History and Development of Radar Technology in Italy
The scope of this paper is to “narrate” in an informational manner the history of the Italian RADAR without descending into too many details, thus bringing to light how the ideas of Italian research were clipped by the obtuseness of those who instead should have made good use of it to promote it. When, later, war events imposed the tragic necessity to start again the research work, the same genial researchers, burning away deadlines and surmounting difficulties of all types, were able to quickly realize apparatuses which were lacking nothing compared to those realized by other nations with very different resources at their disposal. The only great difference between the Italian and other apparatuses was the minimal number built and deployed by Italy up to the date of the armistice.
One cannot talk about the Italian RADAR without a short introduction to the history of RADAR and the events, which brought about its realization and use, because they spanned several countries but had common origins. The problem of detecting echoes generated by electromagnetic waves was posed in 1901-1902 when Kennelly, Heavsyde and Marconi discovered that these waves were reflected by the ionosphere. The same problem of wave reflection was later developed by the German engineer Hulsmeyer who, in 1904, obtained a patent for an apparatus he named the “Telemobiloskop” which was capable of receiving electromagnetic waves reflected by metal object a few hundred meters away.
The study and experimentation went on almost side by side in the United States, England, Germany, French, Japan, and Italy even though in each research laboratory the researcher had not explicitly formulated the final goal of their researches, and more specifically what was later called RADAR (RAdio Detecting And Ranging).
Moreover, while in the world studies begun by Guglielmo Marconi on radio communication were furthered, and long distance communications were being achieved with the use of high-power transmitters utilizing micrometric, meaning very low frequencies, in Italy Marconi proposed and became a supporter of connections based on “short waves”, meaning at very high frequency, utilizing Yagi antennae (named after Hidetsugu Yagi). Beginning in 1916, a series of experiments utilized Yagi antennae begun. This gave light to the possibility of their utilization in the naval arena to detect the presence of metallic objects at a great distance.
In a famous memorandum presented by Marconi on June 20th, 1922 to the “American Institute of Electrical Engineers” and to the “Institute of Radio Engineers”, Marconi formulated a concrete forecast in regard to the possibility of utilizing radio waves to build a navigational auxiliary system based on the ability of electrical waves to be reflected by conducting bodies.
There is no doubt, then, that in Marconi’s mind already since 1922 the concept of the RADAR was unmistakably clear and based not only on theoretical speculations , but also experimental verification. Only starting in 1924 the English physicists Appleton and Barnett, and later the American physicists Breit and Stuve, began the experimentation of the detection of echoes reflected by the ionosphere with completely different procedures, transposing in the radio spectrum the detection technique already developed in the acoustical spectrum; the British used frequency modulation, while the Americans used a schema based on impulses.
These could be considered the starting point of the studies which brought about the construction of apparatuses for radio detection, the real ancestor of the RADAR. From these starting points the research paths in the various laboratories diversified following alternative principles. However, all of them had in common the fact that as the possibility of its military use was becoming more apparent, so increased the secrecy regarding progress made.
Some government and military officials had the foresight to realize the enormous importance of the matter, especially in the naval and aeronautical fields, for the detection of far obstacles (targets) through the use of radio waves. Such foresight caused a different allotment of economic and scientific resources for the better understanding of this important subject. The British command, for instance, fully supported the studies conducted by Prof. Watson Watt (later Sir) which led to the construction in 1935 of experimental apparatuses, later improved, which allowed England in 1940 to be equipped with a network of coastal RADARs for the sighting of airplanes and naval RADARs for the detection of both airplanes and ships and the direction of ballistic fire.
In Italy, instead, in regard to the development of the technical research, things went a different, very different way. In 1933, Marconi completed in the presence of military authorities tests on the fluctuations, which took place in the reception of radio signals due to the transit of cars in the proximity of the beam of a powerful radio transmitting waves of 90 centimeters between Rome and Castengandolfo. In these tests took interest the young engineer Ugo Tiberio. At the time he was a Sub-Lieutenant in the reserve, completing his military service at the “Istituto Militare Superiore Trasmissioni” (ISMT) in Rome.
In the following years, Marconi completed other radio detection tests up to completing, in 1935, in the presence of Italian authorities, the launch of an apparatus named “radioecometro” which, unfortunately, was not powerful enough to be of military use. This test was sufficient in exciting the fantasy of the journalists who went as far as talking about “the ray of death”, mistaking the remains of a sheep for charred by the radiation from Marconi’s apparatus, while instead it had been previously roasted by the local Shepard.
For the furthering of the military aspects of these test was assembled a specific military commission from multiple ministries who assigned the task of continuing the research work to Engineer Tiberio, at the time no longer a reserve officer, but an employee of the ISMT assigned to teaching radio technology.
Tiberio, on his own, had since 1931 independently dedicated time to what was later named “Radio-Detector Telemetry” (RDT) and later simplified to “Radiotelemetri” (RaRi) following the experiences of Marconi until 1937, when the tests conducted by the inventor were interrupted following his death.
During his research, Prof. Tiberio prospected the possibility of furthering the tests following the two methodologies used by the British and American researchers; the method which utilized the frequency modulation and the one which utilized the emission of impulses because, at the time, neither was preferred due mostly to the low power obtainable with the radio components of the time.
For the usual budgetary limitations which have always afflicted (and still do) scientific research in Italy, the committee preferred adopting the solution which appeared to be most economical and Prof. Tiberio continued researching utilizing only frequency modulation. Toward the end of 1935, Tiberio presented his report in which the problem of radio detection was theoretically developed and resolved in all details, calculations included. Of this report, which of course was secret, all traces were lost due to the war events. The same professor was very sorry about this loss because it was the proof of the results he had reached ahead of other researchers in the world.
Fortunately, in recent times, family members of Prof. Tiberio have found a hand-written copy of a second report dated April 26th, 1936 a few months posterior to the 1935 report, and in which there is an indirect reference to the previous document. Of this report we present the first page and its Italian transcription and the photograph of a solemn ceremony in which one of the two sons of Prof. Tiberio presented the document to Admiral Guarnieri, Chief of the Navy in February 2000 at the Italian Naval Academy.
Once again, one can see how the possibility offered by this particular use of radio frequencies had been discovered in time to use them, but unfortunately did not awake any interest in those who had the make the decisions. The proposal of Prof. Tiberio was regularly approved by the committee, but since the issue was considered competence of the Navy – between the two branches it was the one which had shown more interest in building a radio finder and was the one more developed in the area of radio electronic (the term electronic did not exist at the time). In 1936 a team lead by Prof Tiberio was constituted and located at the “Regio Instituto Eletrotecnico e delle Comunicazioni della Marina” (RIEC) physically located within the campus of the Naval Academy and commonly called Istituto EC or “Marinelettro” (today it is named “Istituto per la telecomunicazione e l’elettronica” Mariteleradar and it isdedicated to professor (and Admiral) Giancarlo Vallauri, who was the first director.”
To this team was assigned the task of going from the theoretical studies to practical experimentation. Prof. Tiberio was in the meantime named reserve officer of the Naval Weapons and assigned to the academy as physics and radio technology instructor for the regular and advanced courses for the officers of the naval constructions and weapons.
The financial means and the personnel made available for such a hard task were very limited (four N.C.O.s, a few technicians, and 20,000 lira ($14,000); thus Prof. Tiberio had to move forward with the experimentation of the prototype RADAR of his invention almost by himself. Along with Prof. Tiberio began collaborating Prof. Nello Carrara, another physics instructor for the regular classes at the academy. Prof Cararra, in 1924 already a young physicist, was interested in microwaves and to him is attributed the creation of the term “microwaves” in the scientific literature of the time. In the “RDT” project, Carrara was mainly responsible for the design and construction of the booster valves and magnetrons, parts indispensable to reaching tangible results.
The two professors did not interrupt their academic assignments (lessons, tests, exams) and did not mind participating in the hands-on construction of the equipment. Thus, in 1936, was born the first RDT (Radio Detector Telemeter) on a continuous wave model E.C. 1 (a name derived from the name of the institute, EC). In 1937 followed the E.C.1-bis and the E.C.2, which produced satisfactory results.
In 1937, Captain of Naval Weapons Alfeo Brandimarte joined the group and he immediately began contributing to the construction of the new prototype, the E.C. 3 no longer using a continuous (constant) wave with frequency modulation, but impulses. This collaboration, though, was short lived because Brandimarte, due to a strange Fascist law on single people, saw his Navy career halted and was forced to resign. Unfortunately, he fell during the war of liberation and was awarded the Gold Medal for Valor.
The research time was again made up of the tandem Tiberio-Carrara who, in the meantime, continued their academic work. At this point, it should be remembered the important contributions provided by Prof. Carrara who designed the valve, realized in collaboration with the Italian maker FIVRE (Fabbrica Italiana Valvove Radio Elettriche), which allowed a peak output of 10 Kw which, inserted in the high resonance cavity with high gain, also designed by Carrara, allowed them to overcome the difficulty of obtaining high output on 70 cm waves.
Nevertheless, the slowness of the way in which the manufacturers were building what was designed by the researcher, and also due to the limited production, other ways had to be found to find peak output required for obtaining a discrete range for the radio finder. Since the market was still open, valves of the necessary capacity had to be purchased from RCA in the United States, thus o satisfing the needs of the researcher. The trials of the two prototype, the RDT3 coastal model and the E.C.3 naval model (from December 1940 modified as the E.C.3-bis) allowed to foresee the possibility of obtaining significant results. The trial of the E.C.3-bis were immediately slowed down both by the need for further tuning, and also due to the limited interest of the Naval chain of command, even though in the Navy there was an awakening of what many years later would be called “Electronic Warfare”. In any case, at the end of 1941 the demonstration trials of the E.C.3-bis had not yet been completed.
To highlight the difficulties the small team had to face, it was thought important to reproduce, verbatim, what Prof. Tiberio wrote in 1951 recollecting these events: “In 1938, considering the difficulties in locating researchers to dedicate to the study of RADAR, the Ministry of the Navy decided to engage in the endeavor of an important radio factory from Milan, which limited itself to requesting from the Navy the necessary technicians since all of its personnel was already engaged. The Navy could not fulfill the request, thus this attempt was unsuccessful” (Tiberio – About the development of thought about the RADAR during the war -Rivista Marittima – April 1951). As it is said in Italy, “the dog eating its own tail”.
It was only after heavy losses by the Italian Navy during the night of the 28th of March 1941 off Cape Matapan that doubts about the British Navy’s possession of a RADAR became certainty. Thus, the importance of having such equipment in Italy was reevaluated. Once again, the EC was pressured along with Prof. Tiberio and Carrara. The prototypes were quickly placed back in service and from them were created two apparatuses named “Folaga” and “Gufo”. They differ mainly in the frequency used, making the “Folaga” a prototype for coastal surveillance, and the “Gufo” a prototype for use aboard ships. The “Folaga” operated on a frequency between 150 and 300 MHz (2 to 1 meter), while the “Gufo” operated between 400 and 750 MHz (75 to 40 cm). The performances offered by the two prototypes were excellent. During the testing of the “Folaga” conducted on the balcony of the EC in May 1943 an incoming American formation was sighted.
On an awakening which was nicknamed “Mobilization RaRi”, the “Folaga” was moved to full scale industrial production. The Italian industry (Marelli) was ordered to build 150 initial samples, still under the coordination of the EC, and the SAFAR was ordered to build 50 samples. Finally, economic resources were not spared, but what was missing was personnel. In Italy, neither radio research nor the training of personnel had been promoted, at all levels, including researchers, engineers, and technicians. Thus, in the “Mobilization RaRi” – due to war events, the damage inflicted to the factories by bombardments, in the best cases the decentralization of these factories – the results achieved were quite modest. Practically, before September 8th, 1943 only 13 “Gufo” and 4 “Folaga” were delivered to the Navy, plus four additional prototypes. “This attempt remained without positive result” (Tiberio, idim – 1951)
On September 8th, only 12 operational units were equipped with RADAR type E.C.3 Mark III (“Gufo”). On six of these, the apparatus had been installed only in the previous August. To these, one must add the units which received the German RADAR type Fu.mo24 or Fu.mo25. Documents indicated that all larger units under construction or repair at the date of the armistice were to receive RADAR, torpedo boats included.
It should also be remembered that as part of the “Mob RaRi” studies for the Air Force and the Army for the construction of airborne RADAR for naval surveillance and future counter electronics (jamming) were started. For the army, the intent was the land detection for the defense of the national territory. Thus were born prototypes derived from the original ones which were named “Argo”, “Vespa”, “Razza”, “Veltro”, “Lepre”, “Lince”. The last one produced in two versions: “Lince Vicino” and “Lince Lontano”. This last one, designed by Eng. Castellani of the SAFAR was used for night fighting and use aboard ships. Unfortunately, the paralysis experienced by the industrial establishment following the armistice, did not allow going past the production of some prototypes of the “Lince” built for the Air Force of the “Repubblica di Salт”.
The author was not able to determine how many Italian RDTs for coastal surveillance were ordered, delivered, and installed because the sources consulted give different figures since there were RADARs ordered by the Navy, by the Air Force, passed on to the Army, and so forth. In summary, it was not possible to further this research and remain within the intent of this paper which intends to be informative, not historical research.
In the industrial production the following people should nevertheless be remembered for their ideas and patents for specific components: Eng. Ernesto Monti (1936), Eng. Agostino Del Vecchio (1939), Eng. Arturo Castellani (1941), Prof. Francesco Vecchiacchi (1941), and Commander Pistoia (1942). There was no practical application of these projects, except part of the design by Del Vecchio on the RADAR “Lince” on which worked both Castellani and Vecchiacchi and which was developed and completed for the Air Force.
Although the completion of the RADARs “Gufo”, “Folaga” and “Lince” was in great part assigned to SAFAR, in Italy there were other manufacturers which, before and during the war, operated in the area of radio electronic. With Italian and foreign capital, there were the already mentioned SAFAR, the Allocchio Bacchini, the Radio Marelli, the IMCA Radio, the Philips Italiana, the Officine Marconi, the FIVRE and, from 1942, the Telefunken Italiana.
Even if the topic goes beyond the scope of this paper, a brief mention of the German RADAR should be made. Despite the fact that the Germans and Italians were allies, research from the two nations never established collaboration in the area of RADAR. Only in June 1940, after Italy entered the war and by order of Adm. Reader, the head of the Kriesgmarine, the Italian Navy received information regarding apparatuses built by Germany. A commission composed of three officers from the Naval Ordinance was sent to Germany from the 14th to the 28th of June, 1940 to acquaint themselves with the technological innovations regarding the war at sea. Captain Brandimarte, recently recalled to service after the limitation imposed by Fascist law on non-married people had expired, was part of this delegation. The topics covered and the material shown ranged from magnetic mines to electric torpedoes, magnetic fuses for torpedoes, protection systems for ship against these proximity device, and sweeping technology.
Amongst various things, the Italians were shown a new electronic system for the discovery of airplanes in flight. It was the land-based RADAR “FREYA”, not of the latest generation, and absolutely not utilizable aboard ships. Although the overall performances reached by this German apparatus were inferior to those of the Italian RDT3, some technical details were of particular interest to the researchers of the Institute EC. Nothing was instead shown or said of the RADAR for gun control type “Seetakt”, a real gem of the Kriegsmarine and for over a year installed aboard the Graf Spee (scuttled in 1939) and on the new battleships, pocket battleships, and two very new cruisers. The performances of this apparatus were not special, but for the time were quite respectable, especially at night. To close this brief discussion about the German RADAR and return to the main topic of this paper, one may conclude that the German contribution to the development of the Italian RADAR was quite modest since the transfer of some apparatuses which were installed aboard Italian ships was part of the contribution to the war effort, and not to the technological development of the RADAR.
Blaming those who throughout the years failed to see the importance of electromagnetic waves is useless. Bitterness remains, however, of having to realize how during the war this mental stubbornness cost human lives and materiel. It is our duty to dedicate special thoughts to the Italian researchers who, despite the difficulties, and perhaps even hostilities of who, instead, should have assisted them, carried on their duties.
Finally, to wrap up this synthesis of what happened in Italy in the arena of theoretical studies for the construction of the first RADARS, I would like to remember, with love, the two pioneers, Prof. Ugo Tiberio and Prof. Nello Cararra. After September 8th, 1943 they followed the Academy to Brindisi where they resumed their regular teaching assignments. They had nothing, but discovered the Academy was practically bordering the military airfield and near the border to the Academy were located damaged airplanes (flying fortresses, Liberators, etc.), excellent sources of material. This allowed them to continue, although in a very simple manner, if not the study at least the analysis of apparatuses and the technology employed aboard large aircrafts.
I was a student of both professors for over two years; in particular, I had the privilege of attending a class in which there were 16 students (12 from the Navy and 4 from the Army). We would sit around the table and a lesson would flow without even noticing it. I am referring to the academic year 1949-1950 at the Naval Academy in Leghorn during my specialization course in Telecommunications. Prof. Tiberio, who in the 3rd year (1943-1944) was a Reserve Major in the Navy (Naval Ordnance), taught us applied electronics for apparatus aboard ships, while in the specialization course he focused on radio finder. During his lessons, he would jump with extreme easiness from one topic to another and we had to make a special effort to follow him since, at the time, the were no textbooks nor printouts, and the topic covered could only be recapped with our own notes.
Carrara, who had been my physics professor during the regular course, in the specialization course taught us microwaves (as we mentioned, a word created by him). The peculiarity of these lessons was that, as with the other instructor, he would fill blackboards with equations and formulae with extreme, easiness, but the special thing about these lessons was that at the end, we were all able to follow him with great easiness, reaching the end of the lesson without having realized that time had passed. Furthermore, what he taught was very useful in other disciplines where the instructors were not as clear. “Physics”, the nickname someone had come up with for him at the Academy, always kept this name.
To give a quick insight on the vitality of Prof. Carrara, it should be remembered that in 1990 during the celebrations by his former students and assistants in the Navy, business, and at the University in his 90th birthday he was asked, “Professor, at your age, how do you move about from one point to another in the chaos of Florence? “Simple”, he replied, “I drive a motor scooter!”
I remember these two pioneers who created the Italian RADAR with great affection and I had the privilege of having them as instructors and getting to know them quite well. I would like to dedicate this summary to their memory.