LEONARDO da VINCI is the most famous Italian submarine in the Battle of the Atlantic, holding many Italian records such as:

Greatest tonnage sunk (120,237 tons) and 17 ships;
The biggest ship sunk RMS EMPRESS of CANADA (21,517 tons)
The record of sinking 6 ships (58,967 tons) in one patrol.

In the history of the Italian Navy, LEONARDO da VINCO is second only to SCIRÉ in damage to Royal Navy warships, including battleships, in the Mediterranean. The name is an honor to the Italian artist of the 1500’s, and the boat is MARCONI Class. She was built in the Cantieri Riuniti yards in Monfalcone, Italy.

EDITOR NOTE – During our 2004 “Patrol” in Sough Germany and Austria, we will spend a day in this Italian city and visit the shipyard.

Displacement 1,036/1,460 tons
Length 76.5 meters
Beam 6.8 meters
Draft 4.7 meters
Speed (diesel) 18 knots
Speed (electric) 8½ knots
Range 10,800 miles at 8 knots on diesel
Range 110 miles at 5 knots on electric
Power (diesel) 3,600 hp
Power (electric) 1,240 hp
Tubes eight (carried total of 16 torpedoes)
Deck gun Single 120mm
AA Guns Four 13.2mm
Crew 57 men
Depth of dive 90 meters

The hull was a simple pressure hull with external ballast tanks, saddle tanks, extending outward from the hull.

Her first Skipper was Captain Ferdinando Calda and when da VINCI was commissioned, she was one of the most modern in the Italian fleet. She was delivered to the Italian Navy in February 1940 and was assigned to the First Submarine Group, 22a Squadron based in Naples.

After a few patrols in the Mediterranean, on 22 September 1940 she is transferred into the Atlantic Theater and based at Bordeaux and attached to the 12th U-Bootflottille, where all the Italian submarines and most of the German larger U-Boats were based. She arrived 31 October 1940.

There was nothing special about da VINCI or her accomplishments in the first phase of the Battle of the Atlantic. da VINCI and the other MARCONI Class submarines were not fully tested, and sent into action before they were totally ready. But she was upgraded and modified soon in the Bordeaux shipyards with a smaller conning tower, a new periscope, better AA armament is added and the equipment to overhaul the diesel engines is improved.

In June of 1941, da VINCI and six other Italian submarines are on patrol west of Gibraltar when they locate a well escorted convoy. Her first success comes on 28 June 1941 west of the Azores when she sinks the 8,030 ton British tanker SS AURIS.

At the end of 1941, command was passed to CC Longanesi Cattani who had already commanded BRIN which had sunk two merchant ships in June of 1941. From 7 November 1941 until 20 December, da VINCI patrolled with two other Italian submarines to the south west of the Azores. No successes.

Departing 23 January 1942 for her seventh war patrol, da VINCI and her three accompanying submarines FINZI, TAZZOLI and MOROSINI head west – bound for American waters, for the warm waters between Florida and the Bahamas.

da VINCI had two successes in her area – the 3,557 ton Brazilian merchantman CABEDELO on 25 February then on 28 February, she immobilized the 3,644 ton Latvian steamer EVERASMA with her deck gun, then sank her with a single torpedo. After some fifty days at sea, da VINCI returns to her homeport of Bordeaux.

Then in May of 1942, da VINCI is headed again to the Western Hemisphere, this time headed for Rio de Janeiro to attack any ships in that harbor. She has barely reached Brazilian waters when he mission is aborted and she is ordered to remain in Brazilian waters.

On the morning of 23 May she is patrolling off the Cape St. Roque area in Brazil when her Skipper received word that her sister submarine BARBARIGO under command of Grossi, has sunk an American battleship of the CALIFORNIA Class. Soon da VINCI reports that she has attacked an American cruiser of the PENSACOLA Class but without success.

EDITOR NOTE – BARBARIGO had stumbled upon an American task force in a dark night and fired into the group of ships. Grossi reported sinking an American battleship of 31,500 tons but in fact, her torpedoes went in toward the cruiser USS MILWAUKEE and the destroyer USS MOFFET. Both warships were not even hit, and the task force continued on its way.

Cattani was under the impression that the American ships were searching for shipwrecked seamen when da VINCI attacked.

Soon da VINCI departs Brazilian waters and steams for the coast of Africa and begins her patrol off the Freetown area. On 2 June she fires a single torpedo at the 1,087 ton sailing ship REINE MARIA STUART, which sinks immediately.

7 June, she torpedoes the 6,855 ton British steamer RMS CHILE and three days later she attacks the 5,483 ton Dutch steamer ALIOTH with her deck gun, then a torpedo. The ship sinks quickly. On 13 June 1942, da VINCI attacks the 6,471 ton RMS CLAN McQUARRIE, sinking her.

Her torpedoes all gone, da VINCA departs her patrol area and heads for the French coast and her homeport of Bordeaux. She has a short stop in the area of the Cape Verde Islands to rendezvous with the submarine FINZI, where she transfers eleven tons of fuel to her sister ship, then heads for home.

When da VINCO arrives at base in Bordeaux, Captain Longanesi-Cattani transfers command of the boat to TV Gianfranco Gazzana Priaroggia who had earlier commanded ARCHIMEDE.

Once back in Bordeaux, da VINCI is put into the shipyards for modifications necessary for this boat to transit the Atlantic for her intended attack on………..New York City? With mini-submarines and commandoes??? This was described by the Italian submarine flotilla as an “ambitious project”. It appears that it was.

da VINCI after modifications – note container for the CA-2 units forward of the conning tower

This project is borne from the successes of the Decima MAS Flotilla that sank the Royal Navy battleships HMS VALIANT and HMS QUEEN ELIZABETH in Alexandria Harbor. Unlike these attacks by the mini-submarines launched from SCIRÉ, the men of Decima MAS Flotilla plan a micro submarine called CA-2, which would allow a group of frogmen to go into American harbors and place explosives on ships anchored there.

September 1942, the first prototype of the micro-submarine CA-2 arrives in Bordeaux to test docking and un-docking from the larger submarine. da VINCI is modified by removing the deck gun and installing the watertight hangar for the CA-2 units.

The testing goes well, but the planned attack against American ports is postponed until the CA-2 units were made more reliable and the Italian Navy could gather more information about the American harbors. Therefore, in October 1942, da VINCI is back in the shipyard to have the watertight hangar removed and the deck gun reinstalled.

Once out of the shipyards in October, she heads for Freetown but her patrol area is changed and she is ordered to the Brazilian coast. This change of patrol areas is met with success, as on 2 November 1942, she sinks the 7,010 ton English steamer EMPIRE ZEAL. Two days later, she intercepts the 6,566 ton Greek merchantman ANDREAS and opens fire with the deck gun in concert with torpedo, and the ship goes down.

On 10 and 11 November respectively, da VINCI sinks the 7,176 ton American ship MARCUS WHITMAN and the 5,300 ton Dutch VEERHAVEN. The following day, she attacks another Dutch merchantman but the target evades the torpedoes and is saved.

MARCUS WHITMAN was a new Liberty Ship, built 1942 and owned by WSA and operated by Matson Navigation Company. Her Master was Joseph Pierce and she was armed with one 4 inch deck gun, four .50 cal and three .30 cal machine guns. She drew 16 feet, was making 12½ knots in ballast when she was attacked. She was sailing alone from Cape Town to Dutch Guiana.

The torpedo hit at the #5 hold and the explosion blew the propeller and rudder completely off the ship! The deck was buckled and the ship swung around in a circle. The Armed Guard fired two shots from the 4 inch deck gun, but then secured the weapon for fear of giving away the ship’s position to the submarine in the dark night.

The eight officers, thirty-three men and eleven Armed Guards abandoned the ship at 2135 hours in four lifeboats. Once the men were safely in the water and away from the stricken ship, a second torpedo slammed into her starboard midships and the boilers blew, but the ship remained afloat. Twenty rounds from the submarine’s deck gun sent her down. The motor lifeboat with fifteen men got to Natal and the other three boats, using sails, landed shortly after. There were no casualties in this action.

On 20 February 1943 da VINCI departs her homeport of Bordeaux for her last mission as part of the Italian Navy. She arrives her patrol area off Cape Palmas at the Gulf of Guinea and on the 13th, she spots the huge 21,517 ton British steamer EMPRESS of CANADA, transporting troops as well as 500 Italian P.o.W.’s over the Atlantic. She sinks quickly.

The Command HQ at Bordeaux sends the radio message that the Skipper has been promoted to Captain of Corvette (the German equal of Korvettenkapitän, American Lt. Cdr.) and da VINCI gets orders into the Indian Ocean.

Off Angola, she meets with FINZI and takes on fuel. 19 March, she sinks the 7,630 ton British steamer LULWORTH HILL. She moves into the Indian Ocean for four weeks and on 17 April, sinks the 6,566 ton Dutch merchantman SEMBILAN and on the next day, she attacks the 8,000 ton British merchantman RMS MANAAR with her deck gun, sinking her with a torpedo.

On 21 April 1943, she sank the 7,177 ton American steamer JOHN DRAYTON. Also a new ship, built in 1942, JOHN DRAYTON was owned by WSA and operated by the A. H. Bull SS Company and her Master was Carl Norman. She drew 18’ 2” under her 250 tons of fresh water ballast and was making 11½ knots when attacked. Her armament consisted of one 5 inch and one 3 inch deck gun plus four 20mm automatic guns.

She sailed from Bahrein headed for Cape Town and she departed the convoy on 6 April, proceeding as an unescorted single. About 1500 hours, the lookout spotted a torpedo that just missed ahead of the ship so the Master began a zigzag course but forty five minutes later, a second torpedo missed just astern of the ship. The third torpedo did not miss, and struck amidships, destroying the engine, boilers and many of the steam lines. Abandon ship was ordered and the eight officers, thirty-four men and fifteen Armed Guards got off safely in two lifeboats and a raft. One other boat capsized.

Once the men were safely in the water, the submarine surfaced, fired off a red flare and fired twenty-three rounds at the ship, hitting her with nineteen. The submarine came alongside and took one of the crew aboard for questioning, then released him. About a day and a half after the sinking, the Swedish steamer OSCAR GORTHON picked up the eleven men in one boat. six days later, HMS RELENTLESS (H-85) got the fourteen men (including the Master) off the raft. The last boat, containing twenty-four men was at sea for thirty days before being found. Only eight were still alive, and three of the men later died in hospital in Durban. Five officers, sixteen men and six Armed Guards were lost.

25 April, the 8,072 ton British tanker DORYSEA was sunk – her last success. With this sinking, da VINCI sets the record for shipping sunk in one patrol by an Italian submarine. Her fuel at a dangerously low level, da VINCI sets out for Bordeaux but in the Bay of Biscay, the Royal Navy is waiting and on 23 May 1943, the destroyers HMS ACTIVE and HMS NESS attack and sink this boat at 42º 16’ N x 15º 40’W, only a few hundred miles from her homeport of Bordeaux – and safety.

Thanks VINCENT – another great article.