Fritz X - Combat Service

Combat Service

The only Luftwaffe unit to deploy the Fritz-X was Gruppe III of Kampfgeschwader 100 Wiking (Viking), designated III./KG 100. This unit employed the medium range Dornier Do 217K-2 bomber on almost all of its attack missions, though in a few cases toward the end of its deployment history, Dornier Do 217K-3 and M-11 variants were also used. Fritz-X had been initially tested with a Heinkel He 111 bomber, although it was never taken into combat by this aircraft. A few special variants of the Heinkel He 177 long-range bomber were equipped with the Kehl transmitter and proper bombracks to carry Fritz-X, but it appears this airframe/ordance combination never saw combat.

Fritz-X was first deployed on 21 July 1943 in a raid on Augusta harbor in Sicily. A number of additional attacks around Sicily and Messina followed, though no confirmed hits were made and it appears the Allies were unaware that the large bombs being dropped were radio-guided weapons.

On 9 September, the Luftwaffe achieved their greatest success with the weapon. After Pietro Badoglio publicly announced the Italian armistice with the Allies on September 8, 1943, the Italian fleet had steamed out from La Spezia and headed to Malta. To prevent the ships from falling into Allied hands, six Do 217K-2s from III. Gruppe of KG100 (III/KG100) took off, each carrying a single Fritz X. The Italian battleship Roma, flagship of the Italian fleet, received two hits and one near miss, and sank after her magazines exploded. 1,255 men, including Admiral Carlo Bergamini, died. Her sister ship, Italia, was also damaged but reached Malta.

The light cruiser Savannah was hit by Fritz-Xs at 10:00 on 11 September 1943 during the invasion of Salerno, and was forced to retire to the United States for repairs. A single Fritz-X passed through the roof of "C" turret and killed the turret crew and a damage control party when it exploded in the lower ammunition handling room. The blast tore a large hole in the ship's bottom, opened a seam in her side, and blew out all fires in her boiler rooms. Savannah lay dead in the water with the forecastle nearly awash and took eight hours to relight boilers and get underway for Malta.

Savannah's sister ship, Philadelphia, had been targeted earlier that same morning. While it is often believed the ship was hit by a Fritz X, in fact the bomb just missed the ship, exploding about 15 yards away. Damage was minimal.

The light cruiser HMS Uganda was hit by a Fritz-X off Salerno at 1440 on 13 September. The Fritz X passed through seven decks and exploded under her keel. All boiler fires were extinguished, sixteen men were killed, and Uganda took on 1,300 tons of water. Uganda was towed to Malta for repairs.

Two merchant ships may have been hit by Fritz X bombs at Salerno, though the evidence is uncertain. SS Bushrod Washington was hit by a glide bomb, either a Fritz-X or a Hs 293, on 14 September while offloading a cargo of gasoline. SS James W. Marshall was set afire by a conventional bomb, Hs 293 or Fritz-X on 15 September. As with the Bushrod Washington, the nature of the weapon that damaged James W. Marshall is uncertain. A witness aboard a ship nearby, Joseph A. Yannacci, attributes the attack to Ju 87 "Stuka" dive bombers, which were too small to carry glide bombs. While an attack with a Fritz-X cannot be ruled out, there is at least an equal case to suggest that, if a glide bomb was involved, the culprit was actually a Hs 293 from II./KG 100; Luftwaffe records show that II./KG 100, armed only with Hs 293 glide bombs, was active over Salerno that day.

KG 100 scored another success with Fritz-X while the British battleship Warspite was providing gunfire support at Salerno on 16 September. One bomb penetrated six decks before exploding in number 4 boiler room. This explosion put out all fires and blew out the double bottom. A second Fritz-X near-missed Warspite, holing her at the waterline. She took on a total of 5,000 tonnes of water and lost steam (and thus all power, both to the ship herself and to all her systems), but casualties were few. She was towed to Malta by tugs Hopi and Moreno, then returned to Britain via Gibraltar and was out of action for near 9 months; she was never completely repaired, but returned to action to bombard Normandy during Operation Overlord.

The last Fritz-X attack at Salerno again lightly damaged the light cruiser Philadelphia with two near misses on 17 September. This attack is sometimes reported as taking place on 18 September. However, according to US Navy records, the cruiser Philadelphia departed Salerno the night of 17/18 September. Moreover, according to Luftwaffe records, III./KG 100, the Luftwaffe unit armed with the Fritz-X, flew its last mission on 17 September. Other ships damaged by Fritz-X included Dutch sloop Flores and destroyer Loyal.

The control system used for Fritz-X, known as Kehl-Straßburg and named for Kehl, a German suburb of Strasbourg, and Strasbourg, the French/German city on the Rhine, was also used by the Hs 293. It relied on radio contact between the bomb and the guidance unit, and was susceptible to electronic countermeasures. After the initial attacks in August 1943 the Allies went to considerable effort to develop devices which jammed the 48.2 MHz to 49.9 MHz low-VHF band radio link between the Kehl transmitter aboard the launching aircraft and the Straßburg receiver embedded in the Fritz-X ordnance. Early efforts by the U.S. Naval Research Laboratory produced the XCJ jamming transmitter installed aboard the destroyer escorts USS Herbert C. Jones and Frederick C. Davis in late September 1943, too late for Salerno. The XCJ was ineffective because the frequencies selected for jamming were incorrect. This was updated in time for combat at Anzio with the XCJ-1 system, installed aboard two destroyer escorts above as well as destroyers USS Woolsey, Madison, Hilary P. Jones and Lansdale. These six ships rotated service at Anzio, with three deployed at any time. This manually operated system met with some success, though cumbersome and easily overwhelmed if large numbers of weapons were deployed simultaneously.

In early 1944 the UK began to deploy its Type 650 transmitter, which employed a different approach. This system jammed the Straßburg receiver's intermediate frequency section, which operated at a 3 MHz frequency and appears to have been quite successful, especially as the operator did not have to attempt to find which of the 18 Kehl/Straßburg command frequencies were in use and then manually tune the jamming transmitter to one of those frequencies. This system automatically defeated the ordnance's receiver regardless of which radio frequency had been selected for an individual Luftwaffe missile.

Following several intelligence coups, including a capture of an intact Hs 293 at Anzio and recovery of important Kehl transmitter components from a crashed Heinkel He 177 on Corsica, the Allies were able to develop far more effective countermeasures in time for the invasions at Normandy and Southern France. This included an updated XCJ-2 system from the U.S. Naval Research Laboratory (produced as the TX), the modified airborne AN/ARQ-8 Dinamate system from Harvard's Radio Research Laboratory, NRL's improved XCJ-3 model (produced as the CXGE), the Types MAS system produced by the Airborne Instruments Laboratory (at the time affiliated with the Radio Research laboratory), the British Type 651 and the Canadian Naval Jammer. Even more sophisticated jammers from NRL, designated XCK (to be produced as TY and designated TEA when combined with the upgraded XCJ-4) and XCL, were under development but were never deployed as the threat had evaporated before they could be put into service.

By the time of Normandy landings, a combination of Allied air supremacy, keeping bombers at bay, and ship-mounted jammers meant the Fritz-X had no significant effect on the invasion fleet. Some accounts say the Norwegian destroyer Svenner was hit by Fritz-X at dawn on D-Day. This is highly unlikely as III./KG 100, the unit which carried the Fritz-X into combat, had largely been re-equipped with the Hs 293 missile by that time for its anti-ship missions, and the attack on Svenner occurred before the first glide bombers launched their assaults on the Normandy beaches.

Fritz-X is often incorrectly listed as having been responsible for the loss of the hospital ship HMHS Newfoundland at Salerno as well as the destroyer HMS Janus and the light cruiser HMS Spartan at Anzio. However, these ships were hit by Hs 293s, as clearly demonstrated by a careful analysis of Luftwaffe records regarding the deployment of III./KG 100, the nature of the damage inflicted, as well as reports from witnesses. (In the case of Janus, either an Hs 293 or a conventional torpedo was responsible.)

The closest Allied equivalent to Fritz-X was Azon.