hole in the tang, with the wooden peg being big enough that its a tight fit, while being of a type of wood that isn't overly hard (maybe pine). Meanwhile, the iron pin hole in the joint block would be smaller than the hole in the tang, and driven in centered in the tang mating hole, giving it some "wiggle room." With the wooden peg being the only one of the two actually touching the shaft's tang, it would be primarily responsible for stability until the throw is made.
When the pilum is thrown, and the shank hits an immovable object, the mass of the pilum's heavier wood shaft would continue forward with the room to maneuver by the iron pin being smaller than the diameter of the tang's hole (giving about 1/8"-1/4" of movement). That gives enough room for the entirety of the force to be delivered against that single wooden peg. Helping cause the shearing affect could be using a small file to sharpen the insides of the tang hole meant for the wooden peg, this would assist in cutting it. By the time the iron pin connects with the tang hole edge the wooden peg would have already sheared.
This would then render the pilum unusable, with the shank held on only by the single loose iron pin, which would then cause the shank to swivel at the joint block. Making it impossible to throw back accurately or effectively, and if it were stuck in a shield, then the shaft would droop, maybe even dragging on the ground.
To repair, super simple. Someone takes a hammer and metal pin, knocks out whatever remnants of the old wooden peg remain, straightens everything, and then hammer in a new wooden peg. Done...
I know there is little evidence that Marius' Pilum was actually used, the archaeological evidence of the Late Republic that I'm aware of indicates the Romans and Italians were actually going for a sturdier method of attaching shank to shaft, adding a third pin, adding flanges and collets, with the shank being of unhardened iron (only the tip being hardened).
But at least I finally figured this out.
