The Royal Corps of Signals was only established in the British Army in 1920. Therefore throughout the First World War signals and communications were the responsibility of the Royal Engineers Signal Service and individual battalions. Most signalling at the start of WW1 was done using visual aids, however wire based telephone communications were being introduced and were to play an increasingly important part in the upcoming trench warfare. From the 1907 Army Field Service Manual it can be deuced that in the field a company would have four signallers attached, a Lance Corporal and three privates. A further three signallers, sergeant and corporal would be at battalion headquarters. A 1911 encyclopaedia article wrote of army signalling:
Army Signalling.-Communication by visual signals between portions of an army is a comparatively recent development of military service… Thenceforward, in ever-increasing perfection, the work of signallers has been a feature of almost every campaign of the British army. To the original flags have been added the heliograph (for long-distance work), the semaphore flag system of the Royal Navy (for very rapid signalling at short distances), and the lamps of various kinds for working by night.
This postcard shows a group of men who have been undergoing signalling training at some point in the Great War:The cap badges show that the men are from a variety of regiments:In the background one of the huts of the training camp can be seen:On the ground at the front of the picture can be seen an early field telephone:Whilst on tripods are a pair of heliographs:These instruments used the sun to transmit messages in morse code across long distances. The heliograph used a small key to move the mirror into and out of alignment, creating the flash. The message could be transmitted distances of many miles n strong sunlight and was relatively secure as apparently being as little as 50 yards off the direct line of sight was enough to prevent the message being seen. This instrument worked well in areas of strong sunlight, but was less effective in Europe, so an alternative apparatus using a lamp was employed:This is a sophisticated model for the period, using a battery pack, other examples used oil or lime to create the light. It again used morse code, but was only suitable for short range in the trenches and its use tended to attract rifle fire. Also to be seen are a pair of large signal flags:These had a 3’x3’ flag attached to a 5’6’ pole and a man could send messages using semaphore. This method of signalling, though very effective at sea, was less useful on land. By the end of the Great War visual signalling had become less useful and it was the increasing sophistication of wired and wireless technologies that encouraged the setting up of a dedicated Signal Corps, this would prove to be a prescient move as wireless was to assume an ever more important role on the battlefield in WW2.