How effective were body armors in WWI?

by Bromao

So recently thanks to this clip a discussion sparkled among some of my friends about how much body armors were used during the war and how effective they were. The video, as you can see, shows soldiers using full body armors (which is a mistake: those are American Brewster body armors, the Italian Farinas were much lighter) assault a trench and get slaughtered by machinegun fire.

Now my questions are (not just tied to the Italian front, of course): were those armors really so ineffective? Were they commonly issued to attacking soldiers? How frequently were they used?

LovableCoward

It is important to note that bullet proof armor is just that, bullet proof, not bullet resistant. Such armor is far better at stopping fragments of bombs or shells than direct bullets, though that is certainly better than nothing.

Private firms sold their own versions of body armor, often to those with the means to afford, principally officers. Obviously, the nature of such productions meant that the varieties of shapes and materials used are different from place to place. Numbers are also difficult to determine because of the unofficial nature.

The French ordered 100,000 units of chest armor along with very limited numbers of leg and groin pieces. In early 1916, the French also ordered over 3.2 million units of epauliers Adrian, which were curved armor plates sewn onto the ubiqiutous great coats of the French.

The British tried several different armors, often using materials such as steel, silk, rubber and kapok. The numbers are very limited, and nothing like a standardized armor was really manufactured. Although one "necklet" was issued to the number of 400 per division but fell apart quickly in trench conditions and was prohibitively expensive.

The Germans likely had the most developed armor in the form of the Sappenpanzer. It consisted of three hanging silicon-nickel steel plates that hooked over the shoulders. Around 500,000 were produced during the war and were capable of stopping shell fragments and even long range bullets. The issue was the weight. At either 9 or 11 kilograms it was beastly heavy when one adds in the rest of a soldier's kit. The armor was mostly deployed to sentries and machine gunners, troops whose sedentary duties meant that the cumbersomeness of the armor was not as much of a disadvantage as it would be for an attacking soldier.

Bull, Stephen, and Adam Hook. World War I Trench Warfare (1) 1914-16. Oxford: Osprey, 2002. Print.

Bull, Stephen, and Adam Hook. World War I Trench Warfare (2) 1916-18. Oxford: Osprey, 2002. Print.

Skyicewolf

Those guys look absolutely fucking terrifying.

Was this, what is portrayed in the scene, ever actually done?