Zeppelins were huge airships invented in 1900 by a German, Count von Zeppelin. Hydrogen gas was used to provide lift, and small engines propelled the airship through the sky. By 1914 the Zeppelin could reach a maximum speed of 140 kph and reach a height of about 4,000 metres.
It was equipped with five machine-guns and could carry 2,000 kg of bombs. Navigation was very primitive, and as the war progressed the British used blackouts to make it even harder. Bomb aiming was far from accurate. It is estimated that only 10% of the bombs dropped from Zeppelins actually hit their target.
As a weapon the Zeppelin got off to a bad start. One airship which was sent to observe French troop movements in August 1914 was soon punctured by gunfire and, having lost much of its hydrogen, crashed in a wood. The crew had only just managed to get away when their machine was attacked by a squadron of French cavalry with drawn swords. This particular Zeppelin must be the only flying machine in history to have been destroyed by a cavalry charge!
In the early part of the war Zeppelins were used for bombing raids. A Zeppelin bombed Liege in Belgium on 6th August, 1914. In January 1915, two Zeppelin airships flew over the east coast of England and bombed Great Yarmouth and King's Lynn. The first Zeppelin raid on London took place on 31st May 1915. The raid killed 28 people and injured 60 more. Throughout the remainder of 1915 the Zeppelins raided London frequently, without risk of being shot down. They flew too high for most planes, and when they were intercepted by aircraft the ammunition in use at the time had little effect.
Towards mid 1916, however, the British planes were armed with a mixture of explosive and incendiary bullets. This mixture would prove to be deadly to the airships: the explosive bullets could pierce the Zeppelin's tough outer skin and cause leaks on the inner gas bags. The incendiary bullets could set those leaks on fire, and once on fire a Zeppelin was doomed. On the 2nd September 1916 sixteen airships set off to attack London. Of these, only thirteen would reach their targets.
From a (simplified) newspaper account, September 3rd 1916:
Lieutenant Leefe Robinson last night became the first member of the Royal Flying Corps to shoot down one of the German airships that have been bombing England since the war broke out. The raider was caught in search-lights above Hatfield and the anti-aircraft guns stopped firing once they saw the British plane. Despite not being able to climb as high as the raider, Lt. Robinson emptied his Lewis gun into the tail of the raider which burst into flames and crashed. Lt. Robinson, who has only been a pilot for one year, has been awarded the VC for his brave and courageous action. Last night was the first time British planes have been able to shoot down one of these raiders.
The massive fire of the burning airship was visible for over a hundred miles. Lt. Robinson became an instant hero. He survived the war, only to die a month later in the influenza epidemic.
One eyewitness, then 10-year old Henry Tuttle, remembers this first downing of a Zeppelin:
It was a fantastic sight like a big silver cigar and it seemed to be going very slowly by this time. A lot of people came out of their houses and then all of a sudden flames started to come from the Zeppelin and then it broke in half and was one mass of flames. It was an incredible sight: people were cheering, dancing, singing and somebody started playing the bagpipes. This went on well into the night.
Zeppelins could deliver successful long-range bombing attacks, but were extremely vulnerable to attack and bad weather. British fighter pilots and anti-aircraft gunners now became very good at bringing down Zeppelins. A total of 115 Zeppelins were used by the German military, of which, 77 were either destroyed or so damaged they could not be used again. In June 1917 the German military stopped used Zeppelins for bombing raids over Britain.