Kaiman-class torpedo boat

After the commissioning of the last of four Cobra class torpedo boats for the Austro-Hungarian Navy in 1900, there was a four-year hiatus in Austro-Hungarian construction of destroyers and torpedo boats. In 1904, a prototype of a new torpedo boat was ordered from Yarrow Shipbuilders at Poplar, London, and this became the lead boat of the Kaiman class. The name was in keeping with other reptilian names given to sea-going vessels. Two Austro-Hungarian naval shipbuilders then received plans and engineering assistance from the British and commenced construction; 13 boats were built by Stabilimento Tecnico Triestino, located at Trieste, and the remaining 10 boats by Ganz-Danubius at their shipyards at Fiume. All boats used a single four-cylinder vertical triple expansion engine driving one propeller shaft using steam generated by two coal-fired Yarrow boilers. They had a waterline length of 56 m (183 ft 9 in), a beam of 5.5 m (18 ft 1 in), and a normal draught of 1.3 m (4 ft 3 in). They had a standard displacement of about 209–211 tonnes (206–208 long tons). The crew consisted of 31 officers and enlisted men.[lower-alpha 1] Their machinery was rated at 3,000 indicated horsepower (2,200 kW) and was designed to propel the boats to a top speed of 26 knots (48 km/h; 30 mph). They carried 47 tonnes (46 long tons) of coal, which gave them a radius of action of 500 nautical miles (930 km; 580 mi) at 26 knots (48 km/h; 30 mph), or 1,030 nmi (1,910 km; 1,190 mi) at 16 knots (30 km/h; 18 mph).[1][2][3]

They were armed with four Škoda 47 mm (1.9 in) L/33[lower-alpha 2] guns and three 450 mm (17.7 in) torpedo tubes.[4] The 47 mm guns were license-built versions of the British QF 3-pounder Hotchkiss gun; they had a rate of fire of 25 rounds per minute and an effective range of 3,000 m (9,800 ft).[5] The 450 mm torpedoes were the L/5 type, which carried a 95 kg (209 lb) warhead and had a range of 3,000 m at a speed of 32 knots (59 km/h; 37 mph). Later variants increased the warhead to 110 kg (240 lb) and the range to 6,000 m (20,000 ft) at 27 knots (50 km/h; 31 mph).[6] In 1915, one 8 mm (0.31 in) machine gun was added.[1] The boats were initially given names, but were redesignated with numbers on 1 January 1914, with three suffixes; E for the Yarrow boat built in England, T for the boats built in Trieste, and F for the boats built in Fiume.[4]

At the outbreak of World War I, the Kaiman-class torpedo boats were split between the 1st and 2nd Torpedo Craft Flotillas, based at Cattaro and Pola respectively. In the 1st Torpedo Craft Flotilla, the 3rd Torpedo Craft Division had two groups of Kaiman-class boats: 50 E, 51 T and 73 F made up the 2nd Torpedo Boat Group, and 53 T, 54 T and 56 T made up the 3rd Torpedo Boat Group. In the 2nd Torpedo Craft Flotilla, the 5th Torpedo Craft Division had three groups of the class: 55 T, 68 F and 70 F made up the 4th Torpedo Boat Group; 61 T, 65 F and 66 F comprised the 5th Torpedo Boat Group; and 64 F, 69 F and 72 F made up the 6th Torpedo Boat Group. Also in the 2nd Torpedo Craft Flotilla, the 6th Torpedo Craft Division had three more groups of Kaiman-class boats: 52 T, 58 T and 59 T were in the 7th Torpedo Boat Group; 60 T, 62 T and 63 T made up the 8th Torpedo Boat Group; and 57 T, 67 F and 72 F comprised the 9th Torpedo Boat Group.[7]

The Kaiman class was considered to be a very capable design, and all boats saw significant active service during the war. All survived, although several were badly damaged by naval mines and collisions.[1] On 8 August 1914, 72 F accompanied the protected cruisers Zenta and Szigetvár and the Huszár-class destroyer Uskoke during a shore bombardment of Antivari in Montenegro. This was followed, on 2 September, by another shore bombardment of the Montenegrin coast by the Huszár-class destroyers Scharfschütze and Ulan, assisted by 64 F and 66 F. On 16 September, 68 F and 72 F were involved in a raid and landing at San Giovanni di Medua on the Albanian coast. On 14 February 1915, 68 F, the Huszár-class destroyer Csikos and another torpedo boat bombarded Dulcigno and Antivari on the Montenegrin coastline. On 2 March 1915, the Huszár-class destroyers Ulan, Csikos and Streiter, accompanied by 66 F and 67 F, bombarded Antivari and sank the Montenegrin royal yacht Rumija. Three days later, 57 T also bombarded Antivari.[8]

The French submarine Papin torpedoed 51 T in September 1915.

On 24 May 1915, a large Austro-Hungarian force of three dreadnought battleships, six pre-dreadnought battleships, and four destroyers, accompanied by fifteen Kaiman-class boats and four 250t-class torpedo boats, participated in the Bombardment of Ancona, a shore bombardment operation against the northern Adriatic coast of Italy. On the same day, the pre-dreadnought Radetzky, accompanied by 56 T and 73 F, bombarded Potenza Picena, Termoli and Campomarino.[8] On 18 June, the armoured cruiser Sankt Georg conducted a bombardment of a bridge near Rimini, accompanied by 57 T, 58 T, 63 T and 67 F. On the same day, Szigetvár, 64 F and 69 F bombarded Colonnella, sinking one freighter during the shelling, and sinking two motor schooners encountered off Rimini following the bombardment.[9] On 9 September 1915, 51 T was torpedoed and had her bow blown off by the French submarine Papin while she was patrolling off Palagruža. She was towed to port and presumably repaired.[10]

On 9 July 1916, the scout cruiser Novara, 54 T, 73 F and another torpedo boat raided the Otranto Barrage, the Allied naval blockade of the Strait of Otranto, which resulted in the sinking of two drifters, and damage to two more.[11] Ten days later, 65 F and 66 F sank the Italian submarine Balilla off Lissa.[12] On 8 October, 68 F encountered the Italian Rosolino Pilo-class destroyer Pilade Bronzetti off San Giovanni di Medua, but after a brief chase was able to reach the cover of a shore battery.[13] On 16 November 1917, 61 T and 65 F were part of a minesweeping force supporting the bombardment of a 152 mm (6.0 in) Italian shore battery at Cortellazzo near the mouth of the Piave.[14] All boats were due to have their aft torpedo tube replaced by a single Škoda 66 mm (2.6 in) L/30 anti-aircraft gun in late 1918, but it is not clear whether this actually occurred. 52 T ran aground near Split in December 1918. Following World War I, the Kaiman-class boats were allocated to Great Britain, Italy and the new Kingdom of Serbs, Croats and Slovenes (later renamed Yugoslavia). Great Britain and Italy scrapped their boats, but the Yugoslavs retained 54 T, 60 T, 61 T and 69 F as T12, T9, T10 and T11 respectively. All four were discarded and broken up between 1928 and 1930.[4][15]

• List of ships of the Royal Yugoslav Navy