S-Boats in the Kriegsmarine 1935 - 1945

The S-Boats - Technical Data

S 621 - S 630

The Italian Navy was building 60 t Motosiluranti (MS-Boats) from 1943 onwards on basis of S 2. The boats completed and under construction after the Italian capitulation fell in German hands. The Kriegsmarine took over the orders for boats under construction and planned for. Totally 10 boats of this class were built. 

While the smaller MS-boats of series 1 (Motosilurante) turned out to be less seaworhty the MS-boats of series 2 built on basis of the boats of the "Orjen"-class built for Jugoslavia on the Basis of the German "S 2"-class more seaworthy. Series 2 (MS 11 - 16, MS 21 - 26 and MS 31 - 36) were built of Cantieri Riuniti dell' Adriatico (C.R.D.A.) at Monfalcone from 1942 onwards and were planned with 2 x 20mm Bofors and got two steel 53,cm torpedotubes with long spoon standing free on the forecastle. The hull correspomnded to almost 100 % the hull of type "S 2". Since 20mm Bofors were not available in sufficient numbers the boats got in stead of the bow-gun on either side of the bridge-house a 6,5 mm Breda-MG Mod. 37. The propulsion was given by 3x1100 PS Isotta-Fraschini- ASM-183 gasoline-motors.

"MS 15" - Picture: Regia Marina

Because of shortcomings shown these boats were not introduced in the Kriegsmarine.

The Italian Navy had C.R.D.A. construct 18 boats as improved new constructions on basis of series 2 (MS 51 - 56, MS 61 - 66, MS 71 - 76). These boats got a higher forecastle, two aluminum 53,3 cm torpedotubes of Geman/Italian construction on the forecastle, one 20mm-Breda and two 80mm Breda MG as well as  two 45,7cm torpedolauching divises for sideway-launching. The propulsion was by 3x1100 PS Isotta-Fraschini-ASM 183. MS 76 got 3x1500 PS Isotta-Fraschine-ASM-185 and achieved a speed of 35 knots against 31 of the sisterboats. Because of stronger frames and the high forecastle the boats were more seaworhty and 10 boats of this series were integrated in the 24. SFltl by the Kriegsmarine.

"S 629" (ex "MS 76") in autumn 1944 at Grado - Picture: Archives H.J. Böhlke

MS 51 - Drawing from Fcok: SChnellboote Bd. 2

"S 2" - (Picture from Connelly/Krakow: Schnellboot in action)