The Signal Service in the European War of 1914 to 1918 – Chapter 11

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«-- The Signal Service in the European War of 1914 to 1918
Chapter XI
Chapter X Chapter XII

Chapter XI.



Army Signals. — General Responsibility. — The Permanent Line and Airline System. — Subdivisions of the Army Telegraph and Telephone System. — Intelligence Centres. — Picture of the Army Signal Units at Work. — Indoor and Outdoor Staff. — Army Wireless. — Control of W/T Stores and all W/T Stations in the Army. — D.D. Signals' Office Staff. — Corps Signals. — Lighter Routes and More Alternatives. — Corps Artillery Signals. — A.D. Signals' Distribution and Employment of Corps Signal Personnel. — Special Aspects of Corps Signal Work. — Stores, with Particular Reference to Buried Cable. — Corps Wireless. — The Corps Airline System. — Corps Control of the 1917 Buried System. — Improvements in the Buries of 1917. — Buried Cable in the South and in the North: A Contrast. — Increased Enemy Artillery Attention to Signal Systems. — Refinements of Camouflage and Protection. — Greater Extent of the 1917 Buries. — Duties and Distribution of Area Personnel. — Records of the Buries. — Special Features of the Northern Buries. — Contrast Between Signals in Rear and Forward of Divisional Headquarters. — Rise in Importance of Alternative Means.

The Signal Service at G.H.Q. and on the Lines of Communication was not vitally affected by the reorganization to suit stationary warfare conditions. Its development to meet the largely increased demands of the growing administrative services in rear of the Armies was normal and without marked changes in organization or method. From Army headquarters forward, however, all signal units had shared in the changes brought about less by the increase in the size of the Armies than by the alterations in technique which were the direct result of the deadlock in the Western European theatre of war.

In the Army areas this had been marked in two ways: first, by the appointment of the Deputy Director of Army Signals and the delegation to him of a large measure of responsibility for forward signals; secondly, by the immense growth and the profound changes in organization which had taken place in all the technical arms of the Service. The extension of the responsibilities and improvement in the position of the senior signal officer of the Army has already been referred to as the source of a great accession of strength and efficiency to the Service as a whole. It is the latter aspect of affairs that is most important to a general review of the position battles of 1917.

Throughout the two previous years, the R.F.C. and Anti-aircraft organizations, the light railway system, "Intelligence," and all other technical branches of the Army had increased from comparatively insignificant beginnings until each had reached the dimensions of a separate Service in itself. It was no longer desirable or possible to group the intercommunication required for the whole of the various units administered by Army headquarters under one single signal system.

The problem was simplified to a certain extent by the fact that — even in 1917 — the Army area proper was well outside the normal range of enemy activity. Long-distance bombing planes and long-range guns occasionally played havoc with Army communications of all descriptions, but such damage was not yet so frequent as to make necessary any general use of buried cable or other means of protection either of lines or of offices. That was to come very shortly, but it does not enter into the present problem to any great degree.

On the other hand, the responsibility of the Army signal units had extended considerably further forward than the Army area proper. Indeed, the work of the area detachments — an important branch of the Army Signal Company — only ceased theoretically at the forward limit of the buried cable. In a well-regulated buried system the area officer, who was also usually the O.C. Area Signal Detachment, was responsible for the maintenance of the whole system and for the allotment of all lines. His detachment was attached to, and usually administered by, the Signal Company of the Corps in whose area lay the lines he controlled. His activities are, therefore, better reviewed in detail when considering the signal system in the Corps area.

To the rear of the buried cable a telegraph and telephone system with permanent, semi-permanent, or "comic" lines was the mainstay of the intercommunication system. Despatches of less urgency were dealt with by an organized despatch rider letter service with two or three deliveries daily to all important signal offices, and circular runs to less important units in each formation area. Wireless, on the other hand, was never needed for normal intercommunication purposes, but was confined to Intelligence work and to the various training schemes which were always a prominent part of signal activity in the rear areas.

All urgent traffic was dealt with by telegraph. All personal intercommunication was by telephone. The latter was seldom used for the transmission of messages and as a general rule such a use of the telephone was discouraged by the Signal Service. The available lines would only just accommodate the demands of the Staff for direct conversation with their immediate superiors and subordinates and with the officers of allied services.

The main feature of the Army intercommunication system was, therefore, a network of permanent routes which were of heavy construction and each of which contained many wires. At least one main permanent route led forward to each Army from G.H.Q., while, in addition, other routes led directly back along the Lines of Communication to deal with purely administrative traffic. Forward of Army headquarters, there were heavy main routes to each Corps in the Army and, in addition, a number of somewhat irregularly distributed lighter routes with fewer wires, which connected together the locality exchanges and the various scattered units which these latter served.

Much of the preparation for a position battle of any magnitude consisted in the duplicating of these existing routes. Additional main routes had to be built for every extra Corps which it was proposed to employ on the Army front during operations. Besides the new routes, additional circuits were necessary on almost all of the already existing routes to provide signal communication for the extra formations and units whose arrival in the area was part of the normal preliminaries preceding an offensive.

It was during the preparations which preceded the 1917 position battles that it was finally decided to adopt the policy of giving, so far as possible, separate systems to different departments of the Army. Thus, in one Army, seven telegraph and telephone systems were provided. These were utilized as follows: —

(1) Command system.
(2) Administrative system.
(3) R.F.C. system.[1]
(4) Intelligence and Observation[1] system.
(5) Anti-aircraft Defence system.
(6) Light railways system.
(7) Reserve areas system.

All of these were linked together at the principal exchanges, but every effort was made to keep the traffic of each to its own circuits. The Command and Administrative Systems were, of course, the most important of all and required adequate connection to all the other five. The reserve areas were dealt with by a series of locality exchanges and were linked up to give telegraphic and telephonic communication between all formations down to Brigades and that immediately superior to them. By means of this system and the connections to the command system, all formations and units in reserve could be ordered forward at a few minutes' notice. Undoubtedly this free circulation of orders in the rear areas played a decisive part in battles where the sudden application of unexpected concentrations of troops was of primary importance.

The most interesting features of the Army signal communications, from the point of view of their historical significance, are the special systems which were the outcome of the growth of the Royal Flying Corps, with its collateral branches, the kite balloons and anti-aircraft sections, the field survey companies, and the Intelligence Service generally.

All the above services had this in common. They were of vital importance to the welfare of the Armies in the present type of warfare and they had a large amount of traffic to dispose of if their efficient working was to be ensured. Also each had its special needs, and the greater proportion of the traffic of each was confined within the limits of the particular branch concerned. The signal system of each could be to a large extent self-contained and self-sufficient.[2]

Such a system of independent circuits, connected to common main exchanges had many advantages. The R.F.C. system, for instance, was planned on such an exchange system, and Brigades, Wings, and Squadrons were all connected to exchanges by one or more junctions.

This was found to be invaluable and the increase of Squadrons in the Army areas was accommodated by the allotment of one or two spares upon the main routes, and caused but little extra work. For A. A. defence, on the other hand, direct communication is absolutely essential and a system which could be controlled by the O.C. Anti-aircraft was desirable. Any special instructions he might wish to give, could then be conveyed without any interference with general intercommunication. Light railways equally required a special system apart and merely needed connection to the command system at certain points.

The special feature of the Intelligence intercommunication during 1917 in at least one Army consisted in the formation of a separate system based on a series of Intelligence centres in which the various methods of obtaining and disseminating information were concentrated to permit of all becoming parts of one co-ordinated whole. Scraps of information, apparently unrelated, and obtained by different means, could be made to yield a much greater amount of valuable knowledge of the enemy's movements and intentions if fitted by skilled brains into their proper places in a general imaginative picture.[3]

In its most typical case this system took the form of a central exchange at the Army Intelligence centre which was connected by several junctions with Army headquarters, and from which circuits which were devoted to Intelligence traffic branched forward. These, in their turn, connected through the Corps and Divisional exchanges to all sound-ranging sections, observation posts, and other means of obtaining information. By means of these circuits which were placed directly at the disposal of the Intelligence Corps, information received from one source could be confirmed or denied at once by reference to others.[4]

It is evident that, in spite of recent increases of strength, the Army signal company and its affiliated units had as much work on their hands as they could readily attend to. Even in quiet times everyone was fully occupied. In the feverish preparation for an offensive and while the lines were burdened with the thousands of important "operations" messages which marked the progress of a battle, it was all the Army signal units could do to keep the system in order and to ensure the smooth working of the exchanges. Only the most careful forecast of individual requirements could make certain of a successful sub-division of the available circuits amongst the competing departments and branches of the Army. To be successful, the D.D. Signals of an Army required both the imagination and the courage to anticipate the most unlikely developments. The closest touch with the Staff was essential and sometimes success required that he should anticipate the formulation in the minds of the latter of the plans for a future operation. No officer had a greater variety of considerations to weigh in the balance before deciding on a definite policy; few were compelled to make quicker decisions if preparations were to keep well ahead of events.

The personnel of the headquarters of the Army Signal Company, itself, consisted in the main of "indoor" staff whose duty it was to work the Army telegraph instruments, to man the telephone exchanges, and to keep in repair the instruments and signal equipment of the Company. The Army signal workshops had become an important part of the signal organization. Here, all faulty instruments not hopelessly damaged were repaired and returned to service. A considerable quantity of improvised apparatus was also made up and despatched to the Army signal stores, there to be examined and issued to units. Decentralization had thrown a heavy burden on the personnel at Army headquarters and whether the Army was on the defensive or offensive, the shops were always in full work and required the entire attention of a technically qualified officer. With them, also, was usually situated the portable workshop which carried out repairs to the electric light lorries of the headquarters both of the Army and of all the subordinate formations down to Divisions.

The outdoor staff at Army headquarters consisted of some 20 or 30 permanent linemen. These had perforce to be considerably reinforced from the personnel of the attached airline and cable sections before they sufficed to maintain the routes of the great telephone and telegraph system to which reference has already been made. Isolated parties of three or four men were scattered throughout the Army area at all exchanges, at important junction points, and at other central positions along the routes. These men constituted the permanent line staff and were responsible for the normal maintenance of the lines. Their work was carefully organized and directly supervised by the O.C. lines and his N.C.O.s. In addition, the special breakdown parties with their own special transport and apparatus — including lengths of “interruption cable” and all appliances for making repairs on a large scale — were stationed at the main offices whence they could be dispatched at a moment's notice to the site of any major breakdown.

The scene at any particular signal office was one of ordered activity. Long before this date, signal offices had been standardized at least within the limits of each formation. All wiring was carried out on an authorised plan. Wires were arranged in an accessible manner, but carried from terminal pole to test panel and from test panel to exchange and instruments, by routes which were carefully chosen to avoid obstruction. Tables and operators' seats were arranged to allow free circulation and the portion of the office given over to the operating staff was planned so as to ensure as little movement and noise as possible.[5]

A special room was allotted to the despatch riders and orderlies on duty. Here they could await their turn with the maximum comfort to themselves and the minimum interference with the office routine. Above all, constant supervision was insisted upon and an efficient staff of instrument repairers ensured that all instruments were kept in order and all wiring was periodically overhauled.

In the meantime, new construction of permanent routes was dealt with by the Army Telegraph Construction Company, and of routes of lighter make by such airline sections as had not been absorbed to eke out the maintenance parties and to make up the breakdown gangs. The Army cable sections also had their special duties. Their work varied according to the individual Army in which they served. Some Armies were more fond than others of heavy cable routes. In others they were reserved entirely for attachment to subordinate formations carrying out special duties and needing special help. They were perhaps used more normally for the running of temporary cable spurs where such were necessary and for temporary local lines.

A totally different aspect of Army Signals was cared for by the Army wireless section, and the Army wireless observation group. The former was seldom or never used for the passing of tactical messages. The line system was almost always sufficient to carry the normal message traffic. If a breakdown occurred on one route, there was always a choice of several others available. Nevertheless, the Army wireless stations had important duties to fulfil. Of no method of signalling is it so true as of wireless that central control of message traffic is essential if efficiency is to be obtained. Every spark wireless station can interfere with every other station in its neighbourhood that is working on the same or a near wave-length. Every station can be overheard by special enemy stations devoting their whole energies to this purpose. These are the two cardinal facts that needed to be constantly borne in mind by the officers responsible for Army wireless. The principal activities of the Army personnel resulted from these two facts. It was their business to keep constant watch on all the waves in use in their Army for two purposes. Stations near the front line who could not attract the attention of the stations to which they were working might need the assistance of the higher-powered Army station to help to establish communication. It might even be necessary for the Army station, having picked up such an unacknowledged message, to switch over to the transmitting side and send it out with a strength sufficient to drown all less important but more importunate stations.[6]

The second duty of the Army wireless station was of yet more general importance. It was its duty to watch for errors in wireless discipline from the signal point of view. Any serious error would soon be brought home by the Intelligence Staff working through the medium of the wireless observation groups, but, if strict discipline was to be observed, a careful watch for indiscretions must be kept by the Signal Service itself. It was the duty of the O.C. Wireless of the Army to suppress all tendency to individuality on the part of wireless operators. Innovations in procedure, little mannerisms on the key, irrelevant remarks between operators, indiscreet messages, all of these things needed to be controlled and eliminated so far as was possible, since they might give so much away to a presumably watchful enemy. It was in preventing such occurrences and in tightening up discipline, that the greatest utility of the Army Wireless Section lay, though its other functions were also of importance.

The wireless stations of the Army were of the light lorry type with a range extending far beyond the limits of an army area. Their use except in urgent necessity was, therefore, to be deprecated and they were seldom used except for interception.

The duties of the Army wireless observation group have already been outlined in a previous chapter. The stations were manned almost entirely by Signal Service personnel and from one point of view — that of the provision of reinforcements — they placed a great strain upon the resources of the Signal Service. The diversion of wireless operators to these stations lessened the number available for tactical wireless and helped to produce a shortage that was never thoroughly overcome.

In addition to the units already referred to, there were carried on the strength of the Army Signal Company the Signal Sub-sections of the Army R.F.A. and R.G.A. Brigades. The activities of both these, however, when in action, belonged more to an area nearer the front line and are better considered together with similar units which were grouped for battle under the Corps or the Division.

The whole of the great organization just described, was controlled by the D.D. Signals from his office at the headquarters of the Army. He himself spent much of his time touring the Army area, visiting the A.D. signals of the Corps and the O.C. signals of the Divisions in the Army and inspecting their signal systems. A personal knowledge of forward signals was essential for intelligent direction from the rear. At his office at Army headquarters, however, he had a small clerical staff which was usually slightly augmented by details attached from the Army Signal Company. Here, the general plans for signal communications for the whole Army were revised and coordinated and it was here that the D.D. Signals presided over the conferences of senior signal officers which did so much to advance the interests and to shape the general policy of the Signal Service. Later in the war, the establishment of D.D. signals was increased by the addition of a Staff officer with the title D.A.D. Signals and of an officer whose duty it was to supervise the Army pigeon and messenger dog service. Before the advent of these officers, however, his only assistant was the O.C. Army wireless and he had to rely upon the O.C. Army Signal Company to deputise for him at those times when his absence from headquarters was essential. No small part of his time was taken up with the scrutiny and modification of the indents for stores submitted by the signal officers of the formations within the Army. In 1917, as already pointed out, the decentralization policy resulted in the formation of comparatively large Army Signal Stores where a considerable reserve was kept of all essential signal equipment and line stores. This, again, meant an increase in staff, and an officer and a few other ranks were added to the establishment to cope with the new departure.


The O.C. Army Signal Company was held responsible for the maintenance and construction of lines in rear of Corps headquarters. Further forward the responsibility devolved upon the O.C. Corps Signal Company and the work was carried out by the latter's personnel. Here, also, the main feature of the signal system were the overhead line routes, though in this case the system was modified to a somewhat greater extent by adaptation to minimise interference through enemy action. The main ways in which modification showed itself were in the adoption of lighter routes with more alternatives and in greater care in leading into headquarters and to the principal signal offices. Junctions of routes were made as inconspicuous as possible. At the more important junctions overhead lines were replaced by short lengths of buried cable. Leads in to headquarters were carefully camouflaged, converging routes being arranged to point to some quite different spot from that actually occupied.

The tendency of the routes was to become lighter, both because a Corps must be more mobile than an Army and because more numerous routes containing fewer individual circuits were less likely to be put out of action on a large scale.

One direction in which the researches of the Army and the Corps signal officers were made was the devising of the most suitable light routes for carrying any number of single wires up to sixteen. A large number of such routes were needed for the subsidiary branches of the line communication system and some easily-erected and easily-maintained type was required. This was finally obtained, as already mentioned in the chapter on the rise of the telephone system, by the adoption of the trestle route. (Plate VIIL)

"Comic" airline was still much in use, but single and even double airline was almost obsolete except for special purposes. A revival of this type of line might be expected under mobile warfare conditions, but even there one pair of fines would not be of much use for the service of the major formation headquarters. From comparatively early in the war single and double airline were relegated to the construction of branch lines to subordinate headquarters. The greater proportion of the work of the Corps airline sections consisted in the maintenance of already existing routes and the building of semi-permanent and "comic" routes with from four to 16 or even more lines.

In the Corps area also, as well as the Army, the growth of the signal system of the technical services was one of the features of this stage of the war. Indeed, it was at the Corps that the artillery signal communications with their accompanying specialized means of observation were mainly grouped. The artillery signal system in the Corps rivalled the infantry command system in importance and had long outgrown it in size. One of the chief preoccupations of an A.D. Signals before an offensive was the amount of artillery for which lines must be allowed in his system. A typical observation signal system in a Corps in the summer of 1917 is seen in Plate XVII. It is a complicated system in itself, and, when added to the ordinary command and administrative systems, taxed the resources of the signal units to keep it efficient.

Since the reorganization, artillery signals were cared for by Signal Sub-sections of R.E. personnel who were commanded by the Brigade or Group signal officer. The strength of Corps signals thus fluctuated with the attachment of a greater or less number of artillery formations. These made necessary a maximum development of the Corps signal system which was sometimes not justified by events. It was, however, impossible to take the risk of falling short of supplying unexpected artillery requirements. Spare lines were made essential by the sudden artillery concentrations which were a feature of position warfare. Any review of Corps signals as a whole must give due importance to this aspect of their development. The heavy artillery signal sub-sections, though always a variable quantity and ever changing from one Corps to another, were an essential part of the Corps Signal Company strength. Each on arrival at its battle quarters, took over the Corps lines allotted to its use and built in front of them a system comparable to, but considerably larger than, the telephone system of an infantry Brigade in the line.

Control of all the Signals within the Corps area was vested in the Assistant Director of Signals who had a small office at Corps headquarters and a small clerical staff to keep his records up-to-date and deal with his correspondence. He usually lived in close association with the O.C. Corps Signal Company whose immediate concern was the administration of the Corps signal units and the supervision of the line system. For the latter purpose a particular officer was usually delegated — as in the Army — with the title of "O.C. Lines" and personal responsibility for the maintenance, construction and allotment of routes and circuits.

A separate captain with a small signal section of his own cared for the signals of the Corps heavy artillery headquarters. This was often situated at some distance from Corps headquarters and, in any case, usually had a separate line System of its own, closely connected with the main system by junction circuits between the exchanges of artillery and infantry formations at each step in the chain of command. It was on this officer that the supervision of the special lines of the Survey and other Corps observation posts fell, and he was so fully occupied that, in 1918, he was given a subaltern to assist him.

Other officers at the headquarters of the Corps were the wireless officers and the stores officer who had charge of the Corps signal stores and who was directly responsible to the A.D. Signals himself. In addition were the officers of the various airline and cable sections whose duty was the construction of such routes as were ordered by A.D. Signals or his representative, the O.C. Lines, or who were given responsibility for the maintenance of sections of the Corps line system.

Few special remarks are necessary with regard to the employment of the available personnel in the Corps signal units. The principle adopted was much as in the Army area. One novel feature was the importance of the attached artillery signal sub-sections and the area detachments. Other variations in the duties of the Corps signal personnel were due to the responsibility of the A.D. Signals for the buried cable systems of the Divisions of his Corps.

Much of the work carried out at the Corps signal stores was concerned with the receipt, the preparation, and the issue of armoured cables of all types for burying. Many Corps at first had their cables made up into ropes containing 20, 30 or 40 pairs according to the numbers required for the buries. This was not altogether a satisfactory method, however, though it served well enough on occasion. The prepared ropes were very unwieldy in size and very heavy. Despite the precautions taken they were still liable to "kinks," while testing them was not more easy, nor testing in the field superfluous. The general decision of forward officers actually engaged in burying was in favour of the issue of individual rolls of cable in coils containing a quarter of a mile each of twin, quad, or seven pair cable. These were carried forward independently by men of the cable-laying party and combined into a rope when alongside the site of the trench. The prepared ropes were, however, used with success in the case of buries to reserve positions or in areas not under observation by the enemy and where good roads existed.

The Corps wireless officers were originally charged with the supervision of all forward wireless, but at the time of the later battles of 1917 decentralization had taken effect and the activities of these officers were confined thenceforward to special duties. The senior officer acted, as in the case of the Army wireless officer, as adviser in wireless matters to the A.D. Signals of his Corps. The junior officer was usually responsible for the running of the Stores, the charging plant, and the listening posts. Both supervised the working of the Corps directing station.

The functions of this set were much as those described in dealing with the Army control station, but on a smaller scale. The Corps station was, however, more frequently called upon to help out the forward sets and was expected to keep a very close watch with a view to facilitating the efficient transmission of messages. At this period, also, the Corps wireless officer was sometimes made responsible for such things foreign to his nature as pigeons and messenger dogs, but these were really part of the responsibilities of the O.C. Corps Signal Company and later, in the next year, a special officer was appointed to supervise the working of these services.

As far forward as Corps headquarters, the number of trunks connecting one headquarters with another was determined practically entirely by the amount of traffic with which they would have to deal. Thus, for instance, two telephone trunks and a telegraph circuit passing forward from Army headquarters to Corps headquarters were considered ample for the needs of the General Staff, and these usually did, indeed, suffice. Forward of Corps headquarters, however, enemy action became more common and partial interruption was practically certain during the heavy long-range shelling which invariably preceded offensive action either by the enemy or by ourselves. Mention has already been made of one method of counteracting this, that is by the breaking up of the heavy routes prevalent in rear of Corps headquarters into several lighter routes. By using numerous light routes it was possible to duplicate the main forward circuits of the Corps. During the summer offensives of 1917, three circuits from Corps to Division were the rule, but as many as six were not uncommon. These were taken forward by different routes, and thus it was extremely unlikely that any Division would be entirely cut off from Corps through enemy action.

It was forward of Division, however, that the near presence of the enemy first gave a definite and entirely different character to the signal system. Within the zone of constant shelling, no airlines could be expected to stand and the whole system was taken underground. In a normal Divisional area it was unusual to see any lengths of airline or poled cable with the exception of the few hundred yards connecting the rear dug-out or test box of the bury with the signal office at Divisional headquarters. In particularly favoured areas a little airline existed and poled cable was not uncommon, but almost everywhere buries were the prevailing means of communication.

One of the effects of the advent of the buried cable system was the consequent concentration of all forward circuits — whether required for Corps or for Divisional units — into two or three main routes in each Corps area. This, in its turn, resulted in the forward extension of Corps signal responsibility and maintenance. The routes were necessarily common to all formations and experience speedily proved that control was best vested in the signals of the highest formation using the bury. This lesson was really learnt decisively during the offensives of 1917. Many Divisions in the early months of this year controlled their own buried system, but it was always found that allotment and maintenance worked most smoothly when control was vested in an area officer working under the orders of the A.D. Signals. The earlier method persisted for some time in certain Divisions, but gradually the later and more efficient procedure was standardized. It was admitted by Divisional signal officers that an efficient area officer relieved them of an immense amount of responsibility and added to the efficiency of the system.

His presence and that of the men under him tended to continuity of policy and to a thorough knowledge of the individualities of the bury. He and his men knew its weak places and its good and bad pairs. He knew what pairs could best be spared for more urgent purposes. He had a superior authority to appeal to in support of his decisions. He was usually carefully chosen and carried out his very difficult, arduous, and often dangerous duties exceedingly well. Last, but not least, he had no other responsibilities as had the Divisional signal officer who had been his predecessor.

The Corps-controlled bury was in many ways much more satisfactory. The final policy was for the A.D. Signals of the Corps to decide on what buries were required in consultation with the O.C. Signals of the Division. The Divisions then carried out the portion of the buries which lay within their respective areas, and on conclusion the Corps took over the system and was responsible for maintenance and allotment of circuits. For the latter purpose certain area detachments were attached from the Army to each Corps in the line, and on these men fell the brunt of this work. The way the area detachments carried out their task was beyond cavil and the new units soon created a record of which their successors may well be proud.

The buried cable system of 1917 was planned on the broad lines laid down after the experiences of the Somme battles. In numerous details, however, progress had been made towards greater secrecy in execution of the work and towards the more successful protection of the cables. 6 ft. buries were still the rule, but many trenches in suitable country were dug to 7ft., and under favourable circumstances some Corps even insisted upon buried cable 8 ft. deep within a thousand yards of the front line. The 1917 buries were of much greater extent than those in 1916. In this year it was unusual to meet with airline within 5,000 yards of the front line. The rear cables of the buried system usually finished about on the line of Divisional headquarters, leaving a short overground lead-in as the only vulnerable portion of the intercommunication system. Even this was often eliminated by burying the lead-in right up to the walls of the signal office.

Two distinct problems were presented by the buried cable systems of the battles of Arras and Vimy, and that of the third Battle of Ypres. In the former case, the ground was eminently suitable for burying, and a good safe system, 6 ft. 6 ins. to 7 and even 8 ft. deep, was carried right up to the front line. Even this was improved upon in places and the system made practically impregnable by utilization of the extensive system of tunnels, caves, and sewers, which were a characteristic of this portion of the front. In the use of tunnels, particularly, much assistance was afforded by the local Tunnelling Companies. Some Divisions were in the fortunate position of being able to go into action feeling absolutely assured as to the safety of all their signal communications in rear of the original front line.

In the Ypres, Messines, and Passchendaele areas, on the other hand, the British forces were under the necessity of preparing for the attack from their positions on low-lying swampy ground and under the constant observation of a vigilant enemy. All work for miles behind the front line had to be done at night. The country was about as unsuitable for burying cable as it well could be. The net result was that, while a buried system of fair safety was achieved by the efforts of the working parties — labouring often under intermittent fire and suffering many casualties — much more reliance had to be placed upon alternative methods of communication until the later stages of the battles. Then, when the higher ground which had been the objective of the earlier attacks had been taken, and made to form the basis of further advance, deeper buries were possible and were again carried forward to cable head as near as possible to the front line.

The chief lessons learnt by the Signal Service in 1917 as regards buried cable were the necessity for camouflage and for even greater protection. Early in the summer it became clear to everyone concerned that the enemy's gunners had added the buried cable routes to their list of targets to which special attention should be paid. His activities took two main lines, both highly unpleasant to the Signal Service personnel and working parties, and both a very decided menace to continuity of signal communications.

A careful watch was kept for any sign of working parties or of parties engaged in staking out buried routes on that portion of the front overlooked by his observation posts. Also, enemy aeroplane photographs must have undergone careful examination for any sign of recent buries or of buries in the making. Evidence of enemy deductions from his photographs or from direct observation was invariably unpleasantly direct. Time after time, working parties on the buries were harassed by fire which was obviously intended for their special benefit. Many casualties were suffered from such bursts of enemy fire and still more casualties to Signal Service personnel were the result of the systematic attempts made by the enemy in the phase immediately preceding our attacks to destroy all buries known to him.

So bad was the shelling in some cases that it proved impossible to keep the shell holes on the buries filled in day by day and it was discovered that this was the one set of circumstances that rendered a buried system — however deep it might be — relatively unsafe. Xo bury could withstand the continual impact of shells, one falling on the spot already weakened by its predecessors. This persistent attention became a problem in itself which was dealt with in two ways. One already indicated was by choosing the route more carefully to avoid any country likely to be shelled, the other was by improvement in any direction likely to prevent the enemy from finding the bury, either by direct observation or through his aeroplane photographs.

The danger of direct observation was comparatively easily averted. Buries were carried out in the exposed areas by night only. All reconnaissance which required daylight was done by a single officer, either alone or accompanied by a solitary sergeant or sapper. Orders were issued that maps were to be in evidence as little as possible and any other signs which might give a watchful enemy the idea that anything of special importance was about to take place were carefully suppressed. It was more difficult to camouflage the fines. It would be hard to impress on one who had not actually experienced the doubtful pleasure of picking out his own bury from the detail of a photograph taken from some thousands of feet up in the air, the extreme difficulty of hiding such a track from the argus eyes of the aeroplane cameras. To one who has, on the other hand, seen such photographs of the scene of his activities — possibly in the presence of a justly incensed Brigadier, the position of whose headquarters he has unwittingly revealed — no such difficulty of understanding exists. His efforts would henceforth be mainly directed to overcoming the obviousness which seems to be the chief characteristic of the most carefully dug bury. A thin white straight line which could not possibly be mistaken by the meanest intelligence for a track, a stream, or anything but what it brazenly and patently was, too often showed that all the care devoted to "camouflage" had been in vain.

Still, if buries could not be entirely hidden, much could be done to make them less obvious. The earlier types — nice straight lines from headquarters to headquarters, used as convenient guides by all men and trampled upon by day and by night, in season and out of season — were doomed. As much ingenuity as possible was brought to bear on the question of camouflage and this, in 1917, took certain definite forms. Buries were pointed anywhere but at the headquarters they were designed to serve. They were connected to signal offices by trenches run off at acute angles and hidden from observation from above by all the devices known to the camouflage officer and his trained staff. Strips of wire netting covered with stuffs cunningly coloured to resemble the surrounding soil were the latest and most successful devices used. Previous to the evolution of such artificial means of ensuring freedom from observation, already existing tracks and ditches were made use of or the buries were run in the immediate shadow of hedges or trees. Even so, the unfortunate signal officer was betrayed on more than one occasion by the deciduous nature of the European foliage. Carefully-hidden buries screened from prying aerial observers by the dense summer foliage of shade trees were revealed by the autumn storms in all their nakedness as white streaks, clearly artificial and worthy of enemy artillery attention.

The first step in this campaign for secrecy was an important one in itself. The work on the earlier buries had been haphazard in nature. No steps had usually been taken to suit the task to the power of the men and the time available for work. Long stretches of trenches were half-dug, or wholly-dug, but not filled in, and were then left throughout the daylight hours. They were, however, "noticed" with such painstaking thoroughness that the order was given that work must be completed and the trenches filled in before the working parties were permitted to leave the scene of their labours. This,. in its turn, led to a more careful apportioning of the size of the task. Statistics were compiled and all signal officers employed on cable burying grew accustomed to measuring out each man's task for the night so thoroughly and accurately that the work was normally completed and the party out of range and observation before the early morning light made possible direct observation either from observation post or aeroplane.[7]

Another refinement which was the result of further experience was the reinforcing of the bury in spots where only a comparatively shallow trench could be dug, by building up a mound, two or three feet in height, above the ground. Yet another, was the placing across the bury of obstacles to prevent the rank and file of the Army from using it as a convenient track through otherwise unbroken and uncharted country. It paid the Signal Service to be inhospitable enough to their fellow men to build barricades which could ensure that the ease-loving soldier would find a way forward which was more pleasant and less strewn with unexpected and, from his point of view, entirely unnecessary obstacles. Refinements of "camouflage," again, were (1) the wilful adoption of a zigzag track in which economy of labour was sacrificed to the fostering of an apparent inanity of purpose and (2) the utilization of neighbouring crops and herbage to give temporary immunity from observation. The latter were either plucked at random — if ripe and unlikely to change colour — and flung down across the earth-coloured track of the bury, or — where the herbage was green and likely to die if treated in this way — were transplanted en bloc and planted in growing position over the trench and the trampled ground on either side. It became a regular routine in pasture country to remove the upper sods carefully and place them on one side well out of the way of the working party's feet. The last job of a careful signal party was then the replacement of these sods to restore the face of nature as far as possible. Success varied both with the capacity of the men for landscape gardening and with the character of the turf. Still another way of deceiving the hostile observer was the digging of a dummy trench in a quite different direction from the real bury. The ground was turned over to a depth of two feet or so and a realistic scar left. Such "dummy" buries were often useful as decoys to enemy artillery and were, indeed, frequently a source of chagrin to unfortunate pedestrians who followed the false tracks in the hope of reaching the headquarters they expected them to serve.

From the point of view of protection, much had been done during the winter of 1916. Much more was done in the preparation for the 1917 battles. The digging of the trenches to a depth of 8 ft. near the front line has been mentioned. This was somewhat exceptional, for 8 ft. was a depth almost impossible to reach in the unbroken labour of one night. The 8 ft. trench was mostly confined to the buries further to the rear where time could be taken over the digging without unpleasant consequences.

In the principal dug-outs of the 1917 systems in the south, 15 ft. of headcover was aimed at by some Corps. This was, of course, impossible for such systems as those in Flanders. Here, recourse had to be had to reinforced concrete and iron girders, if any measure of security was to be achieved. Still, everything feasible was done to prevent the signal dug-out from being a weak spot in the system either from its conspicuousness or from lack of fortification. The area detachment had a relatively hard time under all circumstances, but as much was done as was humanly possible to make their life bearable and safe.

A feature of the buried cable system of 1917 was, as has already been pointed out, the much greater extent of the individual systems. In one typical Corps system 1,000 miles of cable were laid in preparation for a single offensive. The making of the system took nine weeks with all the labour Divisions could spare. Main routes contained 40 to 50 pairs and even then were found insufficient. At least one main route, and often two, were taken forward on the front of each Division and it was very seldom that cable head was not within easy distance of the front line. This was the policy aimed at in the Somme offensive, but at that date it had not been possible to carry it out to the full extent. Even routes serving a Brigade front were now completed with at least 20 pairs, in the expectation of their becoming the backbone of the new Divisional signal system in the event of an advance. The year was marked by a multiplication of the number of circuits in the routes which was only limited by the supply of cable. Yet the systems were too often insufficient to meet the needs of the artillery, for 10 to 20 Army Brigades were frequently concentrated on the front of one Army besides those normally part of the complement of the Divisions or Corps.

So much for the buried cable system at the opening of one of the great position battles. To obtain a picture of the forward signal system on the southern portion of the front affected, it is necessary first to visualize for the eyes of the imagination a more or less irregular grid of heavy cable routes securely buried from any single direct hit of a shell of any size less than 8-inch. At frequent intervals the cables are connected through securely protected dug-outs by means of elaborate cross-connecting frames which are equipped with plug and socket boards, terminals and cross-connecting wires, or any other of a dozen devices which might be the particular fancy of the local senior signal officer. At most of the dug-outs and test-points two, three, or more pairs are led up out of the bury and fixed to accessible but protected stakes and boards for the benefit of units whose headquarters are situated in the immediate neighbourhood. At the principal junction points the dug-outs are more commodious, and here, in a kind of warren more or less adequate to their needs, live the maintenance personnel under the charge of a junior N.C.O. or senior Sapper. Certain other dug-outs are manned only during operations. At all, whether manned or not, are notices to the effect that unauthorized persons must not tamper with the lines. At all, also, are diagrams, perhaps only of the immediate connections, perhaps also of the general Corps system. All diagrams are kept up to date and the N.C.O. or sapper in charge at each station is informed daily as to alterations and instructed as to the allotment of his lines.

Finally, at the principal test station lives the area officer himself in constant communication with his A.D. Signals and the "Lines" officers of his Corps and of the Divisions occupying the area for which he is responsible. His books are a compendium of the history and present state of the bury. He should know every detail of its history and the exact state of efficiency of every pair. He should patrol every inch of his bury at frequent intervals to ensure that his maintenance personnel is keeping the routes in perfect order and repairing daily the ravages made by enemy shells.

How is free intercommunication between himself and his men ensured without interfering with the general working of the system? The answer is supplied by yet another improvement. This was the allocation of two circuits, usually of "D5" or "D8" to prevent confusion, for the sole use of the Signal Service. Of these two pairs, one is used by the linemen as they make their daily patrol of their own particular section of the line. The other is the general channel of communication for Signal Service personnel. The signal officer who has planned his system without leaving room for these necessary adjuncts to its smooth working has laid up endless trouble for himself, his successors and his subordinates.

To adapt the above system to the northern area of the British front, it is only necessary to remember that deep delving was impossible, being prohibited by the nature of the ground. All extra protection had to be added overhead. It was, therefore, only achieved as the result of unlimited labour, by the expenditure of relatively large amounts of fortifying material urgently required for other purposes, and at the expense of concealment. In other words, having regard to the practical factors of the situation, it was frequently impossible. Security had to be sacrificed in favour of concealment and the economy of stores and labour. The result was a comparatively unsafe buried system, only rendered successful in any measure by unremitting toil at its daily maintenance, and liable at any moment to interruption for the period necessary to repair a complete break.

The success of the northern buries in low-lying country depended largely upon the care with which they were sited and the promptitude with which they were repaired. In any case, the element of uncertainty was such that much more reliance was perforce placed on the alternative methods of communication as far back as Divisional headquarters. This was an added care to the signal officers concerned, but, on the other hand, it was possibly a potent influence in the development of these alternative methods.

So far, in the picture of the signal activity in the rear areas in 1917. stress has been laid on the telegraph and telephone system, with little mention of other means save a passing reference to wireless. This was, however, necessary if a true picture of the Signal Service in action in position warfare was to be obtained. Tile importance of this system has not been exaggerated. There was, indeed, no reason to depart to any great extent from the most rapid and reliable method of signalling. In rear of Divisional headquarters, alternative means were strictly subsidiary in their functions. Such representatives of wireless, pigeons, visual, etc., as were included in the rear establishments confined their attention mainly to administration and control and to the evolution of signal policy. The rear establishments were a faithful reflection of the rear conditions of signal warfare and the realities of signal practice. Had they not been so, they would have been inadequate and ill-proportioned.


  1. 1.0 1.1 A diagram of R.F.C. Anti-aircraft and Field Survey telephone systems in one Army is illustrated on Plate XIV. (Sept., 1917).
  2. It is not intended to convey the impression that separate routes and separate exchanges were utilized for the different systems. This was not the case. All the circuits of the Army system as a whole were concentrated on certain definite main routes unless the scattered nature of the subscribers rendered shorter and lighter spurs necessary — as they often were. Certain circuits between suitable exchanges were allotted to certain departments or services, however, and these were reserved exclusively for their use, and each series considered as forming a self-contained system. Diagrams issued for the information of subscribers showed these circuits — perhaps differently coloured, perhaps identified in other ways. Frequently special diagrams were issued showing the circuits of one system alone. On the other hand, the Army route maps and the main Army circuit diagrams would simply show — the former, the routes; the latter, the individual circuits — totally undifferentiated except in so far as they might run to subsidiary exchanges which were obviously built for the use of the special branches. The important point, however, is that these specially allotted circuits were considered as separate systems not to be used for the passage of messages alien to the department or branch that they served except in dire emergency. By this means confusion was avoided and a common source of delay — the difficulty of umpiring as to the relative urgency of the "Operations Priority" and "Priority" messages of different arms of the service — was eliminated to a great extent.
  3. The name "Intelligence Centres" originated in First Army, but systems which closely resembled the First Army system were evolved independently in other armies and all had one feature in common. Reform, whatever form it took, was directed towards quicker inter-communication from all sources of information to Intelligence and Artillery headquarters.
  4. Plates XV. and XVI. are diagrams of detailed telephone systems of an Anti-aircraft battery and a Sound-ranging section in September, 1917.
  5. The ideal office included a separate room for the telephone exchange.
  6. An excellent example of the value of the Army control station can be cited from the records of the battle of Cambrai in November, 1917. An infantry Brigade completely cut off by the enemy could not get through by wireless either to its Division or its Corps, possibly on account of the latter headquarters being in retreat, possibly because distances were too great. The Army wireless control station heard its call, took the message and promptly forwarded the latter to its rightful destination.
    This is only one of many examples which in themselves justified the retention of these powerful stations which watched and controlled our own traffic.
  7. Exceptionally hard ground and short summer nights were sometimes the cause of the failure of this policy, resulting in trenches not reaching a safe depth.

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