Austrian semi dreadnought battleship SMS Zrinyi 1908-1919 (1921)

Erzherzog Karl-class

Radetzky-class

Tegethoff-class

Laid down at the Stabilimento Tecnico Triestino, Trieste, Italy on 15 November 1908, launched on 12 April 1910, completed in July 1911, commissioned on 22 November 1911, departed Pola[ Pula, Croatia] on 10 November 1918 and handed over by Yugoslav navy officers which handed her over to an American squadron of submarine chasers, in US navy service retaining her name between 22 November 1919 and 7 November 1920, ceded to Italy and finally broken up between 1920-1921.

The Radetzky-class semi dreadnought battleships consisted of the Radetzky, Erzherzog Franz Ferdinand and Zrinyi. Preceded by the Erzherzog Karl-class and succeeded by the Tegethoff-class. Between 25 and 29 September 1905 were five designs drawn for this class in which the armament differs with Siegfried Popper (1) even advocating the design a real dreadnought although without success.

Preliminary designs:
1. 2x2-28cm/11”guns, 4x1-24cm/9.4” guns, all in turrets and 8-19cm/7.5” guns.
2. 2x2-28cm/11”guns, 4x1-24cm/9.4” guns, all in turrets and 12-10cm/3.9” guns.
3. 4x2-28cm/11”guns and 16-10cm/3.9” guns.
4. 2x2-&2x1-30,5cm/12.0” guns and 16-10cm/3.9” guns.
5. 2x2-30,5cm/12.0” guns, 4x2-19cm/7.5” guns and 12-10cm/3.9” guns.

General technical specifications of this class. Displacement 14.741 tons/14.508 long tons (standard)-16.099 tons/15.845 long tons (full combat load) and as dimensions 137,5 (waterline)-138,8 (overall)  x 24,6 x 8,1 metres or 451.1-455.5 x 81 x 26.7 feet. Two shaft 4-cylinder vertical triple expansion steam engines and 12 Yarrow-type coal-fired boilers supplied 20.000 hp allowed a speed of 20,5 knots and with a speed of 10 knots and a coal bunker capacity of 1.350 tons a range of 4.000 nautical miles. Their crew numbered 890 men. The armour consisted of a 23cm/9.1” thick belt, 4,8cm/1.9” thick deck, 5,4cm/2.1” thick bulkheads with the main gun turrets, secondary gun turrets, casemates and conning tower protected  by respectively 25c,/9.8”, 20cm/7.9”, 12cm/4.7” and 25cm/9.8”. The armoured double bottom was to protect against torpedoes and mines.
The armament consisted of 2x2-30,5cm/12” 45cal Skoda guns, 4x2-24cm/9.4” guns, 20-10cm/3.9” quick firing guns, 4-3,7cm/1.5” guns and 3-45cm/18” torpedo tubes (each beam 1, stern 1).

Note
1. Siegfried Popper (5 January 1848 Prague, Czech Republic-19 April 1933 Prague, Czech Republic), naval architect, ending his carrier in the Austro-Hungarian navy as Generalingenieur on 1 April 1907. Afterwards he worked at the Stabilimento Tecnico Triestino shipyard at Trieste, Italy.