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The Command Bunker - a well-kept public secret

by William Willems

The command bunker was once a top-secret construction inside the Kemmelberg.

Built by the Belgian defence forces, it is a large military underground bunker that was installed during the Cold War period, and is a rare testimony to events of this period in Belgium. This defensive position in 1953 was as a response to the Soviet threat. Today this Cold War relic has become a museum. It not only explains the origins of Nato and the Warsaw Pact, but also illustrates Belgium's role in the Cold War.

Top secret

The only known fact was that the Belgian army built an underground bunker in the Kemmelberg. Furthermore, strict secrecy was kept about the project. The true facts remained something of a great mystery. Until the fall of the Berlin Wall in 1989, for almost four decades, the Kemmelberg bunker remained one of the best kept secrets of the Belgian army.

The construction site was completely screened off and an enormous hole was dug under the southern flank of the Kemmelberg. Hundreds of lorry-loads of soil were taken away by foreign workers. During construction of the underground complex, the construction workers did not know exactly what they were building. They remained on the job site for a limited period of time before being transferred to other construction sites. The construction company's personnel was shown only a small portion of the design drawings. The true function of the structure remained a mystery for years. Only the small ventilation chimney pipes suggested that there was more hidden under the ground.

Kemmelberg command bunker
Photo © Paul Van Caesbroeck

Staff office with ops room view.

Military personnel who did not need to be informed were unaware of the bunker's existence. Only those who were directly involved with the bunker were informed according to the 'need-to-know' principle, either because they had to work in or for it.

Not only were the activities which later took place in the bunker classified as top secret, even the bunker's very existence was so secret that even at the Belgian Defence headquarters almost no one knew anything about it.

Emergence and original objective

After the end of the Second World War, when Nato was founded in 1949, a greater number of countries saw the benefit of the 'Nato Air Defence Ground Environment' system (NADGE), a comprehensive air defence system which would warn against a possible attack from the Eastern Bloc. In Belgium, Semmerzake (East Flanders) and Glons (Liège) were taken into use as military radar stations, but Nato originally showed no interest at all in a bunker under the highest hill in West Flanders.

However, the remote location was excellent, on a ridge that separates the Yser basin in the north and the Leie basin in the south, in a sparsely populated area which would be so much easier to evacuate, and in the far west of the country, close to French, Dutch, and British allies but far from the east, from where the danger could come.

During the Cold War, an underground Nato headquarters was built from 1955, known as the 'Joint Operations Centre' (JOC), and consisting of a high-security and NBC-safe bunker (Nuclear, Biological, Chemical) in a former marl quarry of the Cannerberg near Maastricht (Dutch Limburg). This huge complex was built up to fifty metres deep into the ground and covered almost seven hectares in total, with four hundred offices, a main restaurant, a self-service restaurant with a capacity for six hundred meals, a hairdresser, a bar, 51 toilets, 27 showers, a three-hole indoor golf course on artificial grass, and eight kilometres of corridors. In times of war, troop movements in the Benelux and Germany and aircraft movements from Norway to southern Italy had to be controlled from here.

Meanwhile, however, five European countries: Great Britain, France, and the three Benelux countries, had already decided - in the event of a possible new conflict and potential communist threats - to take military measures themselves by developing their own joint air defence system.

The 1950 'Pact of Brussels' - which was part of this defence plan - brought the Kemmelberg back into the sights of army specialists as a strategically important location. The five countries decided to build a coordination bunker for Western European air defence which would function together with the two radar stations at Semmerzake and Glons. In the event of a possible attack by the Red Army, the Kemmelberg bunker would become the Benelux nerve centre for Nato.

The construction of the Kemmelberg bunker took place between 1952 and 1956. Most of the soil which had to be removed was dumped back on top of the bunker.

However, by the time the shell was finally ready, and regardless of the existence of the new bunker, the newly-established Nato already had its own integrated air defence system installed in Maastricht, and the bunker under the Kemmelberg would be left unused.

As shown, while originally intended as a command post for an international air defence system, the Kemmelberg bunker would never hold that function. At the completion of its construction the bunker was already technologically obsolete, as it cannot withstand an attack by NBC weapons. And the necessary adjustments would have been too expensive.

Building and interior design

The bunker is located at a depth of fifteen metres inside the Kemmelberg. The domain on which the bunker is built originally covered four hectares. The total floor space occupied by the bunker complex is 2,164m². The dimensions of the actual command bunker are 30m x 30m, and the walls are two metres thick. At the top of the bunker is a floating concrete roof measuring 73m x 60m with a thickness varying from 2.9m in the middle to 1.15m at the ends. A layer of soil was placed between this roof and the bunker to provide shock absorption during possible bombing. The outer walls are covered with a copper casing that forms a Faraday cage and serves as a shield against electromagnetic radiation. The outer walls also offer protection against electromagnetic radiation.

There were no bedrooms and no kitchen in the underground bunker. For this, the complex was completely dependent upon the support of the military barracks in nearby Ypres.

Access to the underground bunker is through a hatch, camouflaged by an inconspicuous little brick house with a simple wooden door as the entrance.

Kemmelberg command bunker
Photo © Paul Van Caesbroeck

Access to the command bunker.

Firstly, a staircase has to be descended before one can enter the large map room. This was the operations room and the beating heart of the command bunker and it extends over levels -1 and -2. Each staff arm (from land, air, and naval forces) had a fairly well insulated office on level -1 with a view of the ops room.

Kemmelberg command bunker
Photo © Paul Van Caesbroeck

Central ops room.

On level -1 is where the technical installations were also located, such as two diesel generators for the power supply, plus heating burners and an air ventilation system.

At the lowest level, the communications system was equipped with both an automatic and a manual telephone exchange, a transmission centre with telex equipment, a radio service, and a military postal service.

There were connections via underground telephone cables to the former national telephone company, RTT (Regie van Telegraaf en Telefoon), the Ypres military barracks (via signal cable), and to a station run by the air force's beam transmitter/multiplex network at the highest point of the Kemmelberg, which was already available to the air force telecom service of the 1960s and which covered the entire territory of Belgium.

This air force system was gradually also developed for the other arms of the Belgian national defence forces.

Kemmelberg command bunker
Photo © Paul Van Caesbroeck

Diesel generators.

There were four receiving antennas on the site of the bunker, but there was no transmitting antenna as this could give away the bunker's location. That is why the signal cable to the military barracks at Ypres was used as a connection from the bunker to its transmitter antennae.

At a short distance from the command bunker, land had also been purchased to plant additional antennae. There was a tank for water supply and tanks with a fuel oil supply of 50,000 litres.

An emergency exit was provided which leads to a flank of the Kemmelberg.

Bunker functions after the raising of the Iron Curtain

After the Iron Curtain was raised in 1961, it was not until 1963 that the supreme command of the Belgian armed forces decided to set up the Kemmelberg bunker as a secret command centre in the event of war or conflict, or to use it for training purposes.

The Belgian defence forces took care of the further finishing work, the telecommunications equipment, and the furniture.

From about 1965, the Kemmelberg bunker became the headquarters of the Belgian General Staff in the event of war, as all other Nato member states had a similar complex from which orders would leave for the troops on the ground.

It was used as a command post during organised large-scale commando missions until the mid-1990s.

The exercises that were organised to take place inside the bunker were based on realistic scenarios, with an attack being mounted by the so-called enemy, referred to as 'Orange Block' (or 'Orange Land'), which was threatening to deploy certain (nuclear) means.

For years they trained to cover against a possible nuclear attack: the 'worst case' scenario. To keep the command bunker operational around the clock, a team was organised of three shifts of two hundred military personnel each. They were 'earmarked', ie. they were made aware of the existence of the command bunker.

The maps which display information about the weapons systems in the - still impressive - large central ops room, and the personnel themselves, were constantly updated. The staff of the land, air, and naval forces received the most recent information via the - at the time modern - communications system.

A large clock provided electrical synchronisation of all other clocks in the bunker. Wooden telex cabinets provided some sound insulation for the telex equipment which rattled away day and night. Messages were passed onto the three staff bodies via small hatches in the walls.

Kemmelberg command bunker
Photo © Paul Van Caesbroeck

Map with strategic data.

The Kemmelberg command post also served as the centre from which the logistical orders departed of the 'JS', the Joint Staff (General Staff) for Belgian troops in their own country and for the Belgian Armed Forces in the Federal Republic of Germany (BSD).

The outside world only received orders from 'Fakir', one of the code names for the telephone exchange under the Kemmelberg. Hardly anyone on site knew that orders came from within the Kemmelberg.

In 1995 the last secret underground exercise took place. Until then the bunker had provided permanent surveillance services.

During the Cold War, a command bunker complex was also built by the Eastern Bloc, in the municipality of Kossa in the former GDR, in opposition to the Kemmelberg bunker, at a distance of exactly 866km.

The complex consisted of six underground bunkers, but it was excellently camouflaged and, as more financial resources were available, this complex was much better equipped than the Kemmelberg bunker and much more secure, such as with armoured doors.

Site accessibility

After 1995, supervision of the bunker fell into the hands of the 'Support Equipment and Products Competence Centre' at Ypres, and the command bunker became a witness museum.

In 2009, the bunker was converted into a Cold War museum by the Royal Museum of the Armed Forces and Military History, and the bunker and an area of approximately one hectare around it were overseen by the Historical Pool of Defence, an umbrella advisory board with support from the Ministry of Defence which manages historically-valuable military sites and gives them an educational value.

Also slotted into this concept are Breendonk Fort, the 'Diksmuide Trench of Death', Eben-Emael Fort, and the McAuliffe Cellar in Bastogne.

Finally, the command bunker was opened up to the public. One can visit it either with a guide or individually. Since 2017, the bunker has been managed by the War Heritage Institute in Brussels.



Text copyright © Archeo Kemmelberg. An original feature for the History Files: Kemmelberg.