Yugoslav monitor Vardar

The Yugoslav monitor Vardar was a river monitor built for the Austro-Hungarian Navy as SMS Bosna, but she was renamed SMS Temes (II) before she went into service. During World War I she was the flagship of the Danube Flotilla, and fought the Serbian Army, the Romanian Navy and Army, and the French Army. She reverted to the name Bosna in May 1917, after the original SMS Temes was raised and returned to service. After World War I she was provided to the newly created Kingdom of Serbs, Croats and Slovenes (later Yugoslavia), and renamed Vardar. During the German-led Axis invasion of Yugoslavia in April 1941, she was scuttled by her crew.

Description and construction
The ship was built for the Austro-Hungarian Navy by Stabilimento Tecnico Triestino, and was laid down as Bosna at Linz in 1914, as part of the Austro-Hungarian 1914–15 Naval Program. She was named after the river of the same name, but was renamed Temes (II) during construction, after the sinking of the original SMS Temes by a mine on the Sava river on 23 October 1914. She had an overall length of 61 –, a beam of 10.3 –, and a normal draught of 1.2 –. Her displacement was 530 –, and her crew consisted of 91–100 officers and enlisted men. The ship was powered using steam generated by two Yarrow water-tube boilers, and the ship carried 75 LT of oil. The propulsion system was rated at 1600 – and she was designed to reach a top speed of 13 –.

Her main armament was a twin gun turret of 120 mm/L45 guns forward of the conning tower and a twin turret of 120 mm/L10 howitzers aft of the conning tower. She also mounted twin 66 mm/L26 anti-aircraft guns, two 47 mm/L44 guns, and seven machine guns. Her armour consisted of belt and bulkheads 38 – thick, deck armour 25 mm thick, and her conning tower, gun turrets and cupolas were 51 mm thick. Temes (II) was completed on 9 July 1915.

Commissioning and World War I
Temes (II) was commissioned into the Danube Flotilla in 1915, and was in action against the Serbian Army at Belgrade in early October, when the Serbs evacuated the city in the face of an Austro-Hungarian assault. During the final river crossing and support of the resulting bridgehead, Temes (II) provided close support. During this task, she was drawing fire away from the battle-damaged monitor Enns when she received a direct hit in the crew quarters aft, and had to move out of range. She was run ashore to put out fires and stop leaks, was towed out of the battle area by an armed steamer, and then taken to Budapest for repairs.

In November 1915, the other monitors were assembled at Rustschuk, Bulgaria. The position of Romania was uncertain, with the Central Powers being aware that the Romanians were negotiating to enter the war on the side of the Entente. To protect the 480 km long Danubian border between Romania and Bulgaria, the Flotilla established a sheltered base in the Belene Canal. When the Romanians entered the war on 27 August 1916, the monitors were again at Rustschuk, and were immediately attacked by three improvised torpedo boats operating out of the Romanian river port of Giurgiu. The torpedoes that were fired missed the monitors, but struck a lighter loaded with fuel. The First Monitor Division, including Temes (II), was tasked with escorting supply ships back to the Belene anchorage. This was followed by forays of the monitors both east and west of Belene, during which both Turnu Măgurele and Zimnicea were shelled. On 9 May 1917, she was renamed SMS Bosna as the original SMS Temes was returning to service after a complete rebuild.

In April 1918, Bosna, along with three other monitors, two patrol boats and a tug were formed into Flottenabteilung Wulff under the command of Flottenkapitän (Fleet Captain) Olav Wulff. Flottenabteilung Wulff was sent through the mouth of the Danube and across the Black Sea to Odessa, where it spent several months supporting the Austro-Hungarian troops enforcing the peace agreement with Russia. They returned to the Danube at the end of August, and were anchored at Brăila on 12 September. On 16 October, she and the rest of the First Monitor Division sailed from Brăila to Belene. The Danube Flotilla then protected Austro-Hungarian troops withdrawing towards Budapest, fighting French and irregular Serbian forces as they withdrew, and arrived on 6 November.

Interwar period and World War II
Bosna was temporarily manned by the Yugoslavs between 1918 and 1919, but was officially handed over to the Royal Yugoslav Navy and renamed Vardar in 1920. On 6 April 1941, the German-led Axis invasion of Yugoslavia began, and Vardar was the flagship of the Monitor Division, based at Dubovac. On 11 April, after operating along the Hungarian border during the first few days of the invasion, Vardar and the monitor Sava began to withdraw towards Novi Sad, during which they came under repeated attacks by Junkers Ju 87 Stuka dive bombers. She was scuttled by her crew on 11/12 April.