Arms and Men: Returning Fire | HistoryNet MENU

Arms and Men: Returning Fire

By Noah Andre Trudeau
Autumn 2010 • MHQ Magazine

Led by a Nobel laureate, British gunners in World War I mastered the science of pinpointing— and knocking out—enemy artillery.

By all accounts, the British artillery bombardment that pounded German positions prior to the 1916 Battle of the Somme was apocalyptic. For five days an unprecedented aggregation of guns fired without pause; it was said that 1.5 million shells were used—more than in the entire first year of the war. “It was a real sight to see for miles to left and right, all the guns flash as they fired,” recalled one artilleryman.

On July 1, whistles blew and the first of 100,000 British soldiers rose from their trenches to begin the slow advance across the heavily churned ground. “It’s a walk-over,” their officers assured them. Suddenly and incredibly, the German defenses came alive. Planned defensive artillery barrages rained down on the surprised and dazed Tommies even as streams of machine gun fire stacked up bodies across the no man’s land. At the end of this terrible day, 19,240 of the attackers had been killed, with an additional 35,493 wounded.

By the time the Somme battle ended more than four months later, British casualty rolls stood at around 420,000. Traditional histories of World War I on the Western Front have it that nothing was gleaned from this debacle and that subsequent attacks repeated its tragic miscalculations.

This view ignores lessons learned at the Somme that profoundly changed the operational structure of the British army, particularly the artillery. Indeed, British gunners thoroughly critiqued what had gone wrong and began a transformation that would lead to their battlefield dominance by war’s end.

In broadest terms, artillery backing an assault in World War I had two assignments. One was to directly support the advance by blasting routes across minefields, carving open avenues through belts of barbed wire, and suppressing enemy strongpoints. A second task was to neutralize the opposition artillery and interdict enemy efforts to reinforce the threatened sector. But the latter mission was almost an afterthought; in one instance, knocking out German heavy guns was item 7 among 10 assignments given to a corps battery.

After the Somme, that job went to the top of the list, thanks in part to new and emerging technologies. The new mantra for British artillerymen was: “If a [German] battery can be located, destroy it; the chance may never recur.”

This new thinking was reflected on corps organizational charts with the establishment of the Counter-Battery Staff Office, which coordinated the new effort and analyzed data. While various corps did not immediately embrace the new post, it eventually became an invaluable central control for choreographing effective counterbattery tactics. In some commands, the men manning the office were informally known as “counterblasters.”

The first obstacle to achieving dominance over the enemy’s artillery was a lack of proper equipment. Counterbattery work required heavy guns— something that the British, obsessed on the Somme with the highly mobile battle of maneuver that would follow their breakthrough attack, did not possess in great numbers. The new priorities changed that, and by mid-1917 British batteries were bulked up. Gunners in 1915 and 1916 operated within ranges of little more than four miles. But the addition of 6-, 8-, 9-, 12-, 15-, and even 18-inch howitzers doubled and even tripled their reach.

At the same time, manufacture of guns and shells grew more sophisticated; mass-production machining became consistently precise and powder loads more uniform. Weapons themselves grew more reliable, and mapmaking enjoyed a quantum leap in precision, thanks to meticulous integration of information from aerial photographs and more exact measuring equipment. Distances to targets could be determined to within a few feet, and gunners mastered the art of firing by calculation and not solely by observation.

The problem now became finding the enemy’s guns. As the Germans settled into an essentially defensive posture on the Western Front, they became quite crafty at battery concealment. For the British, sniffing out the positions of those deadly weapons was absolutely crucial.

Though interrogating POWs and aerial observation provided some intelligence on gun locations, neither was especially reliable. Frightened prisoners were notoriously eager to tell their captors what they expected to hear, and reports from flying corps spotters required independent confirmation. According to one officer who regularly debriefed the crews, “[A]t least half of our air intelligence was useless. The pilots just didn’t know where it was that they had seen the flashes.”

Still, such reporting provided a vital piece of the puzzle that could not be ignored, despite the cost, which was high: This same officer noted that “every week or so one of the best pilots who had supplied the most accurate and useful information would fail to return.”

The British also identified gun placements through “flash ranging,” where specially trained observers were posted at multiple locations to track muzzle discharges from enemy guns. While transparent in concept, this method required an extensive communications infrastructure. Observer posts were carefully sited and plotted on survey maps, and each was connected by a dedicated telephone party line. When an enemy battery fired, observers were directed to concentrate theodolites (similar to a surveyor’s instrument) on the flash spot. After the various bearings were charted, the point of intersection revealed the hidden guns. Such a system did not work well in the daytime, nor later in the war, when flashless powder became more commonplace.

At the Somme, a relatively new form of gun plotting called “sound ranging” was refined, and it transformed counterblasting from an art into a science. Australian-born Sir Lawrence Bragg, a lowly second lieutenant with the British army, pioneered this system. A Cambridge scholar, Bragg just months before the Somme had won the Nobel Prize in physics for work that he and his father, William Henry Bragg, had done using x-rays to study crystals. His profound knowledge of sound propagation and the still murky science of electricity held him in good stead as he and his team entered a field with few prototypes.

Yet the basic equation underlying the system of sound ranging was fairly straightforward. Because sound radiates from a source evenly in all directions at a given speed, a gun’s location theoretically could be determined based on when the sound of its report arrived at different locations on the battlefield.

Simple enough. But it was no easy feat to create battlefield listening stations that could precisely record these sounds. Commercial microphones had to be altered since they were designed to capture frequencies higher than those produced by gunshot. “They were excellent at recording traffic noises, rifle fire, people talking near them, dogs barking and, in fact, everything but the muffled low ‘boom’ of a gun going off,” reported Bragg.

After technicians produced a microphone that effectively handled the low end of the spectrum, Bragg’s team concentrated on the critical problem: recording the exact time the sound arrived at the various microphones. This required precision more common to the era of modern computers than to those early years of electronics. For the calculations to work, especially at long distances, the maximum error was hundredths of a second.

Through a combination of trial and error and inspired tinkering, a system emerged: A listening line of microphones (usually six) was set up and exactly fixed on survey maps. One advanced listening post was manned roughly a half mile closer to the enemy lines. When the post’s observer heard the boom of the enemy’s gun, he triggered a switch that turned the sound-ranging system on. The microphones picked up the sound waves and fed electronic signals to a central source, where they were projected onto rolling 35mm film stock in lines that resembled a modern EKG.

Another device etched the film with time markers set at intervals of one one-hundredth of a second. The film was then rapidly developed and examined. Distinctive bumps in the graphed lines indicated the gun blast, and a comparison of the different times the sound waves arrived at the listening stations supplied the data needed for the computations, which usually took from 5 to 30 minutes. The results were plotted on a large-scale map that was continuously updated.

This was a dynamic process. Bragg and his men learned to compensate for varying meteorological conditions that affected how sound traveled. They established a careful system of recordkeeping and kept a running tab of enemy batteries whose locations were known or suspected. When the Germans repositioned their guns, the British technicians charted the new sound calculations accordingly. Lieutenant Bragg also spoke at semi regular meetings at which the officers swapped “stories, schemes, and boasts of their achievements and I am sure emulation made everything go much faster.”

By mid-1917, sound ranging could pinpoint enemy batteries to within 25 yards. The resulting data had multiple applications. Knowing how far the enemy gun fired (the microphones also recorded the shell detonation) and then analyzing the sound wave it produced, the British could often determine the weapon type.

With the range and coverage area of enemy guns plotted on maps, infantry officers could route small-scale operations to bypass killing zones.

To protect large-scale operations, programs of sustained counterbattery fire (or sometimes brief “hurricane” deluges) could put enemy guns out of action— even by simply drenching positions with a mix of explosive and gas shells to make it fiendishly difficult for the German gunners to crew their weapons.

There were limitations to what counterbattery could achieve. Even given the advanced technology, pinpointing enemy guns required a relatively stable front. It took one or two days for the counterblasters to become operational in an area, with six to eight hours needed for the flash spotters. The work depended on German artillerymen registering their weapons with ranging shots. If a gun did not fire until called into action, it could not be located through these means. One way the Germans sought to foil counter blasters was to order their gunners to register their weapons en masse. Also, during mobile battle, counterbattery efforts ceased.

The British were not the first to develop counterbattery tactics. The French maintained a smaller scale operation. The Germans too had a counter-battery program, though most of their activities were decentralized and varied greatly in effectiveness.

But the British, drawing from the experiences of their allies, established the most comprehensive and effective system. Because of this work and other significant technical improvements, British arms achieved an artillery dominance that served them well in the critical period from 1917 to 1918, especially at the battles of Arras, Vimy (where they located 86 percent of the German batteries), Messines, Hamel, and Amiens.

At Cambrai, the Germans were stunned by a massive opening British bombardment that pummeled identified targets at long range from the first shot, with almost all artillery firing based on calculations instead of ranging rounds. Such successes in turn laid the groundwork for further refinement of a system that, much enhanced by computers and very high-tech ranging gear, continues to the present day. MHQ

This article originally appeared in the Autumn 2010 issue (Vol. 23, No. 1) of MHQ—The Quarterly Journal of Military History with the headline: “These Hideous Weapons”

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