Finding the German guns

British officers try to assess the efficacy of an artillery bombardment at Pozières in 1916.

One of the most important aspects of warfare during the First World War was the artillery. Responsible for an estimated 60 per cent of all casualties on the Western Front, the artillery began the war woefully unprepared for what would become a complex task of counter-battery work and intricately moving barrage fire.

Perhaps surprisingly, the artillery was not prepared to hit targets the gunners could not see. Pre-war expectations revolved around artillery pieces being wheeled into line with the infantry, but it quickly became apparent this gave the enemy a clear shot, and so guns were pulled back out of sight to avoid the destruction of each side’s artillery.

This created a mass of problems in effectively directing artillery fire. In order to see where shells were landing, observation officers climbed something high – a tree, building, pole, or hill – and shouted information down to the gunners. The process was eventually streamlined into one observer per battery instead of one observer per gun (with an attending circus of observers in a nearby tree). Eventually the air service became involved, passing on information about the flight of shells.

German Army artillery observation post at La Fere in 1917.

But how to convey that information? Pre-war maps were not on a particularly detailed scale, and did not have grid references to refer to. In the early years of the war, Michelin tourist maps were widely in use, and observers had to resort to referring to locations being “under the A in Amiens in map number 42” or similar. By the end of the war field survey battalions were producing gridded maps for the men in the trenches; an estimated 32 million were sent to France from printing shops in England.

With the artillery of both sides withdrawn from view, the German guns wreaked havoc on Allied positions. Finding the German guns and stopping them with British or French guns was of the utmost importance; work was constantly going on to accurately find and describe the location of the German guns.

An oblique photograph of the railway line at Dernancourt in 1918.

One technique was using aerial photography for surveillance. Patrolling aircraft photographed the terrain behind enemy lines to help with accurate mapping, but also took some of their photographs from an angle. Known as “obliques”, these photos were sent to trained men who searched for shadows and hidden guns.

Flash-spotting and sound-ranging were also developed to find the hidden German guns. Flash spotting was a relatively simple method of observing the flash of a German gun (or the reflection of a flash on the cloud) and plotting a line towards it. With two, or preferably three or more, lines of observation, the gun could be located at the point at which the lines met. Sound ranging was a similar idea, but used sound gathered by microphones strung along the front.

The success of this desperate struggle to locate the German artillery guns, combined with accurately ranged guns, had a revolutionary effect on military operations. At the Battle of Hamel on 4 July 1918, the Australian artillery had accurately plotted the locations of German guns in the area before the battle. When the operation was launched, the Australian artillery was able to put those guns out of action almost immediately, and German artillery fire had little, if any, impact on the conduct of the operation. This new ability was a key factor in the military defeat of the German Army in 1918.

An observation balloon being sent up to spot for the artillery at Ypres in 1917

This article appeared in Wartime issue 84. Purchase the magazine here. 

About the author

Meleah Hampton is an historian in the Military History Section at the Australian War Memorial.