During the period between 1925 and 1940, the Regia Marina dedicated large resources to the strengthening of its submarine force, which resulted in the deployment of 50 large, 89 medium, 2 cargo and 50 small units. At the beginning of the hostilities (June 10th, 1940), Italy had a total of 117 submarinesof which only 7 could be categorized as obsolete.

The first medium displacement boats built were the four 830 ton. “Mameli” in 1929. Later units had larger displacements. In 1932, Italy began producing the class “600“, units of only 650 tons. The same configuration was maintained on the “Sirena” (12 units), the “Perla” (10 units), the “Adua” (17 units). The “Platino” class (13 units) were increased to 710 tons.

From experience gather during the initial days of the war, displacement of all units was increased, with the Tritone class (13 units) reaching 905 tons. The first large submarines were the 4 units of the Balilla class. These double-hull, 1405-ton units were first deployed in 1928. Later models were decreased to about 1,100 tons, with the only exception of the ocean-going “Ammiragli” class (4 units), and the 2 transports of the “R” class.

Most medium and large units were armed with a single gun, placed in front of the conning tower. Some had a second gun place on the conning tower itself or just behind it. Torpedo launchers were installed both forward and aft. Usually, medium size units had two tubes aft and four forward. Some had a four and four configuration with the only exception of the “Bragadin” class, which had the aft torpedo tubes replaced by mine laying devices.

Large units were usually configured with four and four tubes, with the exception of the Balilla, which had only two stern tubes. The Foca, which was dedicated to mine laying, was equipped with only two tubes installed under the aft mine-laying devices. The ocean-going “Ammiragli” class was equipped with six forward and four aft tubes. These were 450 mm torpedoes (nicknamed ‘silurotti‘, small torpedoes) instead of the standard 533 mm ones. The “R” class, which was exclusively used for transport, did not have torpedoes. The standard propulsion system consisted of diesel engines for surface navigation and electric motors for submerged one. The “Ammiragli” and “Balilla” class had a third diesel engine attached to a dynamo used to produce electricity for surface navigation, thus providing for low-speed long-range capabilities.

Although in 1922 the Regia Marina had began research on submerged navigation using diesel engines, a device invented by Major Pericle Ferretti was never fully deployed. Even while collaborating with the German Navy, Italy never implemented this Dutch-invented device, known as the schnorchel, thus greatly impeding the performances of all of its submarines.

At the fall of France, Italy was able to set up an Atlantic submarine base in Bordeaux, thus eliminating the perilous passage through the Gibraltar Strait. Admiral Donitz, the supreme German submarine commander, attempted to integrate the Italian forces in the Wolf-pack strategy, but the Italian boats were technically poor, slow to dive and possessed a large and easily detectable profile. As a result, most Italian submarines operated in the Central and Southern Atlantic in solitary missions.

Adapted and translated from the book “Guida alle navi d’Italia”, by Gino Galuppini, published in 1982 by Arnoldo Mondadori Editore.


Some authors date the invention of the submarine, or at least a conceptual development of it, around the 15th century in England, but the real revolution in underwater warfare began in the United States. John Phillip Holland, a brilliant engineer of Irish origin and militantly anti-British , developed at the very end of the 18th century the first modern submarine, the Holland. The sixth evolution, denominated Holland VI, began a series of naval tests in March 1898, soon proving its excellent military capabilities. Eventually, the U.S. Navy purchased the boat and named it USS Holland, thus giving birth to the illustrious history of the “silent service”. Eventually, Holland’s talent would mature in the highly recognized Electric Boat Company, while a patented copy of his work was also produced by the renowned and respected British shipbuilder Vickers of Glasgow. The Royal Navy was slow in embracing the new weapon, but by 1903 it had already deployed five “Hollands”, while the U.S. Navy had already seven.

Italy, at the time one of the emerging naval powers, experimented with submarines as early as 1890, date of the realization of the first prototype name “Delfino” (Dolphin), a fully electric boat built by the naval shipyard of La Spezia. The boat produced good technical results: it was stable and maneuverable, but due to the absence of an internal combustion engine, had limited endurance. However, it was instrumental in training naval engineers in this completely, and complex new field.

The period preceding the Great War would be of immense importance in defining the technical nature of the weapon, thus inducing various navies into creating practical and theoretical plans for their integration within the existing tactical organizations. One of the technical factors of greater importance was the basic design of the boats. Two different methodologies were followed in organizing the submarines’ means of submerging and surfacing. The two solutions were the simple hull, mostly of American design, and the partial double hull, a French design later improved by the Germans. The Italian designed Cesare Laurenti, still utilizing the American concept of the single hull, introduced a third solution, which provided for internal ballast tanks. Italian innovations, especially in the area of safety, would continue for decades.

These new, larger, and more powerful boats forced an evolution of their strategic employment. The initial models were strictly used for coastal patrol, the defense of ports, and possibly some other minor employments not requiring speed and endurance. The newer boats were faster, and capable of remaining at sea for extended periods of time, thus it was immediately conceived to have them operate as part of the battle fleet – a concept very dear to the British Admiralty and the U.S. Navy – or against enemy merchant ships – a concept later evolved to a level of science by the German Navy.

It is important to consider that in the first part of the 19th century, naval affairs were mostly revolving around Great Britain and the Royal Navy. As the most powerful fleet at sea, the Royal Navy set the standards for all other navies to follow. The British navy was very traditionalistic, sectarian, and intrinsically connected to the mighty British war industry, thus it favored large, powerful, and highly armored ships: the battleships. In 1904, in naval maneuvers conducted off Portsmouth, the British “Hollands”, essentially very rudimental vessels, were successful in simulating the torpedoing of four British battleships. The event was possibly noticed, but the Royal Navy had to wait for the ascendancy of Jacky Fisher to First Lord of the Sea to finally see change take place.

Just before the Great War, most of the larger navies had already developed an adequate submarine force. Great Britain had 92, France 52, Russia 48, Germany 38 , but the United States had only 30, and Italy only 20. Japan, with 13 boats, figured last. Italy, beginning an irreversible trend which would cause many repercussions during the second world conflict, had already fractioned its fleet into multiple classes. In addition to the already mentioned “Delfino”, there were the “Foca” and the “Atropo”, 8 units of the “Medusa” class, 5 of the Glauco class, 2 of the “Pullino” class, 2 of the “Nautilus” class, plus the shipyards were ready to introduce the “Argonauta”, the “Balilla” and two units of the “Pacinotti” class.

German boats were showing their superiority mostly thanks to the quality of their diesel engine, and the Italian shipyard of Muggiano (La Spezia) began utilizing diesel engines produced by FIAT and C.R.D.A. This tendency to develop domestic technology would be omnipresent in the development of the Italian submarine force, but it would also reflect the constant tension present within the high ranks of the Regia Marina, and the service’s inability to define a clear design standard. Furthermore, since some of the design work was conducted by the navy itself, and some by private industry, political mingling and financial interest were omnipresent.

Another aspect of the evolution of the Italian submarine force which we should not ignore is its role in the context of the naval doctrine developed by the Regia Marina at the time. Following the conclusion of the First World War, Italy and many other nations faced very severe financial hardship. In the case of Italy, economic, social, and political turmoil created the necessary fertile ground for the ascendancy of Benito Mussolini’s Fascist Party. The Italian Navy (Regia Marina), perhaps catalyzed by events surrounding it, did not fail to enter the highly controversial debate between the followers of the “Jeune école” and the “old guard”. The new school openly declared that the experience of the war just concluded demonstrated that large capital ships were vulnerable to smaller vessels, an argument this clearly in favor of the submarine forces. Eventually, as in other European countries, the think tanks within the Italian navy were divided between those who believed that the submarine was a new decisive weapon, and those who proposed that the war’s submarines exploits (mostly by the Germans) were simply the result of lack of readiness by the surface forces. This gap, it was asserted, had been filled and the submarine was now highly vulnerable.

Admiral Romeo Bernotti (1877-1974)

Italian naval doctrine was evolving under the impetuosity of the academic diatribe between Admiral Bernotti (new school) and Admiral di Giamberardino (old school). The latter was a prolific writer whose successful career was probably the result of his acclaimed intellectual work. Also prominent during this period was Commander Giuseppe Fioravanzo , who in rebutting di Giamberardino’s concept of “the final battle”, proposed a more defensive standing and a greater reliance on lighter vessels, especially submarines. This same author was also the first proponent of what, later on, would become the LCC-Class or command ship. In 1922 Admiral Bernotti reopened the “Istituto di Guerra Marittima” (Italian War College), but in the eighteen years that follow, Italy failed to establish a clear naval strategy inclusive of all naval elements, limiting itself to what could be considered an excessively simplistic approach: equal the French or else.

Admiral Oscar di Giamberardino (1881-1960)

The clearest demonstration of the divide between the navy’s good intentions and the actual results could be found in Adm. Guido Po’s writing (1940), in which he states that the Italian naval strategy was based on:

(1) the offensive use of warships and extensive use of submarine packs;

(2) the exploitation of Italy’s geographical position in the Mediterranean to disrupt the enemy’s communication lines; and

(3) seeking to maximize cooperation with the Regia Aeronautica (Italian Air Force) to overcome the lack of aircraft carriers.

An analysis of the Italian Navy in World War Two would exceed the boundaries of this discussion, but it should be said that most of these points were clearly missed and that the navy actually operated to the contrary of its established principles. The point which does pertain to this discussion is the utilization of submarines in packs; this strategy, based on the German experience of the previous war, would actually be one of the few areas in which disobedience to the originally established doctrine produced the greatest results.

In World War I, the Germans soon realized that the blockade imposed upon the Central powers would soon deplete these nations of vital imports. Germany had bountiful natural resources, but lacked rare minerals and materials necessary to the war effort. To balance the field, Germany had to impose similar restrictions upon its enemies, and mostly upon Great Britain. Submarine warfare was only partially regulated by the pre-war convention of the Hague. In general, the terms of the Hague agreement did not, and could not consider the technical evolution of the submarine, thus the weapon was bound to rules of engagement designed for surface compact. In essence, in raiding enemy ships, submarines were asked to surface, identify themselves, inspect the enemy vessel, allow for the crew to leave the ship, and eventually sink it.

This almost medieval set of rules, reminding us of the “singolar tensone” (single combat) of a long gone era, would surprisingly be revisited by the Italian boats in the early stage of the Atlantic battle. Two important technical evolutions made this kind of submarine warfare outdated: first, ships began receiving Marconi’s apparatuses, thus they could warn base of the presence of an enemy submarine. Second, even merchant ship began receiving the installation of deck guns capable of causing considerable damage to a flimsy submarine. The German decision to migrate from restricted to unrestricted warfare was inevitable. Despite America’s outcry regarding the barbarism of unrestricted warfare, in reality this conflict had already reached unprecedented barbarism with the massive butchery of troops at the front, the bombardment of civilian targets, deportations , the use of gasses and other means of destruction. Thus, submarines emerged as the villains, but at the same time as one of the most effective weapons of the war. Considering that during the highest point of the crisis up to one forth of all shipping to Great Britain was being sunk, the level of success reached by the German Imperial submarine fleet was unprecedented, unexpected, and almost succeeded in changing the outcome of the war.

This latter aspect should be clearly remembered since it contributed in shaping some of the Italian naval doctrine of the Second World War. German submarine warfare was not limited to the North Sea and the Atlantic, but it also expanded into the Mediterranean where the German boats easily overcame the passage of the Strait of Gibraltar and the Strait of Otranto to reach Austrian ports. This is another factor that should be kept under consideration; geographical barrier did not necessarily limit the effectiveness of the submarine, but German losses in the Mediterranean evidenced that certain conditions dramatically increase the percentage of losses. The end of the atrocious conflict, and the social, economical, and political turmoil that swept Europe and the rest of the world in the 1920 caused a partial loss by amnesia of all lessons learned during the first submarine conflict.

Taken as a whole, Italy’s position was precarious: the nation had participated in the Great War, suffered great losses, and received very little benefit from it (many historians root the advent of Fascism to these factors). Although the nation had now expanded into former Austrian territories with large Italian populations, Italy was still the weakest of the larger powers. The industrialization of the country was mostly reserved to the north western part of the nation (Turin, Milan and Genoa) and the other regions languished in economic disparity, poor communication, and a mostly agricultural economy utilizing antiquated methodologies. The Conference of Washington bolstered the Italian Navy’s confidence especially because it had achieved its primary goal, naval equivalency with what was perceived as its primary foe: France.

Friction between the two nations dated back to the reign of Napoleon III, and French opposition to the establishment of an Italian national identity. Still, a monarch whose family origins were distinctively French governed this recently established unified Italian kingdom. Italy, the equivalent of a European social climber, was forcibly trying to establish itself as one of the major players. As a matter of fact, Italy’s abandonment of the three-way alliance with Germany and Austria in favor of France and Great Britain had been a conniving and well-calculated gamble more than moral support of democracy versus central government.

The Regia Marina did not have a relevant role during World War I, bar the sinking of an Austrian battleship by insidious weapons toward the very end of the conflict. With the advent of a new and stronger government after the 1922 march on Rome, the new prime minister, Benito Mussolini, pursued a noticeably more defined and aggressive naval policy. Mussolini, in addition to consolidating his quasi-democratically obtained power utilizing demagogical, and later authoritarian means, immediately recognized the value of a strong navy, thus dedicating Italy’s scant resources to the building of a world class, qualitatively superior, modern, powerful, and well equipped navy. This “prima donna” role would have to be shared with the Regia Aeronautica (Italian Air Force), while the army remained far behind.

While accumulating massive debts, the Italian government maintained a difficult balance between resources available and the escalating requirements imposed by this newly acquired military leadership. Naval constructions could easily benefit from Italy’s established naval technology, but suffer from shortage of essential material which had to be imported. Although most of the original engine and gunnery technology was clearly of British origin, the national industry had been able to develop a distinct Italian identity producing excellent ships capable of conquering the blue ribbon. As part of this fervent program of naval construction, the Regia Marina deployed the second largest submarine fleet in the World, second only to Russia. The Italian boats, as seen in the period preceding World War One, would be built by different shipyards following radically different designs.

A submarine fleet is not just an assembly of boats, nicely docked, and dressed in colorful flags. Submarines, by nature of their technical complexity, required specialized training and a new class of sailors. Italy established three distinct submarine schools. In addition to the already existing and reputable Royal Naval Academy of Leghorn for officers, the submarine schools were specifically designed for training submarine personnel, mostly specialized non-commissioned officers in the complex operations surrounding the operation of the boat, and their utilization as an offensive weapon (the schools were in Pula). Still, upon Italy’s entry into the war, a shortage of qualified personnel would be one of the most important factors in restricting submarine operations. This shortage of personnel was typical of all submarine services since the harsh and unhealthy conditions aboard diesel submarines did not allow for an extensive service, not to mention that casualties were extremely high.

The submarine force was organized under a single command structure, but its strategy had to fulfill multiple tactical requirements. Italian submarines were asked to defend the coastline, intercept enemy shipping, provide scouting for the fleet, transport essential war material, and lay minefields. Essentially, the submarine fleet had a variety of boats designed for a variety of tasks for a war scenario which failed to materialize. Italy’s “mortal” enemy, France, dissolved under the crushing German offensive of spring 1940 and Italy found itself face-to-face with the mighty Mediterranean Fleet. Although a scenario of a British-Italian conflict had been studied during the Ethiopian crisis, the efforts involved were very limited and consequently the naval command found itself dealing with the unimaginable: an offensive war.

While the surface fleet was tasked with the defense of the traffic with North Africa, Albania, and the Aegean, the submarine fleet had the arduous task of intercepting and sinking the non-existing British commercial traffic. It is interesting to note that, upon the declaration of war, while the air force and the army were given very conservative, if not defensive operational orders, the navy was tasked with providing Italy with all of her offensive initiatives.

Eventually, the war record of the Italian Mediterranean submarine fleet would be a pitiable one with slightly less than 100,000 t. of shipping sunk, and a large number of losses. Additional submarines were deployed in Eastern Africa and later the Atlantic. The first group, with operational guidelines developed before the war failed to produce noticeable results , while the second, faced with unforeseen conditions, would be able to write some of the most lustrous pages in the history of the Italian submarine force. In essence, wherever the Italians planned, they failed, and where they improvised, they succeeded.

With the Italian expansion in East Africa, despite the limited docking facilities, one would have expected a forceful Italian presence in the Indian Ocean and Red Sea to impede British maritime traffic. Unfortunately, due to poor planning, defective equipment, and waning supplies, the fear of an Italian menace in the area failed to materialize. On the Atlantic side, and especially in 1939, no one expected the availability of docking facilities. Spanish support, although much sought after, never materialized and therefore there weren’t any other friendly harbors available. Thus, the Regia Marina envisioned a series of Atlantic sorties which would have originated from Italian bases and had to endure the crossing of the Strait of Gibraltar. On the other hand, German submarines had to sail from their home bases, thus allowing only for very limited patrol time. The Italians, as already mentioned, had to deal with the Strait of Gibraltar and the local British presence, which despite Spanish pro-axis tendencies still gave the Royal Navy dominant control over the narrow passage.

The fall of France and the subsequent occupation of the French Atlantic ports radically changed the scenario. The German navy immediately sought to capitalize on the new opportunity, but the availability of ocean going vessels was very limited. Due to the post war limitations, Germany had to develop its submarines in other nations, mostly Holland, and preferred small, inhabitable boats with the maximum war load, while Italian engineers gave plenty of focus to habitability. Leveraging some of the discussion which had taken place in Friedrichshaffen (Germany) on the 20th and 21st of June, 1939 following the signing of the Italian-German “Pact of Steel”, the Germans requested the transfer of Italian boats to the Atlantic. During these meetings, Admiral Cavagnari, the Italian equivalent of the First Sea Lord, committed to an Italian presence in the Atlantic. It should be remembered that Italy and Germany were conducting parallel wars, and that the submarine agreement amounted to the first practical collaboration.

For a navy specifically built for a strictly Mediterranean war against France, this commitment was a stretch; still the Italian shipyards had developed and built several classes of submarine specifically designed for operations in the oceans. Since the late twenties and early thirties, Italy had begun building high displacement submarines capable of crossing the Strait of Gibraltar, reaching the Atlantic for long patrols along the French and African coast. During the 1939 discussions, the glamorous successes of the German U-Boot during World War I were still vivid in the minds of all Italian naval strategists: the glitter of glory was irresistible.

The communalities of interests between the two navies, especially in the area of submarine warfare, were limited. Although Italy had a larger fleet, it lacked the industrial power, which would later allow Germany to begin a program of mass construction. During the conflict, while Italy was barely able to produce 40 newer boats, Germany’s war machine produced over 1000. Surprisingly, with the evolution of the war, Germany, which had originally sought the collaboration of Italian boats, later would seek Italian crews to man new U-boats.