Fritz X
Fritz X was the most common name for a German
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

 guided anti-ship glide bomb
Glide bomb
A glide bomb is an aerial bomb modified with aerodynamic surfaces to modify its flight path from a purely ballistic one to a flatter, gliding, one. This extends the range between the launch aircraft and the target. Glide bombs are often fitted with control systems, allowing the controlling aircraft...

 used during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Fritz X was a nickname used both by Allied and Luftwaffe personnel. Alternate names include Ruhrstahl SD 1400 X, Kramer X-1, PC 1400X or FX 1400 (the latter is also the origin for the name "Fritz X"). Along with the USAAF's
United States Army Air Forces
The United States Army Air Forces was the military aviation arm of the United States of America during and immediately after World War II, and the direct predecessor of the United States Air Force....

 similar Azon
AZON was one of the world's first smart bombs, deployed by the Allies and contemporary with the German Fritz X.Officially designated VB-1 , it was invented by Major Henry J. Rand and Thomas J...

 weapon of the same period in World War II, it is one of the precursors of today's anti-ship missiles and precision-guided weapons.


The Fritz X was a further development of the high-explosive bomb SD 1400 (Splitterbombe, dickwandig, 1400 kg; German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....

 for "fragmentation bomb, thick-walled, 1400 kg"). It was given a more aerodynamic nose, four stub wings, and a box shaped tail unit. The Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....

recognized the difficulty of hitting moving ships during the Spanish Civil War
Spanish Civil War
The Spanish Civil WarAlso known as The Crusade among Nationalists, the Fourth Carlist War among Carlists, and The Rebellion or Uprising among Republicans. was a major conflict fought in Spain from 17 July 1936 to 1 April 1939...

. Dipl. engineer Max Kramer
Max Kramer
Dr. Max Kramer was a German scientist who worked for the Ruhrstahl AG steel and armaments corporation...

, who worked at the DVL, had been experimenting since 1938 with remote-controlled free-falling 250 kg bombs, and in 1939 fitted radio-controlled spoiler
Spoiler (aeronautics)
In aeronautics, a spoiler is a device intended to reduce lift in an aircraft. Spoilers are plates on the top surface of a wing which can be extended upward into the airflow and spoil it. By doing so, the spoiler creates a carefully controlled stall over the portion of the wing behind it, greatly...

s. In 1940, Ruhrstahl was invited to join the development, since they already had experience in the development and production of unguided bombs.

The dual-axis joystick-equipped Kehl series of radio-control transmitter sets onboard the deploying aircraft were used to send the control signals to the Fritz-X, with the ordnance itself picking up the signals through a Straßburg receiver within it to send the signals on to the movable surfaces in the Fritz-X's tail fin structure.

Combat service

The only Luftwaffe unit to deploy the Fritz-X was Gruppe III of Kampfgeschwader 100, designated III./KG 100. This unit employed the medium range Dornier Do 217
Dornier Do 217
The Dornier Do 217 was a bomber used by German Luftwaffe during World War II as a more powerful version of the Dornier Do 17, known as the Fliegender Bleistift . Designed in 1937 and 1938 as a heavy bomber, its design was refined during 1939 and production began in late 1940...

 K-2 bomber on almost all of its attack missions, though in a few cases toward the end of its deployment history, Do 217 K-3 and Do 217 M-11 variants were also used. The Fritz-X had been initially tested with a Heinkel He 111
Heinkel He 111
The Heinkel He 111 was a German aircraft designed by Siegfried and Walter Günter in the early 1930s in violation of the Treaty of Versailles. Often described as a "Wolf in sheep's clothing", it masqueraded as a transport aircraft, but its purpose was to provide the Luftwaffe with a fast medium...

 bomber, although it was never taken into combat by this aircraft. A few special variants of the long-range Heinkel He 177
Heinkel He 177
The Heinkel He 177 Greif was the only operational long-range bomber to be operated by the Luftwaffe. Starting its existence as Germany's first purpose-built heavy bomber just before the war, and built in large numbers during World War II, it was also mistakenly tasked, right from its beginnings,...

 bomber were equipped to carry the Fritz-X but it appears this 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 the armistice
Armistice with Italy
The Armistice with Italy was an armistice signed on September 3 and publicly declared on September 8, 1943, during World War II, between Italy and the Allied armed forces, who were then occupying the southern end of the country, entailing the capitulation of Italy...

 with the Allies, the Italian fleet had steamed out from La Spezia
La Spezia
La Spezia , at the head of the Gulf of La Spezia in the Liguria region of northern Italy, is the capital city of the province of La Spezia. Located between Genoa and Pisa on the Ligurian Sea, it is one of the main Italian military and commercial harbours and hosts one of Italy's biggest military...

 and headed to Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...

. To prevent the ships from falling into Allied hands, six Dornier Do 217
Dornier Do 217
The Dornier Do 217 was a bomber used by German Luftwaffe during World War II as a more powerful version of the Dornier Do 17, known as the Fliegender Bleistift . Designed in 1937 and 1938 as a heavy bomber, its design was refined during 1939 and production began in late 1940...

 K-2s from the III. Gruppe of KG100 (III/KG100) took off, each carrying a single Fritz X. The Italian battleship Roma
Italian battleship Roma (1940)
Roma, named after two previous ships and the city of Rome, was the fourth Vittorio Veneto-class battleship of Italy's Regia Marina...

, flagship of the Italian fleet, received two hits and one near miss, and sank after her magazine
Magazine (artillery)
Magazine is the name for an item or place within which ammunition is stored. It is taken from the Arabic word "makahazin" meaning "warehouse".-Ammunition storage areas:...

s exploded. 1,255 men, including Admiral Carlo Bergamini
Carlo Bergamini (admiral)
Carlo Bergamini was an Italian admiral.-Early life:Born in San Felice sul Panaro, Bergamini became a Guardiamarina in 1908. He participated in the Italian-Turkish war as an officer on the armoured cruiser Vettor Pisani. During World War I, he was the chief of artillery on the cruiser Pisa...

, died. Her sister ship, Italia
Italian battleship Littorio
|-External links:...

, was also damaged but reached Malta.

The light cruiser Savannah
USS Savannah (CL-42)
USS Savannah was a light cruiser of the Brooklyn-class. She was laid down on 31 May 1934 by the New York Shipbuilding Association in Camden, New Jersey; launched on 8 May 1937; sponsored by Miss Jayne Maye Bowden, the niece of Senator Richard B. Russell, Jr., of Georgia; and commissioned in the...

 was hit by Fritz-Xs at 1000 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
Forecastle refers to the upper deck of a sailing ship forward of the foremast, or the forward part of a ship with the sailors' living quarters...

 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
HMS Uganda (C66)
HMS Uganda, was a Second World War-era Crown Colony-class light cruiser launched in 1941. She served in the Royal Navy during 1943 and 1944, including operations in the Mediterranean, and was transferred to the Royal Canadian Navy in in October 1944. She served in the Pacific theatre in 1945 and...

 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
In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...

. 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 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"
Junkers Ju 87
The Junkers Ju 87 or Stuka was a two-man German ground-attack aircraft...

 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
Gibraltar is a British overseas territory located on the southern end of the Iberian Peninsula at the entrance of the Mediterranean. A peninsula with an area of , it has a northern border with Andalusia, Spain. The Rock of Gibraltar is the major landmark of the region...

 and was out of action for near 9 months; she was never completely repaired, but returned to action to bombard Normandy during Operation Overlord
Operation Overlord
Operation Overlord was the code name for the Battle of Normandy, the operation that launched the invasion of German-occupied western Europe during World War II by Allied forces. The operation commenced on 6 June 1944 with the Normandy landings...


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
In the 18th and most of the 19th centuries, a sloop-of-war was a warship with a single gun deck that carried up to eighteen guns. As the rating system covered all vessels with 20 guns and above, this meant that the term sloop-of-war actually encompassed all the unrated combat vessels including the...

 Flores and destroyer Loyal
HMS Loyal (G15)
HMS Loyal was a L-class destroyer built for the Royal Navy in the late 1930s, although she was not completed until after World War II had begun.-External links:...


The control system used for Fritz-X, known as Kehl-Straßburg, was also used by the Hs 293
Henschel Hs 293
The Henschel Hs 293 was a World War II German anti-ship guided missile: a radio-controlled glide bomb with a rocket engine slung underneath it. It was designed by Herbert A. Wagner.- History :...

. It relied on radio contact between the bomb and the guidance unit, and was susceptible to electronic countermeasures
Electronic countermeasures
An electronic countermeasure is an electrical or electronic device designed to trick or deceive radar, sonar or other detection systems, like infrared or lasers. It may be used both offensively and defensively to deny targeting information to an enemy...

. 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 radio link between the Kehl transmitter aboard the launching aircraft and the Straßburg receiver embedded in the Fritz-X. 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 system met with some success, though because of its manual interface, it was cumbersome to use 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 intermediate frequency
Intermediate frequency
In communications and electronic engineering, an intermediate frequency is a frequency to which a carrier frequency is shifted as an intermediate step in transmission or reception. The intermediate frequency is created by mixing the carrier signal with a local oscillator signal in a process called...

 receiver (3 MHz) 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 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 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
Operation Neptune
The Normandy landings, codenamed Operation Neptune, were the landing operations of the Allied invasion of Normandy, in Operation Overlord, during World War II. The landings commenced on Tuesday, 6 June 1944 , beginning at 6:30 AM British Double Summer Time...

, a combination of Allied fighters, to keep 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
HNoMS Svenner
HNoMS Svenner was an S-class destroyer in the service of the exiled Royal Norwegian Navy during World War II. She was launched on 1 June 1943 as the Royal Navy ship HMS Shark , but was rechristened HNoMS Svenner when she was commissioned in the Norwegian Navy in 1944...

 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
Hospital ship
A hospital ship is a ship designated for primary function as a floating medical treatment facility or hospital; most are operated by the military forces of various countries, as they are intended to be used in or near war zones....

 HMHS Newfoundland
HMHS Newfoundland
HMHS Newfoundland was a British hospital ship. She served during the Second World War and was sunk in an air attack in the Mediterranean.-Career:...

 at Salerno
Salerno is a city and comune in Campania and is the capital of the province of the same name. It is located on the Gulf of Salerno on the Tyrrhenian Sea....

 as well as the destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...

 HMS Janus
HMS Janus (F53)
HMS Janus , named after the Roman god, was a J-class destroyer of the Royal Navy laid down by Swan Hunter & Wigham Richardson Limited at Wallsend-on-Tyne on 29 September 1937, launched on 10 November 1938 and commissioned on 5 August 1939. Janus participated in the Battle of Calabria in July 1940...

 and the light cruiser HMS Spartan
HMS Spartan (95)
HMS Spartan was a Dido-class light cruiser of the Bellona subgroup of the Royal Navy. She was a modified Dido design with only four turrets but improved anti-aircraft armament - aka Dido Group 2. She was built by Vickers-Armstrongs , with the keel being laid down on 21 December 1939...

 at Anzio
Anzio is a city and comune on the coast of the Lazio region of Italy, about south of Rome.Well known for its seaside harbour setting, it is a fishing port and a departure point for ferries and hydroplanes to the Pontine Islands of Ponza, Palmarola and Ventotene...

. 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
AZON was one of the world's first smart bombs, deployed by the Allies and contemporary with the German Fritz X.Officially designated VB-1 , it was invented by Major Henry J. Rand and Thomas J...


Combat procedure

The Fritz-X and the Henschel Hs 293
Henschel Hs 293
The Henschel Hs 293 was a World War II German anti-ship guided missile: a radio-controlled glide bomb with a rocket engine slung underneath it. It was designed by Herbert A. Wagner.- History :...

 were steered by an operator in the launching aircraft. The steering signals were communicated over a radio link between the aircraft's Kehl transmitter and the weapon's Straßburg receiver. The crewman who guided the bomb had to be able to see the target at all times, and the bomb had a flare
Flare (pyrotechnic)
A flare, also sometimes called a fusee, is a type of pyrotechnic that produces a brilliant light or intense heat without an explosion. Flares are used for signalling, illumination, or defensive countermeasures in civilian and military applications...

 in the tail so it could be seen from the controlling aircraft. The disadvantage with this — in comparison to self contained glide bombs like the slightly later VB-6 Felix
VB-6 Felix
The VB-6 Felix was a precision guided munition developed by the United States during World War II. It was one of the precursors of modern anti-ship missiles....

 — were that the aircraft had to be flown toward the target on a steady course and that as the missile neared its target it became possible to misguide by jamming its radio channel.

Unlike the Hs 293, which was deployed against merchant ships and light escorting warships, the Fritz X was intended to be used against armoured ships such as heavy cruisers and battleships. The minimum release height was 4000 metres (13,123.4 ft) and a release height of 5500 metres (18,044.6 ft) was preferred assuming adequate visibility. The Fritz X had to be released at least 5 kilometres (3 mi) from the target. The plane had to decelerate upon bomb release so momentum would carry the bomb in front of the aircraft where the bombardier could see and guide it. This deceleration was achieved by making a steep climb and then level out. The bombardier could make a maximum correction of 500 metres (1,640.4 ft) in range and 350 metres (1,148.3 ft) in bearing. The bomber was vulnerable to fighter attack as well as ship-based air defense weapons while maintaining a slow, steady course so the bombardier could maintain visual contact to guide the bomb. When working properly, the missile was able to pierce 130 mm (5.1 in) of armor.

Accuracy is the main reason for developing a weapon system of this kind, rather than continuing to use so-called "dumb bombs". A skilled operator could get 50% of the bombs within a 15 m (50 ft) radius of the aiming point, and about 90% hit within a 30 m (100 ft) radius. (Other sources say 60% hits within 4.6 meters radius.)

See also

  • List of World War II guided missiles of Germany
  • Kramer X4- Max Kramer's air-to-air guided missile
  • Ohka
    The Yokosuka MXY-7 Ohka was a purpose-built, rocket powered human-guided anti-shipping kamikaze attack plane employed by Japan towards the end of World War II...

  • Gargoyle
    LBD-1 Gargoyle
    -Sources:*This article contains material that originally came from the placard at the Steven F. Udvar-Hazy Center.* Fitzsimons, Bernard, editor. "Gargoyle", in The Illustrated Encyclopedia of Weapons and Warfare, Volume 10, p. 1090. London: Phoebus Publishing, 1978.-External links:* * * * *...

  • GB-4
    GB-4 was a precision guided munition developed by the United States during World War II . It was one of the precursors of modern anti-ship missiles.Following German success with the Hs-293 and Fritz-X, the U.S...

  • GB-8
    GB-8 was a precision guided munition developed by the United States during World War II . It was one of the precursors of modern anti-ship missiles.Following German success with the Hs-293 and Fritz-X, the U.S...

External links

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