Pila bending at the shank

[XorX]

to me the paper shows that the weapons in Smihel  were made from a quite "soft" material...

[Caratacus]

I once attended a lecture a few years back at Caerleon given by the late Peter Connolly on this very subject. He was adamant that the pilum was an armour-piercing weapon and that it was intended to penetrate the shield of an enemy and then pass through whatever armour the man was wearing and kill or incapacitate him. That it sometimes bent was accidental, Roman metal-working techniques not being exactly scientific as to quality controls. As has been stated above, a socking great pole sticking through a shield, in the middle of a battle as well, is going to ruin your whole day. You can't stop to pull the thing out because there is a Roman squaddie coming towards you intent on doing your little pink body all sorts of harm with his little sword. Leg it, boys!

Mike Thomas (Caratacus)

[mcbishop]

David Sim and I have been conducting a range of tests on pila to reproduce the various types of bend found and test penetration capabilities under controlled conditions. We will be publishing the results (I hope) in JRMES 18 later this year. Summary results are in my forthcoming Osprey book on the pilum (out May 18th I believe).

Mike Bishop

[Bryan]

Has anyone actually come out with a working example of Plutarch's pilum, associated with Marius, that has one iron rivet replaced by wood to break purposely?

[Luca]

I did same experiments as Peter Connolly, with same conclusions that I included into a brief article about ten years ago.

Recently I found on italian wikipedia, at the pilum page, another citation of Plutarch from Camillus, 41, 3-6. Here it seems stated again something about bending and soft steel, but I don't know if the translation is correct. Maybe some RATer can check the translation?

[Bryan]

David Sim and I have been conducting a range of tests on pila to reproduce the various types of bend found and test penetration capabilities under controlled conditions. We will be publishing the results (I hope) in JRMES 18 later this year. Summary results are in my forthcoming Osprey book on the pilum (out May 18th I believe).

Mike Bishop

Did you test the wooden rivet model?

[mcbishop]

David Sim and I have been conducting a range of tests on pila to reproduce the various types of bend found and test penetration capabilities under controlled conditions. We will be publishing the results (I hope) in JRMES 18 later this year. Summary results are in my forthcoming Osprey book on the pilum (out May 18th I believe).

Mike Bishop

Did you test the wooden rivet model?

No point (pardon the pun) as it's already been done:

Grab, M. (2011), 'Das marianische Pilum. Der "römische Mythos" im Test', in C. Koepfer, C., Himmler, F. W., and Löffl, J. (eds), Die römische Armee im Experiment, Berlin: Frank & Timme, 83–92

We were more concerned with a) penetration and b) reproducing the same type of bends as seen in real artefacts. The whole 'wooden rivet' subject is discussed in my forthcoming book.

Mike Bishop

[Bryan]

David Sim and I have been conducting a range of tests on pila to reproduce the various types of bend found and test penetration capabilities under controlled conditions. We will be publishing the results (I hope) in JRMES 18 later this year. Summary results are in my forthcoming Osprey book on the pilum (out May 18th I believe).

Mike Bishop

Did you test the wooden rivet model?

No point (pardon the pun) as it's already been done:

Grab, M. (2011), 'Das marianische Pilum. Der "römische Mythos" im Test', in C. Koepfer, C., Himmler, F. W., and Löffl, J. (eds), Die römische Armee im Experiment, Berlin: Frank & Timme, 83–92

We were more concerned with a) penetration and b) reproducing the same type of bends as seen in real artefacts. The whole 'wooden rivet' subject is discussed in my forthcoming book.

Mike Bishop

I don't read German. Can you tell me what the conclusions were of those articles? 

Looking forward to your book! I love the Gladius one.

[Alanus]

On the idea of the pilum head getting stuck in a shield and therefore difficult to remove?

This is similar to an arrow imbedded in a tree. I practiced archery in the woods, using a cellulite arrow stop designed for easy removal. However, once in awhile I'd miss the target and the arrow sometimes hit a pine or spruce tree. I was using target heads, same size as the shaft and (of course) no barb.

Ten years later, there are still arrows stuck to trees at that location! I could not remove them. When an arrow or pilum penetrates wood (in this case softwood), it's nearly impossible to remove it... even when two people pull at the same time. Transferring this problem to a similar pilum-stuck-in-a-shield scenario, I would say the pilum would remain exactly where it landed-- in an enemy's shield-- and that he could not remove it, especially in the heat of battle.

[Bryan]

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.