given to the American, British, and Polish antiaircraft defense of the Belgian port of Antwerp from German V-1 rockets in Fall 1944.
Introduction
A major assignment of the U.S. 50th AAA Brigade, Antwerp X was the name given to the heroic defense of the port of Antwerp against V-1 flying bombs by 22,000 antiaircraft artillerymen from three nations. (The V-1s qualify as the World’s first cruise missile.)
Organized quickly and secretly, this huge command was mobilized just after the V-1 attacks on Antwerp began in late October 1944. Then, for 154 days and nights without interruption, and with ever-increasing fury, the “Battle of the Buzz Bombs” was fought on the cold wet flats of northern Belgium and southern Holland. It is the story of countless hours in freezing gun pits, the sweat and strain of thousands of soldiers “digging in, displacing, and digging in again,” the constant roar of ack-ack guns, the deeper and deathly roar of V-1s in flight, and the burning eyes of gunners constantly seeking to overcome that last small margin of error and knock out the flying bombs.
Hundreds of miles closer to the Allied lines than any other usable port, capable of handling 90,000 tons of freight a day, Antwerp became a priority target of German V-1s (and , later, V-2 rockets, the World’s first ballistic missile) for the last five months of the War in Europe. 5,000 buzz bombs carrying five million pounds of ultrahigh explosives were targeted against the city before the Nazi surrender. Since there was no defense against the V-2s, the Allied mission was to block the V-1 barrage.
The incredible story of how the Allies organized an American-British-Polish joint defense command against the German assault — resulting in some 2,100 V-1s destroyed in mid-air and another 1,500 sent crashing into fields short of their targets — has only been told in privately published regimental and brigade histories. Some of the story is told below, and it begins with the story of Hitler’s “V” (Vengeance) weapons.
A “V” Weapons Primer
The infamous German flying (buzz) bomb, known as the V-1 or “Doodlebug,” was the first successful guided weapon, the forerunner of the modern cruise missile. Its pulse-jet motor pushed it at speeds of over 360 mph carrying a high-explosive warhead weighing just under 2,000 lbs. Launched from ramps using steam catapults, approximately 9,000 were fired against England and other targets, including the Belgian port of Antwerp, during WW II. Far from the simple device it appeared to be on the surface, the internal equipment included a magnetic compass, an autopilot, as well as sophisticated range-setting and flight controls.
The first V-1 (vergeltungswaffe eins or “vengeance weapon number one”) was an air-breathing flying bomb fielded by the Luftwaffe in 1944. Not really a rocket, but more a jet-propelled, aerial torpedo with wings, its mission was to bombard Allied urban areas — London, especially, but other cities as well — with a 1,870-pound, high-explosive warhead. German engineers designed the V-1 so that it could be built of readily available materials, including wood and mild steel, and many of its sub-assemblies could be made by unskilled laborers. However, these features were meant to reduce costs, not performance. For its time, the V-1 was quite fast, with a cruise speed of about 400 miles per hour. Early V-1 models had a range of about 150 miles; later improvements increased this to over 250 miles. Propulsion was by pulse jet, a form of ramjet with a shutter-controlled intake. Its cyclic operation produced a characteristic sound, leading British listeners to give the V-1 a more memorable name — they called it a buzz bomb. Since pulse jets require a high minimum airspeed to operate, most buzz bombs were launched from large, inclined catapults. After launch, the V-1s self-contained guidance system kept the vehicle on a pre-set course and altitude, and a simple, propeller-driven distance log directed the vehicle to enter a vertical dive upon completing the measured flight time.
Given the crudeness of the technology, it should not be surprising that V-1s varied in their performance. In fact, about 20 percent of the missiles proved defective. Still, the overall result was quite acceptable. During the early stages of the assault on London, for example, V-1s had a mean impact point of about four to four and one-half miles from the center of the city.
Launcher construction began on the French coast during the summer of 1943. The first seven sites were immense concrete bunkers, but the Germans also built many smaller, simpler facilities. These often consisted only of a launching ramp and assembly shops, and the Germans requisitioned farmhouses, barns, and outbuildings for V-1 sites wherever possible. This approach speeded installation, reduced costs, and helped mask the sites’ locations. By December 1943 Allied photo interpreters had confirmed 88 “austere” V-1 sites, and they suspected about 50 more. Conscripted laborers finished half of the projected 150 sites before the Allies invaded Europe on 6 June 1944, and the Luftwaffe launched its first V-1 against London shortly before midnight on 12 June. The Germans soon became quite proficient, and on 22 July they launched their 5,000th missile.
The Germans had expected to launch 8,000 V-1s during September, but by that time all of the sites in France were captured. The brief lull led the Allies to conclude that the V-1 no longer presented a danger. They were mistaken. The Luftwaffe simply reworked the V-1 to increase its range and then built new sites in Holland. The bombardment resumed in October 1944 and continued through the winter, with the target list expanded to include the vital Belgian supply centers of Antwerp and Liege. Although dwindling component stocks gradually reduced the frequency of the attacks, the bombardment did not cease entirely until late April 1945.
In all, the Germans produced about 30,000 V-1s. They launched 10,492 flying bombs against England and about 8,000 against Continental targets. A total of 2,419 warheads exploded in Britain’s Central Defence Region, inflicting 92 percent of all English V-1 casualties. London’s civilian losses included 6,184 dead and 17,981 injured, and its military casualties came to about 1,200 killed or wounded. But there were other effects as well. The V-1 bombardment forced British authorities to evacuate between 800,000 and 1.3 million Londoners to outlying areas, and falling warheads destroyed 23,000 buildings and houses. Missile-inflicted casualties on the Continent — mostly in the Antwerp area — totaled 14,758, although only 211 V-1s hit the central port areas. Afterwards, the Allies acknowledged that the V-1 was a tactical success. It was also a very cost-effective weapon:
“From a strictly dollar point of view, the V-1 cost the Germans less to build and to operate than it cost the Allies in damage and defense. A wartime British study [concluded that] using the German costs as unity . . . it cost the defenders 1.46 for damage and loss of production, 1.88 for the bombing, .30 for fighter interception, and .16 for static defenses, for a total ratio of 3.80:1 [in favor of the Germans.]”
Antwerp X report
The buzz bomb exacted a heavy price, but it could have been much higher. Of the 8,500 or so V-1s that crossed the English Channel, the British detected 7,488 (88 percent) and destroyed 3,957 (52.8 percent of those identified). The defense was poorly coordinated at first, but Prime Minister Winston Churchill intervened personally, and the Allies soon developed an effective strategy. This effort — code-named Operation Crossbow — continued the bombing offensive that began in 1943 and reinforced it with a multilayered defense network.
The Allies knew of the V-1 through agent reports, reconnaissance photos, and intercepted radio transmissions well before it posed a direct threat to Britain. They mounted massive bombing attacks against the hardened facilities in France while construction was still under way, and they also targeted each of the smaller austere sites immediately upon discovery. All agreed that bombing was the only offensive measure available until ground troops could capture the launchers, but there were differing views on the effectiveness of the bombing effort. Even the best way to go about it was a matter of dispute.
Long since weary of bombing, English city dwellers put their political leadership under intense pressure to stop the V-ls by every means possible. The British War Cabinet called for direct strikes on the launch sites, even though this diverted efforts away from other important targets. But Air Chief Marshal Sir Arthur (“Bomber”) Harris, head of the Royal Air Force (RAF) Bomber Command, and Major General Jimmy Doolittle, commander of the U.S. Eighth Air Force, disagreed. Both leaders wanted to attack the V-1 sources of supply: the central stockpiles that fed the launchers and the factories that created the stockpiles. Tactical air force units continued to pound the launch sites, but Harris and Doolittle won the argument for putting their heavy bombers to better use. Between 2 and 9 August 1944, the Allies dropped 15,000 tons of ordnance on German support facilities. Losses were heavy — 1,412 airmen and 197 planes — but thereafter the V-1 launch rates dropped by half. The “heavies” continued their attacks afterwards but on a lower priority basis; by late summer, most of the work was being done by tactical air force fighter-bombers based in France.
Unlike the manned bombers in the blitz of 1940-41, V-1s could be launched at all hours and in every kind of weather. The Allies responded with a layered defense net and with measures intended to reduce the target areas’ vulnerabilities as much as possible. One risk-reducing measure was to reevacuate all nonessential civilians, particularly the women and children who had returned to the English target areas after the blitz subsided in 1942.
Another measure was made possible by the successes of MI5, Britain’s secret counterintelligence organization. MI5 had “turned” virtually every German espionage agent in the British isles by late 1939, and it manipulated German intelligence-gathering efforts in Britain throughout the rest of the war. This affected the V-1 campaign because the Germans largely relied upon their agents to report V-1 impact points. By feeding false data to German intelligence agencies through these controlled sources, MI5 made it appear that the V-1s were overshooting London. The launch crews shortened their missiles’ flight times to correct for this “error,” consequently shifting the mean impact point away from the center of the city.
The defense measures took time to become fully effective. By late June 1944, however, the Allies had the outline of a workable system, and they continually strengthened it during the remainder of the summer. This integrated network included an excellent detection and control system, high-speed interceptors, radar-directed guns firing proximity-fused shells, and barrage balloons.
Detection, Tracking, and Force Control
The defenders could usually detect incoming V-1s by radar. The more difficult task was making best use of the available force (e.g., deciding whether to scramble on warning or maintain standing patrols, determining which fighters should be vectored for intercept and which held in reserve, minimizing the number of fighters allocated per missile, and coordinating fighters and antiaircraft artillery (AAA) so that they did not interfere with each other’s efforts). In the end, the system of raid reporting and aircraft control developed for V-1 defense was more elaborate than the one that had worked so well against German bombers during the blitz of 1940-41. Two methods of fighter control were employed.
The first method, called “running commentary,” was used primarily to control fighters operating over England; it required two radar stations and two Royal Observer Corps stations. Each station provided a controller who advised patrolling fighters of the incoming missile’s course and position. Pilots devised their own intercept vectors. Thus, they ran the risk that several aircraft might chase one bogey, but the method worked well overall, especially with additional ground input for final interception (e.g., radio guidance from ground observers in visual contact, marker gunfire, special flares [“snowflakes”], or searchlights).
The second method, called “close control,” was used by fighters patrolling over the English Channel. Radar controllers vectored the pilots on intercept courses with the incoming V-1s. The close control method allocated fighters more efficiently than did running commentary, but it had several drawbacks. The V-1s crossed the narrow channel very quickly — in perhaps as little as four or five minutes — and did not stay on radar for very much longer. This cut reaction time to a minimum. It also meant that the defenders had to commit a larger number of aircraft for the same degree of barrier coverage: they had to travel further to get there, and they had to keep enough fuel in reserve to make sure they got back. And there was another unforeseen difficulty imposed upon close control immediately after D-Day: air traffic over the Channel became much heavier. This increased the controllers’ identification work load, thereby reducing the reaction time still further.
Interception
Fighter interception was not particularly effective during the first few days of the campaign. The RAF Fighter Command’s squadrons had been trained to attack Luftwaffe bombers flying at lower speeds and higher altitudes, and it took time to devise more appropriate tactics and become proficient in their use. The problem was difficult. Minimal warning times and the V-1’s high speed combined to make interception an unlikely proposition for all but the fastest fighters. (Once a V-1 crossed the Channel, the defenders had only about six minutes to bring it down.) The British initially assigned 12 fighter squadrons to the campaign, but many other units tried to engage the speedy missiles on a catch-as-catch-can basis. This only confused the controllers and antiaircraft gunners alike, and many defending aircraft were damaged or shot down by mistake. Within a few days the Allies had limited the effort to their best fighter types, and as the summer wore on, they continually assigned additional units to buzz-bomb defense. By mid-August, 21 Allied squadrons were committed exclusively to V-1 interception, and two more assisted as required. Even so, successful interceptions were not easy. Radar could direct the fighters to the vicinity, but the rest of the work was on visual terms. The buzz bomb’s small size and camouflage paint made it difficult to see from above in daylight, especially in the summer haze. The pulse jet’s exhaust flame was easily spotted at night, but it tended to appear to the eye as a point of light at an uncertain distance. Even if the sky were clear and moonlit, the V-1’s narrow wingspan gave few depth-perception cues for effective gunnery. Moreover, the short reaction time forced the RAF Fighter Command to maintain standing patrols, and fatigue quickly became an additional factor. Many pilots seldom left their aircraft between first light and dusk, although few complained of boredom.
As the defenders became more experienced, they found that the best tactic was to approach the missile from above and astern in a long, shallow dive. They usually opened fire at about 300 yards but were careful not to close to less than 150 yards because of the turbulence of the pulse jet’s exhaust and the lethal radius of the fireball that would be produced by detonation of the V-1’s large warhead. Buzz bombs were reportedly several times more difficult to kill than piloted aircraft at the same range, in part because they were smaller and had fewer critical components, but also because the V-1’s fuselage was a simple metal cylinder tapered to a point at both ends.This shape tended to deflect projectiles fired from a beam-end aspect. At first, pilots averaged about 500 rounds per kill; this dropped to 150 later in the summer. Much more famous, of course, was the tactic of simply flying alongside and tipping the vehicle with a wingtip. This tumbled the V-1’s gyroscopic autopilot, and the missile went out of control.
By every analysis, aircraft interception became very effective. Even though they were sometimes grounded by bad weather, the fighters accounted for 1,846 of the 3,957 missiles destroyed — almost 47 percent. Many pilots achieved multiple kills, with RAF Squadron Leader Joseph Berry leading the list at 61 and one-third, including seven in one day on two occasions. Sadly, Berry was mistakenly killed by Allied antiaircraft fire on 1 October 1944.
Antiaircraft Artillery
AAA was the second line of defense against the V-1, accounting for 1,878 missiles — just over 47 percent of those destroyed. The British began planning AAA requirements for V-1 defense as early as January 1944, and they expected to install 400 heavy and 346 light guns south of London. Unfortunately, their efforts were soon found wanting for several reasons. To begin with, the attacking missiles were far more numerous than the defenders expected; they had overestimated the bombers’ ability to knock out the launching sites. The Allies also underestimated the AAA needs of the invasion force; as a result, only half of the guns the plan had demanded were actually in place at the start of the campaign. Further, the defense planners also presumed that the V-1s would approach London at an altitude of 6,000 to 8,000 feet. As chance would have it, the V-1s flew much lower — 2,500 feet on average —and this zone fell between the respective altitudes at which British light and heavy guns were most effective. Finally, to make matters worse, the initial plan was not well thought-out. It stationed the guns close to London and put their fire-control radars below the terrain line to avoid an anticipated German countermeasures effort. This had the double disadvantage of reducing the gunners’ tracking times and allowing the damaged V-1s to fall within the target areas. These errors were soon corrected, but the most serious problem remained unresolved: how to coordinate the fighter and AAA efforts.
In the beginning of the campaign, fighters roamed at will, and AAA batteries were required to cease fire if the fighters came within range. This allowed the fighters to work very effectively (as of 13 July, 883 of the 1,192 kills had been achieved by aircraft), but it severely hampered the gunners. In mid-July the British decided to move most of the guns to the coast and establish “gun belts,” where aircraft operated at their own risk below 8,000 feet. A large number of bed-down sites for the mobile guns, called “mattresses,” were pre-stocked with ammunition, electric power generators, and other necessities. This .greatly increased the flexibility of the AAA defense network. The number of guns was also continually increased, so that by late summer the AAA batteries included almost 600 heavy-caliber and over 1,400 light-caliber weapons, including some installed on platforms built out over the Thames estuary. The British installed the latest fire-control equipment, including centimeter-band, gun-laying radar sets, and they also obtained large quantities of proximity fuzes from the United States. The net effect was a major improvement in AAA lethality. On the nights of 27-28 August, for example, 90 of 97 V-1s were shot down, and only four hit London.
Barrage Balloons
As a last resort, the British suspended steel cables from barrage balloons in the most likely approach corridors. This effort was the least effective response, in that the defenders had to maintain over 2,000 balloon stations that brought down only about 230 missiles. But it was a relatively inexpensive defense to mount, was clearly visible to the public, and occasionally worked. This effort was often hampered by shortages of hydrogen gas and rubber sheets, and 630 balloons were lost to lightning and high winds. Still, there is evidence that the Germans took the balloons seriously: some of the downed missiles had cable cutters built into their wings.
The Allies failed to successfully coordinate their forces at first, thereby allowing some V-1s to get through that could otherwise have been destroyed. Their failure also contributed to the tragic loss of Allied pilots and planes to “friendly” AAA fire, and this in turn reduced the defenders’ ability to deal with incoming V-1s. Even so, the Allies were fortunate. They only had to mesh the efforts of airmen and gunners who spoke the same language, and they already had a well-integrated command, control, communications, and intelligence apparatus. Their units were abundantly supplied and well equipped, and they had long since been united in an all-out wartime effort. Further, they had to defend only a limited number of targets in a relatively small area against attacks coming in predictable directions from known launching grounds.
Stayed tuned for the rest of the story, including a complete digital reproduction of the official history of the operation.