Alsos Mission - Germany

Germany

When the German Operation Nordwind offensive threatened Strasbourg, Pash ordered all captured documents to be removed. Papers indicating the nature of the Alsos Mission were removed or destroyed. Although Strasbourg was not abandoned by the Allies, and ultimately did not fall, the Alsos Mission departed the city on 8 January 1945. Pash even ordered an evacuation plan to be prepared for the Alsos Mission's main headquarters in Paris. The embarrassing series of intelligence failures that had led up to the Battle of the Bulge cast doubts on the Alsos Mission's own findings. A four-man team under Eckman was sent to investigate a suspiciously devastating V-2 explosion near Antwerp, and Fred Wardenburg had to confirm that it was not a small nuclear explosion. Rumours that Germany had an atomic bomb persisted as late as March 1945.

A new forward headquarters, Alsos Forward North (AFwdN), was opened at Aachen, and on 8 February the Alsos Mission reopened its forward headquarters in Strasbourg as Alsos Forward South (AFwdS). In March, the U.S. 12th Army Group launched Operation Lumberjack, an offensive to clear the Germans west of the Rhine. Pash, who was promoted to colonel on 6 March, led an Alsos Mission detachment into Cologne on 7 March, but little additional information was found.

The interrogation of German prisoners indicated that uranium and thorium were being processed in Germany, mostly at the Auergesellschaft plant at Oranienburg, so Groves arranged for the plant to be bombed on 15 March 1945. Some 612 B-17 Flying Fortresses of the Eighth Air Force dropped 1,500 tons of high explosive and 178 tons of incendiary bombs on the plant.

On 30 March, the Alsos Mission reached Heidelberg, where a number of important scientists were captured including Walter Bothe, Richard Kuhn, Philipp Lenard, and Wolfgang Gertner. Their interrogation revealed that Otto Hahn was at his laboratory in Tailfingen, while Werner Heisenberg and Max von Laue were at Heisenberg's laboratory in Hechingen, and the experimental natural uranium reactor that Heisenberg's team had built in Berlin had been moved to Haigerloch. Henceforth, the main focus of the Alsos Mission was on these nuclear facilities in the Württemberg area.

As the Allied armies advanced into Germany in April 1945, Alsos Mission teams searched Stadtilm, where they found documentation concerning the German nuclear program, components of a nuclear reactor, and eight tons of uranium oxide. A number of scientists were captured at Goettingen and Katlenburg-Lindau, including Werner Osenberg, the chief of the planning board of the Reichsforschungsrat (National Research Council), and Fritz Houtermans, who provided information about the Soviet atomic bomb project. At Celle, the Alsos Mission uncovered an experimental centrifuge for separating uranium isotopes, the result of work undertaken at the University of Hamburg by a team under Paul Harteck.

The problem with the targets in the Württemberg area was that they not only lay in the path of the French First Army's advance, but were also in the occupation zone allocated to France. Groves attempted to get the occupation boundaries changed, but the State Department wanted to know why first, and Groves refused to provide this information. Groves, Marshall, and Stimson then decided that the area would have to be secured by American troops that would carry off what they could and destroy everything else. Pash was sent to ask General Jacob Devers, the commander of the U.S. 6th Army Group, if the zones of the French 1st Army and the U.S. Seventh Army could be swapped around. He was informed that the matter would have to be taken up with Eisenhower.

Groves despatched Lieutenant Colonel John Lansdale, Jr., to Europe, where he participated in a meeting with Lieutenant General Bedell Smith and Major General Harold Bull of SHAEF; Major General Eldridge G. Chapman, the commander of the 13th Airborne Division; Pash, Furman, and Goudsmit of Alsos; and Brigadier General Reuben E. Jenkins from the 6th Army Group. The plan, codenamed Operation Effective, called for the 13th Airborne Division to occupy the area to prevent its capture by the French, and seize an airfield that could be used to fly in an Alsos Mission team, and later to fly it out, along with captured German scientists. Operation Effective was scheduled for 22 April. Meanwhile, Devers took steps to delay the French advance.

The Alsos Mission had learned that the uranium ores that had been taken from Belgium in 1944 had been shipped to the Wirtschaftliche Forschungsgesellschaft (WiFO) plant in Stassfurt. This was captured by the 83rd Infantry Division on 15 April. As it was in the occupation zone allocated to the Soviet Union at the Yalta Conference, the Alsos Mission, led by Pash and accompanied by Lansdale, Perrin and Air Commodore Sir Charles Hambro, arrived on 17 April to remove anything of interest. Over the following ten days, 260 truckloads of uranium ore, sodium uranate and ferro-uranium weighing about 1,000 tons were taken away by an African-American truck company. The uranium was taken to Hildesheim and most of it was flown to the United Kingdom by the Royal Air Force; the rest had to be moved to Antwerp by train and loaded onto a ship to England.

On 20 April, the French First Army captured an intact bridge over the Neckar River at Horb and established a bridgehead. It was decided to send in a force on the ground instead of Operation Effective, which was cancelled on 19 April. This time, instead of following or accompanying the front line troops, the Alsos Mission would operate behind enemy lines. The Alsos Mission had taken delivery of two armored cars, four jeeps with machine gun mounts, and two .50 caliber machine guns. The other two jeeps would carry captured German machine guns. They would be accompanied by three unarmed jeeps. For the operation, codenamed Operation Big, Pash would command a special force called Task Force A, built around his Alsos Misson team and the 1269th Engineer Combat Battalion, less its Company B, which would be commanded by Lieutenant Colonel Wilbur White. Sir Charles Hambro decided to accompany the Alsos Mission with a British group that included Michael Perrin, David Gattiker, Eric Welch, and Rupert Cecil. Lansdale accompanied Task Force A as Groves' representative, and Brigadier General Eugene L. Harrison, the G-2 from 6th Army Group, as Devers' representative.

The Alsos Mission set out on 20 April and rendezvoused with the 1269th Engineer Combat Battalion at Freudenstadt. The intact bridge over the Neckar River at Horb was crossed and Haigerloch was occupied without opposition on 22 April, and the main body of Task Force A arrived on 23 April. In a laboratory in a cellar they found a German experimental nuclear reactor shaped like a cylinder and made of graphite blocks, but the uranium and heavy water were missing. The scientists immediately began dismantling it. Pash left Hambro in charge, while he led troops of Task Force A to Bisingen, and then on to Hechingen, where 25 scientists were captured, including von Weizsäcker, von Laue, Karl Wirtz, Horst Korsching and Erich Bagge. At Tailfingen they took Otto Hahn and nine members of his staff into custody. At Haigerloch, a sealed drum of documents was retrieved from a cesspool, and three drums of heavy water and 1.5 tons of uranium ingots were found buried in a field. The uranium and heavy water were loaded onto trucks. The apertures in the cellar were blown up with minor explosions to prevent their capture by the French. The cellar itself was not blown up, because this would have meant the destruction of the Church and Castle located above the cellar.

Werner Heisenberg remained at large, having left Hechingen on 19 April. On 1 May, Pash set out in pursuit of Heisenberg with ten men in the two armored cars and two jeeps. They teamed up with the 36th Reconnaissance Troop of the 36th Infantry Division and entered Urfeld on 2 May, where Pash found Heisenberg at his home. The Americans became involved in firefights with German troops attempting to enter the town, and the 36th Reconnaissance Troop had to head off on another mission, leaving Pash with just seven men. Fortunately, the German force, which numbered about 700, offered to surrender. Pash returned on 3 May with the 3rd Battalion, 142nd Infantry, which took them prisoner, while Pash and his Alsos Mission team finally took Heisenberg into custody.

By VE day, the Alsos Mission had a strength of 114 men and women. It was officially disbanded on 15 October 1945.