Kaiman-class torpedo boat

The Kaiman class were high-seas torpedo boats built for the Austro-Hungarian Navy between 1904 and 1910. A total of 24 boats were built by three shipbuilding companies. The lead ship was built by Yarrow Shipbuilders, 13 boats were built by Stabilimento Tecnico Triestino, located at Trieste, and the remaining 10 boats were built by Ganz & Danubius at their shipyards at Fiume. The class was considered to be a very successful design, and all boats saw extensive active service during World War I. All survived, although several were badly damaged by naval mines and collisions. One was torpedoed and badly damaged by a French submarine, and two sank an Italian submarine. All the boats were transferred to the Allies and scrapped at the end of the war, except for four that were allocated to the navy of the newly-created Kingdom of the Serbs, Croats and Slovenes. These were discarded and broken up between 1928 and 1930.

Design and construction
The lead boat of the Kaiman class was built by Yarrow Shipbuilders, 13 boats were built by Stabilimento Tecnico Triestino, located at Trieste, with the remaining 10 boats built 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, a beam of 5.5 m, and a normal draught of 1.3 m. They had a standard displacement of about 209 –. The crew consisted of 31 officers and enlisted men. Their turbine was rated at 3000 ihp and designed to reach a top speed of 26 kn. They carried 47 t of coal, which gave them a radius of action of 500 nmi at 26 kn, or 1030 nmi at 16 kn.

They were armed with four Škoda 47 mm L/33 guns and three 450 mm torpedo tubes. 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 3000 m. The 450 mm torpedoes were the L/5 type, which carried a 95 kg warhead and had a range of 3,000 m at a speed of 32 kn. Later variants increased the warhead to 110 kg and the range to 6000 m at 27 kn. In 1915, one 8 mm machine gun was added. 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.

Service history
At the outbreak of World War I, the Kaiman-class torpedo boats were split between the 1st and 2nd Torpedo Craft Flotillas. 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 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 8th Torpedo Boat Group. The Kaiman class was considered to be a very successful design, and all boats saw extensive active service during the war. All survived, although several were badly damaged by naval mines and collisions. On 9 September 1915, 51 T was torpedoed and had its bow blown off by the French submarine Papin while she was patrolling off Palagruža. She was towed to port and presumably repaired. On 19 July 1916, 65 F and 66 F sank the Italian submarine Balilla off Lissa. All boats were due to have their aft torpedo tube replaced by a single Škoda 66 mm 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.