The very idea of creating a human-controlled torpedo for a covert approach to the enemy ships appeared during the First World War. Then a group of Italian engineers offered to build a torpedo with control systems that could get to the target and install a detachable warhead on it. An prototype of such a torpedo was built, which was even planned to be used for sabotage. However, due to the change in the situation on the fronts, such weapons were refused. The original idea was remembered only in the mid-thirties, and this time the project was brought to practical application.
It should be noted that the proposed technique was only called a torpedo. By design and method of application it was a super-small submarine. The fact is that the torpedo must be launched from a ship or submarine, reach the target and blow it up. T.N. Italian-made human-guided torpedoes had a different tactic of use. Starting from a submarine carrier, they had to secretly approach the target, set a charge on it and return to the carrier. However, for certain reasons, the Italian military and engineers preferred to call this technique torpedoes.
The main reason for returning to old ideas was the situation in the Mediterranean. In the mid-thirties, relations between Italy and the UK seriously deteriorated. Rome was well aware that in the event of a full-scale conflict, the British fleet would have significant advantages over the Italian. It required some kind of weapon or equipment capable of causing significant damage to the enemy without engaging in open battle. The man-controlled torpedo (a super-short sabotage submarine) was one of the best means of implementing such a strategy. In addition, firebreaker boats, weapons for combat swimmers, etc. were considered as such tools.
Teseo Tesei - one of the authors of the project
The old idea was remembered by sub-lieutenants Teseo Tesei and Emilio Tosca. At the beginning of 1935, they made a proposal to build a human-guided torpedo on the model of a previously existing project. The proposed project involved the movement of a torpedo in a fully submerged state and the transportation of a dropped warhead. Thus, the fleet could receive the ultra-small submarine carrier mines. The command, remembering the past, became interested in this project and gave the nod to the creation and construction of prototypes.
Works and difficulties
The development of the project was completed in the early autumn of 1935. In October, the workshops of torpedo armament in the city of San Bartolomeo began the construction of an experienced underwater vehicle. Already at the end of the month, the torpedo was completed and delivered to the nearest shipyard, the dock of which became the first test site. Checks began on October 26. By this time, the command of the naval forces ordered the assembly of the second prototype. On November 2, the man-controlled sabotage torpedo was presented to the fleet command, the delegation was headed by Admiral Mario Falangola.
Good weather allowed to conduct tests until the end of autumn and the beginning of winter. During the first stage of testing, the necessary information about the advantages and disadvantages of the design was collected, which allowed for some refinement. Advanced prototypes are back for testing in January on 36. The implemented modifications fully justified themselves, thanks to which, based on the results of the second test phase, it was decided to build four more experimental torpedoes. By this time the project had two unofficial names: the new product was called Torpedine Semovent (“Self-propelled torpedo”) or, on behalf of the author of the project, Torpedine Tesei (“Tesei's torpedo”).
The construction of the second batch of torpedoes again engaged in workshops in San Bartolomeo. Work continued until the summer of 1936, when the order came to stop them. At the same time, the training of future testers and submariners-saboteurs stopped. The project was in limbo over the next year. Only in June 37-th fleet commanders again ordered to start work. In addition, this time the authors of the project were instructed to modernize their torpedoes, issuing updated requirements. Also changed the desire for the number of new technology. The second batch of Tesei's Torpedo was now supposed to consist of six items. However, only five such torpedoes were built, not counting the two experienced ones.
28 September 1938 was created a special unit, which in the future had to use the new Torpedine Semovent, as well as other special equipment and weapons. The commander of the formed 1 light flotilla was appointed Captain Di Corvette (corresponding to the rank of Major or Captain 3 rank) Teppati. During the first few months, the servicemen of this flotilla mastered various equipment, practiced the tactics of its use and were engaged in other important matters. Nevertheless, by the time the flotilla was created, the command had again lost interest in human-guided torpedoes, due to which all the samples of this technology were idle in warehouses.
In 1939, the captain of the frigate (captain of 1 rank) Paolo Aloisi was appointed commander of the 2 th light flotilla. One of the main tasks of the new commander was the resumption of active work on the preparation of sabotage means, including the Torped Tesei. P. Aloisi summoned all the project managers, and also ordered to deliver all the available torpedoes and auxiliary weapons. By the middle of the year, P. Aloisi, T. Tesei, E. Tosca and other specialists of the Italian fleet not only “reanimated” the project, but also significantly updated it. They managed to create an updated version of the "Self-propelled torpedo", which had some differences from the base.
In the summer of 39, the 1 light flotilla was ordered to continue work on the new project, as well as to begin full-scale training of future saboteurs. Despite the criticism of the very idea of creating human-guided low-speed torpedoes, P. Aloisi and other specialists continued to work and carried out the order. Subsequently, such persistence was commended by the command.
In 1939, a new version of the “Self-propelled torpedo” was developed with improved design and enhanced performance. Until the middle of next year, continued testing and refinement. In June 1940, the torpedo was put into service under the designation SLC (Siluro a Lenta Сorsa - “Slow Torpedo”). In addition, by this time there was an unofficial nickname. Acute-language saboteurs nicknamed the slow torpedo “Pig” - Maiale. Official and unofficial names have not changed until the end of operation. In this case, in some sources the designation Mark I occurs, implicitly hinting at the possibility of the existence of other modifications.
Wanting to simplify the development of new technology, T. Teseo and E. Tosca, in the mid-thirties, decided to build their torpedo on the basis of an existing product. One of the 533 mm torpedoes that existed at that time was used as a base for the SLC. As part of the new project, some modifications were made to the internal units of the base torpedo. In addition, a mass of new aggregates appeared on its outer surface. The result of this was the appearance of a structure in the form of a torpedo with seats for the crew and other characteristic features.
The human-guided torpedo Maiale had a total length of 7,3 m, and the diameter of the shell was equal to the original 533 mm. By adding a set of new parts, the maximum width of the torpedo was 1,3 m, the maximum height was 1 m. The torpedo ready for the combat mission weighed 1588 kg.
The layout of the base torpedo was significantly changed in accordance with the intended tactical role of the new product. The nasal compartment is 60 cm long and holds a warhead weighing 220 kg. In the future, new compartments for 250 and 350 kg of explosives were developed. Heavy combat units with increased power had a greater length in comparison with the base. As already mentioned, the SLC torpedo was not a torpedo in the true sense of the word. This technique was intended for delivery and installation of the warhead on the enemy ship. For this, the head of the case could be undocked at the right moment. The warhead was equipped with a fuse with a clockwork.
In the middle of the case there was a battery compartment for batteries, as well as a ballast tank. In the stern was provided an electric motor and steering cars. The motor rotated two coaxial propellers, behind which were located the rudders. Initially, the Torze Teseo was equipped with an HP 1,1 electric motor. In the future, it was replaced by a more powerful, issued to 1,6 HP.
Due to the small dimensions of the torpedo, the crew had to be placed outside the hull. Two saboteurs were supposed to ride literally. Immediately behind the mount of the warhead, on the upper part of the body, there was a shield covering the commander and controls. In earlier versions of the project, a small “windshield” was envisaged on it, but later it was abandoned and only a metal shield was left. At the commander's place there was a compass with luminescent marks, an instrument panel, a smooth depth adjustment valve and a small steering wheel with the ability to control through two channels (direction and depth). In addition, a box for the necessary tools was provided under the shield.
Special crew seats were missing. The functions of the seatback commander served as an emergency dive tank. It was made in the form of a box with a notch in the back. On the side of this tank was provided a lever for quick filling. In case of danger, the second crew member, a miner, could pull the lever and lead the torpedo to the depth. The assistant commander with his back rested on a small back attached to the hull. Behind her were provided cylinders for compressed air.
Two members of the SLC man-operated torpedo crew were to use diving suits. To work on a new technology intended so-called. Belloni costume. It was a special jumpsuit of waterproof fabric with a mask and breathing apparatus on the abdomen. The suit was put on through the hole in the middle part, which was closed with a special sealing buckle. To increase the secrecy of the work, the suit was equipped with a closed-type breathing apparatus. Oxygen from a metal bottle was fed into a rubber bag. Bag with a corrugated tube connected to the mask. Exhaled gas through the same tube was transferred to a cartridge with a chemical composition that absorbs carbon dioxide. The remaining gases were returned to the bag.
The low-power electric engine allowed the Maiale torpedo to produce the lowest possible noise, but it affected driving performance. Power at the level of 1,6 hp allowed to reach a speed of no more than 4,5 node. Cruising speed was the 2,3 knot. Due to the use of limited capacity batteries, the maximum cruising range (at cruising speed) did not exceed 15 nautical miles. At maximum speed, you could go only 4 miles. The strength of the torpedo units was enough to dive to a depth of 30 m. The oxygen supply in the breathing apparatus allowed it to work for 6 hours.
Initially, various delivery options for guided torpedoes to the target area were proposed. The possibility of transporting such vehicles by submarines, surface ships and even seaplanes was considered. However, it soon became clear that only a submarine could be the only acceptable carrier. Only such a technique allowed saboteurs to get to the target for a distance of several miles without the risk of being detected.
In the first versions of the project, SLC diversion vehicles were simply to be mounted on the deck of the submarine carrier and secured to it with cables. However, this was soon abandoned. Immersion of the carrier at great depth threatened torpedo damage. Because of this, a special cylindrical container for the transport of "Pigs" was developed. Such units could be mounted on any suitable submarine, and due to their sealing there were no restrictions on the operation of the carrier.
SLC torpedo carriers were several submarines in service. Ambra and Iride submarines (Perla type) lost their deck 100-mm guns, instead of which were mounted containers for torpedoes. At Ambra there was one container before chopping and two behind it. Iride, in turn, received four containers, two before and after chopping. Similarly, two Adua-type submarines were refined: Gondar and Scire. Also, the carriers "Pigs" were to be the submarine Grongo and Murena (type Flutto), built in 1943 year. It was planned to install four containers on them. However, in early September on 43, before installing the containers, these boats were sunk. Later they were raised, but not repaired and did not return to the system.
In an atmosphere of secrecy
The SLC man-guided torpedoes were one of the most secret types of weapons and equipment in Italy. In 1940, their serial production started, featuring a special approach to secrecy. Various Italian enterprises manufactured and supplied various units and assemblies. The manufacturers were not told what exactly they were doing and in whose interests they were working. The units supplied did not have any labeling. Individual units and assemblies were delivered to the bases of the 1 light flotilla, where ready torpedoes were assembled from them. The final assembly involved cadets who were preparing to become pilots, saboteurs. Until the end of the war, around 80 manned torpedoes were assembled.
The general atmosphere of secrecy and the importance of the new unit affected the selection of personnel. When searching for future saboteurs, both physical training and skills, as well as mental health or moral qualities of the candidate were taken into account. The management of the flotilla was engaged in the selection of candidates, it also distributed recruits to various divisions: some were sent to serve as divers-demolition men, others were pilots of torpedoes, and others were sent to launch boats. Training future saboteurs consisted of several stages. The cadets trained to be in the water for a long time, learned to work with the equipment, etc.
It should be noted that a high level of training was really important for future pilots of SLC torpedoes. One of the main reasons for this is the specificity of combat work. On the road to the goal could take several hours, the installation of mines was also quite a difficult process. The proposed method of combat operation torpedoes Maiale looked as follows.
A submarine carrier with torpedoes in containers was supposed to go to the target area: an enemy base or ships in the roadstead. After receiving all the necessary information, the crew of the torpedo through the gateway left the submarine, opened the container, removed the torpedo and checked its systems. Further, having saddled his apparatus, the saboteurs set off for the goal. At a great distance from the target, it was possible to move at a shallow depth, so that the crew heads remained above the water. Among other things, it saved oxygen. At risk of detection, a quick-dive tank could be used. On the approach to the target, the torpedo plunged to the working depth up to 4-5 m.
Small dimensions allowed the torpedo to overcome various anti-submarine obstacles. Depending on the situation, it was possible to pass under the network barrier or cut a passage in it. The last stage of the approach to the goal was carried out at a minimum depth with a constant willingness to dive. The purpose of the saboteurs was to get to the ship being mined.
Saboteur with respiratory system
Next, the torpedo pilots had to turn off the engine and look for the side keels of the target ship. On them were fixed special clips connected by a cable. On a rope the fighting unit was suspended. After fixing the cable dropped it. Having suspended the warhead, the saboteurs were to install a fuse for up to 5 hours. After that, the pilots could turn on the engine and go back to the submarine carrier or any other point of evacuation. The explosion of the warhead took place several hours after the departure of the saboteurs and led to the destruction of the underwater part of the target with corresponding tragic consequences for it.
Back in March, 1940 of the year, at the direction of the command, the saboteurs conducted their first maneuvers in an environment as close as possible to reality. The Ametista submarine of the Sirena type was involved in this test, on which light mounts for torpedoes were mounted. The commander of the boat at the time of the exercise was Yunio Valerio Borghese. The conventional target was the light cruiser Quarto. 12 March, an hour before midnight, three crews of torpedoes headed for the target. For various reasons, only one torpedo reached the cruiser. The saboteurs successfully arrived at the place of the task, mined the conditional target and returned to the submarine undetected.
Success during the exercise affected the further fate of the project. Man-guided torpedoes showed their capabilities and became one of the main special means of the Italian naval forces. First, the SLC torpedoes were operated by the 1 light flotilla. In the summer of 40, several separate special-purpose units were brought into the 10-nd light flotilla (aka the MAS 10-nd flotilla). Crews of torpedoes Maiale and combat swimmers served in the so-called. group "Gamma."
Installation scheme of the warhead
Combat use of new torpedoes began with failure. 21 August 1940, the Iride submarine with four torpedoes on board was to head for the British base in Alexandria. This campaign was frustrated by the enemy several hours before its start. Shortly before going to sea, the crew of the submarine was performing a test dive. At this time, the submarine attacked the British torpedo bombers. "Irida" went to the bottom with the "Pigs".
About a month later the boat Gondar went to Alexandria. This time the British had time to notice the threat and sink the enemy submarine. Several submariners and saboteurs escaped, but were captured. Among them was Emilio Toski, one of the creators of the project.
Due to the loss of Gondar, the attack on the base of Gibraltar was canceled. In the last days of October, an attempt was made to mine the ships at the base near the strait, but this time one of the three torpedoes was sunk, and the crew was captured. The other two had time to return to the submarine carrier.
26 July 1941, the Italians attempted to attack one of the Maltese ports. The saboteurs managed to destroy one of the large bridges, but the port survived. During this raid, T. Tesei, one of the authors of the SLC project, died.
However, the use of SLC torpedoes several times led to the successful implementation of the task. On the night of December 19 1941, the Scire submarine arrived at the shores of Egypt. All the available torpedoes were fired at a safe distance from the base in Alexandria. The base had a serious anti-submarine defense system, but all the saboteurs managed to penetrate the inner harbor: they were able to pass through the wake of the British ship and slip into the open gate.
The first crew of the SLC torpedoes (Antonio Marcella and Spartak Skergat) successfully approached their target and set up a mine under the bottom of the battleship HMS Queen Elizabeth. Without any problems, they left the enemy base. However, they had to land on the shore, and three days after the operation the saboteurs were taken prisoner.
Battleship HMS Queen Elizabeth after repair, port of Alexandria
The second torpedo, led by Luigi Durand de la Penna and Emilio Bianchi, faced two problems at once. Because of the failed breathing apparatus, E. Bianchi was forced to rise to the surface, and the torpedo with jammed screws fell to the bottom. The second saboteur was able to manually drag a torpedo a few meters and leave it under the bottom of the battleship HMS Valiant. Then he raised the fuse and, unable to leave, rose to the surface. Two pilots were captured by the crew of the attacked ship.
Vincenzo Martellotta and Mario Marino were to attack the tanker HMS Sagona. In addition to the main warhead, they carried with them six incendiary cartridges. It was supposed that the cartridges would set fire to the spilled oil and thereby provoke a major fire. The Italians left, but soon landed on the shore and were captured.
On the morning of December 19 several explosions occurred. The first one was the combat unit fixed on the ship HMS Queen Elizabeth. As later recalled the commander of the Mediterranean fleet of Great Britain Andrew Brown Cunningham, who was at the stern of the ship during the explosion, he threw five feet into the air. The explosion made a big hole in the bottom of the ship and he began to sink to the bottom. Fortunately for the crew and the British fleet, the ship soon sat down and did not sink. Later the battleship was restored, after which he served until the end of the forties.
A few minutes later there was an explosion under the "Valienta." This ship also received damage, but did not sink. Ironically, the captured Italian saboteurs were put in the hold of the battleship, not far from the site of the mine. However, they remained alive. The ship later underwent repairs and served over the next few years.
Undermining the tanker HMS Sagona led to an oil spill and a fairly large fire. However, the original plan of the Italians did not work: burning oil damaged only one ship, HMS Jarvis.
Thus, the Italian Navy lost three human-guided torpedoes, and six saboteurs were captured. Nevertheless, thanks to these victims, it was possible to permanently disable several warships and destroy one tanker. This did not lead to a sharp change in the war in the Mediterranean, but it still affected the balance of power and slightly corrected the position of Italy.
At the beginning of 1943, the 10 light flotilla had a base near the Strait of Gibraltar. In the bay of Algeciras, in the Spanish territorial waters, from the beginning of the war, the abandoned steamer Olterra sat aground. Italian saboteurs managed to get to this ship and equip it with a base for SLC guided torpedoes. The “garrison” of such an improvised base made several attempts to attack the enemy, but only two of them ended in success.
Placement of a secret base aboard the Olterra steamer
On the night of 8 in May 1943, the Italians managed to undermine one American and two British vehicles. Vessels got holes and stranded. On August 4, the Norwegian tanker was sunk, as well as one British and two American vehicles.
The operation of SLC Maiale's human-controlled torpedoes ended after 8 in September of 1943. Fascist Italy capitulated, which stopped the planning and execution of various special operations. Like other fleet vehicles, the Pigs were out of work. In the future, most of the remaining torpedoes were sent for scrap. Some devices were more fortunate and they became museum exhibits, which are carefully preserved until now.
In 1940-43, around 80 controlled SLC torpedoes were built. During the performance of various combat missions, 25 vehicles were lost during the same period. However, some of their crews died, and some saboteurs were captured. Over the entire period of operation, the Maiale torpedoes were able to destroy or damage about two dozen enemy ships and ships. In this case, the Italian fleet lost several submarines carrier torpedoes with crews.
After the successful 1940 march drills, the SLC torpedoes began to be considered a promising and promising weapon. The first setbacks, including those related to the loss of submarines, hit the project’s reputation, but 41 proved once again that the idea was successful in an Alexandria raid in December. Later, Maiale regularly participated in operations, although success was interspersed with regular setbacks.
Shortly after the start of operation of the SLC torpedoes, the development of an upgraded version of this technique began. The work was delayed for several years, because of which the tests of the new torpedo started only at the beginning of 1943. The new project is called SSB. Over time, it was planned to replace all the old SLC torpedoes with new SSBs.
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