Value and Handling of Prisoners in World War I

Published with Permission by:
Lori S. Tagg, Command Historian,
US Army Intelligence Center of Excellence, Fort Huachuca, AZ.

“Prisoners or deserters constitute one of the most fruitful sources from which information of the enemy is obtained.”
Intelligence Regulations, American Expeditionary Forces, October 21, 1918

By the time of the Armistice ending World War I on November 11, 1918, the US held nearly 48,000 prisoners of war. The majority had been captured within the final months as the war moved out of the trenches.  The American Expeditionary Forces (AEF) G-2, Maj. (later Maj. Gen.) Dennis Nolan put much emphasis on the information obtained from enemy prisoners. After the war, he remarked, “[A prisoner] can, as a rule, tell you much more than a spy…who is trying to get around and find out about the enemy.  [A prisoner] knows and the other man is frequently guessing at it.”

In mid-October 1918, Capt. Ernst Howald (standing right), the lead interrogator for the 28th Division, Second US Army, used prisoner statements to construct a detailed template showing the enemy facing the division. After the war, his estimates were proven to be highly accurate.

As Nolan shaped his formal intelligence organization in the early months of American involvement, he recognized prisoners could be captured any time on any battlefield, and commanders at every echelon wanted to examine the prisoners they captured.  He also realized that, due to a lack of personnel and the high operating tempo, in-depth interrogations at lower echelons were not practicable or effectual.  Nolan developed a hierarchical system for the examination of prisoners at all echelons and outlined clear guidelines for handling prisoners in the 1918 Intelligence Regulations and Instructions for Regimental Intelligence Service. Those same guidelines were published in the Army’s first (provisional) Combat Intelligence Manual, also printed in 1918.

Nolan’s system started at the regiment.  The Regimental Intelligence Officer, typically a first lieutenant, determined the name, rank, and organization of any prisoners, as well as the time and place captured.  Prisoners were searched and then quickly transferred to division assembly points.  The division G-2 sections, led by a lieutenant colonel or major, conducted limited questioning, with the help of commissioned linguists from the Corps of Interpreters.  This questioning focused on necessary tactical information about the division sector to a depth of two miles behind the enemy front lines.

From the division, prisoners were transferred to the corps collecting centers, where more in-depth questioning began.  The number of prisoners, especially during offensive operations, often stressed the corps G-2 sections.  At those times, Army headquarters dispatched teams of four sergeants and one officer to augment the corps’ interrogation efforts.  During the St. Mihiel and Meuse-Argonne offensives in the fall of 1918, French interrogators also supplemented the US interrogators.

The corps intelligence sections found that simple and direct questioning, combined with kindness and courtesy, was the most effective method for eliciting information.  Many of the AEF’s interrogators had been lawyers in their civilian lives and could coax information out of the most recalcitrant prisoner.  Corps interrogators used a variety of other tactics to elicit information, as well.  One interrogator found that he could get prisoners to talk openly if he showed them aerial photographs with landmarks they recognized. The II Corps G-2, Col. “Vinegar Joe” Stilwell, recruited a drafted German soldier, who had previously lived in the United States and yearned to return there, to “work the prisoner cages” and glean information from his fellow prisoners.  Additionally, US interpreters donned German uniforms and wandered the collection points to eavesdrop on prisoners bragging about intentionally misleading their interrogators.  This use of “stool pigeons” was common practice throughout the war.

The quality and veracity of the information varied with the rank of the prisoner.  Lt. Col. Walter Sweeney, who served in the AEF G-2 during the war, claimed that “noncommissioned officers were by far the best sources for gaining information” and “few of them resisted insistent interrogation.”  About 60 percent of officers “invoked military honor” and refused to cooperate.  A typical German soldier had little knowledge about the larger battlefield, but he provided details on his own unit, weapons, troop losses, and general morale.  Enemy soldiers from Poland, Denmark, the Alsace-Lorraine region and southern Germany were particularly cooperative.  Unquestionably, the most important information obtained from prisoners was enemy order of battle, but they also gave up their routes of movement; the position and condition of trenches, dugouts and wire entanglements; their capacity to attack; and how susceptible they were to being attacked.

Based on the preceding outline, it is clear that World War I was no different than any other war in US Army history: prisoners of war have always been proven and valued sources of intelligence.  However, formalizing and standardizing the process for handling and examining prisoners in the 1918 Intelligence Regulations and provisional manuals was one more step in modernizing US Army Intelligence.  While field manuals published in 1940 provided more details on accepted interrogation techniques, the system for prisoner-of-war handling Nolan developed for World War I continued, with minor changes, throughout the 20th century.

Sound Ranging in the Great War

Published with Permission by:
Lori S. Tagg, Command Historian,
US Army Intelligence Center of Excellence, Fort Huachuca, AZ.

Private (later Sergeant) Jesse R. Hinman, a native of Astoria, Oregon, arrived on the Lorraine front after three months at the American Expeditionary Forces (AEF) school in Langres, France.  Reaching Mandres on Sunday, March 10, 1918, he was able to watch firsthand the AEF’s 1st Division conduct its first bombardment of the war.  The next day, Hinman’s detachment began its work establishing two forward observation posts, six microphone bases, and a central station all connected by dual lines of communications wire.  Stringing the line was arduous work given the shell-pocked terrain of the area.  Keeping these lines in working order once the German’s launched their Spring Offensive would be even more difficult and hazardous. The detachment’s function, however, was critical to the 1st Division arrayed along the AEF’s sector of the St. Mihiel salient.  Their work was kept highly secret, and the men referred to their unit only by its initials—SRS, Sound Ranging Section.

Hinman was a member of the first SRS to reach the front. By the end of the war, four sections were operational on the American front.  Sound ranging, along with its counterpart flash ranging, was a science new to the battlefield.  Given the static nature of trench warfare over the previous two years, British and French forces had developed and deployed equipment that allowed them to locate enemy guns using sound waves and artillery flashes.  Impressed by the results, General John J. Pershing, commander of the AEF, tasked an officer to study the British and French systems of sound and flash ranging. Simultaneously, the Signal Corps tasked three officers to establish sound and flash ranging companies in the AEF.  The Signal Corps officers and their companies were assigned to Engineer regiments upon reaching France.  However, they operated under the direct tactical command of the AEF G-2.

Each SRS was comprised of a lieutenant, a sergeant, and 39 privates, including linesmen who laid and repaired the communications wires, forward observers on the front lines, and the recorders, computers, and plotters at a Central Station who worked the electrical apparatus.  In simplified terms, the process of locating the position of an enemy gun began with the forward observers stationed on the front lines.  When they heard a significant report by an enemy artillery piece, they pressed a button to activate the recorder at Central Station.  When the sound wave from the report hit a series of six microphones arrayed behind the front line, each microphone sent an electric pulse via communications wire to the recorder.  The recorder documented the exact moments at which the report reached each microphone, similar to the jumps caused by an earthquake on a seismograph.  By plotting the recorded differences in time on a map board, the men at Central Station identified the position of the piece.  Seasoned Sound Rangers could pass the location on to the Chief Intelligence Officer within three to five minutes.  AEF artillerymen could then refine their targeting and conduct a counter barrage to eliminate the enemy’s gun.

As enemy artillery inflicted nearly half of all Allied casualties, the information provided by the Sound Rangers proved to be a significant intelligence source.  In addition to immediately passing on the location of enemy guns, the SRS compiled a daily report for the Artillery Information Service that summarized the class of battery (howitzer or gun), caliber, and probable targets.  Forward observers added their assessments to the report and collected shell fragments, duds, and portions of fuzes for analysis.  The observers’ remarks were critical in many respects.  For example, from their front line posts, observers heard the arrival of German resupply trains.  They also determined that, when the enemy’s band played, new troops were arriving at the front in preparation for an upcoming attack.

The SRS daily reports were compared with information from other intelligence sources, like prisoner-of-war statements, captured documents, and aerial photographs.  As a new science, sound ranging provoked skepticism on the part of many officers who demanded corroboration from other sources, especially aerial photos.  However, sound ranging proved most valuable in locating artillery pieces hidden from visual observation.  In one instance, Sgt. Hinman’s SRS No. 1 had identified the location of a very active enemy battery on the eve of the Battle of St. Mihiel.  Because the information could not be corroborated on an aerial photograph, the sound ranging data was considered an error.  Later it was found that an enemy artillery piece had been hidden in dense woods exactly where the Sound Rangers had indicated.

A post-war study of sound ranging accuracy showed the method could identify the location of an enemy gun within 10-25 meters in ideal weather conditions.  Roughly 80 percent of all battery locations were identified by the Sound Rangers.  Like many new technologies employed during the Great War, sound ranging matured in the postwar period, and by 1927, the function had been transferred from the Engineers to Field Artillery.  The methods continued to be used during World War II, but by that time, sound ranging was being overshadowed by the advent of radar.

Forward observation posts near Forges, France, during World War I.
Forward observers were critical to the effectiveness of sound ranging operations.