War in a global sense never changes. The same cannot be said about weapons and equipment. Since the days of the first civilizations, human engineering genius has been in a never-ending race between means of defense and destruction. An answer is created for each new challenge. The story of the return of steel helmets to the battlefields in the 20th century after an almost 150-year hiatus is the best illustration of this.
The head is the most important and at the same time the most vulnerable part of the human body. In the era of the Napoleonic wars, steel helmets were already abandoned completely, although helmets and cuirass were still produced, and their wearing was "prescribed" for equestrian formations of cuirassiers. Nevertheless, the established military tradition, coupled with the development of means of destruction, made steel helmets virtually useless. By the time of the Crimean War, there was no question of any steel means of defense. The development of the chemical industry and metallurgy made it possible to create models of firearms, both hand-held and artillery, unprecedented in terms of the level of murderous efficiency.
The military tradition of the "Napoleonic" era began to change rapidly in the second half of the 19th century, when the Franco-Prussian war broke out. In the first acts of the conflict, the Germans, who fought "the old fashioned way," suffered simply monstrous human losses from the new French artillery. In the history of the slender ranks of the infantry, a fat point was put. By the beginning of the First World War, the means of destruction of manpower reached a level of development that human civilization previously could not even dream of.
New war - new challenges. New challenges - new solutions. At the turn of the First World War, all the participating countries came out with extremely lagging behind in development means of protecting manpower. The British and French did not use steel helmets for the infantry at all. In Germany, a pickelhelm with a cover was used, which already in the very first year of the trench war showed its extreme inefficiency. The Germans began work on a new helmet as early as 1914, resulting in the Stahlhelm, which was in service with Germany from 1916 to 1945. The second in terms of agility were the French, who began to provide their soldiers with a new helmet of Adrian M1915 in September 1915.
First of all, Adrian's helmet was created not as a means of protection against bullets, but as a means of protecting the head from shrapnel and shrapnel. This, in particular, is evidenced by the presence of a wide visor and brightly prominent fields, which should have covered the neck, back of the head and shoulders from shrapnel flying from above. The fact is that in the First World War, artillery shells with an air detonation mechanism were most actively used. They allowed the infantrymen hiding in the trenches to fall asleep with buckshot.
The British were the least agile. However, at the end of 1915, London engineer John Leopold Brodie patented his famous "flat" helmet with wide brims. This steel helmet was created under the strongest influence of Adrian's helmet, which showed itself perfectly in the conditions of trench warfare. Actually, Brody's helmet was created primarily to protect the head not from bullets, but from shrapnel and shrapnel. It was for this that she needed such strange wide fields and a flat profile. Of course, the English helmet had a terrible drawback - it actually did not protect from the side of the profile in any way. However, in the First World War, this was not required, since a significant part of the loss of personnel before the appearance of Brodie's helmets accounted for shrapnel and shrapnel wounds to the neck and head.
Brodie's helmets were made of Hadfield steel with a high degree of wear resistance. During the First World War, more than 7.5 million of these helmets were produced. One Brodie helmet weighed 0.5 kg. The steel thickness was 0.9 mm. Helmets were made by stamping, so they turned out to be extremely cheap and easy to manufacture. At the beginning of the 20th century, the same helmets were supplied by the British to the United States, where they received the M1917 index.
Interestingly, the design of Brodie's helmet was most likely inspired by a medieval infantry helmet called the chapellina. The first chaplains - helmets with brims, appeared somewhere in the 11th century and were used until modern times. The specific form of these means of protection was primarily dictated by the need to protect the head, neck, shoulders and face from falling projectiles from throwing weapons (arrows, bolts, darts), as well as from "accidental" strikes with pole-cutting weapons.
If you want to know even more interesting things about the war, then you should read about why during the times of Suvorov and Napoleon soldiers fought in lines and walked to their full height.