Technology during World War I

Mobile radio station in German South West Africa, using a hydrogen balloon to lift the antenna.

The introduction of radio telegraphy was a significant step in communication during World War I. The stations utilized at that time were spark-gap transmitters. As an example, the information of the start of World War I was transmitted to German South West Africa on 2 August 1914 via radio telegraphy from the Nauen transmitter station via a relay station in Kamina and Lomé in Togo to the radio station in Windhoek.

In the early days of the war, generals tried to direct tactics from headquarters many miles from the front, with messages being carried back and forth by runners or motorcycle couriers. It was soon realized that more immediate methods of communication were needed.

Radio sets of the period were too heavy to carry into battle, and field telephone lines laid were quickly broken. Either one was subject to eavesdropping, and trench codes were not very satisfactory. Runners, flashing lights, and mirrors were often used instead; dogs were also used, but were only used occasionally as troops tended to adopt them as pets and men would volunteer to go as runners in the dog's place. 

There were also aircraft (called "contact patrols") that carried messages between headquarters and forward positions, sometimes dropping their messages without landing. Technical advances in radio, however, continued during the war and radio telephony was perfected, being most useful for airborne artillery spotters.

The new long-range artillery developed just before the war now had to fire at positions it could not see. Typical tactics were to pound the enemy front lines and then stop to let infantry move forward, hoping that the enemy line was broken, though it rarely was. The lifting and then the creeping barrage were developed to keep artillery fire landing directly in front of the infantry "as it advanced". Communications being impossible, the danger was that the barrage would move too fast - losing the protection - or too slowly - holding up the advance.

There were also countermeasures to these artillery tactics: by aiming a counter barrage directly behind an enemy's creeping barrage, one could target the infantry that was following the creeping barrage. Microphones (Sound ranging) were used to triangulate the position of enemy guns and engage in counter-battery fire. Muzzle flashes of guns could also be spotted and used to target enemy artillery.