History: Measurement Building / TNO on the Plains of Waalsdorp


The history of TNO on the Plains of Waalsdorp


Pre-World War II years: The establishment of the Measurement Building and the first research

In 1924, foreign and Dutch newspapers reported about ‘deadly rays’. These and other mysterious rays would have been observed especially in Germany. [These messages were probably based on the hoax by the English researcher Harry Grindell Matthews].

It took until 1934 before the deadly ray discussion became news in the United Kingdom (see: Brian Johnson, The Secret War). 

As a result of these reports, questions were asked in a secret meeting of the Defence Commission of the House of Representatives to the Minister of War. Minister of War, Dr. J.J.C. van Dijk, however, had already been triggered by earlier reports from other information sources. His conclusions and preliminary decision can be found in Memorandum Minister of War Van Dijk, Secret Litt. P.42 of May 9, 1924:

As you will be aware, the literature and the press have already mentioned several times mysterious means of combat, involving e.g. use of wireless electrical waves and the like for destructive purposes.

Especially in recent times, numerous – usually fantastic – announcements of this nature have been made in newspaper reports from various origins, although further confirmation of the correctness of these reports has continued to fail.

A few months ago, a German party offered me some new means of combat, with the understanding that I was asked for financial support to further develop those inventions. I then made a proposal, which could have been accepted without objection by a bona fide party. However, I have not heard anything about this for several months, so I doubt whether this so-called inventors were in good faith.
The question also arises to what extent other such claimed inventions have any truth behind them. {…}

However, in my opinion, there is now a well-founded reason to suspect that in the near future, in addition to chemical weapons, physical weapons will also be used in warfare and will come to the fore, including completely new means of combat that have not yet been used, e.g. use is made of wireless electric waves, etc. for destructive purposes.” {…}

In the meantime, it seems to me that full attention should be paid to the possibility of the invention of physical means of combat as referred to here. I am therefore considering setting up a physical technical committee, which should devote its attention to these physical weapons, independently of the Committee on Chemical Weapons.  {…}

With regard to the last point [ref to ‘general mandate of a Commission for Physical Armament’], I note that the alleged inventions – or fantasies – in the field of physical means of combat, as far as I know, can be distinguished into:

  1. the targeted emission and concentration of X-rays (Hertzian waves) at great distances and thereby the generation of powerful electrical sparks between metal objects.
  2. the targeted emission of electromagnetic waves and thereby disabling the magnetos of explosion engines (has recently been mentioned in various newspapers and was presented to me as an invention on the above-mentioned occasion).
  3. the targeted emission of wireless electric waves for certain explosives at a specific frequency, in order to cause those explosives to detonate at a great distance (this was – among other things – at the beginning of the month of April mentioned in newspaper reports by the Hollandsch Nieuwsbureau. An English inventor MATH[I]EU GRINDELL is said to be capable of covering an area of 50 miles radius up to an altitude of 5 miles unsafe for anything explosive).
  4. the targeted emission of electrical force rays, which could wirelessly kill living beings at great distances (see – among others – the book by PH. OPPENHEIM; “Mr. Lavendale Diplomat”).
  5. the targeted transmission and concentration at great distances of high-frequency wireless electric power waves of different potential, whereby, with enormous heat development between the focal points of these rays, a “Siedeboog” would be created of exceptionally high electrical voltage which would affect all materials – e.g. also armour steel – would burn through in no time (was offered to me as an invention on the aforementioned occasion).

The Inspector of Engineers, No. 1368 Secret on June 13, 1924: {…} Also in my opinion, the to-be-established Commission for Physical Armaments should be composed of a Professor as chairperson, assisted by one or more assistants (at the discretion of the Professor); an officer of the General Staff; an artillery officer, and an engineer officer. Since the professor-chairman and his assistant(s) will of course fully master the physical part of the issues to be dealt with by the Commission, in my opinion, the military members of the Commission, in addition to their special military knowledge, should jointly be particularly competent in the field of engine and aircraft technology and explosives, all for military purposes.

Minister of War Van Dijk, Secret Litt. C.67, July 28, 1924: The Commission’s task will be to study the full extent of the problem of physical means of combat (including in particular the use of wireless electric or electromagnetic waves for destructive purposes) and to indicate in broad terms the direction in which possible solutions for each part of the problem should be sought by the physical and related sciences, in accordance with our conditions, and finally to advise me on matters related to those questions.
I asked Prof. Dr. KAMERLINGH ONNES in Leiden to accept the chairmanship of the Commission in question, but this Professor asked me to apologize to him, in view of his state of health and his age, for not being able to assume this chairmanship. 

Prof. Dr. Heike Kamerlingh Onnes recommended Prof. Jr. Dr. G.J. Elias (professor of Delft Technical University) in his place. After a discussion with him and the approval of the Minister of Education, Arts and Sciences, the Commission for Physical Combat Equipment was established by Ministerial Order of November 25, 1924 (Minister of War, Secret Litt. R.108). The earlier establishment of the Chemical Warfare Committee in 1923 served as an example of this.

Physical means of combat comprise various new means of combat, which are based on the special application of light, sound, heat or electricity. Some of these means of combat are known, and some are still a subject of study. This includes: devices for determining the position – based on sound or heat – of targets on earth, in the air or under water; electrically charged obstacles; the use of wireless electric waves for controlling motor-driven, unmanned means of transport, for detonating explosives, for destruction or destruction purposes, etc. Insofar as electrical equipment is used in the aforementioned means of combat, this naturally also involves wires for electrical conduction to fit.
Minister of War Van Dijk (21 February 1925) in: First Chamber 1924-1925 parliamentary document number 2 VIII subnumber 2, p 481

This date has since been celebrated annually as the day of the foundation of the laboratory. In order not to create unnecessary suspicion in the pre-war years, the building was given the obfuscating name Meetgebouw (Measurement Building) instead of its official name “Laboratory for Physical Armament”. The name Meetgebouw was in use until the German invasion in 1940. In the Meetgebouw three rooms were available with a total floor area of 130 m2.

Prof. Dr. Ir. Van Soest
Prof. Dr. Ir. Van Soest


The Measurement Building in 1927 - painting by G. Mooij after an original photograph
The Measurement Building in 1927 – painting by G. Mooij using an old photo


Kamp Waalsdorp met het Meetgebouw - foto Koninklijke Luchtmacht (1930)
The military barracks ‘Kamp Waalsdorp’ with the Measurement Building (photo courtesy Royal Netherlands Air Force (1930))

At the end of 1936, the Ministry of the Interior notes that the frequency band 75-81 MHz (4,000-3,750 m), originally reserved for the “deadly beam and killing engines”, is now less needed and “can be given away as needed” (although a certain band in this frequency band would be useful for future military purposes).


Experimental listening device
Experimental listening device

Van Soest began researching acoustic listening devices for aircraft detection and interception (see: Technical topic Air Acoustics) in use by the Royal Netherlands Army. He developed a Dutch listening device because the industrial devices showed insoluble defects. The successful development of the “Van Soest” listening device ultimately led to production in the industry and commissioning by the Royal Netherlands Army.

In 1937, the Minister of War decided that, because of its secret character, the work of the Commission for Physical Capabilities would not come to fall under the competence of the in 1932 established by law Organisation for Applied Scientific Research (TNO).

Subsequent projects were the development of a meteorograph for the Military Weather Service, and the development of infrared equipment for detecting possible hostile ships crossing a river. Projects led by jhr. ir. J.L.W.C. von Weiler, who joined the “Measurement Building” in 1934, included the development of an advanced radio transceiver for the Artillery (see: Technical topic Radio communication), the acoustic listening device for aircraft observation, and the development of the ‘electrical listening device‘ (‘radar’). The topics IFF (Identification Friend or Foe), detection of landmines and underwater acoustics were still in the experimental phase.

The number of employees of the Meetgebouw grew in the pre-war years to 37 in 1940. The floor space increased to 788 m2 in 1940.

During the invasion of the Germans in May 1940, two ‘electric listening devices’ were in operation, one of which was operated on the Malieveld in The Hague. On May 15, a wooden barrack on the Waalsdorpervlakte in which all secret equipment was collected was deliberately set on fire so that the equipment would not fall into German hands. Just before the capitulation of the Netherlands, Von Weiler and Staal escaped to England taking with them the documentation of the electrical listening device. In England, he worked with English scientists on the further development of radar until 1946.

Jhr. ir. J.L.W.C. von Weiler
Jhr. ir. J.L.W.C. von Weiler


German Occupation 1940 – 1945

In 1941, the Meetgebouw with over twenty staff members was included in the PTT organisation as the Physics Laboratory. In 1943, the Meetgebouw employees moved house to the Central Workshop of the PTT on the Binckhorstlaan because the Waalsdorpervlakte became ‘Sperrgebiet’. During the war period attempts were made to avoid work for the occupying forces, which partially succeeded (see personal story). Clandestine work was carried out on a broadcasting station that came into operation as Herrijzend Nederland 3 on wavelength 301.5 metres on May 18, 1945. The transmitter was operated by laboratory staff. Messages of powerful reception and quality came from all over the Netherlands. The station transmissions were also received in Hamburg, south of Paris and in southern England. After the Lopik transmitter came back into operation, the transmitter was changed and worked at 245 m as Hilversum – Herrijzend Nederland until September 4, 1945. The transmitter was then moved and operated as an auxiliary transmitter of the P.T.T. in Beek, Limburg.

After the war

On December 15, 1945, the Physics Laboratory transferred back from the P.T.T. to the Ministry of War. In 1946, the ‘normal work’ was picked up again. The Physics Laboratory remained housed at the P.T.T. until 1 December 1947. Amongst other research topics, the laboratory worked on infrared applications needed by the army in the East Indies.
On July 12, 1947, the Rijks Verdedigings Organisatie (RVO) – ‘National Defence Organisation’-  was established. The Physics Laboratory (PhL) was incorporated into the Netherlands Organisation for Applied Scientific Research (TNO)’s RVO. The laboratory returned to the Vlakte van Waalsdorp where the pre-war activities in areas such as radio, radar, and infrared technology were restarted. Internationally, the war had led to a wide range of (military) technological developments. To catch up on the lost years and to acquire an international position in the field of defence research, the PhL explored new areas of research such as passive and active sonar technology, phased array radar technologies, electronic calculation methods, and operational research. In the 1960s, the laboratory had a global leading role in the field of digital fire control and assisted the United States with this technology. Due to the strong growth in personnel, a stone building was added which was later expanded with more barracks.

In 1969, a completely new building (viewed from above in the form of an eight) was built at the edge of the Waalsdorpervlakte including an atomic bomb shelter given the Cold War era. The story about the artworks in the entrance halls of TNO and NATO STC and the thread sculpture is an interesting story to read. Mid of the 1980s, the Physics Laboratory comprised the following research groups: Physics, Far Infrared, Telecommunication, Microwaves, Information Processing Systems, Signal Processing, (underwater) Acoustics, Mine countermeasures and Operational Research. These research groups were supported by the Electronics group, Computer group, workshops and administration.

Physics Laboratory TNO (1965) - painting by G. Mooij
Physics Laboratory TNO (1965) – painting by G. Mooij


The new building in 1969
The new building in 1969

LEOK at Oegstgeest

After his return to the Netherlands in 1946, jhr. ir. J.L.W.C. von Weiler, who was incorporated into the Royal Netherlands Navy during his stay in England, continued his radar development and consultancy work as Head of the Development and Test Division of the Navy Radio Service, Oegstgeest, Netherlands. In 1950, this department consisted of 25 persons and became the Laboratory for Electronic Developments (LEO). LEO was aimed at filling the immediate needs of the Royal Netherlands Navy with operational equipment for radio communication and radar. In 1955, the LEO activities were extended with activities for both the Royal Netherlands Army and the Royal Netherlands Air Force. For that reason, the laboratory name was changed to the Laboratory for Electronic Developments for the Armed Forces (LEOK). The LEO (and later LEOK) shared a building with the Navy Electronic Optical Works (MEOB) in Oegstgeest.

The LEOK and the MEOB, Oegstgeest
The LEOK and the MEOB, Oegstgeest


First floor of the MEB building in use by the Test and Development Department, later LEO and LEOK
The first floor of the MEB building is being used by the Test and Development Department, which became the LEO and later the LEOK

In 1958, the LEOK moved into a new two-story building, which created space for research in the field of radar systems, training and simulation equipment.

LEOK building in use between 1958-1984
LEOK building in use between 1958-1984

In 1977, the number of employees of the LEOK had grown to 150 under the management of director F. van Hutten. In the same year, the armed forces decided to abandon the military status of the LEOK by having the laboratory incorporated into the TNO organisation. The continuous discussion of overlapping work and the organisation of the future tasks of the laboratories resulted in the decision to integrate both laboratories at one location. In parallel, TNO RVO became TNO Defence Research in 1980.
The laboratory building on the Waalsdorpervlakte was enlarged to accommodate the merge. On December 1, 1984, the (joint) new TNO Physics and Electronics Laboratory (TNO-FEL) started, exactly 57 years after defence research on the Plain of Waalsdorp. TNO-FEL continued in the following years as one of the three laboratories of the TNO Defence organisation in which the approach shifted to a more market-oriented approach based on military and civil needs of the domestic and foreign markets. The laboratory had five divisions:

  • Operations Research and Business
  • Command & Control and Simulation
  • Smart Sensor Solutions
  • Observation systems
  • Telecommunication and Security (mid-2003, a large part of the non-military activities in this area moved to TNO Telecom).
TNO location The Hague Waalsdorp - the 1969 part and the 1984 extension
TNO location The Hague Waalsdorp – the 1969 part and the 1984 extension

On 31 December 2005, TNO decided to end the individual TNO institutes (laboratories) as independent organisational units. TNO-FEL was merged into TNO core’s area TNO Defence and Security. On 1 January 2011, another reorganisation took place. The TNO core area structure was abolished and TNO was transformed into a “single”- TNO in which the areas of expertise that are located at location The Hague Waalsdorp work to a large extent for the unit Defence, Safety and Security.

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