The MAS 500 was an Italian motor torpedo boat class used by the Regia Marina during WW2. MAS is the abbreviation for Motoscafo armato silurante, “torpedo-armed motorboat” in English.
History
The project for the MAS type “500” was presented in November 1935, because Italy needed motorboats armed with modern torpedoes (for that time) with a guaranteed speed of 44 knots assured by 2 petrol engines Isotta Fraschini “Asso” of 1,000 horsepower each, this new class of MAS was studied by Cantieri Baglietto of Varazze and was shown to the Minister of the Navy and then accepted by Prime Minister Benito Mussolini.
The MAS type “500” was a small, fast wooden boat; unlike the MAS of the First World War, they were much faster. They got different armaments over time and also different modifications. The MAS type “500” was composed of almost 100 units. These wooden boats then underwent several modifications, such as the use of metal instead of wood for the hull of the boat, and increases in size and crew complement.
The MAS 500 were produced in four series.
The first units of the MAS “500” had a wooden hull (the MAS 525 had a metal hull) with a hull with two steps and a range of 400 miles at 42 knots and 1,000 miles at 6 knots with auxiliary engines.
1°Serie: 26 units from MAS 501 to MAS 525. In particular, the MAS 524 had 3 Isotta Fraschini engines with 3 propellers instead of 2, but without auxiliary engines.
2°Serie: 24 units from MAS 526 to MAS 550. 2nd Series had the greater dimensions, were built with two-stepped wooden hulls, and had a range of 360 miles at maximum speed or 1,100 miles at 6 knots. MAS 550 had a metal hull.
3°Serie: 13 units from MAS 551 to MAS 564 divided into 2 groups
- 1° Group from MAS 551 to MAS 554 had metal hulls, with a range of 350 miles at maximum speed and 850 miles with auxiliary engines.
- 2° Group from MAS 555 to MAS 564 had wooden hulls, with a range of 395 miles and 913 miles, respectively.
The MAS of 3rd Series changed the 13.2 mm Breda machine gun to the 20/65 Breda machine gun, which made the gun more effective against enemies at medium distances.
4°Serie: 12 units from MAS 566 to MAS 576. These units were almost identical to those of the 3°Series with some minor changes such as the adoption of the helm of manoeuvre in the bridge, the replacement of the shaft with support for the Breda 6.5 mm machine gun and the increase in the supply of ammunition for the 20/65 Breda machine gun.
Service History
MAS 555
After the armistice of 8 September 1943, the MAS 555 was used by Co-Belligerent Italy. In particular, it was used together with two British motor boats against a German landing convoy on 12 November 1943. After a few hours, the MAS 555 was sunk during the German landing at Rhodes in Greece.
MAS 561
Later it was put into service, but before service in the MNR it was modified with the addition of two 12.7 mm Breda-SAFAT.
Later, the MAS 561 was renamed SA 16 for German purposes.
On 23 April 1945, the MAS 561 sank with its entire crew.
MAS 569
The MAS 569 is part of the final series of the MAS type “500” PT boats. It was part of the Italian Black Sea flotilla and participated in the August 1942 attack on Soviet cruiser Molotov.
Deployed in the Alto Tirreno FMO until May 1942, MAS 569 was sent with MAS 568 to the Black Sea, arriving in Yalta on 30 July 1942. MAS 569 was heavily damaged in a Soviet bombing of Yalta in September 1942.
During the evening of 14 February 1943, while returning from a mission, it sighted a Soviet submarine surfacing about 10 miles to the east.
The crew of the MAS 569 went to attack the Soviet submarine, launching 2 torpedoes which did not hit the target. After ascertaining the torpedoes' negative outcome, they headed towards the Soviet submarine to launch depth charges to try to sink the submarine. They also used the 6.5 mm Breda Mod.30 to damage it but it jammed after a few shots, after having damaged it the Soviet submarine submerged and they lost track, between March and April 1943, together with the MAS of the IVa Flottiglia, it took part in numerous battles with Soviet patrol boats and gunboats and some demonstrative actions along the enemy coast.
On 20 May 1943, the MAS 569 was loaned to the German Navy, assuming the German designation S 504, then ceded on 28 August 1943 to the Romanian Navy, and was scuttled at Costanza or somewhere in the Black Sea in August 1944.
Sources:
- Enrico C., Andrea T., MAS “500” Origine, storia e strategia di un sistema d’arma 1935-1945, Ufficio storico della Marina Militare, 2017
- Giuliano Da Frè, Almanacco navale della seconda guerra mondiale (1939-1945), Odoya, 2019
- Franco B., Tutte le navi militari d’Italia 1861-2011, Ufficio storico della Marina Militare, 2012