R. Smg. Alpino Bagnolini

The Alpino Bagnolini was not the most successful Italian submarine of World War II. Neither was it the one which sank the most ships. To the contrary, it only scored slightly more than 11,000 t. of ships sunk, and only if we also consider the Cabo Tortosa, a neutral Spanish cargo ship.

Still, the Bagnoli exemplifies the journey of the Italian submarine forces through most of the war. From the early success in the Mediterranean, to the various phases of the submarine campaigns in the Atlantic Ocean – North Atlantic, African Coast and later American Coast campaigns – to the fateful and last journey to Japan under a foreign flag and with a mixed crew carrying on their duties despite the downbeat turn the Atlantic campaign had already taken, it performed its duties. From “Happy Times” to “Sad Times” under the leadership of too many captains, the Bagnolini served faithfully, at times showing its design deficiencies but always taking the crew back to port but once, during its last fateful journey to Japan under the German flag.

Laid down on December 15th, 1938 in the Shipyard Tosi of Taranto, the Bagnolini, an ocean-going submarine of the Liuzzi class, was launched on October 28th of the following year and delivered to the Regia Marina on December 22nd, 1939. Just before the war, the boat was assigned to the 41st Squadron of the IV Group in Taranto.

Lieutenant Commander Tosoni Pittoni
(Photo courtesy Erminio Bagnasco and Achille Rastelli)

Under the command of Lieutenant Commander Franco Tosoni Pittoni, the boat was part of a group of submarines assigned to a patrol area south of the Greek island of Crete just before the Italian declaration of war (June 10th, 1940). On the 12th, Captain Tosoni Pittoni was about 50 miles SE of the small island of Gavdo when, early in the morning, he sighted a destroyer squadron navigating at high speed which soon failed over the horizon. It was 10 minutes to 1:00 AM. A few minutes later, around 00:56 AM, two new vessels appeared in the periscope’s lenses. They were two cruisers of the Caledon class on a NW route navigating in line. Two minutes after the sighting, the Bagnolini ejected the first torpedo against the foremost unit, which was hit between the forward stack and the bridge. The hunt by the escort units began right away, thus the boat desisted from any further offensive maneuver and disengaged.

H.M.S. Calypso

The surviving cruiser was the H.M.S. Caledon, and its crew had to witness the sudden loss of the twin unit H.M.S. Calypso. The 4,118 t. light cruiser was lost in position 34°03′ N 24°05′ E. The Calypso, laid down on February 7th, 1916 and launched on January 17th, 1917 did not enter service until June 1917. After having served with the Home Fleet, the vessel was stationed to Alexandria as part of the Mediterranean Fleet. During the sinking, 1 officer and 38 ratings lost their lives. The remaining crewmembers were rescued.

The Alpino BAGNOLI returning to Taranto after the sinking of H.M.S. Calypso in June 1940
(Photo Fraccaroli)

It was a brilliant beginning for the Italian submarine campaign in the Mediterranean, but a short lived one. Soon, successes dwindled and losses started mounting at an increasingly alarming rate. A second patrol followed from the 15th to the 24th of July in the same area, but this time without any success. Upon returning to base, the boat was sent to the yards for refitting in preparation for its transfer to the Atlantic Ocean.

The Alpino BAGNOLI with the original and quite voluminous conning tower
(Photo U.S.M.M.)

Along with other boats of the Liuzzi class, the Bagnolini left Trapani (Sicily) on September 9th, 1940 less than ten days after the Tarantini. The boat was part of a second transfer group, which also included the Marconi and Finzi. The crossing of the Strait of Gibraltar took place on the 13th, with surface navigation at night and submerged during daylight. Having completed the crossing, the submarine was stationed off Oporto (Portugal) for war patrol. Only a day after its arrival to the assigned area, the Bagnolini sank the Gabo Tortosa, a neutral ship flying the Spanish colors and belonging to the Ybarra & Compania of Seville. The sinking, in position 41° 20’ N and 9° 16 W, took over 90 minutes and did not cause any loss of life, but still was a regrettable incident. In fact, the Spanish vessel was signaled as having cargo destined for Great Britain, but it did not, as it was simply ferrying from Huelva to Bilbao. Lieutenant Commander Tosoni Pittoni was well intentioned to emerge and verify the identity and cargo of the ship, but smoke on the horizon forced him to make the critical decision to attack.

Towards the end of the patrol, on the 24th, the Bagnolini was attacked by a British airplane, which was repelled and, according to the crew, possibly damaged. Soon after, the boat continued on to its final destination reaching the newly established submarine base of Bordeaux on October 30th. Upon returning to base, Tosoni Pittoni escaped the scorn of Admiral Perona, the base commander, highly disappointed by the poor showing after the first sortie into the Atlantic. Perona, as he would many times, disapproved of the Italian captains’ lack of aggressivity, especially if compared to the German skippers.

The Submarine Alpino BAGNOLI in Bordeaux docket with the CAGNI following a heavy bombardment of the facilities
(Photo courtesy Erminio Bagnasco and Achille Rastelli)

After almost a month in Bordeaux, on the 24th of October the Bagnolini was again at sea part of a large group of Italian submarines operating in coordination with their German allies. In all, 13 boats left for the North Atlantic and two, the Faa di Bruno and Tarantini, failed to return. The Bagnolini itself narrowly escaped disaster when, on the 28th, water entered the control room, badly damaging several systems. But let Captain Tosini Pittoni describe the ordeal:

After the necessary refitting, the Bagnoli was ready to rejoin the fight, part of a second wave of Italian submarines set off the Irish coast from December 1940 through February 1941. As before, there would be tragic losses, this time the Nani, while the Bagnoli once again narrowly avoided being lost. After having left on the 8th of December, the boat reached the patrol area 10 days later. On the 11th, the crew sighted the British cargo ship Amicus of 3,360 t., a straddle unit of convoy SC15 belonging to the Tempus Shipping Co. Built by Northumberland Shipbuilding Co. Ltd of Howen-on-Tyne in 1925, the boat went down in position 54° 10 N, 15° 50 W after a single torpedo hit it after sunset. The entire crew was rescued after the Italian boat had moved on. After having celebrate the New Year, January 1st at 7:20 PM in position 54° 13N, 13° 55’W, the crew sighted an aircraft when it was too close to attempt to escape by diving. It took 40 minutes for darkness to engulf the area and allow the boat to safely dive, but by then the British had already dispatched antisubmarine vessels that immediately gave chase.

The boat went down to 60 meters and established silent run. Inevitably, the chasers located the boat and the captain dove down to 80 meters, but he failed to fool the British. He dove again to 90 meters, and then the first salvo of depth charges came crashing down. A total of six charges exploded in proximity of the hull, causing the electric breakers to pop, the compass to fail, water leaks through the conning tower’s hatch and the torpedo-loading hatch. The loss of power caused the boat to dive even deeper reaching 130 meters. Fearing that all was lost, the captain gave order to blow the tanks and come to the surface and face the enemy.
What followed was later described by Captain Tosoni Pittoni in his war report:

October 28th, 1940

“5:15 PM 160 miles from my assigned area, a wave out of sequence and sideways in relation to the main waves hit and engulfed the submarine and the men on the conning tower, pouring down into the control room and dragging away the second in command and the torpedo man guarding the foredeck.

The submarine slowed down under the weight and before it could reemerge from under the wave, it was hit by a second wave, which followed very closely the first one.

From the control room I ordered an increase in speed and also ordered to ready the second engine while exhausting the water which had entered the control room. Once on the conning tower, I ordered the rudder 20° to the side because I considered facing the waves too dangerous. I also ordered the personnel on deck below, along with the torpedo man who was stunned after the blow received, but during these actions we were hit by a third oncoming wave.

After a few seconds, having rescued the men on deck, I stopped the engine and closed the hatch ordering “dive” but at the same time the chief electrician manning the panels informed me that he could not power the electric motors because the solenoids were under water.

In the control room water had reached the lower part of the hatch and did not start pouring into the forward compartment (with danger to the batteries, compass, and converter), thanks to the prompt closure of the hatch. Nevertheless, water had invaded the motors and electrical panels located below the control room. To avoid ending up sideways to the main wave, I ordered the main hatch reopened and the diesel engine started. The boat went back along the wave as before. I took advantage of this time to expel water from the control room and verify the electrical motors’ control panels.

The serious deficiency in the operational efficiency of the boat caused by this incident forced the Bagnolini to return to base where it arrived on November 15th ( a source reports the 14th).

Note: The opening of the conning tower’s hatch was necessary because the intake valve for the diesel engines was located under the conning tower’s deck and had to be kept closed to avoid water entering, in great quantity the engine room and the ventilation system.”

The ordeal was not over. On the 3rd, on the way back to base, the Bagnolini was attacked by a British Bristol Blenheim airplane which dropped a few bombs, but missed the target. Three days later, on January 6th, 1941 the boat was finally back to base. The intense damage suffered during the mission forced the boat to the docks for repairs and refitting. Work began on January 20th, and was not completed until April 18th. During this period, Lieutenant Commander Tosoni Pittoni was transferred to the submarine Bianchi aboard which he lost his life, while another experienced officer, Lieutenant Commander Giulio Chialaberto, replaced him. Tosoni Pittoni later received the Gold Medal for bravery for the sinking of H.M.S. Calypso. During this period, the Italian command decided to transfer the Bagnolini to the German training base in Gotenhafen, but later the order was reversed and only the Giuliani reached the Baltic.

On July 10th, the Bagnolini was again at sea, this time assigned to a patrol area off Gibraltar in a newly attempted collaboration with the Germans. Lieutenant Commander Chialaberto took the boat east of the Strait to explore the area and scout for possible enemy traffic. On the 23rd, a large convoy of about 20 ships with 4 destroyers in escort was sighted in position 35° 45’ N, 14° 15’ W proceeding at 7 knots. According to the commanding officer, the Bagnolini was able to torpedo an 8,500 t. tanker and possibly a smaller cargo, but war records do not confirm these sinking. The Bagnolini had stumbled across convoy OG.68 from Liverpool to Gibraltar, which had left port July 12th with a total of 33 cargo ships, all of which made it to port on the 26th. A second convoy was sighted on the 29th and a signal broadcast, but the submarine was not able to take offensive action due to intense fog. On August 8th, the boat was sent back to Bordeaux where, once again, there was a change in command with Lieutenant Commander Chialamberto relinquishing command to Lieutenant Mario Tei. Chialamberto eventually would become the commanding officer of Maricosom in Taranto.

This time the refitting required several months of intense work and the vessel did not see action until early 1942. On January 18th, the Bagnolini left port and moved off the Azores Islands were it remained on patrol from the 23rd until February 10th. Having failed to intercept any traffic, the submarine returned to base arriving on February 22nd. Upon returning, the vessel was again sent to the yards where it remained for repairs and refitting until April 15th.

On April 24th, the boat left for a long mission to South America, not returning until June 28th. The operational orders, issued by Betasom in coordination with B.d.U., called for patrols off Cape San Rocco (Brazil) where it was assumed there would be intense traffic and minimal antisubmarine activity. Also part of this patrol was the Barbarigo and, during the famous attack of this boat under the command of Captain Grossi against a mistakenly identified California class battleship, the Bagnolini was only 70 miles away. Reaching the assigned patrol area on the 20th, the captain decided to move further south toward Port Natal, especially after having been sighted by two aircrafts. On the 21st, another aircraft spotted the submarine and soon after a destroyer or similar unit began a systematic chase which lasted for over 90 minutes. Later, as soon as the submarine had reached the surface, another aircraft, this time a Catalina, forced yet another crash-dive.

On May 12th, having sighted smoke on the horizon, the Bagnolini attempted an attack which had to be abandoned due to the presence in the area of an escort unit. Later the same day, there were two more sightings: first an airplane, and later a ship which soon faded from sight. Light escort units present in the area began giving chase dropping depth charges, but causing minimal damage, but having assessed that the two units were not to give up too easily, the captain moved the boat further south.

On May 26th, Betasom sent a signal ordering the boat off Pernabuco. The same day, at around 04:15 AM, the Bagnolini reported an isolated ship moving at about 12 knots, too fast for any offensive action. The night of the 27th, there was a real attack; this time with the launch of four torpedoes, one of which, according to the patrol report, was on target, but the tanker in question was able to move on, avoiding further attacks. There is no further information about this attack, but we know that the crew identified the large tanker as one of the type “Canadolite”.

Another signal from Betasom ordered the boat off Freetown, thus on May 31st Captain Tei began the transfer arriving in the new area a few days later. On June 7th it attempted to follow an isolated ship which, due to the poor weather conditions, was able to escape. Out of fuel, the Bagnoli began the return voyage, reaching Le Verdon the morning of June 28th. Of the 5 boats taking part in this operation (Da Vinci, Cappellini, Archimede, Barbarigo, and the Bagnolini), the Bagnolini was the only one which did not score a success. On the other hand, Captain Longanesi’s Da Vinci sank 19,997 tons of enemy shipping.

At the end of this long patrol, Lieutenant Tei, promoted to Lieutenant Commander, was transferred to the Giuliani while Commander Ferdinanto Corsi, formerly the captain of the destroyer Dardo, took command. On September 15th the boat was again at sea for a patrol off the African continent near the estuary of the Congo River. The night of September 28th, in position 19° 33N, 20° 06 W (about 300 miles north of Capo Verde), the lookouts sighted a ship with the navigation lights on, and soon after a destroyer, against which the skipper launched two torpedoes, missing the elusive target. Soon after, retaliation began with a long hunt and the launch of several depth charges that did not cause much damage. Orders from Betasom had the boat relocated south of Freetown and later on the route between Brazil and Sierra Leone. Without encountering any traffic, but sighting several planes and escort units, the submarine left the patrol area on October 26th reaching Bordeaux, along with the Archimede, on November 7th. Soon after, the captain disembarked leaving the Bagnolini in the hands of the new skipper, Lieutenant Angelo Amendolia. Of the four boats that had participated in this mission (Archimede, Barbarigo, Bagnolini, Cappellini) only Captain Saccardo’s Archimede was able to achieve any result, sinking a total of 20,043 tons of enemy shipping.

After a relatively small period for refitting, on February 14th the Bagnolini left La Pallice and was again on patrol and this time again assigned to the distant waters of the South American continent. The boat reached Brazil on March 8th, remaining until the 14th off Cearà and later until the 22nd off Cape S. Rocco. Immediately, the crew noticed an increased aerial activity that made the transfer tense and dangerous. Off the Canary Islands an aerial attack came close, but the boat did not register damages. Upon reaching the patrol area, it was noticed right away that there was very limited if any traffic, but a strong aerial surveillance.

The night of the 15th, just off the Island of Fernando De Noronha, a sudden airplane attack caused the forward portside fuel tank to rupture. With the boat already suffering from a previous water infiltration and limited fuel, on the 18th the boat began the return voyage. Two more sightings took place, on the 20th (a cargo ship) and the 22nd (a destroyer), but in neither case did the cinematic conditions favor an attack. This long and last mission under the Italian flag ended on April 13th with the arrival in France. As noted by the official Italian documentation, this mission did not produce any result, but helped demonstrate that the targets most preferred by the Italian submarines, isolated ships, had almost disappeared and aerial surveillance had increased dramatically, and had become quite efficient.

Following negotiations with the Germans, the Bagnolini was one of the seven submarines designated to be transformed into transports. Supposedly, the idea of transforming these vessels originated with C.V. Enzo Grossi, then commander of the base (Betasom), who had realized that these submarines were no longer fit for offensive operations. Grossi made a proposal to Adm. Donitz: in exchange for the 7 Italian submarines, the German Navy would transfer 7 newly constructed U-boats to the Italian Navy. Although it could appear that the proposal was preposterous, it was actually warmly welcomed, especially because the Germans were producing a boat a day, but did not have enough personnel to man them.

As part of the final agreement reached between the two navies, the Krigsmarine transferred seven U-boats of the class VII-c (designated by the Italians as class S) in exchange for an equivalent number of Italian boats which, due to their dimensions, were better suited for the long voyage to Japan. Of the seven vessels, only five began the refitting work. This operation was completely under German control, but the submarines were to retain their Italian crew. Of the five boats, the Tazzoli was lost soon after its departure, while the Barbarigo was lost probably soon after. Both losses were never documented and remain a mystery to these days.
At the end of July 1943, both the Bagnolini and Finzi had completed the refitting necessary to transform the boat into transport submarines. Lieutenant Aldo Congedo took the boat from Bordeaux to Le Verdon at the estuary of the Gironde. The night of September 8th, having received news from Italy of the capitulation, the Germans kept the boat from leaving. The base commander, Captain Grossi, was ordered to destroy the remaining boats, but instead he had the Germans take them to the XII Flotilla pens where, still flying the Italian colors, the Bagnolini rested until the 14th. That day, following the Italian declaration of war on Germany, the tricolor was lowered, and the Italian crew disembarked.

The former Italian submarines were renamed “Aquila”, later changed to “Mercator”. The Bagnolini was renamed Mercator II, and later UIT-22. Under the command of Sub-lieutenant Wunderlish, the boat left Bordeaux on January 26th, 1944. The delay in departing was caused by the need for the German crew to master the Italian machinery, but with 12 Italians joining the Germans, safe operation was guaranteed.

The Submarine UIT-22 (formerly Alpino BAGNOLI) in Boardeaux (1943)
(Photo courtesy Erminio Bagnasco and Achille Rastelli)

On February 22nd, 900 miles from Ascension, the boat was damaged by an American airplane, causing loss of fuel and forcing a mid ocean refueling by the U-178, at the time returning from Panang, off the South African coast. At the meeting point, 500 miles from Cape Town, U-178 found the ocean covered by a large amount of oil. On March 11th, UIT-22 (Bagnolini) had been sunk by three British Catalinas belonging to the 262nd Squadron. According to records made available only many years after the conflict, the South African squadron was sent to the attack area after detailed instructions about the rendezvous point had been deciphered by ENIGMA. The Bagnolini still rests at the bottom of the ocean.

Operational Records

Patrols (Med.)Patrols (Other)NM SurfaceNM Sub.Days at SeaNM/DayAverage Speed
38464133908349 144.19 6.01


6/12/194000.59C.C. Franco Tosoni PittoniMediterranean34°03’N-24°05’ETorpedoSankHMS CalypsoLight Cruiser4180Great Britain
9/18/1940C.C. Franco Tosoni PittoniAtlantic Ocean41°20’N-09°16’WTorpedoSankCabo TortosaSteam Freighter3302Spain
12/19/194017.50C.C. Franco Tosoni PittoniAtlantic Ocean54°10’N-15°50’WSC.15 dTorpedoSankAmicusSteam Freighter3660Great Britain
1/1/194120:00C.C. Franco Tosoni PittoniAtlantic Ocean54°10’N-13°55’WTorpedoFailedNorthen prideGunboatGreat Britain

Crew Members Lost

Last NameFirst NameRankItalian Rank
ArmitanoLeoneNaval RatingComune
BalestrieriDomenicoChief 2nd ClassCapo di 2a Classe
BartolozziRenatoNaval RatingComune
BuosiBrunoChief 3rd ClassCapo di 3a Classe
MazzoniGiuseppeChief 2nd ClassCapo di 2a Classe
PacittiVincenzoJunior ChiefSottocapo
PetrelliSerafinoJunior ChiefSottocapo
RossillaCarloSublieutenant G.N.Tenente G.N.
TiniSuperoJunior ChiefSottocapo
ValentiBrunoChief 2nd ClassCapo di 2a Classe
ZampieriGiordanoJunior ChiefSottocapo
ZarelliLindoNaval RatingComune