Force of impact test

Force of impact test

After filming the first 5 AvA2 films, we realised there was another set of questions and another film that needed making so Tod wrote out a quick ‘story’ and made the film. Because of this the “story’ is a little unpolished.

An after thought……..

Intro to me – the guys are not here today.

We really do pay attention to the comments and try to weave them back into our thoughts and there has been lots of comments about ‘getting knocked off your feet’ ‘driven back by the force’ ‘blunt force trauma causing damage through the armour’ and so on.

This is such a repeating theme we felt the need to have a look at the concept and see if there is any basis for it, but to do this we need to go back to school – sorry.

The ability of an object to penetrate is based on a several key variables and is a massively complicated area, but lets simplify it.  I have a rock and an arrow.

This arrow weighs xxxg.  Lets shoot this arrow at a target with our longbow simulator.


It is moving rapidly and carries energy with it which is mostly transferred into the target when it strikes – we saw that

But this rock weighs xxxg and of course if I drop this, it falls and carries energy with it, which is mostly transferred into the target when it strikes – we saw that too.

It may surprise you to know both of these had the same energy on impact – 135J

But there is literally a massive difference between them.  The arrow is quite light and so has relatively little momentum; its ability to keep driving forward.  The rock has far more mass  as compared to the arrow and so is much more able to keep moving forward after impact.  The momentum of the arrow is xxx and that of the rock is xxx.

So what?  If you want to push something or someone over you need a hard push and that comes from the momentum part of all this and a rock has loads of it, but we are not shooting rocks, we are shooting arrows and arrows do not have loads of it. But does an arrow have enough momentum to push someone over?

I have two free standing torso simulations here, one in ballistic gel somewhat similar in weight to a human torso and one in un weighted foam – much lighter and so more likely to go flying backward.  Both will stop the arrow so all of the available energy and momentum will be given up into the target.


But of course these are dumb and non reactive.  People are amazingly resilient to this kind of thing; just watch this clip I pulled off You Tube. 

So as far as I can see knights will not get thrown off their horses, knocked off their feet or stopped by arrow impacts

Now lets look at blunt force trauma.

I often hear people explaining that even though a knight is struck by an arrow on his armour, there is enough transfer of force through the armour to cause blunt force trauma injury. Clearly some areas like a finger or other delicate joints may get effected by a hard knock to the armour plate and so this is technically blunt force trauma,  But really what people mean is that in some manner, shock waves pass through the armour and damage organs inside.  Time to find out.

I have modified our gel knight so that he has two eggs set in his chest , over that we have our cote and mail and then a similar breastplate, also in variable thickness and made by Ash for another project, as our AvA2 plate has gone to our super sponsor.


Lets have a look – strips knight, eggs un broken.

I don’t find this surprising because the as we have seen arrows carry relatively little energy and momentum and this is spread over the whole breast plate, distributed over the whole torso, so the amount of energy in any area is miniscule and watch this – YT footage of man in plate armour getting shot.  He was subjected to far higher energy levels spread over his chest and has remained unharmed. 

A head in a helmet and liner is in a similar situation.

Even when we look at soft body armour, again with far higher energy levels, people largely remain unharmed.  Clip of chap with pistol.

To conclude, Knights don’t fly backward or even get knocked off their feet when struck and would not prevent them walking forward.  Shock waves do not pass through armour to damage organs inside.

Loads more AvA films thanks.


Arrows vs Armour2

AvA1 Arrow heads

Arrow head material test


Plate armour material test


Mail penetration test


War bow weight test 

Joe Gibbs

Joe Gibbs and the Longbow simulator