I suppose even the French Knights at Agincourt had head protection, albeit from arrows, sword blows and assorted blunt instruments However, the arrival of bullets (lNCOMING…) introduced a whole new dynamic to this essential piece of kit. So I have two questions:
One - I wondered, given the advancements in both metallurgy and firepower, how the balance between protection and penetration has evolved in the past 100 or so years. I assume, in relation to design, there has always been a balance drawn between weight and effectiveness, whereas velocity and penetrative ability have just grown more powerful. Also, one assumes there’s an issue of the skull suffering from the impact rather than the bullet so padding is important…I just don’t really know ?
Two - About the general effectiveness of helmets: Presumably a straight on shot will mostly penetrate (subject to velocity) but an angled hit won’t, but actually I don’t know. What are the dynamics involved ?
I believe Kevlar has been explored as a possible option for helmets (but I know no more than that) and the Taliban rely mainly on AK47’s - How will the Special Forces head gear fare when they begin their helicopter based day trips ?
Helmets made in the last 100 years were not not designed to deflect a weapon, as a mounted knight’s helmet may have deflected a sword. They were primarily designed to protect the head from shrapnel.
In the late early 1980s I started reading about the Israeli’s use of Kevlar helmets. I read an article that compared bullet strikes on a Kevlar helmet with those on the trusty ol’ “steel pot”. At a given range (I don’t remember what it was) a 9mm round went all the way through the steel helmet, and a .45 calibre round caved in the side. A 9mm round imbedded itself in the side of the Kevlar helmet (without penetrating enough to injure the wearer, had there been one), and the .45 round bounced off. I don’t know if the Kevlar helmet was tested against a rifle round. I’m sure that any rifle round would probably go right through it if it hit dead centre, but I think there is a greater chance of an un-centred shot being deflected by a Kevlar helmet than a steel helmet.
Thinking that having a helmet that protected against (some) bullets was better than a helmet that just protected against shrapnel, the U.S. adopted the Kevlar “Fritz” helmet in the 1980s. I had assumed that British helmets were also Kevlar.
So. Helmets are still primarily for protection against flying bits of jagged metal, but they now offer limited protection against some bullets. They might not protect the soldiers’ noggins against a 7.62x39mm round, but they’re better than the old steel helmets.
I remember a news story (sorry, no cite right now, but it might ring some bells with others) about an injured US paratrooper during the Panama invasion who was shot in the head (“execution style”) by a Panamanian soldier. The bullet struck his Kevlar helmet and instead of penetrating, it ricocheted around between two layers of the helmet shell, passing completely around the back of his head and exiting the front of the helmet . The only injuries the paratrooper received were some minor cuts on his cheek and nose where fragments of shredded bullet and kevlar bits grazed him on their way out of the helmet.
The gentleman who designed the current US helmet worked for my father.
Without going into specifics, the US helmet was designed to be effective against fragmentation and shrapnel, but will provide limited protection against small arms fire, more effectively for pistol-caliber rounds, and rather less so for rifle-caliber rounds. Anything above .30 cal, forget it.
The helmet itself, despite being much heavier than the old steel pot, was designed to sit on the head with a lower center of gravity, and thus be less fatiguing, and to cover a greater percentage of the head.