Insidious Weapons

“Pig” or “Chariot”, SLC (Siluro Lenta Corsa)

The SLC (Slow Moving Torpedo) was the best known assault weapon of the Regia Marina during World War II. This new torpedo, nicknamed “maiale” (pig or hog, depending on the author), was equipped, amongst other things, with diving planes, ballast tanks, and compressed air for the release of ballast, thus allowing for full underwater navigation, just like a submarine.

SLC (Slow Moving Torpedo also knows as maiale or pig).
Museo Navale di Venezia, Italy.
(Photo Cristiano D’Adamo)

The models built after the original 1936 prototype employed an electric motor with power increased from 1 to 1.6 HP. Batteries were increased to a total of 150 Amp. Specific efforts were made in bettering equipment; a magnetic compass, for instance, was preferred to a gyroscopic one, due to the difficulties encountered in miniaturizing such a complex device. The magnetic compass was improved, rendering it less susceptible to magnetic interference.

Tail section.
Museo Navale della Spezia, Italy.
(Photo Cristiano D’Adamo)

The breathing apparatus used by the operators was also notably improved. After having noted the unreliability of the Davis hoods used on submarines, studies were began on specific apparatuses capable of providing longer autonomy and complete safety.

To avoid bubbles rising to the surface, which would have revealed the presence of a diver, the Regia Marina employed special devices, specifically built by Pirelli, which utilized a sealed system. These breathing apparatuses were not fueled by compressed air, but instead used pure oxygen. The use of oxygen eliminated the presence of bubbles since it did not produce exhaust gases. During breathing, the expended oxygen is turned into carbon dioxide (CO2) which is then purified by a lime-based filter (sodium carbonate and lime). A closed system allows for the apparatus to function until the lime is saturated and cannot any longer absorb the carbon dioxide (CO2). The ARO, as it was designated by the Navy, eliminated the risk of the bends typical of the compressed air apparatus (designated as ARA), and the fastidious decompression stages required during ascent.

Head gear.
Venice Naval Museum, Italy.
(Photo Cristiano D’Adamo)

Nowadays we know that breathing pure oxygen stresses the central nervous system and can cause epileptic episodes, but no one recollects such occurrences during the training conducted by the Italian divers. Therefore, it is believed that the oxygen in use was not 100% pure. As a matter of fact, it is recorded that divers experienced “breathlessness” typical of carbon dioxide (CO2) intoxication. Regardless, divers experienced some maladies caused by oxygen breathing at certain depths. The maximum submerged depth of an ARO apparatus should have not exceeded -15 meters (- 45 feet), but it was known that depths of up to -30 meters (-90feet) were often reached.

Adapted from: ‘Imagini di Storia – Decima MAS: I mezzi d’assalto della Marina Italiana – N7 gennaio 1995

Modified Touring Boat MTM – Barchino

Also known as “barchini” (little boats), the M.T.M represented an evolution of a fast surface attach vessel conceived in 1936 as the M.A. (assault motorboat) and the M.A.T. (airborne assault motorboat) and built in 2 exemplars by the Biglietto Varazze shipyard. The same shipyard, in 1938-39, built two series of the new type M.T.; the first of 6 units, and the second, slightly larger and with motor of 95HP, of 12 units.

Venice Naval Museum, Italy.
(Photo Cristiano D’Adamo)

This last experience allowed, in 1940-42, for the tuning and the construction of the M.T.M. of which about 50 were built. From the M.T.M. derived, in 1942-43, the M.T.R. and the M.T.R.M. of which about 20 were laid down, but only one entered service with the navy of the Republica Sociale Italiana.

Venice Naval Museum, Italy.
(Photo Cristiano D’Adamo)

Admiral Iachino, in his book “Sunset of a Great navy” describes the M.T.M. as small motorboat-torpedo (M.T.S.M. invented by Capt. Guido Cattaneo), and commonly known as “barchini”, piloted by a single man who would through himself into the water about 100 meters before hitting the target, abandoning the vessel in full speed.

Venice Naval Museum, Italy.
(Photo Cristiano D’Adamo)

Adapted from: “Imagini di Storia – Decima MAS: I mezzi d’assalto della Marina Italiana” – N7 January 1995

Modified and Enlarged Touring Boat – MTMSA

After the construction of the first “barchini” (small boats) M.T.S. (Modified Torpedo Touring Boats) in summer of 1941, the Regia Marina studied some improvements which produced the the M.T.S.M.A., an enlarged version of the previous model. The first version had a displacement of 1.75 tons and dimensions of 7.1 x 2.1 x 0.5 meters. The engine was a gasoline-powered 90HP which produced a maximum speed of 28 knots with an range of 90 miles.

Museo Navale della Spezia, Italy.
(Photo Cristiano D’Adamo)

In the “modified” version, produced in 1941, the displacement was increased to 3 tons and the dimensions to 8.4 x 2.2 x 0.6 meters. The power plan was doubled and the output was increased to 190 HP total for a speed of 32 knots and a range of 200 miles. The version M.T.S.M.A. was further improved with the installation of a single cabin for both operators which differed from the previous version which had two distinct cockpits built in tandem.

Museo Navale della Spezia, Italy.
(Photo Cristiano D’Adamo)

Translated from: “Imagini di Storia – Decima MAS: I mezzi d’assalto della Marina Italiana” – N7 gennaio 1995

Naval Guns Database

TypeUsemmInchesCaliberMakerYearWeight KgAngle of ElevationAngle of DepressionVelocity MphPressure AtmProj. Weight KgRange MetersRate of Fire
Machine GunLight Units401.5739Vickers-Terni191580-56101.34400200
Machine GunLight Units401.5739Vickers-Terni191780-56101.34400200
Machine GunAll Units371.4554Breda193280-108001.64000200
Machine GunAll Units371.4554Breda193880-108001.64000200
Machine GunAll Units371.4554Breda193990-108001.64000200
Machine GunAll Units200.7965Breda1935100-1083026000.32500240
Machine Gun200.7970Scotti-Isotta Fraschini1939100-108400.322500230
Machine Gun200.7970Scotti-O.M.1941100-108400.322500230
Machine GunAliseo, MAS200.7965Flakvierling mod. 3814509009200.322800300
Machine GunAll units13.20.52Breda193185-1179026000.122000500
Machine GunAll units80.31Breda193780-107802.9000000000000001E-21000460
Machine GunLight Units6.50.26FIAT193580-107502.9000000000000001E-21000600
Machine GunSimilar to the FIAT 19356.50.26Colt191580-108002.1999999999999999E-2800
Machine GunMAS6.50.26Breda193580-106202.1999999999999999E-2800500
Large Caliber – Naval GunBattleships of the “Littorio” class3811550Ansaldo and O.T.O.193435-58703700882428001.3
Large Caliber – Naval GunBattleship Cavour32012.644Ansaldo and O.T.O.193427-58303100525286002
Large Caliber – Naval GunBattleship Duilio32012.644Ansaldo and O.T.O.193630-58303100525294002
Large Caliber – Costal DefenceBarge GM. 1943811540Armstrong-Vickers19147008841.2
Large Caliber – Costal DefenceOlder guns from the battleships of the Cavour and Duilio class3051246Armstrong-Vickers190920-5860452180002
Large Caliber – Costal DefenceUsed on barges and costal defences3051246Armstrong190425-5780417140002.1
Large Caliber – Costal DefenceHowitzer3051217Tipo G mod. 176520412442145000.2
Large Caliber – Costal DefenceMortar208119Mod. 14756369217.690000.2
Medium Caliber – Naval GunHeavy cruiser Zara203853Ansaldo192745-59003200290003.8
Medium Caliber – Naval GunHeavy cruiser Bolzano203853Ansaldo192945-59003200290003.8
Medium Caliber – Naval GunHeavy cruisers Trento and Trieste203850Ansaldo192445-58402800882280003.4
Medium Caliber – Naval GunObselete gun in used on older units203845Armstrong18977901163
Medium Caliber – Naval GunOld cruiser San Giorgio1907.545Armstrong190825-786490.9220003.2
Medium Caliber – Naval GunBattleship Littorio and light cruisers of the Garibaldi class.152655Ansaldo193445-5925360049.5257004.5
Medium Caliber – Naval GunBattleship of the Littorio class (Vittorio Veneto and Roma)152655O.T.O.193645-5925360049.5257004.5
Medium Caliber – Naval GunLight cruisers class Da Barbiano, Eugenio, Montecuccoli152653Ansaldo19268500045-5935307047.5226005
Medium Caliber – Naval GunLight cruisers class Cadorna, Aosta, Attendolo152653O.T.O.19298500045-5935307047.5226005
Medium Caliber – Naval GunFormer German cruisers Bari, Taranto1495.843Krupp191423-10890240045.3176007
Medium Caliber – Naval GunFormer German cruisers Bari, Taranto1495.843Krupp191635-10890240045.3176007
Medium Caliber – Naval GunBattleship of the Duilio class1355.345Ansaldo193745-7825882196006
Medium Caliber – Naval GunLight cruisers class Capitani Romani1355.345O.T.O.193845-7825882196006
Medium Caliber – Naval GunDestroyers class Navigatori, Dardo, Folgore1204.750Ansaldo 19262023845-10950315023.496
Medium Caliber – Naval GunDestroyers class Maestrale, Oriani, Soldati1204.750O.T.O.19311765035-10950310023.49182006
Medium Caliber – Naval GunDestroyers class Maestrale, Oriani, Soldati1204.750O.T.O.19332280033-7950310023.49182006
Medium Caliber – Naval GunDestroyers class Maestrale, Oriani, Soldati1204.750O.T.O.19362280033-7950310023.49182006
Medium Caliber – Naval GunBattleship of the Cavour class1204.750O.T.O.19332280042-10950310023.49190006
Medium Caliber – Naval GunDestroyers class Soldati1204.750Ansaldo 19362160040-10950315023.49190006.2
Medium Caliber – Naval GunDestroyers class Soldati II1204.750Ansaldo 19372160040-10950315023.49190006.2
Medium Caliber – Naval GunArmored Train1204.750Canet-Schneider-Armstrong1918893030-5850315023.15134007
Medium Caliber – Naval GunDestroyers class Leone and colonial sloop Eritrea1204.750Canet-Schneider-Armstrong1918893032-5850315023.15154006
Medium Caliber – Naval GunAuxiliary cruisers1204.750Armstrong1918988830-5750315023.15126007
Medium Caliber – Naval GunAuxiliary cruisers1204.750Armstrong1918893030-5750315023.15126007
Medium Caliber – Naval GunDestroyers class Sauro, Turbine1204.745Vickers-Terni19241690033-10850315023.15145007
Medium Caliber – Naval GunDestroyers class Sella1204.745Vickers-Terni19261690033-10850315023.15145007
Submarine GunBalilla, Fieramosca, Micca, Calvi1204.745O.T.O.193132-422140008
Medium Caliber – Naval GunBattleships of the Littorio class, Auxiliari ships and costal defences1204.745Armstrong1891845032-770019.75120006
Medium Caliber – Naval GunBattleships of the Littorio class, Auxiliari ships and costal defences1204.745Armstrong1889845032-770019.75120006
Medium Caliber – Naval GunDestroyers of Maestrale, Oriani, Soldati class and heavy cruiser Zara1204.745O.T.O.1933161050-540019.864008
Small Caliber – Naval GunTorpedo boars of the following classes: Generali, Sirtori, La Masa, Palestro, Curtatore102445Schneider-Armstrong1917460035-584016150007
Small Caliber – Naval GunOld destroyers of the Generali, Sirtori, La Masa, Palestro, Curtatore class102445Schneider-Armstrong1919460035-584016150007
Small Caliber – Naval GunOld destroyers of the Mirabello class and other minor units102445Canet-Schneider1917460030-588816146007
Small Caliber – Naval GunTorpedo boats of the Pilo, Audace and old submarines102435Schneider-Armstrong-Ansaldo1914500045-575516120007
Small Caliber – Naval GunTorpedo boats of the Spica, Orsa, Aliseo, Ariete class and corvettes of the Ape class1003.947O.T.O.1935631045-685513.81540010
Small Caliber – Naval GunTorpedo boats of the Spica, Orsa, Aliseo, Ariete class and corvettes of the Ape class1003.947O.T.O.1935631060-1085513.81540010
Small Caliber – Naval GunTorpedo boats of the Spica, Orsa, Aliseo, Ariete class and corvettes of the Ape class1003.947O.T.O.1931631045-685513.81540010
Submarine GunSubmarines1003.947O.T.O.1931460032-584013.8126008
Submarine GunSubmarines1003.947O.T.O.1935460032-584013.8126008
Submarine GunSubmarines1003.947O.T.O.1938460032-584013.8126008
Small Caliber – Naval GunSubmarines and light units1003.947O.T.O.1928440032-590013.8126008
Small Caliber – Naval GunBattleships of the Cavour class, cruisers of the Condottieri class and old cruiser San Giorgio1003.947O.T.O. (Skoda)19241500080-585013.8152408
Small Caliber – Naval GunBattleships of the Cavour class, cruisers of the Condottieri class and old cruiser San Giorgio1003.947O.T.O. (Skoda)19271500085-588013.81524010
Small Caliber – Naval GunBattleships of the Cavour class, cruisers of the Condottieri class and old cruiser San Giorgio1003.947O.T.O. (Skoda)19281500085-588013.81524010
Submarine GunSubmarines1003.947O.T.O.1924460035-5800279013.8110008
Submarine GunSubmarines1003.947O.T.O.1927460035-5800279013.8110008
Small Caliber – Naval GunBattleship of the Littorio, Duilio class903.550Ansaldo-O.T.O.19391907275-3845357010.11600012
Small Caliber – Naval GunBattleship of the Littorio, Duilio class903.550Ansaldo-O.T.O.19381907275-3860357010.11600012
Small Caliber – Naval GunMinor units76340Armstrong1916270042-106806.51000010
Small Caliber – Naval GunMinor units76340Armstrong1917270042-106806.51000010
Small Caliber – Naval GunMinor Units76340Ansaldo-R.M.1916297265-106906.021000012
Small Caliber – Naval GunMinor Units76340Ansaldo-R.M.1917303275-107606.021000012
Small Caliber – Naval GunMinor Units76330Armstrong1914260042-105504.28600012
Small Caliber – Naval GunVedetta76323Ansaldo191845-104204.28500012
Small Caliber – Naval GunLanding Units76317Schneider19121063753.3
Small Caliber – Naval GunAquila (carrier), Capitani Romani, Etna652.564Ansaldo-Terni193980-10950750020
Small Caliber – Naval GunAurora572.200000000000000243Nordenfelt188715-106652.974005
Small Caliber – Naval GunSan Marco landing troops471.8532Terni-O.T.O.193556-156301.5700012
Small Caliber – Naval GunSan Marco landing troops471.8532Breda193956-156301.5700014


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.

Armored Trains

Throughout World War I, armored trains were one of the principal means of defense against Austrian ships in the upper Adriatic, and were particularly used in the final stages of the conflict. Practically, at least one train was always on the move along the higher risk areas of the coastline. Naturally, these trains served more as spotters and means of first reaction rather than real defense because they were poorly armed, and therefore quite vulnerable. At the end of the conflict, all armored trains were disarmed and converted to civilian use.

An armored traini Breda Mod. 37 with a 47/32 Mod. 1935 gun.

During the arms race of the 1930s, when conflict with France appeared very probable, it was thought that armored trains could be of use and therefore it was ordered the construction of 8 armored trains with two logistical bases: La Spezia and Taranto (the two largest naval bases). In August 1939, two Command Groups Armored Trains were constructed under the authority of two C.C.; one in Liguria, with headquarters in Genoa, and one in Sicily, with headquarters in Palermo. These two regions were the closest to French territories from which could have easily originated both naval and aerials attacks (Tunisia to the south and Provence to the northwest). On April 15th, 1940, assuming Italy’s imminent entry into the war, the trains were placed in full war conditions as dictated by the mobilization act.

A train ready for action had, in addition to the railroad personnel, three officers and a variable number of crewmembers based on the train’s firepower. At the very most, it would include 25 non-commissioned officers, and 101 petty officers and ratings. The makeup of the trains varied over the years, evolving from the experience meantime acquired; the final layout included 1 locomotor (at one of the two ends), 4 to 6 cars for heavy guns, 2 flat cars for the machine guns, 1 car for the fire control equipment, 1 car for ammunitions, 2 cars for additional ammunitions, 1 car for administrative use, 2 cars for housing, 1 car for the kitchen, 1 car for baggage, 1 car for spare parts, and another locomotor (at the other end).

On June 10th, 1940 there were 9 armored trains with naval guns and 3 with antiaircraft guns; the latter, statically placed, assisted with the antiaircraft defenses in the area where they had been located. The other trains used their antiaircraft guns only in self-defense. The two groups of armored trains were organized as follows:

Group based in La Spezia:

T.A. 120/1/S with 4 120/45 mm and 2 13.2 mm machine guns
T.A. 120/2/S with 4 120/45 mm and 2 13.2 mm machine guns
T.A. 120/3/S with 4 120/45 mm and 2 13.2 mm machine guns
T.A. 120/4/S with 4 120/45 mm and 2 13.2 mm machine guns
T.A. 152/5/S with 5 152/40 mm and 2 13.2 mm machine guns
T.A. 76/1/S with 6 76/40 mm and 2 13.2 mm machine guns

Group based in Taranto:

T.A. 152/1/T with 4 152/40 mm, 2 76/40mm and 2 13.2 mm machine guns
T.A. 152/2/T with 4 152/40 mm, 2 76/40mm and 2 13.2 mm machine guns
T.A. 152/3/T with 4 152/40 mm, 2 76/40mm and 2 13.2 mm machine guns
T.A. 152/4/T with 4 152/40 mm, 2 76/40mm and 2 13.2 mm machine guns
T.A. 102/1/T with 6 guns 102/35 and 2 13.2 mm machine guns
T.A. 76/1/T with 4 guns 76/40 and 2 13.2 machine guns

These trains were deployed as follows:

In Liguria 5 T.A. in Vado, Albenga, Albissola, Cogoleto, Recco and an antiaircraft T.A. in Sanpierdarena

In Sicily 4 T.A. in: Carini, Termini Imerese, Crotone, porto Empedocle, and Antiaircraft A.T in Syracuse and Porto Empedocle.

In August 1940, following the armistice with France, two trains with 120/45 guns were transferred from Liguria to Sicily and Calabria, while another one, at the beginning of the campaign against Greece, was sent to Puglie. In November 1941, it was decided to replace the two a.a. (antiaircraft guns) 76/40 guns on each of the T.A. 152 in Taranto with 20 mm machine guns. The eight guns made available were used to arm new trains with 4 76/40 guns and 2 20 mm machine guns each; these new trains were the 76/2/T and T.A. 76/3/T and were assigned to Licata and Mazara del Vallo.

During the conflict, armored trains intervened several times against enemy ships, while during the land offensive against France they were used against bunkers on the Ligurian-French border. These trains had special depots in which they were kept ready to move with the locomotors fired up. In case of alarm, the decision to stop all traffic on the rail line was solely up to the train’s commander, as was the reopening of the line to commercial traffic.

On July 1st, 1943, at the beginning of the Allied landing in Sicily, there were 10 armored trains located as follows:

T.A. 152/1/ T in Termini Imprese
T.A. 152/2/T in Carini
T.A. 102/1/T in Syracuse
T.A. 120/3/S and T.A. 76/1/T in Porto Empedocle
T.A. 76/2/T in Licata
T.A. 76/3/T in Mazara del Vallo
T.A. 120/4/S in Catania
T.A. 120/1/S in Sidereo
T.A. 152/3/T in Crotone.

Practically, all these trains were lost during the Sicilian campaign; only single cars from some of the trains were transported to the mainland where they were used as stationary batteries.

An Italian armored train hit near Licata, Sicily

Only the armored trains left in Liguria were utilized up to the armistice, continuously moving along the coast; at least two were later utilized by the Germans.

Translated by Cristiano D’Adamo and edited by Laura K. Yost

Antisubmarine Warfare

In the period between the two world wars, of the various weapons used by the Regia Marina, the anti submarine ones were those which benefited the least from any technological improvement. In his official book “Organizzazione della Marina durante il conflitto” (Organization of the Navy during the Conflict”, Admiral Giuseppe Fioravanzo clearly states that between the end of World War I and 1936, the Italian Navy dedicated almost all of its resources solely to the development of ballistic weapons. During the conflict, ballistic weapons (guns) would be the least successful, while less conventional weapons, such as the “maiali,” scored the greatest successes.

Underwater bomb of the type BAS with a charge of 75Kg. of TNT – Museo Navale della Spezia, Italy
(Photo Cristiano D’Adamo)

At the beginning of the hostilities, enemy submarine activity was so minimal that not much attention was placed on the improvement of the few available weapons. Simply, the Regia Marina relied on defensive minefields and patrols conducted by torpedo boats equipped with depth charges and trailing torpedoes. The only unit specifically built for antisubmarine activities was the Albatros, laid down in Palermo’s shipyards in 1934.

Depth Charge
(Photo Cristiano D’Adamo)

The detection of enemy vessels, which up to the 30’s had relied solely on the use of a mechanical hydrophone (Tubi C also known as idrofoni meccanici) was substantially improved with the introduction of an electronic amplifier and headsets. Later equipment allowed for direction finding, a feature initially missing. In 1931, some units were also equipped with echofinders of the Langhiria-Florison type. Later evolution of this device would become standard equipment aboard torpedo boats and corvettes. These devices had a range of only 2000 meters and an error of up to one degree (0.3%).

Underwater bomb model de Quillac F/35t used in obstruction nets – Museo Navale della Spezia, Italy –
(Photo Cristiano D’Adamo)

Once localized, an enemy submarine would be attacked using B.T.G. (bomba torpedine da getto). These weapons would be either dropped or launched by the pursuer and, once in the water, would immediately sink under their own weight and then explode at a predetermined depth. Either a depth actuated switch or a timer actuated the trigger.

The principal models employed were the B.T.G. 100/1927 built by Moncenisio and loaded with 100 Kg. of TNT and a hydrostatic fuse (depth actuated). Predetermined depth settings were set at 25, 50, 75 and 100 meters. Another model, also by Moncenisio, was the B.T.G. 50/1917, 1927 with a charge of only 50 Kg, hydrostatic fuse, and setting for 20, 40, 70 and 100 meters. It is to be noted that there are historical references to lesser common models, such as the B.T.G. 50/1930, also by Moncenisio with a charge of 50 Kg and a diameter of about 30 cm.

The depth charges could be deployed by several means.

  • Tramoggia singola (Mud Hopper) Capable of launching a single charge
  • Tramoggia Multipla (Multiple Mud Hopper) Capable of launching a cluster of weapons at once.
  • Scaricabombe (Discharger) Capable of deploying a salvo of multiple weapons
  • Ferroguide (Railings) Railing for the spacing of weapons, practically capable of discharging the entire ordnance.

In the case of multiple launches, the charges would have different buoyancy, thus sinking at a different speed and therefore covering a greater area.

Pneumatic thrower 432/302 mm.
(Photo Rastelli)

Another weapon used by the anti submarine units was the towed torpedo of which several variances were available; notably the TR 1917, 1927, 1936, 1937 all having different weights and payloads. These weapons were towed by the unit at a depth ranging between 37 and 95 meters and would explode upon contact. Later models were equipped with magnetic fuses.
During the war, when the shortcomings of the antiquated Italian industry became evident, Italy began importing German weapons. These depth charges designated as W.B.D. had a charge of 125 Kg, while the W.B.F. had a smaller charge of 60 Kg. A thrower made by Krupp could deploy these depth charges easily and economically by propelling them upward and outward utilizing a small pyrotechnical charge These launching devices were known to be small, practical and highly reliable.

Discharger and towed torpedo on the R.N. Sirio

During the war the manufacturing company Laerte dell’Olio of La Spezia was contracted for the construction of new charges of 30, 100 and 150 kilos. New to the scene was also a thrower built by Menon of Roncade and used for the deployment of the German W.B devices which, unfortunately for the Italians, became in very short supply starting in 1942. Other companies involved in the research and development of new weapons were the Pignone, Bargiacchi and the already mentioned Moncenisio.


With the generic term of mine, the Regia Marina classified a series of static underwater weapons designed to explode upon contact with the hull of a ship. Later, this definition was broadened to include all new triggering mechanisms which, instead of physical contact with the target, were activated by magnetic influence, acoustics or water pressure.
Mines evolved dramatically during the beginning of the century when a laborious manual deployment process was replaced by an automatic mechanism which would precisely deploy the weapon. One of the Italian pioneers in this area was Emanuele Elia (1866-1935), a Lieutenant in the Regia Marina who, after leaving the Navy, dedicated himself to technical studies. Another pioneer was Admiral Gerolamo Bollo (1866-1931), a specialist of underwater weapons. During World War I, Bollo and Elia mines were equally used and both models were substantially improved.

In 1936, the Regia Marina introduced the P 200 built by Pignone(1) of Florence. This was a much-improved model which, after the beginning of the hostilities, would be further modernized by the introduction of the antenna(2), thus greatly improving its effectiveness. At the beginning of the hostilities, Italy had almost 25,000 mines distributed amongst several naval bases from La Spezia to Massawa. As with many other ordnance and war material in general, these weapons were not available in sufficient quantities and, later in the war, Italy had to resort to German mines.

Italy entered the war with the following models:

Elia V.E. (Vickers – Elia) with 145 Kg of explosive.
Bollo Type B with 125 Kg of explosive, later increased to 130 Kg.
P 200 Pignone with Kg. 200 of explosive.
Coloniale P 125 similar to the P 200 but with only 125 Kg of explosive and a maximum depth of 200 meters. Specifically built for tropical waters with a greater buoyancy to allow for the formation of barnacles
C.R. (Reduced characteristics) Similar to the P 200 but with only 150 Kg of explosives, a maximum depth of 200 meters and only two settings, 4 and 9 meters.
T 200 (Tosi) used by submarine of the classes Atropo and Bragadin.
P 150 used by submarines of the class Foca

Also available were some older models, mostly left over from the previous war:

Harlè a French model with a charge of 100 Kg.
C. 15 an Austrian model also with a charge of 100 Kg.

In February 1941, following the conference of Merano, Germany began providing the Regia Marina with several shipments of mines of the following models:


These last ones were of the very effective magnetic type. In total, Italy received 12,224 German mines.

Mines were generally of two kinds: moored and ground. The moored mines were designed to operate at a predetermined depth, while the ground mines would lie on the ocean floor. It should be noted that a drifting mine would be nothing else but a moored mine which had lost its anchor, and that the Regia Marina did not intentionally employ any such device. Some British sources report the existence of two Italian drifting mines, the IN and IO, but no reference can be found in the official Italian documentation.

Mines were usually activated on contact. Most moored mines were of this kind. The mine, usually of spherical dimension, was equipped with spikes, called hertz horns which, once touched, would cause the weapon to detonate. Later, following the example of other navies, the Regia Marina introduced mines which could be remotely triggered by a nearby magnetic field, sound or change in water pressure. Some special purpose mines were also produced and they were designed to operate for a determined period of time and then self-destruct. Magnetic mines were activated by the magnetic field of a ship, also known as the magnetic signature. This force was relatively miniscule, usually around 50 milligause, but tended to be similar amongst different kinds of ships.

To provide for defense against this new kind of weapon, the Royal Navy experimented with a degaussing system first employed on the cruiser Manchester and later on the passenger ship Queen Elisabeth. Later, British scientists developed several mine sweeping technologies including, an airborne one installed on Wellington bombers, which was used to remove German mines from the Suez Canal.

The moored mine represented the vast majority of the type used. The depth of the weapon would be configured based on the intended target. An anti-submarine mine would usually be placed between 8 and 9 meters, while an anti-ship one would be moored between 3 and 4 meters from the surface of the water. The mooring cable could extend up to 800 meters from the ocean floor. The low tide of the Mediterranean would facilitate the accuracy of these settings. Mines were susceptible to bad weather conditions and the most common failure was the breakage of the mooring cable. The resulting drifting mine could easily float for over a year and then succumb to the weight of the marine vegetation which would inevitably form around it, causing it to sink.
Mines were laid both defensively and offensively, and usually anti-submarine mine fields required less powerful charges. These fields could assume several shapes, from single line to a serpentine, parallel lines or multiple lines at various intervals. Most of the older models were used defensively, while the P 200 was the primary offensive weapon. Submarine-laid mines, due to the unusual delivery system, were slightly different and, employed additional safety devices such as the “salt of ammonia” safety pins which, once dissolved in salt water, would activate the weapon.

For the deployment of mines, the Regia Marina employed several units, from ferry boats, to mine-layers, from submarines to cruisers. Most units were equipped with removable railing. Mines were equipped with small casters, which would fit these railings, thus easing the process of pushing the mines towards the stern of the ship from which they were usually deployed. This mechanism was not fool proof and many derailments were actually reported. With the introduction of German mines, the original Italian railings had to be modified to support these new mines which had a different gauge. It is reported that the Germans demanded that the removable railing be welded, thus reducing the possibility of derailment. Naturally, welded railing could not accommodate Italian mines.

All mines were properly marked with a unique serial number to allow for quick identification. A mine found adrift would first be identified and then exploded. Using the serial number, naval authorities could identify the origin of the weapon and eventually restore the minefield. Mines are non-discriminatory weapons which could easily strike friend and foe alike. Italian minefields were in general accurately mapped and, especially at the beginning of the conflict, properly advertised.

The successes of both the defensive and offensive fields deployed during the war should be considered adequate. Quite relevant is the large number of British submarines sunk by Italian mines. Also relevant is the fact that the famous Malta-based H force was nearly destroyed by an Italian minefield.

(1) Founded in 1842 as a foundry, it is currently known as “Nuovo Pignone” and fully owned by GE.
(2) A remote triggering device.

Torpedo Launchers

The torpedo launching equipment used on Italian ships during World War II was basically two types of both 533 mm and 450 mm.

Submarine tube with a restricting cage for smaller torpedoes.

Axial boost (the torpedo is pushed forward):
Underwater torpedo launchers, not movable and installed on submarines.
Deck mounted torpedo launchers: fixed and not installed on surface vessels, including motor torpedo boats.

Lateral boost (the torpedo is pushed laterally)
Installed on MAS, VAS and MS.

On the submarine-installed torpedo launchers the expulsion of the weapons was obtained through the introduction of compressed air. On later models, called “bubbles,” a mechanism was to capture the air, but it never functioned properly. On most Italian submarines, tubes were divided between bow and stern and were of the fixed type. On smaller submarines (called pocket subs), the torpedoes were installed in external torpedo launchers which were sealed by a cup and in which the weapon would float and leave under its own power.

Triple launcher on the Ariete
(Photo Elio Ando`)

On surface vessels the expulsion of the weapons was usually obtained through compressed air generated by a small pyrotechnic charge. These launchers were usually of the kind mounted on deck and were movable. They could have a single, double, triple or quadruple set of tubes. Some fixed models were also used, such as the 533mm ones used on motor torpedo boats (MS) which had one tube installed on each side, and similar ones installed on the “Trento” class cruisers which had four twin apparatuses installed on deck, two on each side.

Generally speaking, on surface vessels the tubes were of the following types:

Single, on some torpedo boats.
Double, on torpedo boats, older destroyers and light cruisers.
Triple, on newer destroyers, light cruisers and the torpedo boats of the “Ariete” class.
Quadruple, on the heavy cruisers and on the light cruisers of the “Capitani Romani” class.

Usually, the single tubes were installed two on each side. The double and quadruple tubes on some torpedo boats and on light cruisers were mounted one on each side, but newer destroyers and torpedo boats had them mounted centrally.

The later lateral boost launchers were powered by compressed air. This equipment, invented by Commander Masini, was very simple, light in weight and specifically suitable for use on the small and fast MAS. This installation was peculiar to the MAS and appeared on the American PT.s in 1943-44, undoubtedly a practice that had originated from the Italian design.

The equipment used by the Regia Marina was built by numerous companies, but they were generally designed by only four: Whitehead, S.I. (Silurificio Italiano), San Giorgio or Bargiacchi.

Adapted from “Le Armi delle Navi Italiane Nella Seconda Guerra Mondiale” by Erminio Bagnasco published in 1978 by Ermanno Albertelli – Parma
“Naval Weapons of WW II” by John Campbell, pupished by Conway Marittime Press


On June 10, 1940 the Regia Marina had a total of 1.450 torpedo launchers installed on units of all categories. There were 3.650 torpedoes available, both 533-mm and 450-mm models, for an average of over 2,5 weapons per torpedo launcher.

Model W (Whitehead) 270/533 x 7.20
A Warhead, B Tanks, C Heater, D Stern, E Tail

Nevertheless, this average was down to only 1,5 weapons per launcher on submarines and more modern surface vessels. There was, in fact, a surplus of antiquated 450-mm torpedoes but these models could only be used on older vessels, while the 533-mm models were barely available.

Whitehead W200/450, Museo Navale della Spezia, Italy.
(Cristiano D’Adamo)

Before the hostilities, the Regia Marina gave a notable boost to the production of torpedoes and improved the facilities for the maintenance, tuning and storing of these weapons.

Tail unit of an airborne torpedo – Museo Navale della Spezia, Italy.
(Cristiano D’Adamo)

In 1940, Italy had three manufacturing facilities specialized in the construction of torpedoes:

  • Silurificio Whitehead of Fiume, the oldest factory in the world, founded in 1860.
  • Silurificio Italiano in Baia, near Naples, operating since 1915.
  • Silurificio Motofides built near Livorno in 1937 as a secondary facility of the plant in Fiume.

Altogether, from June 10th, .1940 to September 9th, 1943 Italian units expended over 3,700 torpedoes, mostly of the newer type:

  • 546 in 1940
  • 1,185 in 1941
  • 1,600 in l942
  • 350 in 1943

The torpedoes in service in the Italian Navy during World War II were, as those of most other navies, of two caliber: 533,4-mm (21″) and 450-mm (17,7″). A few dozen weapons of French origin, caliber 550-mm, constituted the only exception. (21,7 “) and 400-mm. (15”) torpedoes were used on some French and Yugoslav units captured during the war.

Section: A 140/450 1917, Museo Navale della Spezia, Italy.
(Cristiano D’Adamo)

Excluding a few French weapons, and about ten German torpedoes of the type «G.7e» of 553 mm received in 1942, all the torpedoes employed by the Italian units were of domestic origin. Almost all weapons were propelled by over-heated air, with a reciprocal engine. This engine was a for-cylinder Brotherhood on the older models, a two cylinder on the W models and a two-row eight cylinder radial on the SI. Later, SI introduced an eight-cylinder in line, and it is thought that a V-12 was also considered. In the mid 30s both Whitehead and the Silurificio Italiano succeeded in designing a 533mm torpedo capable of 50 knots over 4,000 meters, and a 450mm torpedo capable of 42 knots over 3,000 meters.

Despite these excellent results, which gave Italy world supremacy in heated air torpedoes, this technology was surpassed by pure oxygen or oxygenated mixtures. The Regia Marina decided, after several trials, to also reduce the maximum speeds respectively to 48 and 40 knots to assure greater safety and better reliability. Notwithstanding, having succeeded in bringing the air pressure up from 200 to 220 kgs./cmq, thanks to a notable improvement in construction, the Italian weapons were able to provide the following performances:

533 MMS: 4.000 MT. @ 50 knots for subs and 10.000 mt. @ 40 knots for cruisers and destroyers.
450 MMS: 4.000 MT. @ 42 knots for Subs and Mas and 7.000 mt. @ 35 knots for torpedo boats.
As already mentioned, since the availability of 450 mm weapons was much higher in comparison to those of 533 mm, several units were equipped with 533 mm «reducing cages » to allow for the employment of 450 mm weapons.

SI 270/533 4×7.2.
(Photo Aldo Fraccaroli Collection)

The Italian torpedoes were equipped with fuses of the type “inertia pendulum”, which would go off when the weapon hit against the hull of a ship (with a limit of 15 degrees and 5 knots). Such type remained the standard for almost all the duration of the conflict. Only in 1942 did Regia Marina start introducing fuses of the magnetic type «S.l.C.» produced by the Silurificio Italiano.

In the same period, Italy started employing on submarines German torpedoes type «G.7e» with magnetic fuses. This weapon did not generate a wake and was extremely efficient, but available in limited quantities.

In general, Italian torpedoes were very satisfactory and they did not have the well-known technical problems experienced by both the American and German models. As a matter of fact, the US Navy used some captured Italian torpedoes to study ways of improving their own models.

Adapted from “Le Armi delle Navi Italiane Nella Seconda Guerra Mondiale” by Erminio Bagnasco published in 1978 by Ermanno Albertelli – Parma
“Naval Weapons of WW II” by John Campbell, published by Conway Marittime Press

Technical Specifications

MakerCharge (Kg.)CaliberLength Speed Range YearSubCruiserDestroyerTorpedo BoatMASAerial
W = Whitehead    S.L = Siluricifio Italiano
W270533.47.2 F 48.0 4K37XXX
38.0 10K
W250533.47.5 Veloce 50.0 4K36XXX
30.0 12K
W260533.47.20 50.0 4K34XXX
30.0 12K
S.L.270533.47.2 I 48.4 4,000 37XXX
38.0 10K
S.L.270533.46.84 L 50.0 4K 35X
38.0 8K
W270533.46.84 48.0 4K 35X
38.0 10K
W300533.46.84 41.0 4K29X
28.0 10K 
W260533.46.86 43.0 4,000 30X
30.0 10,000 
W260533.47.20 42.0 4K 29XXX
26.0 10K
S.I250533.47.5 A 40.0 3K30X
26.0 12K
W250533.46.50 43.0 3,000 1927X
28.0 10,000 
W250533.46.50 40.0 4,000 1925XXX
27.0 10,000 
W250533.47.50 42.0 4,000 1925XXX
24.0 10,000 
W2004505.75 44.0 3,000 1935XX
30.0 8,000 
W2004505.70 43.7 2,000 1932XX
27.5 8,000 
S.I.1704505.25 41.0 4,000 1934XXX
30.0 8,000 
W1704505.46 42.0 4,000 1934XX
– – 
W2004505.45 40.0 4,000 1936XX
30.0 8,000 
W1704505.53 44.0 2,000 1926XX
29.0 6,000 
W1154505.27 – – XX
– – 
W1004505.00 44.0 2,000 1923X
– – 
A1104505.10 44.0 2,000 1930X
– – 
A1104505.28 38.0 2,000 X
26.0 2,000 
W1504503.30 24.5 2,000 1941X
– – 

Data from  from  “Le Armi delle Navi Italiane Nella Seconda Guerra Mondiale”
by Erminio Bagnasco published in 1978 by  Ermanno Albertelli – Parma

Naval Guns

The first heavy guns used on the earlier battleships were British-made Armstrong. Also, Italy deployed some Skoda and other foreign-made equipment. With the modernization of the Italian fleet, along many innovations in the general area of engineering, came the development of highly sophisticated naval guns. Unfortunately, Italy never realized the true threat of aerial attacks, and consequently anti-aircraft guns were never developed to their full potential. This lack of understanding of the changing warfare was also reflected by the absence of anti-aircraft cruisers in the Italian arsenal.

Ansaldo 381mm.

During the modernization project of the Cesare and the Cavour, the original 12 guns were reduced to 10 and bored out to increase the internal diameter to 320 mm or 12.6 inches thus creating the 320/44 model 1934. The 381/50 model 1934 used on the Littorio class were powerful weapons for the caliber, with a maximum range exceeding that of all other battleship guns despite its modest elevation of only 35 degrees. Only the Japanese 18.1″ (46 cm) and the US 16/50 (40.6 cm) had superior penetration at the muzzle. This superb performance had a price in that their barrel life was only about half that of other nation’s guns.

Ansaldo 320mm.

The 152/50 model 1924 was used on the Trento class, the 8/53 model 1927 on most of the other heavy cruisers and it was thought to be a very good gun. The 6/53 model 1926 and 1929 were on all “Condottieri” class light cruisers except the Garibaldi class which used the 6/55 1933, also used as a secondary gun on the Littorio class. The 1926 and 1929 models differed only in the manufacturer. The 5.3/43 Model 1933 was deployed on the battleship Andrea Doria as a secondary weapon and on the “Capitani Romani” class light cruisers as the main weapon. The 4.7/45 model 1918 was based on a design by Armstrong dating back to WWI, and subsequently built by Vickers in 1924 and by OTO in 1926.

Breda 20/65 mm.

The 4.7/50 model 1926 was first built by Odero-Terni-Orlando (OTO) in 1926, and then continually modified throughout the 1930s by Ansaldo. The 4.7/45 model 1931 was a low power gun exclusively used on submarines. The 4.7/50 model 1933 was built by Odero-Terni-Orlando (OTO) and used only for the modernization of the Cavour class battleships. The 4.7/50 model 1936 and model 1940 was probably the best Italian destroyer guns, and it was used in both single and dual mountings on the Soldati (2nd series) class destroyers.

Breda 37/54 mm.

The 3.9/47 model 1924 and model 1927 was originally designed in 1910 by Skoda, and remanufactured between 1924 and 1927. Used on most cruisers it was considered to be a good AAA weapon. The 3.7 cm/54 Caliber AA MG was a common anti-aircraft gun just like the 9 cm/50 (3.5″) Caliber Model, but it was not plagued with as many technical faults.