The attack of the “paradummies”

Deception on D-Day

In one of our recent articles, we wrote about Operation Bodyguard, the series of deceptions that kept the Germans confused about the time and place of the Allied invasion. Today, we'll take a look at the aerial, ground and naval tricks under Operation Bodyguard and other subsequent operations that were employed to keep them on the back foot even as the invasion fleet set sail for Normandy. Among others, this included the use of Radio Countermeasures (RCM), dummy paratroopers and commandos playing pre-recorded battlefield sounds to the German defenders.

One element of Bodyguard the Germans swallowed hook, line and sinker was General Patton's fake First US Army Group (FUSAG) gathering for an attack on Calais on the other side of the Strait of Dover. In order to further the deception, Operation Glimmer was put into effect. A flight of six Short Stirling bombers with two reserve craft took off towards Calais on the night before June 6. Carried onboard were radio jamming systems and canisters of small aluminum strips codenamed “Window,” known today as chaff. When dropped from the air, German radar systems would detect the clouds as radar blips and misinterpret them as the approaching FUSAG fleet. This idea was jointly developed by the British Telecommunications Establishment and the American-British Laboratory Division 15.

The bombers had to fly in a complex circular pattern and release the chaff at just the right time to make sure the radar cloud moved at a believable pace for ships and didn't have any suspicious gaps between the signals. A dozen British Harbor Defense Motor Launches (HDMLs) accompanied the squadron, carrying jamming systems, radios broadcasting fake chatter and special radar-reflecting balloons to make the ghost fleet even more realistic. Under Operation Taxable a similar but larger group, comprising Lancaster bombers from the No. 617 “Dam Busters” squadron, performed similar maneuvers towards La Poterie-Cap-d’Antifer near the major port town of Le Havre. A third group with only boats, under Operation Big Drum, accompanied the actual invasion fleet on its western flank.

Between Glimmer and Taxable, a squadron of 29 specially equipped Lancasters flew the “A.B.C. Patrol”, short for ‘Airborne Cigar’, the name of a jamming device used to confuse German night fighters. A.B.C. comprised three radio transmitters attached to a microphone in the bomber's engine compartment, handled by a German-speaking operator. Whenever German radio stations broadcasted orders to night fighters in the air, an oscilloscope blip immediately notified the operator of the broadcast's frequency. In seconds he ascertained whether the transmission was really meant for night fighters, then turned on one his own three transmitters to the same frequency, drowning the frequency in engine noise for anyone within 50 miles.

Between them, the patrol’s planes could simultaneously jam up to 82 different frequencies. This caused much confusion among the Germans and led them to believe that the patrol was in fact the top cover for the “real” invasion by FUSAG. While these ghost fleets were making as much noise as they could, Royal Air Force bombers in Operation Mandrel were flying around above the sea, using powerful transmitters to jam German coastal radar stations to hide the signals of the real fleet.
 
The planes carrying paratroopers the night before D-Day also had their deceptive guardian angels, thanks to Operation Titanic, which revolved around “Rupert” (or called “Oscar” by the Americans), a dummy on a parachute one-third the size of a human. The objective was to create spoof airborne attacks in Normandy. The use of dummies for deception purposes was not new, since the Germans used them also in their airborne operations in the early stages of the war, for instance in the Netherlands. While the 1962 war movie, The Longest Day depicted Rupert as an elaborate rubber figure, the real deal was a rough construction of sackcloth filled with hay and sand. Officially named Device, Camouflage, No. 15, it was nicknamed Rupert, possibly after the derogative term Scottish soldiers used for English officers. Rupert was equipped with noisemakers, called “Pintail”, that simulated rifle shots and a small timed explosive. The explosive would ignite the dummy and parachute after a while, so German troops arriving at the scene would find not a dummy (which would expose the duplicity) but only the remains of the parachute which its user assumedly burned before hiding nearby.

In four segments, some 500 Ruperts were dropped in various spots around the general Normandy area, always in spots away from actual parachute and glider landing locations. Near Saint-Lô, two small British Special Air Service (SAS) units also dropped as part of Titanic. Their mission was to attack small groups of Germans and allow some to escape, so the survivors could report incorrect news of a major airborne attack in the area. The paras also played 30 minutes of sound footage with shouts and gunfire to make the threat sound more credible to nearby defenders. The SAS paid a high price for the operation: of the twelve men who jumped, after a month of operations behind enemy lines, only a few made it back home; the others were either killed in action or captured and executed.

While the efficacy of some elements of the deception is under debate, the operations are considered a general success. The ghost fleets reinforced the German misperception that the real threat will be Patton's army near Calais, and Hitler still held on to this idea even after the actual landings in Normandy began. The fake threat of the dummies and SAS paratroopers caused the 12th SS Hitlerjugend Panzer Division and part of the 352nd Infantry Division to spend the night combing the forest for the apparent airborne threat, preventing them from fighting at Omaha and Gold beaches or around the drop zones of the 101st Airborne Division.
 
The German commander in Le Havre believed that Operation Taxable was a real fleet and that he was cut off from Normandy. The massive efforts at misdirection, both in Operation Bodyguard and the tactical operation on the night before D-Day, paid off when they made it easier for the landing forces to take the beaches of Normandy. Even some of the Ruperts survived the battle. For instance, one of the original dummies, found in a house of a former British soldier, was sold for £2,500 (USD 3,500) at an auction in Stansted in 2017.