Why wouild you need to leave the trench when you have this?
In 1884 Hiram Maxim created the first prototype machine gun of its time that was not hand-cranked. He first offered his Idea to Britain, but they declined not seeing its usefulness. Germany, seeing the idea starting to make machine guns based off his design, which led to them having the most machine guns at the start of the war(the number is almost 12 to 1 even including the french machine guns).
The first machine guns usually required about 5 people to operate and could fire on average 500 rounds a minute. The british still didn't see how it was useful until the first day of the battle of the Somme, where the british lost almost 30,000 men to machine gun fire from german trenches. After about 1915, every country was producing these on a mass scale. They just weren't used to defend trenches, later in the war they were put on tanks, aircraft, zeppelins, and even cars. The machine gun was a new and exciting invention that was one of the reasons people preferred to stay in the trenches and is still used today.
The first machine guns usually required about 5 people to operate and could fire on average 500 rounds a minute. The british still didn't see how it was useful until the first day of the battle of the Somme, where the british lost almost 30,000 men to machine gun fire from german trenches. After about 1915, every country was producing these on a mass scale. They just weren't used to defend trenches, later in the war they were put on tanks, aircraft, zeppelins, and even cars. The machine gun was a new and exciting invention that was one of the reasons people preferred to stay in the trenches and is still used today.