How many armor soldiers did the Roman soldier bring to the battlefield

[Mark Hygate]

What makes you think that Praetorians wore segmentata? There is no evidence that segmentata was worn by anyone except lower ranked/classed soldiers. It is exactly the same as medieval munitions plate. It was only worn by those who couldn't afford anything better. Those with the means preferred mail or scale or musculata.

You are seriously overestimating the effectiveness of blunt trauma. The only way to incapacitate someone through body armour without penetration is with firearms. Muscle-powered weapons simply can't deliver enough energy. I've personally worn mail over nothing but a regular sweater and been hit multiple times in the ribs with a baseball bat hard enough to knock me off balance and the only injury I suffered was bruising.

Once you understand that all of the different types of armour that Romans used provided similar levels of protection, armour study makes more sense. You will start to look for other reasons why they chose a particular type of armour - cost, weight, coverage, production time, comfort, prestige, fashion, donning time, transportation and storage capacity, longevity, maintenance considerations, spare parts, ease of repair, etc. Mail is superior in the vast majority of those.

Rolled metal plate is an advanced process but it drops the cost and production time considerably. The whole point of segmentata was to produce metal armour cheaper and faster than any of the alternatives. It was an ingenious solution given the technologies available to them but it was still only "peasant" armour. We actually have no direct evidence that the Romans had rolled steel but it is a possibility. Personally I think they just had hammer mills.

Thanks Dan, that's rather interesting.

 - I have believed the Praetorians wore Segmentata simply because I am given to understand that is how they are represented on Hadrian's column; let alone my previous understanding that it was indeed considered 'better'!     Whilst, indeed, some believe that said column is very stylised and shows all legionaries in Segmentata and all Auxiliaries in mail (less archers in Squamata) simply as a matter of course; is it not true that the general understanding is that some legionary troops (Western?) re-equipped with Segmentata for a ~200+ year period, whilst lower paid Auxiliaries wore mail.  If your assertion is correct, leaving out instances of much richer individuals who are dressing, perhaps, with a much greater emphasis on style as opposed to function, then why is that the case - and not, indeed, exactly the other way around?

- There are many here, I believe, who have much greater experience than I of actually making and indeed wearing the various armours that Roman soldiers seem to have worn; but I do have a reasonable background in the theory although slanted to more modern usage (armoured vehicle and tank armour) and my Masters thesis dealt with modelling ballistic impact and deformation of body armour.  The maths is the same, it's just the material and velocity that changes (although the velocities we now deal with can have even greater effects!).  The question I would like to ask, however, is whether you believe the experience you have with a relatively 'soft' baseball bat (in the scheme of things) would be replicated with a wild Celt slashing sword, an axe blade, or even the feared Falcata - let alone even a basic light javelin that could possibly penetrate mail, but bounce off said plate.  I would certainly not dismiss the force and momentum that can be delivered by a human well trained in weapons when delivered over a very small area of impact, such as a blade.  I have come across a very similar issue when looking at modern body armour designs that can resist a high velocity bullet (but transmit significant trauma), but fail when penetrated by a well wielded knife point!

- I completely agree with the points made about the greater versatility and longevity of mail over plate, but therefore look for more pragmatic reasons that it was chosen.  Why is it that it's legionaries who wore plate and not the auxiliaries, it cannot be down to cost; why is it that the next time it seriously appears in history is the medieval one when it's the 'Knights' who wear it and the 'poorer' men at arms wear only some and supplement with mail?  I believe it's because it must have been perceived as 'better' for some reason; and that would be as a defence.  Plate is a better defence against the bladed weapons detailed above simply due to the lack of deformation and subsequent distribution of force and momentum by longitudinal stresses.

I have, I am sure, seen some videos made by reconstructionists that show the effect of weapons on various armours on top of pig carcasses - I must see if I can find them again...