Signals troops using a field set in a trench

WW1: First World War communications and the 'Tele-net of Things'

The exigencies of the 1914-1918 conflict meant that electronic communications on the Allied side had to find new ways to interoperate both on the battlefield and on the Home Front: but can the beginnings of 2014's interconnected domains be found in innovations that came out of the necessities of that war?

When the First World War began the British War Office seemed to pay little initial attention to the development of new technologies to be deployed in the prosecution of hostilities. There was, of course, no way of knowing in 1914 that the conflict would last more than four years, or that electronic communications would come to play such an integral part of the Allied war effort on both the Front Line and the Home Front.

The general stance was that significant new technological development proceeded gradually, as no one could foretell that they would be needed or that the fighting would last long enough for new products to be realised. The assumption was also that basic communication methods such as semaphore, lamps, and telegraphy would suffice for tactical communications, as well as sending in reinforcements to critical battle points.

In fact the contending military forces discovered, as the war plodded from bloody stalemate to murderous stand-offs, that the Allied forces needed to revolutionise thinking on communications before hostilities could be brought to an end.

The First World War quickly wrought innovation and advancement in several key areas of technological application. Hopes for a short war lasting less than a year were blasted to smithereens by the massive power of artillery and other armaments used to try and smash the pattern of entrenched defensive positions that soon conditioned military strategies on the Western Front. For the next four years the opposing armies gradually developed technological tactics and that allowed them – with greater or lesser degrees of success – to counter the impasse (such as the British 'rolling barrage' used to clear trenches just in front of an assaulting force), plus, of course, 'game-changing' new weapons such as the tank and attack aircraft.

Less well-known and understood are the variety and scope of electronic communications deployments that increasingly came together due to the exigencies of war, so that by the end of the conflict there were thousands of wireless sets, telephony systems and other devices attached to a range of communications channels: cable, wireless and visual.

In terms of better understanding how these networks developed, we can, perhaps, usefully borrow the modern concept of the 'Internet of Things', which tries to view the Internet conceptually through the range of different device types connected to it – and posit a 'Tele-net of Things', as the core modes were the telephone and the telegraph along with increasing use of wireless telegraphy and even wireless telephony later on.

The 'Tele-net' describes the co-existent networks that, although not directly interoperative, did provide the 'coverage' needed for the new warfare. As the 1914-1918 conflict unfolded the Tele-net was loaded with an ever-extending array of connected technologies and applications such as direction-finding, artillery aiming and ranging, and air defence. Furthermore, these devices were more closely connected to complex command-and-control networks that also used telecommunications to direct the allocation of resources.

Often, these Tele-nets relied on intermediation by humans for connections to succeed in their purpose; but arguably the general principles of interconnectivity between various 'local-area networks' and 'wide-area networks' in general terms is also applicable. It's worth noting that much of the functionality for which the contemporary Internet is esteemed still involves human transmission somewhere along the way.

What's wrong with dogs or pigeons?

Soon after it crossed to mainland Europe and was sent into action against the headlong advance of the Imperial German Army through Belgium and France, the British Expeditionary Force (BEF) had a grand total of four wireless receive/transmit sets. One was based at the BEF's General Headquarters (GHQ), while the other three were deployed with the cavalry.

In 1914 apparatus for wireless communications was still a relatively new development, having only been invented a few years earlier. Sets were bulky and unwieldy, requiring wagons and horses to transport them from location to location. An added complication was that they did not have battle-zone robustness built into their design: this made them impractical for use by the infantry on the move, so they were given to those troops with horses and thus, the logic ran, the means to transport them.

The Army's primary communication methods had, for some time, been signal dispatch – messengers on foot/horseback, animal conveyance (dogs, carrier pigeons), and visual signalling; the BEF command was in any case somewhat suspicious of the new-fangled wireless, and made limited use of it for strategic communications.

Notwithstanding, during the initial phase of the war the allied British and French armies fought a highly mobile battle against the advancing German Army, eventually halting it (thanks to intercepts of clear language German wireless messages) at what is now known as the First Battle of the Marne (September 1914). The Germans may have been stopped, but they were not forced back out of France and Belgium. Instead, the armies on the Western Front dug-in for years of atrocious trench warfare: this became a major factor in reshaping the way in which military communications were deployed.

With the onset of 'static warfare' the use of wireless fell away significantly. Instead the contending armies relied increasingly on older techniques: semaphore and other visual techniques (such as lamps), as well as signal dispatch mentioned earlier, but supplemented by the widespread use of wires for telegraph and telephone communications between the front lines and the more distant command HQs.

The Allied artillery and the infantry soon separately developed complex 'closed-circuit' wireline networks for both Morse telegraphy and voice telephony, with the two distinct sets of networks interconnected at headquarters and at 'forward positions'. Some tens of thousands of miles of copper-core cables were laid behind the trenches as well as right up to the frontline itself, initially resulting in a chaos of interference and interruption which was only later overcome by the use of insulation.

Developing frontline networks

The requirement to semi-improvise a new approach to mission-critical communications resulted in repeated innovation and adaptation in the networks. It was comparatively easy to lay lines on the ground (or on low poles), even to bury them in the ground down to 12in deep, though they were likely to be ripped apart by shellfire and other explosive impacts. Experiments and experience, however, showed that communications lines buried 6ft below the surface were reasonably safe from being damaged. In preparation for attacks, courageous army technicians laid interception lines and made connections perilously close to enemy lines.

The wired telephone, with its ease of direct, two-way communication, increasingly became the BEF's preferred means of keeping in contact. It seemed to offer precise and timely two-way exchange of information contrasted with rigid, one-way at a time communications made possible by telegraphy, which was made even more difficult by the need for minimally competent Morse Code operators.

However, the effective impossibility of avoiding the use of plain language on the telephone was to offer the German eavesdroppers some access to the BEF's plans throughout 1915 and well into 1916, including giving away details of its plans for launching the Battle of the Somme in mid-1916. Both sides quickly exploited security vulnerabilities in their respective technology.

As with modern datacommunications networks, information security and data integrity was an operational issue for the Tele-net. Both sides laid down lengths of wire in their forward trenches to act as antennae which could intercept enemy telegraph and telephone messages by induction through the soil (until the introduction of insulated twisted wire pairs, which could only be tapped by physically-applied connections).

Some of these information security vulnerabilities were rectified by the introduction of the Fullerphone, devised by Royal Engineer signals Captain (and Institution of Electrical Engineers (IEE) associate member) Algernon Clement 'AC' Fuller (1885-1970). This was a portable Morse telegraph that transmitted a DC signal through a single wire, but incorporated what was, in effect, a method of 'scrambling' messages to prevent enemy interception. The Fullerphone was later modified to also carry voice communications.

Germany's army had invaded French and Belgium territory and was seen as essential to push the invading armies out of the conquered areas before seeking an end to the war. Even when the attackers did break through the enemy defence lines, there was often no way to exploit the situation.

Attempts were made to lay down telephone or telegraph lines immediately behind the advancing troops, using special signals troops who followed the lead assault. Shell fire destroyed or damaged the cables laid out at the cost of many lives, with units of the Royal Engineers Signal Service experiencing casualty rates of up to 50 per cent during major offensive actions.

It took several hours for runners to relay reports on the progress of an advance back to HQ, to request reinforcements or a concentration of shell fire on a specific locational reference, or to relay further orders. Such messages arrived too late to be of help as the situation would have changed.

New solutions to the problems of maintained electronic communications on the battlefront were developed. Complex matrix networks (or 'laddered' wiring) allowed communications to continue even with several line breaks as wired communications always failed during attacks; but these techniques were hardly totally robust. This was a key factor in the pointlessness of frontal attacks against well-prepared defences until near the end of the war when wireless sets became small enough for troops to carry, or even to install in attack vehicles – as was the case at the Battle of Cambrai (November-December 1917), where some tanks had wireless sets on board in an effort to overcome the ever-present communications relay problem; there was also a tank in the field tasked with communications cable laying.

At the Battle of Loos (September-October 1915) three critical messages were sent by wireless that would not have been sent by other methods: one warned of 'friendly fire', another of advancing into a trap, and the third told isolated troops to expect reinforcements, thus directly changing the battle's outcome.

During the First World War there was rapid development of wireless technology with great improvements in transmitters and receivers, reducing power demands to more practical levels, and even introducing the use of early electronic valves, which led to better wireless sets as well as new applications such as radio telephony.

The first major innovation in application was the use of wireless sets as direction-finding devices employing 'triangulation' to locate enemy wireless sets – thus providing vital 'order of battle' intelligence. One signals historian wrote that "it was already realised from previous interception that certain wireless stations were associated in the German Army with certain definite formations ... the Intelligence Brigade of the General Staff had by this innovation a weapon of incalculable value".

The BEF and its European Allies started to set up a direction-finding network in the autumn of 1914, with the same technology then being adopted for use by the Royal Navy. This would pay dividends in its prolonged battle with German torpedo ships, mine-layers and submarines, though German Hochseeflotte (High Seas Fleet) generally avoided use of wireless once at sea.

The direction-finding system, which relied on very sensitive receivers, was developed by Captain Henry Joseph 'HJ' Round (1881-1966) of British Military Intelligence, on secondment from the Marconi Company, where he had worked since 1902. Round – later also an IEE member – was a pioneer of the use of electronics. By 1916 he had developed a wireless set weighing 57lb, which was light enough for observation balloons on the Western Front for intelligence gathering.

Round was part of the transformation between 1914 and 1918 of innovation in wireless technology from being a one-person affair into a determined corporate effort. Valves enabled more compact wireless sets. This made it feasible to put sets into airplanes which could then be used either as spotters – communicating intelligence back to the ground – or as bombers supplementing ground-based artillery, directed by spotters on the ground or aloft in balloons. Special short codes had to be developed that could be remembered and easily transmitted or understood by pilots who also had to keep an eye all around them to avoid being fired upon as well as actually operating their aircraft.

There were real problems to be overcome, however – even in 1916 aircraft sets weighed some 300lb and required a trailing antenna up to 400ft long. Although there was intense development work, use was still limited by the Armistice in November 1918, but lessons learned conditioned the trends for the future.

Communications on the move

One 'portable' wireless set issued for use by the infantry required the operator to strap an accumulator to his back and the wireless apparatus on his chest. He also needed the active assistance of two comrades: one to walk 50ft in front, and the other 50ft behind, carrying the necessary length of antenna wires. There was also work on developing wireless-guided torpedoes and even pilotless aircraft, a forward-facing development that arguably anticipated 2014's unmanned aerial vehicles (UAVs).

As months turned to years in the First World War, the 'Tele-net of Things' phenomena started to emerge on the UK Home Front. Following the highly aggressive threat posed to the existence of the British nation state by Germany's adoption, at the start of 1917, of 'unrestricted submarine warfare', incoming Prime Minister David Lloyd George insisted that the Admiralty, despite its resistance, adopt convoys. The grouping of merchant ships, aided by the national network of direction-finding sets, plus interception of U-boat wireless transmissions, allowed ships to be routed away from U-boat predators. Considerable effort was invested into extending the domestic telephone and telegraph networks, and of finding ways for them to integrate more effectively and efficiently. Given the greater demands of being engaged in a state of war, military and civil administrations escalated their use of the electronic communications infrastructures.

Work conducted by intelligence units such as the Admiralty's Room 40 on breaking enemy codes and ciphers intensified as it became increasingly obvious that wireless and other communications were inherently vulnerable to proactive interception. The British built a far-ranging communications network to support the interception, transmission, decoding/deciphering and dissemination of intelligence, as well as providing direction-finding support.

By the summer of 1918 the Allies were more assuredly making advances on parts of the Western Front. Portable wireless was becoming common among the infantry and their armoured tanks. More robust wireless field sets were used for emergency communications, as a supplement to cables and even, in places, to replace cables altogether. The First World War Tele-net brought communications systems to a remarkably high level of finesse. 

Additional reporting by James Hayes.

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