great mod but one question

[MeinPanzer]

A javalin is will quite happily go straight through mail, or a car door. Those numbers also say an arrow is better than a bolt from a catapult.

Check again.

Check it yourself.

[McHrozni]

Check it yourself.

I think I found the sticking point. Here it is:
Arrow: 3mm radius

Sure, the shaft of an arrow is around 3mm thick. But the head of the arrow is usually wider, even a bodkin point would be almost 10mm thick (3/8 of an inch, slightly more than 9,5mm). While it certanly is possible to make a smaller arrowhead, those won't do much more than pierce the armor either - the lower the radius (calibre) the smaller the chance of a serious wound being inflicted. I'd say that the bodkin points were close to the minimum radius required to make the wounds they inflicted serious. The square of the radius is in the equation of the needed thickness, and this would correspond to approximately 1/10th penetration capacity - a 1,5mm thick steel plate should defeat the projectile.

This would also mean that an arrow would have a penetration power much closer to the value of a javelin, noted below - same energy, similar radius.

Secondly, this value is probably calculated for a heavy bow at pont blank range.

Lastly, this would fit well with anecdotal evidence of plate mail withstanding voleys of arrows and making archers obsolete without requiring that armor being made of as-yet-unknown high strength low weight materials.

It's called critical thinking. Again, how many bows will punch straight through a church bell?

McHrozni

[Philippus Flavius Homovallumus]

Yes, there's also the fact that with the exception of the slingshot all the projectiles are pointed.

The amount of presure applied to the armour at the Point of Impact is what determins the penatrating ability. Once the armour buckles and deforms job is mostly done.

A javalin has a higher force because of it's much greater mass but it has a very similar PoI and therefore a greater penatrating ability.

[Kugutsu]

Theres two factors which have an effect: the pressure and the momentum.

Pressure can be worked out by: Pressure (N/m2) = Force (N) / Area (m2)

Momentum (or kinetic energy) depends on the speed and the weight of the object, the speed being more important: Kinetic Energy (J) = 1/2 mass (kg) x speed2 (m/s2)

Linking the two is a bit tricky, as you need to divide the kinetic energy by the distance over which the force has been applied to work out the force, however given the mass, speed, area of point and distance from when it hits to when it stops (thats the tricky bit) it should be possible to work out which projectiles are best...

[McHrozni]

Theres two factors which have an effect: the pressure and the momentum.

Pressure can be worked out by: Pressure (N/m2) = Force (N) / Area (m2)

Momentum (or kinetic energy) depends on the speed and the weight of the object, the speed being more important: Kinetic Energy (J) = 1/2 mass (kg) x speed2 (m/s2)

Linking the two is a bit tricky, as you need to divide the kinetic energy by the distance over which the force has been applied to work out the force, however given the mass, speed, area of point and distance from when it hits to when it stops (thats the tricky bit) it should be possible to work out which projectiles are best...

There is another, the differance between the materials - hardness and toughness, or however they're called in english. If the projectile is softer than the armor, it could buckle at impact, causing it to loose penetrating power or even deflect altogether, even if it otherwise could penetrate.

Secondly, a structuraly stronger material (steel vs bronze, for example) will resist being pushed out of the way with greater force, therefore diminish the penetration. This is covered to some extent, by providing two values, one for bronze armor and another for steel armor, but neither is by any stretch of imagination a single metal, but a family of different metals.

The estimates there are, at best, rough estimates. But the arrow is still way off the mark.

Overall, the simpliest way to figure it out would be to build a set of armor you were trying to test, and an authentic set of weapons, and start testing. You'll have to do that anyway, if you intend to verify your model. I imagine that there are fairly accurate models in existance, but this wasn't one of them

McHrozni

[Philippus Flavius Homovallumus]

There's also the shape of the projectile. Most of these weapons have cutting heads, which will litterally slice through armour once that little hole is made on impact. Bodkin arrows mark the high point of that technology.