Nazi Rocket Bunkers

Jon Trigg takes us inside the secret facilities that could have decimated the UK and turned WWII in favour of the Nazis.

D-day. The Allies had successfully landed in Normandy and begun the liberation of France. The Nazi empire was crumbling. In desperation, Hitler turned to Germany’s scientists and their vaunted ‘Wunderwaffen’ (wonder weapons) with the order: “Destroy London!”

The man entrusted with carrying out Hitler’s command was an undistinguished 63-year-old artillery officer – Generalleutnant Erich Heinemann, and his Luftwaffe subordinate, Oberst (Colonel) Max Wachtel. On the night of 13 June 1944 it began, as one eyewitness remembered: “The air raid sirens sounded in Woolwich just before the first light of dawn …. a strange sounding ‘plane’ was over Blackheath Park less than two miles from us, flying low … with its tail ablaze and leaving a short trail of brilliant flame.” Then it fell to earth and exploded next to the railway bridge on Grove Rd in Mile End, killing a number of civilians. This was the first FZG.76 missile to hit London – nicknamed ‘doodlebugs’ or ‘buzz-bombs’ by the British, they were christened ‘V-1’s’ or ‘Vergeltungswaffen-1’ (‘Revenge weapon-1’s’) by the German journalist Hans Schwarz van Berkl. Londoners soon learned to dread them: “…the trauma of hearing the approaching sound, hearing it close overhead, then the abrupt cease of the deafening pulsation, followed by those dreadful seconds of silence until the ear shattering explosion came.”

In reality, the V-1 offensive was a marked failure. Of the 8,617 fired at Britain that summer, over a thousand crashed shortly after taking off, and an additional 3,852 were brought down by Allied fighters, barrage balloons or anti-aircraft guns – only around one in four actually hit the country. Air attacks on the V-1’s distinctive ski-shaped storage bunkers, and the transport links that supplied those same sites with fuel and additional missiles, further degraded the effectiveness of the assault, and with the German disaster at Falaise in early August, the Allied armies were able to advance across northern France and capture the vast majority of the V-1’s launch sites. During that advance, Allied soldiers came across several massive concrete bunkers – too far inland to be part of the Nazis’ flawed Atlantic Wall coastal defences, these were the precursors to today’s modern underground missile silos – Hitler’s secret rocket bunkers.

The V-2

Two years earlier in 1942, Arthur Harris’s RAF Bomber Command began its campaign against Nazi Germany in earnest. The first 1,000-bomber raid against Cologne devastated the city and caused terrible casualties. Hitler demanded revenge, but Hermann Goering’s Luftwaffe was outmatched and overstretched. It was down to his architect-cum-armaments minister, Albert Speer, to propose a solution – the world’s first ever longrange ballistic missile offensive. The V-1 was but one of a whole series of technologically-advanced weapons developed by German scientists in an attempt to turn the tide of a war that was increasingly flowing against the Third Reich. At the Peenemünde rocket research facility on the Baltic coast, Walter Dornberger and Wernher von Braun had built and tested a rocket designated

“The question for the Nazis was where to target it? For Hitler the choice was obvious – London”

as the Aggregat 4 – the A-4 for short. The world would come to know it as the V-2. At a thousand kilos, its warhead was bigger than the V-1’s, and its range of some 200 miles was 40 more than its little brother, but it was its speed that really set it apart. The V-1 flew at 400 mph – a bit more than a Spitfire – whereas the V-2 reached almost 3,600 mph; it was untouchable, undetectable in flight and there was no defence against it. During a test flight on 20 June 1944 a V-2 became the first man-made object to travel into space. The question for the Nazis was where to target it? For Hitler the choice was obvious – London. On 22 December 1942 he gave the go-ahead to start mass production of the rocket.

Concrete megaliths

While the army, and indeed some voices within the rocket programme – including that of Dornberger himself – advocated mobile launching as the way forward, Hitler preferred the grandiose, and opted instead to replicate the huge reinforced concrete U-boat pens, built on France’s Atlantic coast, as the best way of protecting the V-2s from Allied aerial attack. The U-boat pens were proving almost impervious to even the heaviest bombing, and the Nazi dictator believed that underneath the safety of a massive hardened dome, the V-2s and all their associated infrastructure and personnel would remain unmolested and able to launch wave after wave of missiles against the British capital and other major cities.

Surveys over the winter of 1942/43 identified a suitable location on the south-eastern edge of the 850-hectare Forêt d’éperlecques in the Pas-de-calais. Just to the west is the village of Watten, leading to the site being called the Blockhaus d’éperlecques, the ‘Watten bunker’ or simply ‘Watten.’ Codenamed Kraftwerk Nord West (Powerplant Northwest) by the Nazis,

6,000 forced labourers were shipped in to begin excavation and construction in early 1943.

The bunker was huge. Built by the paramilitary Organization Todt (OT) to a ‘special fortification standard’ – Sonderbaustärke – the main building would be the liquid oxygen (LOX) production facility that fuelled the rockets, and this was 92 metres (302 ft) wide, 28 metres (92 ft) high, with working levels descending 6 metres (20 ft) below ground. It was protected by a reinforced concrete roof five metres (16 ft) thick, and walls 3.5 metres (11 ft) thick. Two hundred thousand

tons of concrete and 20,000 tons of steel were needed for the bunker, within which some 250 personnel would man and run a mini-production plant capable of assembling, fuelling, arming and launching 36 missiles a day, as well as storing up to one hundred and eight. External supplies would be brought in by rail to the bunker’s own bomb-proof railway station on a specially-built spur line, with the entire site powered by an integral power station with a 2,000 horsepower

(1.5 MW) generating capacity.

As far back as November 1939, the British began to pick up information about ‘secret weapons development’, and Peenemünde itself was identified as a site of special interest by aerial photo reconnaissance as early as January 1943.

The result was Operation Hydra – an RAF bombing raid conducted by almost 600 aircraft during the night of 17/18 August 1943, which damaged the facility, killed over 180 German staff including technicians and scientists, and severely delayed rocket testing.

Hydra was the opening salvo in Operation Crossbow – the Allies’ plan to search out and destroy the V-weapon threat.

Operation Crossbow

The first phase of Crossbow from August 1943 up to June the following year, saw mainly American bombers drop 12,658 tons of bombs on over 60 V-1 launch sites, as well as hitting Watten and another site at Mimoyecques’. The raids were so heavy and persistent that the Luftwaffe regiment tasked with the V-missile programme wrote in its War Diary that: “The number of French workers on the sites is diminishing because of the continual air raids. Even the system of bonuses for increased production is no longer attracting them.” Watten, first attacked on 27 August, had over 500 tons of bombs dropped on it in eight additional raids between January and June 1944, and while none penetrated the concrete roof, the damage to the site in general, as well as its road and rail links, was so complete that the idea of using it as the main V-2 launching base was abandoned.

The OT settled on an alternative site less than nine miles away in an existing limestone quarry at Wizernes. A new construction technique pioneered by the OT engineer Werner Flos, called ‘earth forming’, would be used to frustrate Allied air attack – this approach called for the reinforced concrete roof; 5 metres (16 ft) thick and 71 metres (233 ft) in diameter – to be built on top of an earthen mound, and then once complete, the earth would be dug out from underneath its 55,000 ton mass to form the inner chamber. This chamber was a huge octagonal rocket-preparation hall directly under the dome. It was never completed but would have been 41 metres (135 ft) in diameter and up to 33 metres (108 ft) high – easily enough to accommodate a fully-fuelled and armed 12.5-ton V-2 standing 14 metres (46 ft) high.

Running away from this central chamber would be some seven kilometres (4.3 miles) of tunnels cut into the side of the quarry itself, housing barracks, LOX production facilities and missile storage bays. An underground rail tunnel – codenamed Ida – would connect Wizernes to the main line some miles away, so missiles could be delivered unhindered, and then launched from one of two launchpads, Gustav and Gretchen.

Overseen by the German construction firms Philipp Holzmann AG of Frankfurt am

Main and the Grossdeutsche Schachtbau und Tiefbohr Gmbh, some 1,400 workers beavered away to first build the dome and an additional bomb-proof ‘skirt’ or Zerschellerplatte of steelreinforced concrete, 14 metres (46 ft) wide and 2 metres (6.6 ft) thick, surrounding the dome itself and supported by a series of buttresses. Codenamed Schotterwerk Nordwest (Northwest Gravel Works), the site was quickly identified by Allied overflights – perversely it was the elaborate care taken to camouflage it that gave it away – and bombed. Beginning in March 1944, Wizernes was repeatedly raided with the dome suffering one direct hit on 6 May, although it wasn’t penetrated.

Eventually it was decided to use Barnes Wallis’s 12,000lb Tallboy ‘earthquake’ bombs to pierce what were termed the ‘Heavy Crossbow’ sites at Watten, Wizernes and Mimoyecques. Beginning on the night of 19 June over Watten, the elite crews of the RAF’S 617 Squadron of Dambuster fame sought to smash the Nazis’ giant concrete rocket bunkers. Wizernes was attacked on the 24 and again on 17 July, and although not a single bomb hit the dome itself, several near-misses undermined the super-heavy structure and its foundations, forcing the Nazis to abandon any further work on the site. As Dornberger commented: “Persistent air attack with bombs so battered the rock all around that in the spring of 1944 landslides made further work impossible.” A German report dated 28 July 1944 stated that, “…the whole area around the dome has been so churned up that it is unapproachable, and the bunker is jeopardised from underneath.”

As for Mimoyecques it was raided on 6 July, its entrance tunnels and shafts were collapsed, entombing several hundred forced labourers and their German co-workers.

The Anglo-american ‘bomber barons’, the

RAF’S Arthur Harris, and the USAAF’S Carl

Spaatz and Jimmy Doolittle, were no fans of Crossbow, believing it an unnecessary diversion from their main focus – the destruction of Nazi Germany’s industries and cities. Churchill thought differently. To his mind the British population had suffered enough after nearly five years of war on their doorstep, and while the V-missile threat never achieved any real military significance, the potential for it to cause massive damage and horrific casualties, couldn’t be discounted. Hence the priority placed on Crossbow and its destruction of Hitler’s secret concrete rocket bunkers. The results speak for themselves – not a single rocket of any type was launched from the designated sites at Watten and Wizernes.

Aftermath

With France liberated, the V-2s withdrew to the Netherlands, and without a bunker site to utilise, the Army reverted to its preferred launch approach using Meillerwagen mobile firing batteries, manned by regular soldiers with specialist training, which presented an almost impossible target for the Allied air forces. The first V-2 hit London on 8 September 1944, and the very last on 24 March 1945 – Norwich and Ipswich were also targeted. Eventually some 1,359 V-2s would be sent hurtling towards England, with just over a thousand of them hitting the country, killing 2,754 people and wounding another 6,523.

In 1943, Hitler declared that; “The A-4 is a measure that can decide the war”, but in reality the A-4/V-2 ended up failing as much as its predecessor the V-1. Innocent civilians were killed and injured, but the course of the war wasn’t altered. At a time when the Wehrmacht needed every fighter aircraft, panzer and gun the country could manufacture, huge effort and resources were poured into a programme, that while revolutionary, came too late to save Hitler’s Nazi empire. As it was, the huge scale of the bunker construction project grabbed Allied attention, and the subsequent bombing campaign crushed it.

With the war over, the Americans and Soviets scrambled to secure Nazi rocket technology and the men who invented and developed it. The most famous – Wernher von Braun – ended up in the US working at NASA and helping the Americans not only develop a nuclear missile arsenal, but also reach the Moon, while Coalition forces in the First Gulf War came under attack from Soviet-made Scuds that were directly descended from the V-2.

In France, both the Wizernes site – now known as La Coupole (the Dome) – and Watten are now museums, the former opened to the public in 1997, and the latter a privately-owned attraction that details the history of the site and the story of the V-weapons programme.

The leading lights of Nazi Germany’s rocket programme after their capture by US troops on 2 May 1945. The man with his left arm in a cast is Wernher von Braun, and on his right wearing a hat and smoking is Walter Dornberger Washington DC, 1969 – Wernher von Braun sits in his NASA office; behind him are scale models of all the rockets he worked on, including the V-2

The carnage of a V-2 attack – Farringdon Market in London, 9 March 1945 V-2 missile body parts awaiting assembly at the Mittelwerk production facility near Nordhausen after its capture by US troops in 1945. Thousands of slave labourers were worked to death at Mittelwerk

A V-2 is test fired in Germany by Allied troops in October 1945

Unfinished Plans This sketch shows a little of how the missile base was supposed to operate, with rockets wheeled out of the facility ready for firing. However the Allies captured it before it could be used Operation Crossbow Once discovered, Allied forces began air raids on La Coupole without much success. However they switched to the 5,400 kg Tallboy bombs, which devastated the outer construction area Bomb Proof The design of the facility was supposed to make it bomb proof with a 5-metre thick concrete dome protected by another 2 metres of steel reinforced concrete on top of that Target: London La Coupole was built on the site of an abandoned chalk quarry and its purpose was as a launching ground for rockets that would bombard London and the south of England Inside The Dome This is Wizernes, now known as La Coupole (The Dome), a V-2 Rocket bunker built between 1943 and 1944 in Pas-decalais, Northern France. The site was converted into a museum in 1997

After the Watten rocket bunker was repeatedly bombed by the Allies, the site was rendered unusable

The Nazis’ rocket bunker at Watten near St Omer, France. In the foreground is a WWII-ERA Bofors light anti-aircraft gun

An aerial view of the rocket bunker complex at Wizernes. The planned rail tunnel entrance is at the bottom left, and the square concrete box building visible next to the dome is the unfinished ventilation shaft