Glued Linen Armour- a simple test

[PMBardunias]

Given a specific weapon, looking at kinetic energy isn't so bad.

The key is that you have to define with great care your variables. Willaims does this well, but you can see from his data that arrow X will penetrate armor Y becomes at Z joules is pretty meaningless when we start to add in other variables such as the angle of impact. At best we get a broad range and without knowing the likelyhood of impact at each angle, we cannot even give a decent average penetrability. There is no reason to expect armor to be made to withstand the rare impacts that are ideal for penetration.

Williams takes care to define what he considers a "defeat", something not always done, because the real question is not will the armor be penetrated, but will the weapon get through far enough to wound. A point will make a hole in plate at far less force than needed to get the weapon through to wound. Then you have to add the skin behind it, etc.

When we start to add non-ballistic tests, things get more difficult because we now have the weight of the man behind the weapon to deal with and the impact becomes more complex on a reduced time scale. Some have treated such blows as ballistic, which greatly underestimates the penetration of a hand held weapon. Blyth dismissed the weight of the man behind a blow through a loss of "linkage", but this cannot be the case or a punch would be of force Zero. The strength of the friction force between gripping fingers and spear shaft, and not the amount of weight a hand can hold is what is important here to include the weight of the arm in the strike.

When done incorrectly you get such obvious fallacies as the edge of swords penetrating plate better than the point.