Communications in WW1

Wednesday, July 14, 1915

Relief in Place of 13th CEF (Royal Highlanders)

The Battalion War Diarist wrote for this day: “Battalion relieved 13th Canadians in Ploegsteert Trenches, completed by 8:15 pm.  Nos. 2 & 3 Coys. front line, and Nos. 1 & 4 support.” [1]

THIS DAY IN RMR HISTORY: “Moving forward on the evening of July 14th, the Royal Montreal Regiment occupied the crater frontage.  Heavy rain fell during the night and again on the 15th, interfering to some extent with work in the craters , where sniping had become exceedingly active.” [2]

Communications in the First World War

“A matter of life and death: Battles are won and lost on the strength of an army’s ability to communicate on the battlefield. On the Western Front the British Army hoped wireless radio and telephones would keep its rear-echelon commanders in touch with their front line troops. But when the shelling started these lines of communication were all too easily broken or intercepted, and carefully laid plans could quickly descend into chaos. In the thick of battle officers in the trenches were often in need of a Plan B.

Telephones and telegraphy: The telephone was the preferred means of communication in World War One. Its immediacy allowed commanders to give orders directly to those on the front line. The telegraph, meanwhile, was incredibly effective at sending a message over distance, but each one had first to be written out, transmitted and then transcribed by the receiving operator. Both telephone and telegraph were lighter and more portable than radio, but depended on landlines which were unreliable. Lines broke for many reasons, including the clumsiness of soldiers and enemy fire, and it was not uncommon for signallers to fix 40 cable breaks per day.

Runners: Red badge of courage. Soldiers employed as runners had one of the most dangerous jobs in the war, as they had to leave the relative safety of the trenches and cross open ground. Exposed to enemy sniper fire, death was a constant threat. Runners were comparatively slow, often reaching their destination with messages that were out-of-date and inaccurate. But they were able to read maps, think on their feet and adapt to the changing circumstances around them. Speed and fitness were key, and as runners often worked in pairs the value of comradeship was highly prized. Many were decorated for their bravery. Runners wore red armbands but, as infantrymen, were required to carry weapons. They were, though, excused from carrying the full rifleman’s kit. When telephones lines were down it often fell to man or man’s best friend to fill the breach.

Dogs of war: Around 20,000 dogs served during World War One. Until the War Dog School of Instruction was set up in 1917, they were mostly family pets donated to the war effort or strays recruited from pounds. Dogs were sent out during barrages or under machine gun fire when conditions were considered too dangerous for human messengers. Faster and lower to the ground, they were less likely to be shot and could cross most forms of terrain. Trained to return one-way to their keeper’s station, they could cover 10-15 miles in one to two hours. But the companionship of dogs was so highly valued in the trenches that men would often offer to deliver messages in their place.

Visual Signalling:

Flags: Lightweight silk flags were portable but needed daylight and good visibility. Messages were easily intercepted by the enemy, and flags fell out of use after 1916.

Lamp: Signals could be sent 24/7, but attracted enemy sniper fire. Lamps needed oil, gas or a battery, but were easily transported between locations.

Heliograph: Flashes of sunlight were sent as signals using a mirror. Heliographs were cumbersome and only useable in daytime, but with larger mirrors were visible up to 100 miles.

These three forms of signalling were each based on Morse code and required a trained signaller and a trained receiver, with a telescope, pencil and notepad, at either end. Visual communication was more immediate than conveying messages by runner, but by its very nature could give away the position of your unit, and signallers often found themselves exposed to enemy sniper fire.

The problem with radio: Radio, patented by Marconi in 1896, was still in its infancy during World War One. It was used throughout the war, but it would be years before it became truly reliable and secure. In 1914 the Army’s longwave wireless sets were heavy, fragile and expensive. They did become smaller but not as small as the pool of operatives trained to use them. As radio transmissions were extremely vulnerable to enemy interception, elaborate codes had to be used, which slowed everything down.

Improvements through war: The British government soon took over parts of the Marconi Company and focused it on the demands of war. The use of radio in the trenches, in the air and on the water led to technical advances. Kits were slimmed down, and became more mobile. Voices rather than just code could be transmitted.

By 1917 the army was holding races between radio and telephones. A detachment from each would race from a trench and establish their communications 500 yards away. Radio tended to win by around thirty seconds – a potentially life-saving difference in the heat of battle. Radio’s biggest success in the war came in helping scout plane pilots to report in real time on the accuracy of artillery fire and the location of the enemy

Pigeons take flight: At the start of the war the British had just 60 pigeons and 15 handlers in the warzone. By 1918 there were more than 20,000 pigeons and 370 handlers. Pigeons could fly long distances and over 100 miles (160km) could average a speed of 50 mph (80 kmh). When it arrived back at its home loft the bird would trigger a wire that rang a bell and alerted the handler.”

Limited Communication with Aircraft: Aircraft flew “contact patrols” to observe the forward movement of troops. They were only fitted with transmitting wireless sets, as receivers added too much weight to the airframe. Aircraft could also drop messages near a headquarters or friendly position. Troops on the ground used various methods, such as signal lamps, panels, and flares, to send messages to aircraft.

Unresolved Problems: Despite these tools, communication often broke down between the attacking infantry and their headquarters in the rear. When this happened, commanders did not know the location of their troops and were unable to support them with accurate artillery fire, ammunition, or supplies. This failure in communication was never fully solved during the war.” [4]

[1]   War Diary, 14th Canadian Battalion, The Royal Montreal Regiment, July 14, 1915.  Library and Archives Canada, Ottawa
[2]   R.C. Featherstonhaugh, The Royal Montreal Regiment 14th Battalion C.E.F. 1914-1925, Montreal, The Gazette Printing Co., Ltd., 1927, pg. 64.
[3]   Rory Cellan-Jones, Technology Correspondent, The B.B.C.; “Pigeons vs Telephone: Which Worked Best in the Trenches?”
[4]   Canadian War Museum, “Canada and the First World War, History, Communication,”