German Remotely Piloted Bombs

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weighed 680 kilograms (1,500 pounds). The weigh¹ consisted of a 500-kilogram (1,100 pounds) warhead, ^a fuel supply of 64 kilograms (140 pounds), and a bod) of 116 kilograms (255 pounds). Propulsion was sup' plied by a Walter rocket motor hung under the body ⁰ the bomb which gave it a maximum speed of kilometers per hour (375 m.p.h.) and a range of l¹ kilometers (6.8 miles) when released at an altitude o

1.0           meters (3,280 feet) or a maximum range of 1 kilometers (10 miles) when released at an altitude °

6.0          meters (19,700 feet). Normal attack altitude wa^s

1.0           meters (3,280 feet) so that the bomb could be aimed at the ship’s waterline.

The HS 293 was guided to its target by the bomb^ar dier who superimposed the weapon over the target in h^lS bombsight after the bomb had been released from th^e plane. He then "flew” the bomb to the target by m^eanS

While work was proceeding on the FX 1400, a true guided antishipping bomb was being developed by the Henschel aircraft company. Dr. Herbert Wagner, the study project team leader began work on this missile shortly after the invasion of Poland. This team effort resulted in the development of the HS 293, a glider version of the SC 500 high explosive bomb. Like the FX 1400, it would be controlled by radio during its descent from the launching aircraft, but its vertical range was increased by the use of a rocket.

The HS 293 project was undertaken after the com­mencement of development work on the FX 1400, but it successfully completed its testing trials earlier—in De­cember 1940. However, operational trials conducted by the Luftwaffe during predeployment exercises revealed problems in tracking the bomb during descent. Visual identification of the bomb had to be maintained by the bombardier throughout if it was to be guided to the target. This problem was overcome by fitting a flare in the tail of the bomb so the bomb’s descent could be tracked. The flare’s glow would remain hidden from the vessel being attacked. This solution, however, was con­tingent on the weather being clear; haze or cloud cover would obscure the flare from the bombardier’s sight.

Operational testing of the FX i4oo finally commenced in early 1942. The first tests were conducted from Peenemunde-West on a partially sunken ship off the port of Garz in the Baltic. These tests quickly revealed that the weapon had to be dropped from an altitude of at least 4,000 meters (13,125 feet) if the bombardier was to have sufficient time to gain visual control of the weapon and guide it to the target. Normally, though, the attack was launched from an altitude of 5,500 meters (18,000 feet), to give the bombardier an opportu­nity to control the bomb’s fall longer and thus increase the probability of scoring a hit. As in the HS 293, the problem of gaining visual control was solved by use of flares; however, clear weather was needed. The main disadvantage, though, in the use of the FX i4oo was that the weapon had to be released at a distance of at least 5 kilometers (3 miles) from the target. Once the weapon was released, the parent plane had to decelerate quickly so the bomb could pass in front of the aircraft an allow the bombardier to gain visual control. Once the bomb was released, the maximum correction the bona bardier could make was 500 meters (1,640 feet) in range and 350 meters (1,148 feet) in bearing.

As a whole, the FX 1400 was very similar in app^ear'

ance to the SD 1400 from which it was developed. Four

•                                                          ^r ’AA\c

wings 1.2 meters (4 feet) long were added at the miaa

of the weapon, dive brakes were installed around th^e

tail fins to limit the terminal velocity to 290 meters p^er

second (950 feet per second) and control spoilers were

mounted on each of the four tail fins. The spoilers, by

being extended or retracted, broke up the air fl°^

around the bomb, causing it to drift from its usual fal •

The guidance center, which contained a radio receiver

and a gyroscope, was located in the tail.

The HS 293 retained little in common with the ap pearance of the SC 500 bomb from which it was deve' oped. The HS 293 resembled a small airplane rather than a bomb. The missile had an overall length of 3-5 meters (11.7 feet), a wing span of 2.9 meters (9.5 feet) °f a joy stick connected to a radio transmitter in the plane broadcasting to a receiver in the missile’s tail.

In March 1943, these two weapons became opera- honal when the Luftwaffe activated bomber Gruppen I ^ar>d II of KG 100 at Usedon near Peenemunde for train- ^lng with the radio-controlled bombs. The former was ^to carry the HS 293 and the latter the FX 1400. Initially ^tne two Gruppen were to be equipped with the four- ^engine Heinkel He 177 Greif. The Do 217 was "tempo­rarily” substituted, however, because the Greif’s engines hud an unfortunate habit of catching fire in flight. The ^D° 217 was the Luftwaffe’s largest medium bomber, ^hile the He 177 constituted the only heavy bomber. Although eventually some He 177s were assigned to the ^Un>ts, there were never enough to completely reequip both Gruppen.

The original Luftwaffe plan for the use of these two Capons—as conceived by General Werner Baumbach— ^was to strike against the vessels of the Russian Black Sea Fleet, North Sea convoys, and Russian vessels at Kfonstadt and Leningrad. Adolf Hitler, however, ve­toed the plans for security reasons. Instead, he proposed ^to use the weapons against the Atlantic convoys, but ^tbis plan had to be scrapped when the Luftwaffe was Suable to provide enough He 177 bombers. The Do 217s, however, could reach and attack the Mediterranean ^convoys. This new plan was approved by Hitler who ^also ordered the weapons stockpiled at various bases in Norway, France, and Italy. Upon receipt of intelligence ^fhat the Allied invasion fleet was approaching Fortress Europe, the Luftwaffe was to order its bombers to the airbase nearest the invasion site containing a stockpile °f remotely-guided bombs. Here the bombers would

load up and then attempt to sink the invading fleet at the beachhead. Although this plan showed some signs of success at Salerno and Anzio on the west coast of Italy, it was a total failure at the Normandy landing.

The Luftwaffe’s first successful attack with its anti­shipping guided bombs was during the summer of 1943. It had ordered a number of its air units to operate over the Bay of Biscay to help relieve the air and surface pressure being mounted against Admiral Karl Donitz’ U-boats by the Allies. On 27 August 1943, the II/KG 100, equipped with the HS 293, was flying an antishipping patrol over the bay. During its sweep the unit made contact with the British First Support Group, then engaged in an anti-U-boat sortie through the waters south of Cape Finesterre on the Spanish coast and launched an attack with 18 aircraft. The Germans sank the escort sloop HMS Egret and inflicted heavy damage on the destroyer HMCS Athabaskan. This suc­cessful attack paid untold dividends to the U-boat command. In reaction to this new form of attack, the British Admiralty ordered all of its warships in the Bay of Biscay to retire at least 320 kilometers (200 miles) from the coast of France until countermeasures could be found against the HS 293. Thus, the U-boats were once again able to transit large areas of the bay free from surface attack.

The next successful attack was carried out against Germany’s former ally, Italy. At 0300, 9 September 1943, the Italian fleet, consisting of three battleships (Roma, Italia, and Vittorio Veneto), three cruisers, and eight destroyers under the command of Admiral Carlos Bergamini put to sea from La Spezia, Italy, and joined up with three cruisers from Genoa, ostensibly to attack the Allied invasion force heading for Salerno. Once at sea, though, the fleet defected and made for Malta. German intelligence quickly learned of the defection, and the Luftwaffe ordered III/KG 100, armed with FX 1400, to attack and destroy the Italian ships.

At 1400, the Luftwaffe launched a strike of six Do 217s which sighted the Italian fleet at 1550 off Sardinia near La Maddalena. The attackers were mistak­enly identified by the Italians as Allied planes sent out from Sicily to provide air cover. Only after III/KG 100 had commenced its attack did the Italians realize their mistake and start to take evasive action. The Roma was hit by an FX 1400 which started a major fire forward of the bridge. At 1600, the fire reached the forward maga­zine which blew up. The Roma sank, taking Admiral Bergamini and 1,254 officers and men to their deaths. The Italia was also hit by an FX 1400, but she was able to contain the damage and proceed to Malta under her own power.

Although the Luftwaffe now had in its arsenal a highly successful weapon, news of its success was with­held from the high command. Hitler never learned that the Roma was sunk by an FX i4oo. Instead, he was informed that it was sunk by conventional bombs. Even Hermann Goring, head of the Luftwaffe, did not learn the truth until much later. The person responsible for misleading Hitler and Goring was Adolf Galland, Gen­eral of the Fighters. He and the Luftwaffe Air Staff were engaged in a battle with Hitler for an increase in fighter production at the expense of bomber production. Even General Baumbach recognized that the continued ex­istence of his bomber force was dependent on more fighters to protect his airfields and Germany’s war indus­try. Hitler, however, favored increasing bomber pro­duction so the Luftwaffe could strike back at England- The Air Staff feared that if Hitler learned of the success of the FX 1400 and HS 293 he would order a further increase in bomber production (thus causing a decrease in fighter production), using as justification the success of the remotely-controlled bombs.

The first test of the FX i4oo against an invasion fleer came in September 1943, when the Allies landed at Salerno. This invasion presented the Luftwaffe for the first time with the theoretically perfect target for its antishipping guided bombs. Laid out within close range of major Luftwaffe airfields were a large number of ships at anchor or forced to maneuver at slow speed m confined waters. At 1000 on 11 September, the Luft­waffe launched a robot bomb attack, scoring hits on the cruisers Philadelphia (CL-4i) and Savannah (CL-42)- Hardest hit was the Savannah which had an FX 1400 p^asS through a forward turret and exploded in the lower handling room, killing the turret crew and a damag^e control party. The explosion tore a large hole in the ship’s bottom, opened a seam in her side, and pur out the fires in her boiler rooms. She was left dead in the water with her forecastle nearly awash. Prompt shifting of the ship’s fuel oil and fresh water kept her on an even keel. By 1800, the Savannah had her fires relit and got under way on her own power for Malta for temp⁰' rary repairs before sailing to the United States.

At 1440 on 13 September, iii/kg 100 scored again- hitting the light cruiser HMS Uganda. The bomb pene­trated all seven of her decks before exploding below the ship’s bottom. The blast caused extensive damage to the hull and killed 16 men. As a result of this hit, the Uganda took on 1,300 tons of water, and her fires were extinguished. The next morning, escorted by three destroyers, she was taken under tow by the USS Narrd- gansett (AT-88) for Malta. In the same attack, the Phil#' delphia and two British destroyers, the Nubian and the Loyal, were narrowly missed by FX Moos.

The following day saw the merchantman Bushtod Washington sunk by an FX i4oo while she was offloading a cargo of gasoline. On the 15th, iii/kg 100 severely

'-larnagcd and set fire to the merchantman James Marshall, causing her crew to abandon ship. Salvage ^tugs, however, were able to put out her fires and save P^art of her cargo. After being offloaded, she was towed ^t0 Bizerte, Tunisia, and then to England where she was declared a total loss and expended as part of the Mulberry breakwater at Normandy.

On 16 September, the Luftwaffe achieved a major Access with the FX 1400 when it twice hit the British battleship Warspite just as she completed a gunfire ^SuPport mission. The first bomb penetrated the mess ^^ecks and exploded in number 4 boiler room. This ^explosion blew out her double bottom and put out all ^^er fires. A second FX 1400 then hit close alongside, °pening a large hole in her hull at the waterline. The ^anpite soon relit her fires and got underway for |^^aka. She was, however, unable to maintain power and °^st her headway. Two U. S. Navy tugs, Hop! (ATF-71) ^and Moreno (ATF-87), were ordered to take her under ^t0w for Malta, where she arrived on 19 September, ■^fter brief repairs, she steamed for Gibraltar where two ^c°fferdams were built onto her bottom. She was then jeered to proceed to England for permanent repairs, ^Ut before they could be completed she was ordered out °^r the Normandy landing. As a result, when she went ^to the breakers in 1946, the damage she had sustained ^at Salerno still had not been made good.

The last FX i4oo attack at Salerno was directed against Philadelphia on 18 September. Once again the ^hiladelph id’s luck held good, and she suffered only ^'nor damage as a result of near misses.

In the fall of 1943, the Luftwaffe activated another ^tuppe, 11 kg 40, equipped with He 177s and Do 217s to ^Carry the HS 293 against the Mediterranean convoys. The PUn called for I/KG 40 to sink or disrupt the convoy ^esc°rt and clear a path to the merchantmen for Junker

Ju 88 bombers armed with torpedoes. In all, the Gruppe launched four attacks against the Mediterranean con­voys during October and November 1943. The only success gained in these attacks was against KMF-25A, a fast convoy which had sailed from the Clyde for the Mediterranean. On 6 November, the attacking planes scored three near misses on the USS Tillman (DD-64i), knocking out her fire control gear and damaging the superstructure. The Gruppe launched its last attack on 26 November against a convoy in the Gulf of Bougie, again with no success. This lack of success, coupled

with a 20% loss in aircraft, led to a withdrawal of all the Gruppen from the Mediterranean for reequipment with the Focke Wulf FW 200C Condor, a long-range mari­time reconnaissance bomber, and the He 177. This pe­riod also saw the withdrawal of the FX i4oo from service in favor of the more maneuverable HS 293.

With the cessation of the remotely-controlled bomb attacks on the Mediterranean convoys, the scene of action shifted back to the Atlantic Ocean. In December 1943, the British Admiralty had become aware that the Germans were preparing numerous blockade runners to break through to France. To counter this, the British cruisers Glasgow and Enterprise were ordered to cruise off France and intercept the German ships. The German Navy was at the same time marshaling its forces in the west to provide an escort of ten destroyers and torpedo boats for the blockade runners. These two naval forces collided on the night of 29 December 1943. During the course of the action, the British sank the German de­stroyer Z 27 and the torpedo boats T 25 and T 26. In response to this action, the Luftwaffe ordered its aircraft to sink the British cruisers. This order led to one of the major aerial battles of the war as the Luftwaffe attacked the two cruisers with conventional and robot bombs, and the RAF strove to protect the ships. When the action was over, the two cruisers had suffered no damage from the bombing. The Luftwaffe, however, suffered heavy losses of aircraft outfitted for remotely-controlled bombing. These aircraft suffered heavy casualties as a result of having to fly a straight course at slow speed to allow the bombardier time to guide the bomb to its target. After this attack, the Luftwaffe launched no more coordinated guided bomb attacks in the Atlantic theater.

Although Allied intelligence was aware of the exist­ence of the HS 293 and FX 1400 before the Salerno land­ing, the only countermeasures available were fighter interception of the bombers before they launched their missiles and expert shiphandling after the missiles were launched. At the Anzio landing, though, radio jam­ming was added. Jamming gear was installed on the American destroyer Woolsey (DD-437) and the destroyer escorts Herbert C. Jones (DE-137) and Frederick C. Davis (DE-136). Only the equipment on the destroyer escorts proved effective. The jamming was done by a Y-team of three Army radio technicians on board each ship. Throughout the agony of Anzio, one of these two escort vessels was always stationed off the beach. They, however, were not able to prevent all of the robot bombs from reaching a target. On 23 January 1944, the British destroyer Jervis was the first of a series of ships to be hit off Anzio by an HS 293. Although seriously damaged, she was able to make Naples under her own power.

Six days later, the men of II/KG 100 sank the British light cruiser Spartan and the liberty ship Samuel Hunt­ington at Anzio. At the time of the attack, the Spurtan was anchored near the beach to provide close-in antiair­craft gunfire coverage. Hit by an HS 293 at 1905, she quickly capsized and sank. At almost the same time, the Samuel Huntington was also hit by an HS 293 and set afire. At 0300 the next morning, she blew up when the flames reached her cargo of ammunition and gasoline-

The destroyer escort Herbert C. Jones was the next ship to receive attention from the HS 293. On 15 Febru­ary, one exploded close alongside, causing damage to her port side. She was able to remain on station until 17 February when relieved by the Frederick C. Davis. On 16 February, the Luftwaffe scored its last success with the guided bombs by sinking the liberty ship Elihu Had and the LCT-35 which was alongside taking on ammu­nition. Although further HS 293 strikes were flown against the beachhead, they were not successful, and the attacks were discontinued after 4 March. Allied coun­termeasures of radio jamming, artificial smoke, heavy antiaircraft fire, and air superiority made the cost of the attacks too high in return for the number of hits achieved.

The final antishipping radio-controlled bomb attacks launched by the Luftwaffe were against the Normandy beachhead between 6 and 8 June. These attacks, how­ever, were unsuccessful, and, since the Allies held ait superiority over the beachhead, the aircraft were with­drawn to Germany and Norway. On 21 August 19^> the campaign came to an end with the Luftwaffe’⁵ disbanding of KG 4o and KG 100. This move was under­taken to conserve fuel for fighter plane use and i° recognition that German bombers could no longer survive behind the Allied lines. The Luftwaffe would launch a few more conventional bombings again^st Allied shipping before the war ended, but they would be hit-and-run raids.

Mr. Bogart is president of the Kentucky chapter of ^the Navy League of the United States, administrative secretary of the Internationa] Naval Research Organization, an naval consultant to the Kentucky Military History Mu­seum. He served as a radarman on board the USS Dennis]' Buckley (DDR-808) from 1959 to 1961. A graduate ⁰ Thomas More College and Ohio State University, be ^,s now employed by the Kentucky Disaster and Emergency Service as ^lC nuclear preparedness planning director.