British intelligence had some significant breakthroughs in discovering the German secret weapons programs in 1942. Resistance organizations in Poland and Luxembourg forwarded reports from forced laborers who had worked at the Peenemünde test center. After the RAF conducted reconnaissance flights, Churchill authorized Operation Hydra, which was carried out on the night of August 17/18, 1943. The bomber attack forced the Wehrmacht to abandon plans to mass-produce the A-4 missile at Peenemünde and to look for other alternatives. In conjunction with technical problems with the missile itself, the raid managed to push back the operational deployment of the A-4 missile by several months.
The discovery of the German test site also led the RAF to pay special attention to any unusual construction in France, especially in the Pas-de-Calais area closest to Britain. In May 1943, aerial reconnaissance first showed the start of construction of the large facility in the Eperlecques Woods near Watten. While the RAF was familiar with the numerous coastal bunkers that formed the Atlantic Wall program of coastal defenses, the Watten Bunker was extremely odd due to its distance from the sea. Although there were suggestions that it might be an operations control bunker, the details of the construction led to the growing conviction that it was part of a German secret weapons program. The US Army Air Force (USAAF) staged a daylight precision attack on August 27, and a second attack was staged on September 7, 1943.
The RAF raid on Peenemünde forced the Wehrmacht to abandon plans to massproduce the V-2 missile there. Instead, the main center became the underground Mittelwerke tunnel complex in the Harz Mountains near Nordhausen. (NARA)
The Mittelwerke complex was so well hidden that the Allies did not bomb it. This shows one of the camouflaged entrances after its capture by the US Army in April 1945. (NARA)
The heavy damage sustained by the KNW Bunker forced a significant revision in German plans for the missile sites in September 1943. The partially completed south side of the bunker had collapsed and so it could no longer be used as intended as a missile launch site. The northern half of the bunker could be repaired, so its role was downgraded to that of a liquid oxygen factory. The SNW supply depot in the limestone quarry at Wizernes suddenly attracted more attention since it held the potential to be converted quickly into a ballistic missile launch base. Instead of constructing a bunker in the open, a reinforced concrete dome could be created above the launch facility, and then the cavity for the launch bunker could be carved into the quarry, limiting the amount of damage that could be inflicted on the structure during construction.
As in the case of the V-2, Allied air attacks on exposed V-1 production plants led to a shift to the Mittelwerke for massproduction late in 1944 with the Mittelwerke II “Zinnstein” facility taking over the majority of production after November 1944. (NARA)
The heavy damage inflicted on the Watten Bunker forced the Wehrmacht to abandon plans to use it for launching V-2 missiles. Instead, the undamaged southern side of the building was completed for use as a liquid oxygen production bunker. This shows the preserved bunker from its southern side. Had it been completed as a missile bunker, large portals for the V-2 would have been exited on this side to launch the missiles outside the bunker. (Author’s collection)
The Watten debacle turned the Germans’ attention to mobile basing. The November 1943 plan envisioned a total of four A-4 battalions along the French coast, each with three batteries. Two battalions would be stationed in Artois near the Pas-de-Calais with 26 launch bases and five guidance bunkers; one battalion with six launch bases and two guidance stations would be completed near Dieppe, and one battalion with nine launch bases and three guidance bunkers near Cherbourg. Two other large bunkers associated with the A-4 ballistic missile were also added, the Reservelager West (RLW: Reserve Store West) near Brix/Sottevast and the Ölkeller Cherbourg (Cherbourg Oil Cellar) near Brécourt. As late as November 1943, the precise role of these two facilities had not been finalized. Sottevast was a large protected bunker, comparable in size to the original Watten design, which could be used for housing one of the mobile missile regiments as well as serve as a store for about 300 missiles, fuel and other supplies. Brécourt included a series of protected tunnels for storing the missiles.
The damage inflicted on the Watten Bunker led to a revised construction method for the Wasserwerk bunkers, called Verbunkerung or Erdschalung. The construction began with (1) a simple set of trenches; (2) the basic side wall foundation; (3) excavation for the complete side walls; (4) completion of the side wall foundation; (5) construction of roof over an earth core; and (6) excavation of the earth core, completing the construction. (NARA)
The Kraftwerk Nordwest missile bunker at Watten was hit by USAAF heavy bombers starting on August 27, 1943, which wrecked the northern side of the building. This photo was taken in the summer of 1944 after the site was revisited by RAF Lancasters armed with Tallboy bombs, which account for the enormous crater in the foreground. (NARA)
The first Allied air attacks forced changes in the construction plans for the Wasserwerke as well. Instead of creating a bunker in the traditional fashion, a new six-step process called Verbunkerung or Erdschalung would be undertaken to shield the bunker from air attack during construction: the side walls would be created first while protected by an earthen berm, the cavity between the walls filled, the roof poured over a temporary inner earthen core, and then the internal cavity excavated to form the main bunker chamber. Completion of the Wasserwerk 1 design permitted construction to begin in late September 1943. The bunker was essentially a 212m long protected tunnel. Each Wasserwerk could contain up to 150 FZG-76 cruise missiles along with their associated fuel and support equipment, and this entire inventory could be expended in one or two days depending on the launcher configuration. Although the design was ready, the construction program for the Wasserwerke came at an inopportune time and the deadline for starting the missile campaign in December 1943 was not met. Organization Todt was diverted to reconstruction efforts in Germany as a result of RAF attacks on the Ruhr. The Sonderbauten effort required about 1.83 million cubic meters of concrete, competing with other construction programs such as the Atlantic Wall coastal defense program. To further undermine the program, there were significant delays in the mass-production of the missiles after the RAF had bombed the Fieseler plant in Kassel on the night of October 22/23, 1943.
With the Watten Bunker no longer viable as a missile launch base, the tunnel complex in the chalk quarries at Wizernes was expanded to include a massive missile complex under a special reinforced concrete dome. Two tunnels would have exited the complex to permit V-2 missiles to be launched from the open plaza below the dome that were sealed by Allied bombing. The tunnel entrance to today’s museum as seen here is based on the Ida railroad tunnel. (Author’s collection)
The last of the V-weapons sites to enter construction were the FZG-76 cruise missile “light” launch sites. Although Generalfeldmarschall Milch, the head of Luftwaffe production, originally favored the heavy waterworks, by September 1943 he had changed his mind. He became convinced that a large number of FZG-76 missile sites would inevitably divert the attention of the RAF away from Germany, relieving the pressure on the Luftwaffe, and making the bombers more vulnerable to fighter attack since precision daylight missions would be needed. He dubbed the Sonderbauten effort on the Pas-de-Calais “the graveyard of the RAF.” In mid-August 1943, Luftwaffe personnel began to visit locations in the Pas-de-Calais area, informing the local farmers that their property was being requisitioned. In many cases, the farmers were allowed to continue to work their farms, though they were kept away from some areas that were being used for construction. This was the first step in the creation of Stellungsystem-I, the “light” launch sites for the FZG-76 missile. The plan was to deploy the newly formed Flak Regiment 155(W) in these sites. At the time, FR 155(W) was still training on test launchers at Peenemünde, and it was anticipated that it would have four launch battalions ready by the start of the missile campaign scheduled for December 1943. Each battalion had four launcher batteries with four launchers each, for a total of 64 launch sites under the regiment’s control. These 64 launch sites formed Stellungsystem-I and they were located primarily in the Pas-de-Calais region of northeastern France from Lille through Dieppe. Besides the 64 primary launch sites, steps were also underway to create Stellungsystem-II, with a further 32 sites that were intended to serve as reserve launch locations as well as supply bases, two per launch battery. The last portion to be started was Stellungsystem-III, located southwest of the Seine from Rouen to the Cotentin Peninsula in lower Normandy. Stellungsystem-III was located for attacks on British cities in southern England after London had been destroyed and would be manned by a second regiment, FR 255(W), which was organized in the late spring of 1944.
This wartime intelligence drawing shows the typical layout for a Bois-Carré site. The main facilities include:
(1) the launch rail and protective wall;
(2) fire-control bunker;
(3) three “ski” stowage buildings;
(4) the compass correction building;
(5) personnel bunker;
(6) missile servicing building;
(7) launcher service building;
(8) water reservoir;
(9) cistern and pump station;
(10) storage building.
The Bois-Carré sites protected the Walther catapult with reinforced walls on either side. This is a typical example near the Chateau de Sorrelerie in the Cherbourg area, one of the batteries of Abteilung IV. (NARA)
Construction of Stellungsystem-I began in the late summer and early autumn of 1943 under the direction of the Luftwaffe’s Sonder Pionier-Stab Frisch (Special Engineer Staff Frisch) of the Fifteenth Army (AOK 15) in the Pas-de-Calais area and Sonder Pionier-Stab Beger of AOK 7 in the Normandy area. These units supervised the construction work undertaken by Organization Todt, though most of the actual labor was subcontracted to French construction firms. Each site centered around a platform for a Walter catapult, protected on either side by a concrete blast wall. Each site included a standard assortment of support buildings, though the layout of the buildings varied from site to site. The layout was intended to facilitate a high missile launch rate. The Walter launch rail could be fired and reloaded in 20-minute intervals so it could launch 72 missiles per day at its maximum rate. This was not entirely realistic since each site had accommodation for only 21 missiles, so a more realistic rate of fire per site was about 20 per day.
Certain of the structures essential for the launch process were located near the launch rail, while other preparation buildings were arranged based on the layout of the terrain, for example placing the long storage building along hedgerows to provide natural camouflage. The missiles arrived at the site, usually by truck, in a partially assembled form on special dollies. The launch battery had to complete the final assembly of the missile, as well as fuel, fuze, and arm the missile. Besides the missile-related facilities, most sites also had a few 20mm or 37mm Flak guns to protect the site from air attack.
| Designation | length × width × height (m) | Description |
| Abschussrampe | 58.4 × 9 × 5 | Launch ramp |
| Kommandostand | 5.9 × 3.6 × 2.7 | Launch bunker |
| Eingangslager | 29.5 × 4.3 × 3.0 | Ready storage building |
| Montagehalle | 21.4 × 8.25 × 4.05 | Preliminary assembly building |
| Werkstat/maschinenhaus | 14 × 8.1 × 3 | Workshop |
| Wasserbehalter | 10.1 × 10.1 × 3 | Water reservoir (200m3) |
| Stofflager | 7.8 × 6.2 × 3 | Propellant storehouse |
| Betriebswasser zistern | 15.3 × 6.8 × 3.8 | Water cistern |
| Vorratsblager | 82 × 4.3 × 3.35 | Main “ski” storage building |
| Richthaus | 14.8 × 17.6 × 9.7 | Non-magnetic guidance adjustment building |
| Zünderbunker | 5 × 4 × 2.8 | Fuze storage bunker |
| Unterstand | 14.2 × 11.6 × 3.3 | Personnel accommodation |
| Unterstand für trafo | 5.5 × 4.8 × 3.7 | Transformer shed |
| Pumpstation | 8.8 × 6.6 × 5.6 | Pump station |
The rocketgun coast: German V-Weapon sites in France 1944
| FZG-76 missile supply depots | ||
| Location | Codename | Missile capacity |
| Ytres Canal Tunnel | Karl-Theodor | 1,000–1,500 |
| St. Leu-d’Esserent | Leopold | 1,600–2,400 |
| Nucourt | Nordpol | 1,000–1,500 |
| Bessancourt | Bertha | 1,000–1,500 |
| St. Maximin | Martha | 1,000 |
| Fort VII-Antwerp | Anton | 240 |
| Fort Cruybeke | Christa | 200 |
| Fort Rochambeau | Robert | 150 |
| Fort Hirson | Hildegard | 150 |
| Balleau | Biber | 275 |
| Mamers | Murmeltier | 375 |
| Luché | Luchs | 300 |
| Cherbourg | Chamäleon | 300 |
The primary construction material for Stellungsystem-I/-II was concrete bricks (cinder-block), consuming some 336,000m3 of concrete and 180,000 concrete bricks. With the exception of the command bunker located near the launch rail, none of the structures was fortified. The principal building types are listed on page 25 by their German designations and role.
While construction was underway at the launch sites, a parallel program was underway to create storage facilities for the missiles in the neighboring areas. In some cases these were converted from tunnels or other existing structures. The first nine of these were planned for the Pas-de-Calais while the last four were located in Normandy.
As construction of Stellungsystem-I progressed in the autumn of 1943, it increasingly came to the attention of British intelligence. French resistance organizations had noted the flurry of activity in the Pas-de-Calais region and began to systematically collect information on the sites which was forwarded to London. At first, the role of the sites was not very clear as they were not especially large, and British intelligence had a very cloudy view of what types of weapons the Germans were developing. The Joint Intelligence Committee (JIC) was aware of the possibility of some form of jetpropelled missile and in late August 1943, a FZG-76 test fired from Peenemünde crashed on the island of Bornholm and Danish resistance spirited out photos of the wreckage. By November, the scattered evidence began to coalesce, especially after RAF reconnaissance aircraft again photographed the test site at Peenemünde. Sitting on a long rail was a small aircraft, and nearby were storage buildings suspiciously similar to those being erected in France. Photographic reconnaissance missions over France were accelerated, and a site near Bois-Carré seemed to be nearest to completion. The most distinctive element of these sites was catapult walls ominously pointed towards London, and several “J”-shaped buildings, which were dubbed “ski” buildings by the photo interpreters. As a result, the Stellungsystem-I sites were nicknamed “ski sites” or “Bois-Carré” sites by British intelligence. By late November 1943, some 75 sites had been spotted in the Pas-de-Calais area, and seven near Cherbourg. In mid-November, a sub-committee of the JIC was created codenamed “Crossbow” to coordinate the intelligence collection directed against the German missile program. As a result, the German missile sites in general were often referred to as “Crossbow sites,” a term that will be used here for convenience.
The Bois-Carré sites used a large concrete structure designed to be non-magnetic. It was aligned on London and used to adjust the magnetic compass in the V-1 flight control system prior to the missile launch. This type of structure is easily identified by its distinctive arched entrance and this partially destroyed example is preserved at the Ardouval/Val-Ygot site. (Author’s collection)
The distinctive “ski” buildings used for missile storage gave the Bois-Carré sites their name. When possible, they were buried for further protection, and protective walls erected on either side of the entrance, as is seen at this site of Abteilung IV south of Cherbourg near Martinvast. (NARA)
On December 1, 1943, the Wehrmacht operations staff created the 65. Armee Korps zur besonderen Verwendung (65th Army Corps for Special Employment), to command the planned missile attacks on London that were scheduled to begin at the end of the month. This corps headquarters was an unusual organization including both Army and Luftwaffe missile units, as well as the Tausenfüßler gun regiment and the various support units associated with the new weapons. As it transpired, the start of the missile campaign was delayed by production and technical problems with the missiles, but the corps set up its headquarters in St. Germain, France, in early 1944.
This Abteilung IV ski site near Cherbourg has extensive camouflage netting over the work area. The building is the non-magnetic compass alignment garage so typical of the Bois-Carré sites. (NARA)
The threat of air attack led FR 155(W) to make extensive use of camouflage nets around the launch sites. This is a “ski” stowage building at one of the Abteilung IV sites near Cherbourg. (NARA)