Acciaio-class submarine

The Acciaio-class submarine[1][2] (also sometimes called Platino class[3]) was the fifth subclass of the 600 Series of coastal submarines built by the Regia Marina. They were completed during the early 1940s and saw service in World War II.

Italian Acciaio-class submarine (Porfido)
Class overview
Name:	Acciaio class
Builders:	Odero Terni Orlando (OTO), Muggiano Cantieri Riuniti dell' Adriatico (CRDA), Monfalcone Tosi, Taranto[1][2]
Operators:	Regia Marina
Preceded by:	Adua class
Succeeded by:	end of 600 series
In commission:	1941–1966
Completed:	13
Lost:	8
General characteristics [1][2]
Type:	Submarine
Displacement:	697 long tons (708 t) surfaced 850 long tons (864 t) submerged
Length:	60.18 m (197 ft 5 in)
Beam:	6.44 m (21 ft 2 in)
Draught:	4.78 m (15 ft 8 in)
Propulsion:	2 diesel engines, 1,400 hp (1,000 kW) 2 electric motors, 800 bhp (600 kW)
Speed:	14 knots (26 km/h; 16 mph) surfaced 7.7 knots (14.3 km/h; 8.9 mph) submerged
Range:	3,180 nmi (5,890 km) at 10.5 kn (19.4 km/h) surfaced
Test depth:	80 m (260 ft)
Complement:	45
Armament:	1 × 100 mm (4 in) / 47 caliber deck gun 1-2 × 20mm/70 AA 6 × 533 mm (21 in) torpedo tubes (4 forward, 2 aft) 12 × torpedoes

Design and description

The Acciaios were a development of the Adua and Perla designs, with some improvements, such as a lower conning tower to improve stability and reduce the silhouette.[2] Of the 13 vessels in the class, six were built by CRDA at Monfalcone, four by OTO at Muggiano, and three by Cantieri Tosi in Taranto, the three main Italian shipyards for submarines. They were single-hulled with side tanks, and built to a Bernardis design, though the Tosi vessels had more powerful engines (at the expense of the two stern torpedo tubes), giving a surface speed of 14.7 knots (27.2 km/h; 16.9 mph).

The word Acciaio means "steel", and all vessels in this class were named for metals and minerals.

Ships

Ship	Builder[1]	Launched[1]	Fate[1]
Acciaio	OTO	20.7.41	torpedoed 13.7.43 by HMS Unruly
Alabastro	CRDA	18.12.41	bombed 14.9.42 by Allied aircraft
Argento	Tosi	22.2.42	sunk 3.8.43 by USS Buck
Asteria	CRDA	25.6.41	sunk 17.2.43 by HMS Easton, HMS Wheatland,
Avorio	CRDA	6.9.41	sunk 8.2.43 by HMCS Regina
Bronzo	Tosi	28.9.41	captured 12.7.43 by British destroyers
Cobalto	OTO	20.7.41	rammed 12.8.42 by HMS Ithuriel
Giada	CRDA	c10.7.41	surrendered at armistice Sept 1943
Granito	CRDA	7.8.41	torpedoed 9.11.42 by HMS Saracen
Nichelio	OTO	12.4.42	surrendered at armistice Sept 43
Platino	OTO	1.6.41	surrendered at armistice Sept 43
Porfido	CRDA	23.8.41	torpedoed 6.12.42 by HMS Tigris
Volframio	Tosi	9.11.41	scuttled at armistice sept 43; raised by Germans, sunk in Allied air raid 1944

Service

Of the 13 vessels completed 8 were lost in action, serving in the Mediterranean theatre of operations.

See also

• Italian submarines of World War II

References

Notes

1. Conway p310
2. Bagnasco p163
3. C Adamo at regiamarina.net

Bibliography

• Bagnasco, Erminio (1977). Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
• Brescia, Maurizio (2012). Mussolini's Navy: A Reference Guide to the Regina Marina 1930–45. Annapolis, Maryland: Naval Institute Press. ISBN 978-1-59114-544-8.
• Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. London: Conway Maritime Press. ISBN 0-85177-146-7.
• Dodson, Aidan & Cant, Serena (2020). Spoils of War: The Fate of Enemy Fleets after Two World Wars. Barnsley, UK: Seaforth Publishing. ISBN 978-1-5267-4198-1.
• Frampton, Viktor (2010). "Question 22/44: HMS X-2". Warship International. XLVII (3): 218. ISSN 0043-0374.

External links

• Acciaio class at regiamarina.net