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German Armed Forces Research 1918-1945

The Imperial Austrian-Hungarian Danube Flotilla

When the Austrian-Hungarian Empire collapsed in 1918, the Imperial Danube Flotilla (Kaiserliche- und Königliche-Donau-Flotilla) was stationed mainly in Hungary. By default, Hungary took over the vessels that were in its territory, which meant that it took over virtually the entire flotilla consisting of eight armored gunboats, the Czuka, Wels, Stör, Vizu, Lachs, Fogas, Barsch, Compó (although a ninth ship, the Bodrog stayed in Austria), eight armored patrol boats, and 55 miscellaneous unarmored vessels. The nine gunboats were valued at the time at 17.5 million golden crowns, the patrol boats at 9 million, and the rest at a total of 4.5 million golden crowns. Personnel consisted of approximately 1,000 officers and men.

Count Mihaly Károly's National Council took over the government on October 30, 1918, which then proceeded to turn over the powers of government to the Bolsheviks on March 21, 1919. The Bolsheviks established the Soviet Republic of Hungary. Unfortunately, the Flotilla was also used to fight against soldiers who have turned against the Reds. These were not in fact part of Horty’s counter-revolutionary center. In November 1919, the Allies transferred all of the fighting vessels in Hungary to the occupying Serbian army, leaving only some tug boats and motor boats in Hungarian hands.

The Trianon Peace Treaty

After the Serbs returned the ships given to them by the Allies, the Trianon Peace Treaty of 1920 divided the Danube Flotilla between Austria and Hungary. As one of the defeated powers, Hungary was only authorized a small force for police duties on the Danube to consist of eight patrol boats, two launches, and ten motor boats, The Hungarians obtained the Csuka, Wels, Viza, and Lachs and the Austrians the other five gunboats. Hungary also received three of the armored patrol boats, the Honvéd, Huszár, and Tüzér. The other vessels were more or less also proportionately divided between Hungary and Austria, although Czechoslovakia and Yugoslavia also received a few smaller vessels. The terms allowed the Hungarian navy to expand. The Hungarian ships allocated were four relatively modern patrol boats and four small minesweepers. However, the Treaty only allowed Hungary to possess three armored ships, so that only the Szeged (formerly Wels), the Debrecen (formerly Lachs), and the Kecskemet (formerly Viza) were kept in commission. The rest were stripped of their armament under the supervision of the Allied Commission and then were supposed to be scrapped.

The Secret River Flotilla in 1920, the headquarters for the newly designated River Flotilla, was raised. Plans were immediately laid for raising several sunken ships (Munka, Bácska, Janka, and even the ML-343, a former British boat). It also proved necessary to repair the vessels returned by the Serbian army, as they had been plundered and severely damaged.

In January 1921, the Hungarians established the Royal Hungarian River Guard, and began training officers and sailors. This new organization was to have a mobilized strength of 5,000 men. Peacetime strength was authorized at 1,620 men and up to 1,800 civilians. However, budgetary problems precluded this number being attained. As with all other branches of the Hungarian military forces, the River Flotilla existed in secret. It was officially known as the Royal Hungarian River Guard, which supposedly consisted of only river and harbor police units. To maintain the pretense, the River Flotilla was publicly subordinated to the Ministry of the Interior and was featured in its budget. On the other hand, its organization, training (all members received regular military training), and equipment were obviously military, including the vessels of the former Austrian-Hungarian Danube Flotilla. In reality, it was part of the Hungarian Army, which was controlled by the Honvéd Ministry through the River Forces Inspectorate. The Ministry of the Interior, through the Inspectorate of the River Police, in fact only controlled the civilian river police and harbor police units.

In 1922, the Hungarian river forces consisted of the gunboats Szeged, Debrecen, Kecskemet, and Siofok (out of commission), all launched between 1915 and 1918. The Hungarians also operated a number of small auxiliary vessels, among them the armored patrol boats Honvéd, Huszár, and Tüzér; two minesweepers, the Maros and Baja (the Baja was later renamed Hegyalja), equipped for mine laying and mine sweeping; the steamer Badacsony, which was used as a command ship during flotilla exercises, but otherwise served as a supply ship; the supply ship Körös; the armored tug Csobánc; the training ship Csepel, the repair ship Vulkán; and the tanker Bukk. The river and harbor police used about 30 motor boats, four of which were of a larger type (8 to 10 men), each armed with a machine gun.

Reorganization and Expansion

By 1927, supervision by the Control Commission had ceased. The Hungarians proceeded to repair and rearm those hulls that were still available. Economic recovery enabled the purchase of three sister-ships from Austria in 1927. The boats that were already in Hungary's possession and renamed were the following: Györ (formerly Stör), Gödöllö (formerly Fogas), and Sopron (formerly Compó). In 1929, the Siofok (formerly Czuka) was repaired. It was traded to the Austrians for their Barsch, which was promptly renamed Baja. The original Baja having by then been redesignated as Hegyalja. After its armor was removed, it was converted to a minesweeper. After being repaired and rearmed, Sopron and Gödöllö were launched in 1930.

During the period of 1928 to 1930, the River Flotilla was reorganized and expanded. Authorized personnel were increased by 20 percent. The planned number of armored ships was increased to 10; construction of new vessels was started. A River Flotilla Anti-Aircraft Battalion was raised. The motorized Anti-Aircraft Battalion had a headquarters and three batteries, with an authorized strength of 25 officers and 290 other ranks. It was equipped with twelve 80mm guns, 6 heavy machine guns, 15 motorcycles, 4 cars, and 27 trucks. The 1st and 2nd Batteries were stationed in Budapest; the 3rd Battery was at Szeged. Hungary faced the prospect of defending herself against the combined forces of the members of the Small Entente (Czechoslovakia, Yugoslavia, and Romania), who outnumbered it in combined ship strength. The River Flotilla's mine laying capabilities were consequently emphasized and the minelayer Máros was launched in 1928.

Starting in 1929, barracks, a supply depot, and a repair workshop were built at Csaky, near the end of the Pest docks. By 1930, the River Flotilla had reached the strength it would maintain for the rest of its existence, namely 96 officers, 1,524 NCO and sailors, 147 government service officials, as well as 128 civilian employees. Its strength at this time was 6 armored ships, 3 minelayers, and 3 armored patrol boats.

The national budget (1932 – 1941) did not allow further expansion of the River Forces, so that during the period 1932 through 1938, it was concerned mainly with training. During the occupation of southern Slovakia, ceded by Czechoslovakia in accordance with the 1st Vienna Award of 1938, the 1st Battle Group screened the Army while it was crossing the Danube north of Medvedona. The 2nd Group was stationed at Komarno.

In 1939, a new series of fast, unarmored mine-layers was developed by the Laczkovics shipyard in Budapest. A total of 11 boats of the AM type (AM-1 to AM-11) were built from 1940 through 1941. At the same time, Ganz Danuvius shipyard started development of PM type armored gunboats. These fast (36 km/h) boats were well armored (up to 40mm armor plate), and were equipped with two Csaba armored turrets each with one 40mm gun and two machine guns. They were the most modem ships of the Danube Flotilla.

The Second World War

During the first years of the Second World War, the Danube Flotilla was not mobilized and remained at a peacetime strength of 109 officers, 302 NCO, and about 1,000 men. During the 1941 Yugoslavian Campaign, the Danube Flotilla laid several mine fields in the Danube and Tisza Rivers and accompanied the Mobile Corps as far as Belgrade.

In May 1942, Szeged, Kecskemét, Györ, Sopron, PM-1, and Tüzér were sent to Belgrade. When the Germans occupied Hungary in March 1944, the River Forces had no more than 1,700 men. At the time the only armed resistance offered by the Honvéd was by units of the 2nd Battle Group stationed at Ujvidek.

The armored minelayer PAM was a new development during the Second World War. Though a total of 17 units were planned, only PAM-21 and PAM-22 were finished by summer 1944. In April 1944, the British Royal Air Force started mining the Danube River. They dropped several thousand magnetic and induction mines specially developed for use in rivers. River traffic subsequently suffered heavy losses. Mine clearing activities were carried out mainly by the German Kriegsmarine, who used both ships and aircraft to clear the mine fields. As they cleared only the main ship channels, the Danube Flotilla was given the mission of clearing the banks of the river. The mines the Allied dropped were highly sophisticated, and the job of clearing them required modern equipment and proper training. Modern equipment was initially not available, and the River Flotilla was not trained in mine clearing, and the Hungarians suffered some casualties. The mine-layer Hegyalja was lost in November 1944 while carrying out this dangerous work. After this loss, the Germans finally gave the Hungarians several induction mine clearing sets of equipment. This equipment was towed behind the AM boats. The River Flotilla then managed to clear 700 mines by the end of December 1944 without further losses to mines. But vessels were lost for other causes. PM-2 was hit by a bomb in 1944. PM-3 was sunk by Russian tank fire while fleeing to the West. The gunboat Gödöllö was sunk by a bomb in late 1944.

Admiral Horthy had decided on September 24, 1944 to withdraw from the war, and had prepared a plan for this event. In connection with this plan, all units of the Danube Flotilla were gathered in the vicinity of Budapest to support Horthy in case of resistance. When Horthy proclaimed an armistice on October 15, 1944, the quick and unexpected reaction of the Germans prevented him from taking Hungary out of the war. Rear Admiral Kalman Hardy, Commander of the Danube Flotilla, and his staff were taken prisoner on October 16, 1944. He was replaced by Admiral Odön Trunkwalter. Admiral Hardy was the only Hungarian officer who was sentenced to death by the Germans. He was sent to Mauthausen, where he was liberated by the US Army just prior to the sentence being carried out.

Various River Flotilla officers and men went over to the Allies, some of which even engaged in active fighting against the Germans. The remainder of the Flotilla sailed west before the advancing Soviet Army. The unfinished PM-4 and PM-5 successfully fled to Germany in 1945. By May 1945, almost all the vessels of the Danube Flotilla had surrendered to the US Army.


The Danube Flotilla was made up of First World War equipment and applied a doctrine to match. Though slowly modernized, it was vulnerable to modern, more mobile tanks and aircraft. It never engaged in ship-to-ship combat, for which it was mainly trained. Its main task during the Second World War was mine clearing, for which it was neither trained nor equipped. The Honvéd Ministry was aware of these shortcomings, and so concentrated its efforts on building up the ground and air components of the Honvéd.