Yugoslav monitor Sava

The Yugoslav monitor Sava is a Temes-class river monitor that was built for the Austro-Hungarian Navy as SMS Bodrog. She fired the first shots of World War I just after 01:00 on 29 July 1914, when she and two other monitors shelled Serbian defences near Belgrade. She was part of the Danube Flotilla, and fought the Serbian and Romanian armies from Belgrade to the mouth of the Danube. In the closing stages of the war, she was the last monitor to withdraw towards Budapest, but was captured by the Serbs when she grounded on a sandbank downstream from Belgrade. After the war, she was transferred to the newly created Kingdom of Serbs, Croats and Slovenes (later Yugoslavia), and renamed Sava. She remained in service throughout the interwar period, although budget restrictions meant she was not always in full commission.

During the German-led Axis invasion of Yugoslavia in April 1941, Sava served with the 1st Monitor Division. Along with her fellow monitor Vardar, she laid mines in the Danube near the Romanian border during the first few days of the invasion. The two monitors fought off several attacks by the Luftwaffe, but were forced to withdraw to Belgrade. Due to high river levels and low bridges, navigation was difficult, and Sava was scuttled on 11 April. Some of her crew tried to escape cross-country towards the southern Adriatic coast, but all were captured prior to the Yugoslav surrender. The vessel was later raised by the navy of the Axis puppet state known as the Independent State of Croatia and continued to serve as Sava until the night of 8 September 1944 when she was again scuttled.

Following World War II, Sava was raised once again, and was refurbished to serve in the Yugoslav Navy from 1952 to 1962. She was then transferred to a state-owned company that was eventually privatised. In 2005, the government of Serbia granted her limited heritage protection after citizens demanded that she be preserved as a floating museum, but little else was done to restore her at the time. In 2015, the Serbian Ministry of Defence and Belgrade's Military Museum acquired the ship. She was restored by early 2019 and opened as a floating museum in November 2021.

A Temes-class river monitor, the ship was built for the Austro-Hungarian Navy by H. Schönichen, and designed by Austrian naval architect Josef Thiel. Originally named SMS Bodrog, she was laid down at Neupest on 14 February 1903. Like her sister ship SMS Temes, she had an overall length of 52.6 m (172 ft 7 in), a beam of 9.5 m (31 ft 2 in), and a normal draught of 1.2 m (3 ft 11 in). Her standard displacement was 440 tonnes (430 long tons) with a full load displacement of 484.1 tonnes (476.5 long tons), and her crew consisted of between 77 and 79 officers and enlisted men. Bodrog had two triple-expansion steam engines, each driving a single propeller shaft. Steam was provided by two Yarrow water-tube boilers, and her engines were rated at 1,400 indicated horsepower (1,000 kW). As designed, she had a maximum speed of 13 knots (24 km/h; 15 mph), and carried 62 tonnes (61 long tons) of coal.

Bodrog was armed with two 120 mm (4.7 in)L/35 guns in single gun turrets. These were positioned forward on either side of the conning tower, which greatly reduced their firing arcs from the gun arrangement on previous Austro-Hungarian river monitors. She also mounted a single 120 mm (4.7 in)L/10 howitzer in a central pivot mount, positioned aft, but it was a far less effective weapon than the forward guns. The maximum range of her Škoda 120 mm guns was 10 kilometres (6.2 mi), and her howitzer could fire its 20 kg (44 lb) shells a maximum of 6.2 km (3.9 mi).

Her armour consisted of a belt ranging from 40 mm (1.6 in) to 10 mm (0.39 in) in thickness, casemates and gun turrets 40 mm (1.6 in) to 70 mm (2.8 in) thick, and deck armour 19 mm (0.75 in) thick. The armour on her conning tower was 50 mm (2.0 in) thick. Her armour, made of iron–nickel alloy, was an improvement on that of earlier Austro-Hungarian river monitors. Bodrog was launched on 12 April 1904, commissioned on 2 August 1904, and completed on 10 November 1904.

Bodrog was part of the Danube Flotilla, and at the start of World War I she was based in Zemun, just upstream from Belgrade on the Danube, under the command of Linienschiffsleutnant (LSL) Paul Ekl. She shared the base with three other monitors and three patrol boats. Austria-Hungary declared war on Serbia on 28 July 1914, and a little after 01:00 on the following day, Bodrog and two other monitors fired the first shots of the war against Serb fortifications on the Zemun–Belgrade railway bridge over the Sava river and on Topčider Hill. The Serbs were outgunned by the monitors, and by August began to receive assistance from the Russians. This support included the supply and emplacement of naval guns and the establishment of river obstacles and mines. On 8 September, the Austro-Hungarian base at Zemun was evacuated in the face of a Serbian counterattack. Bodrog and the minesweeper Andor conducted a deception operation towards Pančevo on 19 September, and six days later, Bodrog bombarded Serb positions on the bank of the Sava near Belgrade. On 28 September, she rendezvoused with the monitor SMS Szamos at Banovci, and the following day the two monitors targeted the Belgrade Fortress and conducted a reconnaissance of Zemun. On 1 October, Bodrog sailed to Budapest, where she was placed in dry dock for two weeks. She returned to the flotilla on 15 October. By November, French artillery support had arrived in Belgrade, endangering the monitor's anchorage, and on 12 November, Ekl was replaced by LSL Olaf Wulff. The stalemate continued until the following month, when the Serbs evacuated Belgrade in the face of an Austro-Hungarian assault. On 1 December, Bodrog and the newly commissioned monitor SMS Enns engaged the retreating Serbs. After less than two weeks, the Austro-Hungarians retreated from Belgrade, and it was soon recaptured by the Serbs with Russian and French support. Bodrog continued in action against Serbia and her allies at Belgrade until December, when her base was withdrawn to Petrovaradin, near Novi Sad, for the winter.

The Germans and Austro-Hungarians wanted to transport munitions down the Danube to the Ottoman Empire, so on 24 December 1914, Bodrog and the minesweeper Almos escorted the steamer Trinitas loaded with munitions, the patrol boat b and two tugs from Zemun past Belgrade towards the Iron Gates gorge on the Serbian–Romanian border. The convoy ran the gauntlet of the Belgrade defences unharmed, but when it reached Smederevo it received information that the Russians had established a minefield and log barrier just south of the Iron Gates. It turned back under heavy fire, and withdrew as far as Pančevo without serious damage to any vessel. Bodrog returned to base, and the monitor SMS Inn was sent to guard the munitions and escort the convoy back to Petrovaradin. In January 1915, British artillery arrived in Belgrade, further bolstering its defences, and Bodrog spent the first months of the year at Zemun. On 23 February, LSL Kosimus Böhm took command. On 1 March, Bodrog and several other vessels including the monitor SMS Körös were relocated to Petrovaradin. After the commencement of the Gallipoli campaign, munitions supply to the Ottomans became critical, so another attempt was planned. On 30 March, the steamer Belgrad left Zemun, escorted by Bodrog and Enns. The convoy was undetected as it sailed passed Belgrade at night during a storm, but after the monitors returned to base, Belgrad struck a mine near Vinča, and after coming under heavy artillery fire, exploded near Ritopek. On 22 April 1915, a British picket boat that had been brought overland by rail from Salonika was used to attack the Danube Flotilla anchorage at Zemun, firing two torpedoes without success.