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U.S. Army Model 1913 Cavalry Saber
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Britain's Participation Justified?
Lafayette Escadrille Pilots
Dead Man's Penny
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One of Ten Thousand
The Design Was Not Passed On
Subverting the Sultan
The Russian Army in 1914
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Del Kostka Articles
The Somme
Mapping the Western Front in WWI
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Air Recon in WWI
Banzai Attack on Attu

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Bloody April: Slaughter in the Skies Over Arras, 1917

Artillery in the Great War

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A Crisis of Cartography: Mapping the Western Front in World War I
A Crisis of Cartography: `Mapping the Western Front in World War I
by Del Kostka

The Great War

When the great armies of Europe converged on the border region between Belgium and France in August of 1914 they were not concerned with map making or topography. After all, it was very familiar territory. Just forty-four years prior, the most decisive battle of the Franco-Prussian War was waged outside the French town of Sedan near the Belgian border, and every commander in every nation knew by heart the epic campaign of Napoleon, Wellington and Blucher, and the roads that led them to a quiet Belgian village named Waterloo. Besides, each side was confident that this would be a very short war. Germany’s Schlieffen Plan, which called for the invasion of France through Belgium, set a timetable of six weeks for total French capitulation, and eager British recruits were discouraged when assured that the war would be over by Christmas.[1] But the Great War would not be quick and it would not be easy. In fact, it would become a bloodbath of horrific proportions. Before it was finished over 37 million people were either dead, wounded or had simply vanished from the face of the earth.[2]

The reason for the unprecedented carnage of the First World War was the technological development of weaponry in the decades preceding the war. World War 1 was a virtual incubator of advanced weapons and tactics. The years 1914-1918 saw the first systematic use of the machine gun, poison gas, flame throwers, trench mortars, hand grenades and battle tanks. And then there was the artillery; the horrible, viscous artillery that could pulverize both landscape and flesh from a range that was measured in miles. Trench warfare and the new weapon systems befuddled military commanders who spent their entire lives studying classic Napoleonic tactics of maneuver, and soldiers who left their homes expecting a short and glorious war of conquest found instead a stagnant, brutal slugfest. World War 1 was a human catastrophe without precedent. It was also a new kind of warfare where life or death hinged on a little known science that depicted the battlefield as an interconnected series of geographically referenced data points.

The Mapping Requirements of Trench Warfare

At the outbreak of the war none of the armies that took to the field were equipped for the cartographic challenge of trench warfare and new weapon technologies. Throughout the nineteenth century major military operations were based on small scale map products that best suited maneuver over vast stretches of territory. In fact, many of the maps used during the initial phase of the war were merely updated versions of the same 1:80,000 scale campaign maps used during the Franco-Prussian War.[3] These small scale maps were typically produced by each nation’s state mapping industry to military specifications. Topography was considered a function of intelligence at the General Staff level, but the armies themselves had no resident map-making capability, and there was no prophecy of having to re-map any portion of the well-documented countryside.[4]

The first indication that World War 1 would be fought according to a new set of rules occurred shortly after the first major engagement of the war. In early September the combined French and British forces stopped the German advance at the First Battle of the Marne. The Germans withdrew across the Aisne River in eastern France, stopping on a high plateau with a commanding view of the river valley and the low-lying countryside. On the evening of September 13, the British Expeditionary Force (BEF) crossed the Aisne River under the cover of darkness, but as the sun rose the BEF found itself a very conspicuous target on the broad Aisne floodplain and was soon subject to devastating mortar and artillery fire. Unwilling to retreat and with no natural concealment from the rain of artillery, BEF commander Sir John French ordered the British forces to entrench across the length of the front.[5] The era of trench warfare had begun.

Trench Warfare was the antithesis of the classic war of maneuver the armies had prepared for.

To both the Allies and the Germans the unique cartographic requirements of stationary warfare were soon apparent. The paramount need was an accurate, large scale map of the immediate vicinity that depicted the burgeoning network of trenches and the location of enemy artillery. There was, of course, no possibility of a fresh cartographic survey given the chaos of the moment, and even if there were there was simply nobody available to do it. Most experienced surveyors, draftsman and cartographers were plying their trade in company level artillery survey units.[6] As an interim solution, engineering units began enlarging the original small-scale campaign maps and annotating trench details based on simple compass readings and hand sketches provided by aerial observers. But the original campaign maps had a shortfall that could not be overcome by even the most meticulous editing; the vintage graphics used an artistic form of shading called hachures to depict terrain elevation rather than precise contours.[7] As a guide for tactical planning and targeting, the enlarged 1:80,000 scale maps were woefully inadequate.

In desperation, staff officers began a frantic scavenger hunt for existing large-scale cartographic products that could help them visualize the neighboring terrain. In France, the entire country had been mapped at a scale of 1:2500 for public record purposes. These cadastral maps included geospatially referenced datum points for prominent features such as public buildings, churches and crossroads, but most of the map features were generalized and overall accuracy varied from map to map.[8] The engineering units also obtained a variety of road maps, railroad profiles and mine surveys, but in many cases the actual location of a road or railway was found to be significantly different from its depiction on official plans.[9] The lone exception to this plague of arbitrary accuracy was a series of maps depicting the French fortresses that commanded key strategic locations throughout region. These 1:10,000 scale maps were compiled with a highly accurate 5m contour interval to cover all the ground that might be of importance during the siege of a fortress. Unfortunately, these maps covered too small of an area to be of any real value.[10]

The lack of accurate large-scale map products drove the BEF to a desperate decision; they would re-survey, to the greatest extent possible, the territory impacted by the ever-expanding network of trenches and staging areas. The resulting cartographic products were to be based on a 1:40,000 scale map series produced before the war by the Belgian military that covered the entire country of Belgium at 5m contour intervals. Adoption of the Belgian projection and sheet lines would give the Allies a consecutive series of maps stretching as far as the German frontier.[11] The task was assigned to the Royal Engineers who promptly pulled experienced surveyors out of artillery ranging units to help perform the survey.[12] The project, however, was rife with difficulty from the start.

First, the improvised field survey crews attempted to compile a traverse network from known control points depicted on the existing French cadastral maps. Unfortunately, many of the key benchmark features depicted on the original cadastral maps had already been leveled beyond recognition by artillery, and those few distinctive benchmarks that still remained were found to be very inaccurate.[13] The ever changing landscape was also a problem. As each trench network was expanded and modified, the large-scale trench maps required constant revision.[14] The survey crews also had difficulty maneuvering to the required survey locations. Traffic congestion on the roads, a pitted and churned landscape, and near constant interruption from enemy artillery all conspired to make the field surveys extremely difficult. As if surveying in an artillery barrage wasn’t problematic enough, some survey teams even came under fire from their own forces. In fact, the very first surveyor to start work with an alidade equipped plane table was promptly arrested as a spy on the grounds that no one except a German agent would be found lurking behind British lines with such an ominous looking instrument.[15]

The responsibility of the engineering survey crews ceased at the front line. Beyond that mapping was carried out by General Staff Intelligence who depended greatly on existing maps and manual sketches of the enemy trench system provided through aerial reconnaissance.[16] But the existing maps were approximate at best, and the quality and accuracy of aerial reconnaissance reports were limited by the observers experience and artistic ability. The intelligence officers did their best to extrapolate elevation contours from benchmark features on cadastral maps and railroad profiles, but it was soon obvious that map compilation where actual survey was impossible called for expert handling.[17] In July of 1915 the cumbersome and disjointed effort to map the front inspired the British to establish a dedicated Topographical Section for each Army.[18]

Maps were everywhere on the Western Front. Here a British officer and sergeant consult a map, seated on the trail of a captured German mortar.

Mapping from the Sky

The original intent of aerial observation was simple visual reconnaissance. Pilots and observers would carry note pads to record observations and sketch hostile positions, but their reports were often met with skepticism by commanders who still felt reconnaissance was the exclusive domain of mounted cavalry. Then, in September of 1914, an industrious British observer took his personal box camera along on a mission and took five photographs of enemy positions. The oblique photographs were grainy and blurred, but on close examination the prints revealed details about the elaborate German trench system that would have been overlooked by even the most sharp-eyed observer.[19] The science of air photo reconnaissance had been born.

Soon, air crews of both sides were using hand-held cameras to record their observations, but these early photographic efforts only recorded images that were already determined to be of interest by the observer, so there was no real role for photo interpretation. In March of 1915 the British unveiled the first camera designed specifically for air photo reconnaissance.[20] Strapped to the outside of the fuselage, the camera captured sequenced images of the terrain directly below the aircraft, providing a platform for more rigid and systematic photo interpretation. Since most trench construction, resupply operations and artillery movements occurred at night under the cover of darkness, the great majority of photo reconnaissance missions were conducted at the first light of day. The long shadows cast by the morning sun also helped photo interpreters identify and measure features. The abundance of air reconnaissance missions in the early morning hours was not lost on the fighter patrols of both sides who also took to the sky at daybreak in order to prohibit access to the airspace over front lines. Thus the “dawn patrol,” celebrated in movies and literature, owed it’s infamy to the advent of aerial reconnaissance operations.[21]

The French were the first to recognize the mapping potential of aerial photography. Their first effort to revise maps from imagery was a manual process to transfer photo details onto a map framework using mechanical dividers.[22] The Germans developed a similar technique using a proportional grid overlay on both the base map and the aerial photo. Prior to World War 1 very few maps included a measured grid, but the system proved such a simple and intuitive way of determining map location that it remains a staple of cartography to this day.[23] A third common method of map revision used an optical device called a camera lucida to project a photo image onto a map that was mounted on a pivoting board. The tilt and angle of the map board were adjusted so that known control points on the image aligned with coincident points on the map. Once the key features were aligned, the remaining photo features could easily be traced onto the map surface.[24] All of these map revision methods had a major drawback; since there was no way to determine the exact altitude and tilt of the camera at the moment of exposure, the resulting map revisions were approximate at best. Nevertheless, the imagery-based map revision processes were a major improvement in speed over the laborious surveys.

The success of the photo-based map revision techniques proved the immense value of air photography, but the evolving requirements of trench warfare soon demanded even greater innovation from cartographers and topographic units. The proliferation of specialized, large-scale products such as trench schematics, barrage maps and communication diagrams soon surpassed the compilation capacity of field survey units, and the close proximity of friendly forces to hostile targets required a level of precision far beyond the accuracy of existing map revision methods. The great challenge facing military engineers was to develop a systematic process that combined the speed and consistency of photoreconnaissance with the topographic control and accuracy of field survey operations. But as the engineers soon realized, compiling completely new maps from air photography implied an entirely new set of complications.

The first basic requirement of aerial mapping was to acquire a series of overlapping photographs of sufficient scale so that several fixed control points appeared on each photograph. Unfortunately, the reconnaissance cameras developed during the early stages of the war were tailored for high altitude operations in order to collect imagery beyond the reach of hostile ground fire. The camera’s long focal length provided tremendous detail of features, but the photographs themselves covered a relatively small geographic area. In early 1917 the British developed a special camera for mapping operations with a shortened focal length to produce relatively wide angle photographs.[25] By capturing the same known control points on adjacent images, a controlled photo mosaic was created that served as the skeletal framework for a topographic line map. Cartographers added contours to the map by visually comparing topology on the image with the known datum points.[26] The process required considerable judgment and experience, but the resulting map was considered to be a major improvement over any cartographic product of the era.

An air reconnaissance mission in support of mapping operations was exceptionally dangerous work. Most early photo missions were conducted between 4000 and 5000 feet, well within range of anti-aircraft guns.[27] An accurate photo mosaic also required total concentration by both pilot and observer. The pilot had to continually look from map to ground to instrument panel in order to keep the aircraft on a precise course with consistent air speed and altitude. Managing the camera was the full-time duty of the observer, who used a stop watch to ensure the correct overlap of each exposure.[28] It was extremely easy for an enemy aircraft to sneak up on a pre-occupied photo reconnaissance aircrew. In fact, over half of Manfred von Richthofen's 80 aerial victories were over observation aircraft.[29]

Despite dangers in the sky and equipment shortfalls, the quality and efficiency of Allied mapping continued to improve throughout the war, thanks in large part to the US Army Corp of Engineers. The American Expeditionary Force (AEF) that sailed to France in June of 1917 may have been untested in combat, but they boasted some of the world’s most advanced topographic survey capabilities. The main reason for American expertise in the subject was the US Geological Survey (USGS), which the United States established in 1879 to consolidate multiple survey efforts related to western expansion. The great American west provided the fledgling USGS with an experimental laboratory and proving ground for cartographic techniques far beyond the relatively sedate survey requirements of nineteenth century Europe. In January of 1917, as the prospect of war loomed, the USGS instituted a dedicated Division of Military Survey to support the US Army General Staff. The Division’s technical personnel were offered commissions in the US Army Corp of Engineers.[30] Once in France, these same professional scientists, surveyors and cartographers launched an aggressive campaign to develop systematic photogrammetric techniques to derive more detailed terrain data. By the time of the armistice, Allied mapping efforts included rigid control of contour intervals through stereographic analysis, and complete uniformity of grid line and symbology along the entire western front.[31]

US Army Engineer recruiting poster, ca. 1917-1919, underscoring the relationship between topographic survey and aerial reconnaissance.

Topographic Survey and Targeting

The datum collected by topographic survey units at great personal peril provided essential control points for mapping and advanced photogrammetric applications, but the overwhelming priority for survey operations in World War 1 was to support artillery targeting. To really appreciate the importance of artillery on the Western Front, one needs to understand the incredible advances in artillery technology in the decades preceding the Great War. Just 40 years prior, the French and German armies were still using horse-drawn cannon to pound each other during the Franco-Prussian war. Targeting of hostile artillery was generally accomplished through a time honored system of flash spotting and sound ranging.[32] As the name implies, a designated spotter would use a stop watch to calculate range based on the interval between the flash of the muzzle and the report of the guns. Once the range was determined, the cannons were aimed entirely by sight, and their stiff recoil knocked the cannon out of position with every shot. By the later part of the 19th Century, breech-loading howitzers were developed that could absorb the recoil, allowing the gunners to engage enemy positions with far greater consistency, range and rate of fire.[33]

Flash spotting and sound ranging remained the principle method of locating hostile batteries at the outbreak of the war, but the vast range of the new guns added an entirely new element to the science of targeting. On the rare occasions when a target was actually visible to the gun crews, range could be determined using an optical rangefinder. More often than not, however, high value targets such as ammunition stores, supply routes and hostile artillery batteries were located well behind the front lines and visible only through aerial reconnaissance or stationary observation balloons. The German’s were the first to devise an accurate method of targeting via aerial observation.[34] As early as September of 1914, German reconnaissance aircraft were flying over British and French positions at a predetermined altitude and dropping smoke bombs when directly over a target. Ground spotters, who used binoculars to keep watch on the aircraft, would then calculate range to the target using the known altitude of the aircraft and its look angle above the horizon.[35] The introduction of wireless radio transmissions from airborne observers improved the accuracy of aerial targeting even more, but the reconnaissance air crews and artillery batteries still required a common frame of reference to coordinate barrages. This common reference was provided in the form of a battery board.

A battery board consisted of a linen chart mounted on a sheet of zinc to avoid expansion and contraction due to temperature. The boards were produced by a team of topographers, draftsmen and intelligence officers who sorted through air photographs, intelligence reports and field survey metrics to compile the required content for the chart. One battery board was produced for each specific artillery battery. Each chart included the precise position of the battery, a surveyed aim point or visual point of reference, key landmark features and trench locations relative to the battery, and a map grid to help plot the location of targets. The gun crews themselves would add their assigned targets, the range to the targets, and the bearing of the targets relative to the aim point.[36] Determining the precise position of the guns was the job of the artillery survey units. An enormous number of survey pickets were fixed in connection with battery survey during the Great War, and few combatants remained busier than the artillery survey units. Not only did they need to survey and document the location of each battery and aim point, but also the location of alternate battery positions and new aim points to replace ones that had been destroyed. Some artillery barrages were so intense they literally obliterated every visible aim point beyond enemy lines. In these instances a sun azimuth could be used as an alternate aim point to calculate bearing to the target.[37]

Counter-battery operations were among the highest priority missions on the Western Front, with each side aggressively developing ways to locate enemy guns and report target coordinates to their own heavy artillery units. One of the more novel efforts was a precise examination of shell craters to determine the line of fire, angle of descent and range of the gun that fired the round.[38] Another experiment measured seismic earth tremors.[39] A more advanced and successful method involved electronic sound ranging to determine the location of enemy artillery. Sound ranging was implemented through an array of microphones spread over a distance of several miles. As the sound of a gun reached each microphone in turn, a signal was sent by wire to a central galvanometer, an instrument used to indicate the presence, direction, and strength of an electric current. The galvanometer readings where captured on photographic film where they were measured to indicate the distance and direction to the offending artillery relative to the microphones. The precise geographic location of the hostile gun was then calculated and reported to friendly artillery as a map grid coordinate. When used in conjunction with aerial observation, sound ranging had a near 100% success rate in locating enemy gun positions.[40]

Aerial reconnaissance and mapping came of age during the Great War. Here, a British observer adjusts his camera prior to a mission.


Before 1914 the cartographic requirements of entrenched warfare were not realized. Consequently, the European powers entered the First World War with inadequate topographic knowledge and no established procedure to create the maps needed to conduct operations on the Western Front. In response to this overarching shortfall, essential mapping techniques and technologies developed with extreme urgency. Topographic survey remained a continuous and indispensible activity throughout the war, but it was the unexpected alliance of survey with two ostensibly unrelated technologies, the camera and the airplane, that ultimately provided the timely and accurate view of the battlespace required by front line commanders and artillery targeteers.
* * *

Show Footnotes and Bibliography
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Copyright © 2013 Del Kostka

Written by Del C. Kostka. If you have questions or comments on this article, please contact Del Kostka at:

About the author:
Del C. Kostka is a staff officer at the National Geospatial Intelligence Agency in St. Louis, Missouri. He has a Masters Degree in Operational Arts and Military Science from the US Air Force Air Command and Staff College.

Published online: 12/01/2013.
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