The Balilla-class submarines were the first cruiser submarines built for the Regia Marina. They displaced 1,450 metric tons (1,427 long tons) surfaced and 1,904 metric tons (1,874 long tons) submerged. The submarines were 86.5 meters (283 ft 10 in) long, had a beam of 7.8 meters (25 ft 7 in) and a draft of 4.7 meters (15 ft 5 in).[1] They had an operational diving depth of 110 meters (360 ft).[2] Their crew numbered 77 officers and enlisted men.[1]
For surface running, the boats were powered by two 2,450-brake-horsepower (1,827 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 1,100-horsepower (820 kW) electric motor. The submarines were also fitted with an auxiliary diesel cruising engine that gave them a speed of 7 knots (13 km/h; 8.1 mph) on the surface. They could reach a maximum speed of 17.5 knots (32.4 km/h; 20.1 mph) on the surface and 8 knots (15 km/h; 9.2 mph) underwater. On the surface, the Balilla class had a range of 12,000 nautical miles (22,000 km; 14,000 mi) at 7 knots; submerged, they had a range of 110 nmi (200 km; 130 mi) at 3 knots (5.6 km/h; 3.5 mph).[2]
Bandini, the officer on watch at the time, sighted the Triad on the surface at 01:00, and sounded battle stations on board the Italian submarine. Both submarines altered course until they were heading towards each other.
Italian accounts record that the British submarine was the first to open fire with her deck gun, but she overshot.[6]Triad also fired one torpedo, which the Italian ship turned to avoid.[7] Bandini's vessel opened fire on the British deck guns with her four 13.2 mm (0.52 in) machine guns,[6] preventing the Royal Navy personnel from operating their deck gun and driving them below deck. Accounts show that the two submarines passed within four yards, with Triad cutting across the stern of the Italian vessel.[6]
In an account of the engagement published in 1940, Italian writer and then navy war correspondent Dino Buzzati, who interviewed the Enrico Toti officers and crew after their return to base, reports that both submarines were so close that an Italian gunner, furious because he could not yet train the gun to the British submarine, actually threw his shoes at the head of a British gunner.
Enrico Toti launched a torpedo; however it caused no damage to the British submarine.[6] At this stage, Lieutenant-Commander Salt began to dive his ship, however she was sunk during this manoeuvre by two direct shell hits from the 120 mm gun.[6]
First Lieutenant Giovanni Cunsolo writes: "The submarine sinks, then in a desperate attempt to escape she tries to surface, stern-first, but soon after she disappears under the surface of the sea."[6]
The time from first sighting until sinking was 30 to 45 minutes,[6] and there were no survivors picked up by the Italian submarine or any other vessels. For this action, the entire crew and their commander received an award.
From March to June 1942, Enrico Toti was transferred to the Italian naval base at Pola, where she carried out 93 training sorties.[8] She was later deployed to transport supplies to Italian forces in North Africa. The submarine accomplished four round missions to Libya carrying 194 ton of cargo.[9] Decommissioned on 1 April 1943, Enrico Toti was converted into a blockship at Taranto, her hull being used as submarines' battery charger.[8]
HMS Rainbow
It was long believed that HMS Triad had been sunk by a mine, and that the ship sunk by the Enrico Toti was in fact the R-class submarine HMS Rainbow, which was patrolling nearby and had not been in contact. However, research in 1988 by the Royal Navy came to the conclusion that HMS Rainbow had been sunk in a collision with the Italian cargo ship Antonietta Costa[6] which was part of an Italian convoy sailing back from Valona on 4 October 1940.[10]
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Brescia, Maurizio (2012). Mussolini's Navy: A Reference Guide to the Regina Marina 1930–45. Annapolis, Maryland: Naval Institute Press. ISBN978-1-59114-544-8.
Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN0-85177-146-7.
Frank, Willard C. Jr. (1989). "Question 12/88". Warship International. XXVI (1): 95–97. ISSN0043-0374.
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