Station HYPO

The European Theater

The U.S. Third Army.

The U.S. Third Army posted one of the most impressive records among U.S. forces participating in the European campaign. The Third Army had moved from the U.S. to England in December 1943, but did not take part directly in the Normandy invasion. It moved to the continent shortly after the initial wave of troops and equipment had landed.

Meanwhile, LTG George S. Patton, one of the most prominent U.S. generals of WWII and highly respected and feared by the Germans, had incurred the anger of his superiors in 1943. As a disciplinary measure, he had been relegated to a diversionary role just prior to the invasion of the continent. He was placed in charge of a largely phantom army stationed across the English Channel from Pas de Calais in an attempt to reinforce the Germans’ erroneous belief that the Allies would invade directly across the Channel. In combination with other imaginative deception operations, the ruse worked perfectly and then General Patton, known for his aggressive strategy, was assigned as commander of the Third Army.

Providing intelligence to an army with such mobility was a challenge. The 3253/4/5 Signals Service Companies were established in April and May 1944 for that purpose. These units trained in England and then were attached to the various Third Army Corps; the 3253rd deployed to Omaha Beach in France, arriving on July 12, 1944. The intelligence units provided information to the various elements of the Third Army throughout its movements through France and into Germany.(19) T/A, and its incorporation of RDF, was a critical source of the intelligence information provided to the Third Army. The two were so closely interdependent that arrangements were made to perform the tasks together where a traffic analyst usually plotted the RDF bearings.(20)

The principal source of information derived from T/A came from German armored units. Even before the Third Army deployed to France, it was found that the German 21 Panzer Division was committed to the Caen area of France. Later on July 31, 1944, the HQ of the 2 SS Panzer Division was located at Montbray, and they needed ammunition. Information also was provided on infantry deployments. The German 268th Infantry Division was located in the Guingamp area directly in the path of the U.S. VIII Corps. All of this information gave the Third Army an indication of what they were about to face.

As the Third Army moved east through France in August 1944, there was an Allied operation to trap German units in the Falaise area known as the “Falaise pocket.” Third Army intelligence, mainly through T/A, was following the locations of many German armored units, and all were determined to be on the left flank and not on the Third Army front, thereby allowing Patton to move forward expeditiously. Six Panzer units were deployed on Patton’s left: the 116, 2 SS, 9 SS, 130, 17 SS, 10 SS, and two other elements. These units were described as “the real backbone of the German Army.”(21) Through August 15, 1944, constant monitoring of these units indicated no movement to the Third Army front, allowing Patton to move forward in an attempt to close the pocket. General Patton is known to have chided his competitors for not moving fast enough to successfully close the gap.

Later in August, the 2 SS Panzer and the 130 Panzer moved eastward through the gap in the Falaise pocket. T/A then detected the 130 Panzer moving north beyond Paris well away from the Third Army, thereby removing it as an immediate threat. T/A and RDF continued to provide the Third Army with information on the identification and movement of other German units opposing it and, on 30 August, identified and located the 3 Panzer Grenadier Division, which had just arrived from Italy to oppose the Third Army. It was the first of several German divisions to move in from Italy. A wide variety of SIGINT continued to be provided throughout September, including daily reports on the enemy order of battle, reorganization of units, movements and location of units including withdrawal and reinforcements. Then in October and November there was a reduction of German activity. Further, the Germans instituted an extensive change in their communications procedures. Both of these factors resulted in a significant reduction in the production of intelligence. Meanwhile, however, analysis indicated a general move

back to the “static Moselle front,”(22) and one message said that the 130 Panzer was to move north to an assembly area.

Activity on the Third Army front remained quiet until late December 1944 when the “Von Runstedt” offensive took place, more commonly known as “the Battle of the Bulge.” The 130 Panzer became active in the area of Bastogne, and shortly thereafter many other German units appeared in that sector. The 3 Panzer was located there on 30 December.

As the recovery of the German communications systems progressed, by January 1945 information from T/A increased significantly in volume and quality. Five Panzer divisions were located in new locations, and the 3 Panzer was located retreating east from the Bulge, as were the 130 Panzer and the 2 SS Panzer, in spite of rumors that the latter had gone to the Russian front. The 21 Panzer and the 17 SS Panzer moved south, and there was an almost complete withdrawal of German armor from the Third Army front. Meanwhile, painstaking analysis of procedural characteristics and good RDF determined that the 130 Panzer was located in an assembly area at Bitburg.

Valuable information was provided to General Patton, assisting him in the difficult process of crossing the Rhine. The German resistance was in a general state of disarray, but fragmented reports on miscellaneous German units pressed into defense were available to the Third Army. Reports were issued on the status of Rhine bridges around Mainz and on the bridge at Remagen.(23) Information on German vehicles heading toward the bridges at Mainz was sent to the U.S. Army Air Force, which reacted adroitly and destroyed the vehicles.

In February 1945 T/A reflected the general disintegration of the German forces. On the other hand, the Allied front was converging with the Russian front, and interception of communications from German units on both fronts became common. Having this access to information was fortuitous in one respect as the German units from the Russian front could quickly turn and attack the Third Army. In this regard, the Third Army continued to receive locations of the 9 SS Panzer, the 21 Panzer, and the 10 SS Panzer even though at that time they were facing the Russian front.

In summary, the Third Army received intelligence of inestimable value during its entire campaign across Europe. Although some information was provided by reading low-level codes, photography, prisoners’ interrogation, and scouts, the preponderance of accurate and timely information was provided by T/A in combination with RDF.

The Army Air Corps

The German Air Force produced a large amount of tactical traffic in the course of training, and this allowed T/A to accurately estimate the current operational strength and disposition of Germany’s bombers and reconnaissance units.(24)

Notes 19-24

19. Third Army Radio Intelligence History in the Campaign of Western Europe, Signals Intelligence Service of Headquarters Third U. S. Army (Undated [18 Sept. 1945]), 1.

20. Ibid., 11.
21. Ibid., 32.
22. Ibid., 41.
23. Ibid., 47, 48.
24. Hinsley, 53.

Source: Center for Cryptologic History National Security Agency