Technology during World War I

The new metallurgical and chemical industries created new firepower that briefly simplified defense before novel approaches to attack evolved. The application of infantry rifles, rifled artillery with hydraulic recoil mechanisms, zigzag trenches and machine guns made it difficult or nearly impossible to cross defended ground. The hand grenade, long used in crude form, developed rapidly as an aid in attacking trenches. Probably the most important was the introduction of high explosive shells, which dramatically increased the lethality of artillery over the 19th-century equivalents.

Trench warfare led to the development of the concrete pill box, a small, hardened blockhouse that could be used to deliver machine gun fire. Pillboxes could be placed across a battlefield with interlocking fields of fire.

Because attacking an entrenched enemy was so difficult, tunnel warfare became a major effort during the war. Once enemy positions were undermined, huge amounts of explosives would be planted and detonated as part preparation for an overland charge. Sensitive listening devices that could detect the sounds of digging were a crucial method of defense against these underground incursions. The British proved especially adept at these tactics, thanks to the skill of their tunnel-digging "sappers" and the sophistication of their listening devices.

During the First World War, the static movement of trench warfare and a need for protection from snipers created a requirement for loopholes both for discharging firearms and for observation. Often a steel plate was used with a "key hole", which had a rotating piece to cover the loophole when not in use.

Clothing

German helmets went from leather to steel.

The British and German armies had already changed from red coat (British army) (1902) or Prussian blue (1910) for field uniforms, to less conspicuous khaki or field gray. Adolphe Messimy, Joseph Gallieni and other French leaders had proposed following suit, but the French army marched to war in their traditional red trousers, and only began receiving the new "horizon blue" ones in 1915.

A type of raincoat for British officers, introduced long before the war, gained fame as the trench coat.

The principal armies entered the war under cloth caps or leather helmets. They hastened to develop new steel helmets, in designs that became icons of their respective countries.

Observation Trees

Observing the enemy in trench warfare was difficult, prompting the invention of technology such as the camouflage tree, a man made observation tower that enables forces to discreetly observe their enemy.