In a war that was to be increasingly dominated by the artillery, the maximisation of its efficacy was always a prime consideration; knowledge about the opposing army's tactical dispositions was equally essential.Before the onset of trench warfare in the Western Front in September 1914, reconnaissance was largely the duty of the cavalry. Whilst tethered lighter-than-air observation balloons* had been used in earlier conflicts, and were seen by some of the belligerents as a useful observational tool, their role was by no means universally accepted in the early days of the Great War. Until the Spring of 1915, the British Expeditionary Force (BEF) did not have any observation balloons of its own on the Western Front.
* N.B.: The German observation balloons of 1914 were known as Drachen a name commonly adopted for all sausage-shaped kite-balloons. Spherical balloons were also used and, later in the Great War, the classic World War II, barrage-balloon type 'Jumbo' shapes were introduced.
On the other hand, the military view concerning the potential and utility of the newly introduced reconnaissance aircraft was generally rather jaundiced: the French General Ferdinand Foch considered that 'Aviation is a good sport, but for the army it is useless'. The BEF had arrived in France with only a couple of dozen reconnaissance aircraft.The artillery guns of both sides in the Great War wrought grievous casualties on the advancing columns of infantry and cavalry in the early days of open-warfare and drove the infantry into the trenches. But ever-bigger leaps in technology and technical expertise meant that from the end of 1917 the artillery became the major dominant factor on the battlefield. To the army commander in the field, improvements in the artillery guns and precision in mapping and targeting became a sine qua non.
Progressive improvements included:
- Better propellants and high explosives that gave longer range and more explosive power.
- Recoil mechanisms that absorbed much of the shock of firing and stabilised the guns so they remained on target and could be fired at a higher rate.
- More reliable prediction of targeting by a better understanding of the ballistics of the individual artillery piece, and batch of shells, and the effect of weather conditions on the flight of the shell.
- New detection methods that located the enemy guns by trigonometric sound-ranging and flash location, eliminating the need for registration shots or line of sight firing. (The subsequent development in 1917 by the Germans of flashless shell propellants stymied the Allies gun-flash detection method).
However, an equally important improvement in war-skills was the quality and accuracy of the mapping of the whole battlefield by means of aerial observation.As stated previously, before the Great War reconnaissance was a largely a function of the cavalry, the lighter-than-air observation balloon (kite-balloon) and the dirigible (Zeppelin). Just in time for the Great War the reconnaissance aircraft appeared on the scene.
The Germans carried out their aerial observation of the Western Front battlefield in the very earliest days with specially trained observers suspended in fragile baskets hanging below the tethered lighter-than-air 'Drachen' observation balloons. The availability of eight German Balloon Companies gave the Germans a distinct tactical advantage over the French. The French put up a solitary balloon on 25th August 1914 that was soon followed by several more in September and October 1914.
When the British Expeditionary Force arrived in France in mid-August, it had no observation balloons at all. It was not until April 1915 that the British commander of the BEF, General John French, got his first balloon company, on loan from the French Aérostiers. The first fully British unit only arrived on May 8th 1915, in time for the Battle of Aubers Ridge.
On the other hand the British reconnaissance aircraft with its observer quickly made its appearance, as did, sometime later, the purpose-made aerial camera, be it both heavy and cumbersome.
On the 22nd August 1914, a British Royal Flying Corps (RFC), pilot - Captain L.E.O. Charlton - and his observer - Lieutenant V.H.M. Wadham - made the crucial observation of the attempt of the German General von Kluck's army to out-flank the British Expeditionary Force. This allowed the British BEF Commander-in-Chief, Field Marshal Sir John Denton Pinkstone French, to realign his front and save his army at Mons. Captain Charlton and his observer were part of a limited force of only about 20 reconnaissance aircraft with the BEF at that time.
Of perhaps even greater import, were the reports of French aerial surveillance aircraft on the 3rd September 1914 that the German 1st, 2nd and 5th Armies were moving towards Paris. General Joseph Gallieni, commander of the defence of Paris, and an early supporter of aerial reconnaissance, acted promptly and Paris was saved.
Meanwhile, on the Eastern Front, German and Austrian reconnaissance aircraft were credited with tracking the movements of the Russian army in Poland and that enabled the Germans and the Austrians to halt a Russian advance during the Battle of Tannenberg in late August 1914.
But by no means were all the aerial observations by balloon and aircraft taken with the same seriousness, and many opportunities were lost.
On the 15th September 1914, a Lieutenant Lawes of the RFC took the first aerial photograph of the Great War over the German lines.
There was no smooth transition on either side from balloon observers telephoning their observations to the commanders below, to the creation of specialised units studying daily up-dated products of 'photogrammery'.
Initially, aerial reconnaissance was carried out at the Corps level for the express use of local commanders. But the demands of HQ level commanders for more long-range reconnaissance on transportation systems, supply dumps, troop movements and dispositions meant 'eye-ball' reports were still required for much of the war. Most of the aircraft lost on the Western Front on both sides were involved in aerial reconnaissance over enemy lines.
Observations from balloons
Observations from balloons continued throughout the war. Apart from being a highly hazardous occupation that made continuous observations of any duration difficult (15 days was thought to be a reasonable expectation of life for a kite-balloon - that of many balloonists was considerable less), the results were highly dependent on the skill of the observer. These could be rather subjective and difficult to validate promptly.
Due to the need to keep the balloons out of the range of counter artillery fire, it was often necessary to locate the balloons farther away from the site(s) of military operations than was optimal. Also the extent to which the balloon was optimally located above its putative target was dependent on the wind direction which could quite quickly veer adversely and regularly. However, a great deal of importance was given to the stable platform that was offered by the kite-balloon, And this, initially, made the kite-balloon more suitable than an aircraft for the available cameras of the day.
In any event, the flying of the observation balloon was always subject to the weather conditions, and involved quite a lengthy process in relocation as the Front moved across the battlefield. It also took an enormous expenditure in time and dedicated manpower to just get them up into the air and safely down again.
Observations from aircraft
Improvements in aircraft technology and reliability gradually allowed increasing numbers of observers to be taken into the air for reconnaissance purposes. But, of course, the aircraft was continually in motion, making sustained observation of a particular location difficult; progressively so, as the enemy's skills at anti-aircraft artillery grew with experience and improved technology. Also, the duration of the observation was limited by the flying endurance time of the aircraft. Certainly, the earlier types of aircraft were more susceptible to weather conditions than even the kite-balloon was.
When, in early 1915, the British reconnaissance aircraft pilots were supplied with Morse transmitters the inherent problem of how the aviator would convey his observations quickly enough to the commander concerned was largely resolved.
As already related, early efforts at aerial photography were very amateurish requiring the pilot to simultaneously fly his aircraft and manipulate the camera at the required target. The inclusion of an observer/cameraman simplified matters, but, due to the cold at altitude, gloves were often needed which made the essential fine manipulations difficult.
In 1915 the British Lieutenant Colonel J.T.C. Moore Brabrazon designed the first practical aerial camera.
Fixed semi- automatic cameras became a high priority and purposely-fitted photo-reconnaissance aircraft were soon operational. The camera was usually fixed to the side of the fuselage of the aircraft, or operated through an aperture in the floor.
Moreover, the increasing awareness of the Allied and German commanders of the sheer necessity of accurate surveys of the entire battle zone made aerial photographs essential. Aerial photographs were exclusively used in the compilation of the new 1:10,000 scale maps that began to come on stream in mid-1915 i.e. in time for the Battle of Neuve Chapelle in Northern France. Such were these advances that the entire July 1916 Somme Offensive was based on aerial photography maps, and both sides re-photographed the entire Front twice a day when weather permitted.
Far from 'aviation being a good sport', a point was reached in the late Summer of 1915 when it became clear that the control of air-space was essential if proper aerial surveying and mapping of the Western Front was to be maintained. Aerial supremacy became an aim in itself, and the Germans seriously challenged the British and French air forces. New aircraft types, called fighters, were introduced with the task of eliminating the reconnaissance aircraft and, in turn, fighter escort aircraft were deployed to protect the reconnaissance aircraft from the enemy fighters.
The first serious German challenge against the RFC came at the end of 1915 in the form of the new Fokker monoplane with a forward firing machine gun synchronised to fire between the propeller blades. The elderly British 'pusher' reconnaissance planes with their flexible mounted Lewis machines just managed to hold the fort, with considerable losses, until the RFC introduced, in March 1915, its own hydraulic powered, Vickers machine gun version of the German device.
On two other occasions during the War, the Germans again attained air supremacy and threatened the Allies' aerial reconnaissance ability. Firstly, in September 1916 with the new wave of Halberstadt and Albatross fighter aircraft and then in April 1917, when the German 'flying circuses' again briefly ruled the air. There was another major contretemps for the British in August 1918: on 8th August 1918 alone, the newly formed RAF lost a total of 96 aircraft, over 10% of its fighting strength. But thereafter after mastery of the skies was increasingly in Allied hands.
This mastery presented itself in the ability of the Allies to photograph virtually any German position and, using these photographs, to produce maps that would enable the artillery to eliminate them promptly and economically. New enlargement processes allowed photographs to be 'blown up' to show even the smallest details on the ground. This enabled a new cadre of photograph interpreters to make sense of what seemed to the uninformed an almost featureless mass of muddied humanity amidst their warren of trenches and fortifications. Armed with this information, army commanders and their staffs were able to plan and execute elaborate schemes of defence and offence whilst thwarting the enemy's own plans.
An often quoted statistic which indicates the amazing development of aerial photography in the Great War, is that in 1918 the French claimed to have taken and printed 100,000 reconnaissance photographs each night. Additionally, over four days in the Meuse/Argonne Offensive, the French made 56,000 aerial prints and delivered them to the American Expeditionary Force.
With the realisation by Western Front commanders of both sides that the cavalry's role of reconnaissance was no longer a viable option in the conditions of trench-warfare, new means of observation had to be created to support the limited possibilities of lighter-than-air balloons and dirigibles. The enormous leaps in technology and organisation in the deployment of reconnaissance aircraft quickly filled the void. Thereafter, within a very short period, aerial photography from aircraft was developed, and a whole now science of war was created.
The improved maps necessary for the full deployment of the increasingly technologically advanced artillery guns were a sine qua non that could not be achieved without the supply of a constantly revised source of photographic intelligence that reached an incredible density and intensity as the war reached its conclusion. In the final stages of the war, it is said that standard aerial reconnaissance photographs could detect the footprints of a German soldier who had left his trench.