Operation Spark (1940) - Attempts at Army Group Centre

Attempts At Army Group Centre

Hitler flew to Werwolf, his "field headquarters" near Vinnitsa in Ukraine, on 19 February 1943, staying until 13 March. He decided that before returning to Germany, he would also visit AGC headquarters near Smolensk that same day. He would meet with Kluge, and dine in the officers' mess before departing. This was the first opportunity for his assassination by Tresckow's group.

For such an occasion, Tresckow had prepared three options:

• Major von Boeselager had formed a cavalry "honor guard" unit secretly packed with anti-Nazi officers. With this force he could intercept Hitler in the forest between the airfield and the HQ area, overwhelm Hitler's SS escort in a fair fight, and kill the Führer. This option was rejected because even the plotters disliked the prospect of German soldiers fighting each other, and because the attack could fail if the escort was stronger than expected.

• The plotters could shoot Hitler during dinner in the mess. This option was abandoned as many of the plotters abhorred the idea of shooting an unarmed man and would not go along.

• A timebomb could be smuggled on Hitler's plane. This was the plan ultimately attempted.

The bomb was adapted from a British Plastic-C silent timebomb, which had been seized by the Abwehr from captured SOE agents.

The bomb was a simple one. The operator would break a glass vial of acid, allowing the acid to drip onto a wire and eat through it. When the wire broke, it would release a spring-driven hammer. The hammer would strike a percussion cap, setting off the explosive. The acid eating away the wire provided a time delay for detonation, without any telltale ticking of a clockwork mechanism or smell from a burning fuse.

The bomb was disguised as a box supposedly containing two bottles of cognac. Tresckow was acquainted with Lieutenant Colonel Heinz Brandt, an officer on Hitler's staff, who traveled on Hitler's plane. Tresckow asked Brandt to take the parcel with him to Germany for delivery to Tresckow's friend General Helmuth Stieff. (Stieff was anti-Nazi, but not then part of the conspiracy.) Tresckow said the liquor was the payoff for a bet he had lost to Stieff.

Tresckow's aide, Schlabrendorff, carried the parcel to the airfield. As Hitler and his entourage prepared to board his plane (a Focke-Wulf Fw 200 Condor), Schlabrendorff secretly cracked the acid vial with a pair of pliers, then reclosed the parcel and handed it to Brandt as he boarded the plane.

The bomb was expected to explode about 30 minutes later, with the plane near Minsk, close enough to the front for the plane's loss to be attributed to Soviet fighters.

When the crash and Hitler's death were reported, General Olbricht would use the Replacement Army to seize control in Berlin, Vienna, and Munich, and in the centers of the Wehrkreis (the German military supply system). It was an ambitious but credible plan, and might have worked if Hitler had indeed been killed, although persuading Army units to fight and overcome possible fierce resistance from the SS could have been a major obstacle.

But, as with Elser’s bomb in 1939 and all other attempts, luck favoured Hitler, which he attributed to Vorsehung ("Providence"). The British-made detonator had been tested many times and was considered reliable. It operated correctly, but the bomb did not explode. The percussion cap apparently became too cold as the parcel was carried in the unheated cargo hold.

Displaying great sangfroid, Schlabrendorff took the next plane to retrieve the package from Colonel Brandt before the bomb was discovered or eventually detonated late. The explosives were later used by Gersdorff and Stauffenberg.