World War II Day by Day

London, England • August 4, 1944

In early June 1944 the Royal Air Force began deploying the first of several bunker-buster bombs—the 4,000‑lb Tall­boy S (small), Tall­boy M (medium) weighing in at 12,000 lb, and its suc­ces­sor Grand Slam (Tall­boy L, large) at 22,000 lb, whose blast yield was equi­va­lent to 6.5 tons of TNT. Mean­while the United States Army Air Forces had nothing simi­lar to deploy (its largest gene­ral pur­pose bombs weighed 1,000 lb), much less a deliv­ery mecha­nism capa­ble of dropping a 12‑ to 20‑ft‑long bomb on its target. On this date, August 4, 1944, the U.S. Eighth Air Force oper­a­ting out of England kicked off Opera­tion Aphro­dite, a pro­gram devel­oped in total secrecy and designed to deliver precision-guided, bunker-busting muni­tions using a pilot­less deliv­ery system. Aphro­dite and the U.S. Navy’s equi­valent, Opera­tion Anvil, were experi­mental methods for destroying high-priority enemy tar­gets that were heavily defended and hard­ened, such as V‑wea­pon sites and U‑boat pens, and simul­taneously dis­posing of B‑17 Flying Fort­resses, B‑24 Libera­tors, and Navy PB4Y‑1 Libera­tors that had outlived their operational usefulness.

U.S. war-weary bombers were stripped of all non­essen­tials right down to the air­crafts’ machine guns, which were replaced by broom­sticks painted black. Instead, the bombers were packed to capa­city with Torpex, a new, more power­ful explo­sive, plus were out­fitted with advanced elec­tronics con­taining a (as it turned out in at least one case, jerry-rigged) arming panel that set off the Torpex. The planes were then flown by volun­teer pilots and co-pilots, even­tually descending to an alti­tude of 2,000 ft, at which time the pay­load would be armed, followed by the two avia­tors bailing out the bottom of their air­craft. Guided by a mother ship using radio-con­trolled equip­ment and a TV camera in the nose cone, the pilot­less drone would fly into its bomb-resistant target and explode.

In this first mission four B-17 drones flew to the Pas-de-Calais region in occupied North­ern France to destroy cruise missile or bal­listic rocket storage facili­ties and a hardened bunker. Neither this nor the other twelve mis­sions were suc­cess­ful. They were ex­pen­sive and excep­tion­ally dan­ger­ous. On the fifth mis­sion to the Pas-de-Calais (the first of two for Pro­ject Anvil)—this on August 12 against the For­tress of Mimo­yec­ques near the ham­let of the same name that was to house a bat­tery of V‑3 can­nons aimed at London—Navy Lt. Joseph P. Ken­nedy, Jr’s plane, Zoot­suit Black, escorted by a dozen planes and under con­trol of the mother ship, deto­nated pre­ma­turely off the North Sea coast of England. The largest bomb explo­sion up to that time in his­tory—as power­ful as a dozen V‑1 rockets—left not a trace of pilot and co-pilot. Falling wreck­age onto a near­by village caused wide­spread damage and small fires, but no in­juries. The shock wave blew roofs of several houses, doors off hinges, ceilings to collapse, and shattered windows up to 9 miles distant. (Lt. Joseph Ken­nedy was the elder brother of future U.S. President John F. Kennedy.)

Operation Aphrodite/Anvil effectively ended on Janu­ary 1, 1945, when both explo­sive-laden B‑17 drones were shot down by flak bat­teries over Olden­burg, Northern Germany. The pro­gram was termi­nated on Janu­ary 27, 1945, when Gen. Carl Spaatz, com­mander of Stra­te­gic Air Forces in Europe, banned any further drone opera­tions. In the Pacific Theater a ver­sion of Opera­tion Aphro­dite was in the ini­tial stages—a few surplus B‑24D/J Liber­ators had been con­verted into radio-controlled flying bombs for use against forti­fied instal­la­tions on Japanese-occupied islands—but the Japanese campaign was scrubbed before launch date.

Operation Aphrodite, 1944

Left: An Aphrodite assault drone at takeoff from a relatively remote air­field in Norfolk, Eng­land. The drone carried a payload of 30,000 lb of Tor­pex, an explo­sive used in the British Tall­boy bombs that was 50 per­cent more power­ful than TNT by mass. Drones required a pilot and a co-pilot because the remote control system was insufficient for safe takeoff.

Right: After completing 80 missions, this Aphrodite B‑17F (The Careful Virgin) was used on August 4, 1944, against Mimo­yec­ques, near Calais in Northern France. (The site is very close to the French end of the present-day Chan­nel tunnel.) Dug nine stories deep into a lime­stone hill, the Mimo­yec­ques site was to fire 9‑ft-long, dart-like, 300 lb high-explo­sive projec­tiles from 412‑ft-long V‑3 “super­gun” can­nons (gun tubes) on London at a rate of 600 every hour. With­out knowing the exact pur­pose of the site, the U.S. Eighth Air Force and the Royal Air Force, as part of Oper­a­tion Cross­bow, bombed Mimo­yec­ques twice in November 1943, six times in March and April 1944, and six times between May and July. The Aphro­dite mis­sion against Mimo­yec­ques on August 4, 1944, the first using a remote-controlled air­craft, failed when the worn-out B‑17 spun out of control and impacted short of its target.

Left: A four-engine RAF Halifax flies over Mimoyecques on July 6, 1944, as exploding bombs send smoke and dust into the air. Mimo­yec­ques was put out of com­mis­sion on this date when RAF heavy bombers dropped three deep-pene­tration Tall­boy M earthq­uake bombs to col­lapse under­ground rail­way tunnels, ele­vator shafts, storage areas, and inclined gun tubes, leaving enor­mous craters. Two of the 12,000 lb bombs were direct hits, entombing and drowning hun­dreds of workers, among them engi­neers and miners from the German Ruhr Valley and forced laborers from 18 nations. The July 6 raid was in response to the Germans test firing Mimo­yec­ques V‑3 can­nons that delivered seven shells 32 miles from London 4‑1/2 weeks earlier. An RAF squa­dron of 226 bombers made a final appear­ance over Mimo­yec­ques on August 26, 1944, with­out losing a single plane. Shortly after that the Germans aban­doned the V‑3 site, which the Canadians captured on September 5.

Right: Two U.S. Army soldiers with a captured 150mm (5.9 in) finned projec­tile “Spreng­gra­nate 4481,” a very-long-range shell similar in design to one that had been test fired on June 13, 1944, from Mimo­yec­ques’ V‑3 cannon. (The V‑3 can­non was also known as the Hoch­druck­pumpe, “High Pres­sure Pump,” HDP for short; aka London Gun and Busy Lizzie.) The 150mm shell for London was designed to have an explo­sive charge of 25 kilos (55 lb). The pro­jec­tile pictured here was the kind fired on Luxem­bourg, where 142 rounds fell, killing 10 and wounding 35. The U.S. Army dis­assembled cap­tured gun tubes, spare parts, and ammu­ni­tion and shipped them to the Aberdeen Proving Ground in Maryland for testing and evaluation

Operation Aphrodite, a Dangerous Weapon for Its Users