River Gunboats Read online

  Lagoon gunboat profile. (Drawing courtesy of Karl Klaus Körner)

  Six lagoon gunboats were built, and when Venetia was ceded to Italy in October 1866 they were sold to the Italian Navy for 20,000 florins. The Austrians could very well have evacuated them along with the naval base contents and the rest of the fleet, but these gunboats were so specialised that they were probably thought unfit for any other duty, and in any case they would probably have had to be dismantled for sea transport. Then just five years later the Austrians decided to start building monitors for the Danube. For the lagoon gunboats’ later configuration, see ITALY.

  Launched:

  1855, by J Ruston, Vienna/Florisdorf. Sent in parts to Venice and reassembled by Guidecca.

  Dimensions:

  Displ: 75 tons; L: 30.5m/100ft; B: 5.18m/17ft; D: 0.9m/2ft 11in.

  Crew:

  29–32.

  Power/Speed:

  Side paddle wheels; steam engine, 25 nominal hp/8 knots.

  Guns/Armour:

  1 × 48-pounder iron SB; 1 × 7-pounder bronze SB howitzer Model 1842.

  Fate:

  Sold to Italy October 1866.

  LAKE GARDA FLOTILLA

  A little-known aspect of the Austrian Navy was its presence on Lake Garda during the wars of Italian unification. In June 1859 the Hess and Franz Joseph, plus the Benaco, took part in the Second War of Italian Independence. The Benaco was lost on 20 June when she was sunk by a Piedmontese field gun battery at Salo. The lack of any French and Piedmontese naval units meant that the Austrians had complete dominance of the Lake.

  During the Third War of Italian Independence which began in June 1866, the Hess and Franz Joseph with six modern screw-driven gunboats – Wildfang, Raufbold, Wespe, Uskoke, Scharfschütze and Speiteufel – faced the five Italian gunboats supplied by France plus two Italian-built steamers Solferino and Saint Martino, along with Benaco, which the Austrians recaptured on 19 July in Gargano. With the end of the war, Lake Garda was ceded to Italy, except for a small strip of shoreline around Riva del Garda. The Austrian flotilla was dissolved and the vessels were sold to their former enemies for the sum of one million florins.

  Gunboat Franz Joseph on Lake Garda. When sold to Italy she was renamed San Marco, and was used as a passenger steamer. (Photo from Ogliari, Francesco: La navigazione sui laghi italiani – Lago di Garda, Milan : Cavallotti, 1987)

  Hess

  Launched:

  As Hess May 1852, by Escher Wyss, Zurich, assembled by Riva del Garda shipyard. Wooden hull.

  Dimensions:

  Displ: 360 tons; L: 45.4m/149ft; B: 5.5m/18ft; D: 1.5m/4ft 11in.

  Crew:

  55.

  Power/Speed:

  Side paddle wheels; steam engine, 100ihp; brigantine rig.

  Guns/Armour:

  2 × 18-pounder MLR; 2 × 7-pounder bronze SB howitzers Model 1842. In Italian service as gunboat: 2 × 12-pounder MLR; 1 × 3-pounder howitzer.

  Fate:

  Sold to Italy 2 December 1866 as Prince Oddone. Passenger steamer 1867. Scrapped 1890.

  YANGTZE EXPEDITION

  The Austro-Hungarian Navy were participants in the exploration of China’s rivers. In 1890–1 the iron corvette SMS Zrinyi (launched 10 December 1870 by the Stabilimento Tecnico Triestino), explored the Yangtze River as far upstream as Nanking (Nanjing) and Hankow. Her crew sketched and mapped the river banks and took especial notice of the fortifications on both banks. Their work was useful during the fighting in the Boxer Uprising a decade later.

  Ex-Austrian Hess as Italian Prince Oddone. (Painting by D Cavarrone, in the Genoa Naval Museum)

  RIVER MONITORS

  All the Austro-Hungarian river monitors were named after tributaries of the Danube.

  Maros and Leitha

  Although the American armoured vessels derived from the original Monitor were far from safe on the open seas, they performed well enough in the confines of river systems, where their low freeboard made for a small target, and their cylindrical Coles-style turret allowed for virtually all-round fire from just two guns.

  Following the Crimean War, Turkey ordered five armoured gunboats of the Feth-Ül-Islam class from France, and their appearance on the lower Danube from 1865 onward spurred the Austrians into responding. It was decided to build two armoured monitor-style gunboats, to be designed by the experienced K.u.K. Naval Architect-Inspector Josef Ritter von Romako. He would produce a design inspired by the USS Monitor type but incorporating several innovations.

  The most obvious new feature was the downward curve of the armoured deck at the bow and stern. This arrangement reduced the weights at both ends and contributed to the shallow draught of the vessels. Interestingly, in Britain Yarrow would be taking the opposite view as regards the stern of their river vessels, building a flat, wide stern to spread the weight. Yarrow’s version did, however, require placing the screws in tunnels which Romako avoided, the hull being cut away aft for the screws.

  Previous steam engines were slow-turning low-pressure types, usually employing a single large horizontal cylinder. For his new river monitors, Romako fitted a pair of 2-cylinder vertical engines turning at relatively high speed. This allowed him to use smaller propellers, essential given the vessels’ shallow draught.

  The riveted hulls were made of iron which in the case of Leitha has lasted for almost a century and a half. For the first time Bessemer steel was used for the armour, a 25mm layer being placed directly on the deck, and 44mm of vertical hull armour was fixed to 203mm of teak backing. The turret and conning tower had 50mm armour. In 1871, to protect against attacks by spar torpedoes, and particularly in view of the recent Austrian adoption of Whitehead’s locomotive torpedo, thought was given to providing the monitors with a comprehensive anti-torpedo net protection, which would be hung at a distance from the hull on booms hinged vertically at the deck edge. Such an arrangement would have added substantial weight on a hull where shallow draught was essential, and the danger of part of the net coming adrift after battle damage or by snagging on a river obstacle, and entangling the screws or the rudder, meant it was quickly forgotten. For the later anti-mine protection, see below.

  Profile of the Maros class as originally built in 1871. Note the conning tower built on top of the turret, as used on many early monitor designs. This arrangement was copied by the Germans on Rhein and Mosel. Not shown are the two spars mounted one each side of the bows for spar torpedoes, copying contemporary Turkish river monitors which used spar torpedoes at bow and stern as defence against enemy spar torpedo boats. There was originally no foremast, just a large flagpole on the conning tower. The structures on the foredeck are WC boxes (the ‘heads’). The galley is the box with a chimney in front of the funnel.

  An early modification was the addition of a spark-arrestor on the funnel, to avoid starting forest fires on the banks of narrow waterways. This was soon removed and would not be copied on subsequent designs. During the 1873 refit the flagpole on the conning tower was removed and replaced by a foremast in front of the WC boxes.

  Another innovative feature was the addition of flushing toilets, in the boxes on the deck forward, which were among the very first of their kind on-board ship. They have been faithfully reproduced on the reconstructed Leitha, as later repositioned on either side behind the funnel.

  Laid down in 1870 at Pest Flumaner Schiffbau AG in Budapest, both monitors were accepted into service in 1872. They first went into action during the Austro-Hungarian occupation of Bosnia-Herzegovina in September 1878, when they provided fire support to troops on the banks of the River Sava.

  Modern replicas of the two 15cm System Wahrendorf breech-loading guns originally mounted in each of the Coles-type turrets on Maros and Leitha in 1871. The turret crew numbered sixteen men, and a further ten ammunition handlers worked in the magazine below the turret, handing up charges. The guns used separate loading of shell and silk propellant bag, and could achieve a rate of fire of between four and six rounds a minute. The turret was rotated
by hand, and for large degrees of training the whole ship was turned towards the target. (Photographed inside the replica turret on the reconstructed Leitha).

  Specifications as built 1870–1

  Launched:

  Maros: April 1871; Leitha: May 1871, by Pest Flumaner Schiffbau AG, Budapest.

  Dimensions:

  Displ: 310 tons; L: 49.98m/164ft; B: 8.12m/26ft 7in; D: 1.07m/3ft 6in.

  Crew:

  50.

  Power/Speed:

  Twin screws; 2 × 350ihp 2-cyl vertical steam engines/8.3 knots.

  Guns/Armour:

  2 × 15cm L/21 Wahrendorf BL; + from 1878: 2 × 25mm Palmkrantz manually-operated HMG/Deck 25mm (Maros), 19mm (Leitha); Hull 44mm on 203mm teak backing; Turret 51mm front, 44mm sides and rear; Conning tower 64mm.

  Fate:

  Rebuilt 1893–4.

  The original pair of monitors had been in service for over twenty years, and in reserve for several more, when it was decided to build a new pair, which would become the Körös and Szamos. At the same time as they were building, the improvements incorporated in the new pair were incorporated in the Maros and Leitha, giving them a new lease of life, and providing the Danube Flotilla with a quartet of monitors sharing common armament and similar performance.

  Their old engines were replaced by a pair of vertical triple expansion engines of greater power, raising their maximum speed to match that of the new monitors. The old twin turret and Wahrendorf guns were removed, and replaced by a new cylindrical turret mounting a single Škoda 12cm L/35 gun, the same as in the newer monitors. A new bulletproof citadel was installed, and a new oval-shaped conning tower was fitted behind the turret, with an 8mm Salvator-Dormus MG in a shield mounted on top. On each side of the funnel, the old 25mm Palmenkrantz MG were replaced by a pair of 47mm Hotchkiss revolver cannons with a cyclic rate of fire of forty rounds a minute, providing a much improved defence against torpedo boats. During the Great War this armament would be further modified, as shown in the following drawings: Leitha would receive a 7cm L/42 gun in a large shielded mounting at the stern, a short-barrelled 7cm L/18 gun would be mounted to the rear of the superstructure, and two tall cylindrical MG turrets would be installed, each armed with an 8mm Schwarzlose.

  25mm Palmkrantz four-barrelled manually-operated MG. In 1881 it was proposed to fit two mountings, one behind the pair of WC boxes on the forward deck, and one near the stern. These mountings were given more command by placing them on either side of the funnel on a platform deck, supported by the boxes for the heads which were moved from the foredeck to either side behind the funnel. The complete gun weighed 300kg, and the magazine held a total of thirty-two rounds, eight for each barrel. The cyclic rate of fire was over ninety rounds a minute.

  Maros would be rearmed with a total of three 7cm L/18 guns, all in shielded mounts, two of which replaced the 47mm Hotchkiss.

  The rebuilt Maros on the Danube in about 1900. At that time she was armed with a single modern Škoda 12cm L/35 turret gun, a pair of 47mm Hotchkiss revolver cannons mounted port and starboard behind the funnel, in place of the 25mm Palmkrantz, and a shielded 8mm Salvator-Dormus Model 1893 MG on top of the new conning tower. Two spars were carried on board, as mooring poles (Schorbaum) to distance the vessel from a sloping riverbank.

  Maros as rebuilt 1893–4, with a central superstructure and modern armament. The drawing shows her with the three 7cm L/18 guns fitted as secondary armament during the Great War. One has replaced the 8mm MG on the conning tower, and the rear pair are situated on top of the repositioned WC boxes, and replace the earlier Palmkrantz MG and Hotchkiss revolver cannons. (Drawing by Erwin Sieche)

  The replacement turret fitted to Maros and Leitha mounting a single 12cm L/35 Škoda gun. Two identical turrets and Škoda guns were also fitted to Szamos.

  As the conflict progressed both monitors would also carry a pair of 37mm Pom-Poms to subdue small-arms fire from the river banks.

  With the planned introduction of Monitors VII and VIII in 1914, both Maros and Leitha were due to be deleted. However, with the imminent outbreak of war both were retained, and the old ships saw considerable action.

  At first part of the Sava River monitor group based at Breko, they provided fire support to the Austro-Hungarian army. In late September 1914, on forcing the entry to the Sava River, Leitha received a hit on her turret: the gun crew were killed and the guns put out of action. She was repaired at the Slavonic-Mitroviça yard. Then in October 1915 they joined the other monitors in the attack on the Serb capital of Belgrade, fighting duels with Serb and Allied artillery.

  Between December 1915 and August 1916 both monitors remained at Ruschuk. Then Leitha shelled Romanian oil and harbour installations at Giurgiou. Meanwhile, Maros guarded the Belene Channel. From the winter of 1916 up until the end of the war both ships were based on the river between Budapest and Orsova.

  In 1919 Leitha was renamed Lajta in Hungarian service, and fought the Czechs and Slovaks, before both monitors were handed over to Yugoslavia. They never entered service, being discarded in 1921. While Maros was scrapped, Leitha was sold into commercial service, and in 1928 became the elevator hulk József Lajo.

  Specifications as rebuilt 1894

  Dimensions:

  Displ: 310 tons; L: 49.98m/164ft; B: 8.12m/26ft 7in; D: 1.07m/3ft 6in.

  Crew:

  57.

  Power/Speed:

  Twin screws; 2 × 600ihp 2-cyl VTE steam engines/10 knots.

  Guns/Armour:

  1 × 12cm L/35; Secondary armament 1897: 2 × 47mm Hotchkiss revolver cannons; 1 × 8mm Salvator-Dormus MG. 1916: Maros: 3 × 7cm L/18; Leitha: 1 × 7cm L/42 + 1 × 7cm L/18 + 2 × 8mm Schwarzlose MG. Later 2 × 37mm Pom-Poms added on open mounts/Turrets 75mm front (3 × 25mm laminates), 50mm sides and rear (2 × 25mm laminates); Hull 44mm on 90mm teak backing; Deck 25mm (Maros), 19mm (Leitha); Conning tower 50mm (2 × 25mm laminates); Superstructure: bulletproof.

  Fate:

  Maros scrapped 1921; Lajta disarmed 1921, from 1928 used as elevator hulk; museum ship 2010.

  In the 1970s Hungarian naval historian Dr. Károly Csonkaréti discovered the old ship, and with naval enthusiast Dr. András Margitay-Becht worked to try to preserve her.

  Leitha as rebuilt in 1893–4, with new superstructure and new guns, in a different layout to those on her sister. Again, the drawing shows her Great War configuration of 1915–18. (Drawing by Erwin Sieche)

  The 7cm L/42 gun mounted on the stern of the rebuilt Leitha.

  7cm L/18 gun.

  The 37mm Vickers Pom-Pom fitted during the Great War to counter enemy small-arms fire.

  Salvator-Dormus Model 1893 delayed-blowback machine gun manufactured by Škoda. In view of its lightweight construction, and the curious arrangement whereby the rate of fire was controlled by adjusting the swinging pendulum exposed below the breech, it was rejected by the Army. However, it functioned well enough on fixed mountings in fortresses and on naval vessels. (Photo via Wikipedia)

  They had a difficult task, as the ex-Leitha consisted of simply an empty hull, lacking her internal partitions and watertight bulkheads, with no steering or mooring fittings, which prevented her legally from being moved. Her superstructure had gone, and new holes had been cut in the deck. The side armour had long disappeared. Despite all the problems, in 2005 she was hauled up on dry land for preservation, and by 2010 had undergone a complete transformation, restoring her to the state she was in when first commissioned. At the time of writing, Lajta serves as the honorary flagship of the Hungarian Army’s river warship regiment.

  Szamos and Körös

  More than twenty years after the introduction of the Maros and Leitha, it was decided to build a second pair of river monitors for the Danube. Designer Josef Thiel took advantage of the developments since the launch of the original pair, and produced two miniature pre-dreadnoughts with a main gun turret fore and aft of a substantial superstructure, topped with an imposing funnel for forced draft, and numbers of smaller guns. Note th
at the class still retained the deck profile of Maros and Leitha, curving downwards at bow and stern. For the first time, the screws turned partly in shallow tunnels in the underneath of the hull.

  A full-scale wooden dummy of the Maros class built in the spring of 1915, intended to draw fire from hidden French and Serb batteries at Belgrade, thus exposing their positions. Unfortunately, details of the dummy were leaked and the ruse failed.

  Lajta as reconstructed as a museum ship in 2010 to her configuration in 1873. (Drawing by Dr Balagh Tarras)

  The armoured conning tower was now circular, and separated from the main superstructure. A second cylindrical tower supported the gun mounting at the rear of the superstructure. Armour was now nickel-steel, increased to 50mm for the belt, backed by 90mm of teak, with 75mm on the turrets, 19mm on the deck, and 40mm on the conning tower. The remainder of the superstructure was built of bulletproof plating.

  The main guns were 12cm L/35 models, those on Körös being supplied by Krupp, and those on Szamos by Škoda, presumably to compare the two types. Significantly, no more Krupp guns were ordered. Each of the cylindrical structures carried a long 7cm gun, and a tall cylindrical turret amidships mounted an 8mm MG, initially a Salvator-Dormus model, with a second MG carried in the crow’s nest. Both would later be replaced by the 8mm Schwarzlose.

  Körös in pre-war livery. Her main armament guns were built by Krupp, whereas the guns on her sister were built by Škoda.

  Szamos in wartime livery. Note the semaphore device mounted above the bridge, and the raised forward bulwarks. Also the Škoda 12cm guns are mounted higher in the turret with a smaller embrasure than on Körös.