The Russian and Romanian naval forces annoyed Mackensen enough in October for him to order that a mining detachment be sent overland to the Dobrudja army to counter their activities. But the Russians and Romanian naval forces were not sufficient to stop Mackensen.48 The Russians and Romanians apparently did not work well together. The Russians initially were under the command of a Romanian admiral who attempted to use the gunboats and monitors together despite the fact that the gunboats drew twice as much water and their guns had twice the range of the monitors. The Russians accused the Romanian monitors of going close to the bank, camouflaging themselves with branches, and then refraining from opening fire. The fact that the Romanians reportedly had only 100 rounds per gun when the war began and were down to only 20 to 25 rounds per gun by early November might be at least partially responsible for their attitude. Furthermore, there were seldom accurate maps for artillery spotting. Lack of Romanian cooperation meant that the Russians also landed their own observers and signalmen for spotting. The Romanian army appeared to be equally deficient in its liaison with both the Russian and Romanian river forces, and they were ignorant of troop movements. This was dangerous, for their first knowledge of a rapid Romanian retreat was when they came under fire from light guns mounted on motorcars while still at anchor.49
The Romanians made a bold attempt to retrieve the situation in the Dobrudja early in the morning of 1 October when General Alexandru Averescu secretly concentrated a few divisions of the Third Romanian Army and then sent several battalions across the Danube in lighters at Flaminda, approximately 25 kilometers downstream from Giurgiu, near the Bulgarian towns of Rjahovo and Martin. The first wave of troops were rowed across in approximately 120 small boats, which had been brought up in ox-drawn carts. Romanian engineers and sailors hastily began to build a pontoon bridge across the Danube for more troops and supplies to follow. This was well to the rear of Mackensen’s army, and with only weak Bulgarian forces to oppose them, the Romanians soon penetrated some 5 miles on a front of 10 miles. The Germans rushed Bulgarian reservists, stiffened by German and Austrian artillery, from Tutrakan and Rustschuk to contain the threat. The Danube Flotilla was sent into action with the obvious mission of destroying the pontoon bridge, although the first serious disruption in its construction, according to two French observers with the Romanians, was accomplished by German aircraft on the afternoon of the 1st. Nevertheless the Romanians managed to finish the bridge around 7:00 in the evening, about half an hour after the last of the German planes departed. Unfortunately for the Romanians, rainy weather and a storm during the night whipped up waves and broke the bridge in three places, delaying further passage of troops for twelve hours.50
The Danube Flotilla made its first attempt against the bridge with mines before the monitors could come into action. The officer commanding the field of observation mines protecting the Austrian base was ordered to launch mines from a suitable location on shore, to be carried by the current against the pontoon bridge. The Austrians worked their way behind Romanian lines, but lacking boats, the attempt to launch mines from the shore was probably doomed to failure. The winds carried the mines ashore, and the Austrian mining party narrowly escaped capture.
The Romanians initially were fortunate, for the stormy weather that hampered the crossing also affected the Danube Flotilla. Moreover, the area they had chosen around Rjahovo was very difficult to navigate because of numerous shifting sandbanks. On 2 October the patrol boats Viza and Barsch, under heavy fire from artillery and machine guns on the shore, managed to approach the bridge and hit several of the pontoons with their light artillery and machine guns, clearing the bridge of troops. The two patrol boats were hit by the shore batteries firing from both sides of the river, and once their ammunition was exhausted by rapid firing they retired. The third monitor group, the Bodrog and Körös guided through the treacherous sandbanks by the patrol boat Wels (which was forced back by enemy fire), took up the fight from a position near Lungu Island, roughly 3 kilometers upstream from the pontoon bridge. For the next few hours the two monitors directed their fire against the bridge, constantly changing their position. Both came under heavy fire from batteries on shore upstream from the bridge, and both were repeatedly hit. At about 2:00 P.M., the Bodrog, with her turret and electrical circuits out of action, had to haul off out of range to effect repairs. The Körös continued the battle alone until her main steam pipe was cut, and then, with steam pouring out, she drifted rudderless onto the Romanian shore. The Körös could not regain the channel until the pipe had been repaired—a difficult job—and after dark both monitors retired to Lelek because of the danger from mines. The pontoon bridge, according to Austrian accounts, had been badly damaged and would require repair before it could be used again. The French officers with the Romanians, however, reported the bridge intact. The Austrian shells had landed either 600 meters over or 200 meters short, with none on target. Nevertheless, the Romanians had begun their retreat. The combined threat of monitors, aircraft, and stormy weather to the operation’s lifeline caused Averescu to treat the undertaking as a diversion, and for the moment, to merely hold a bridgehead on the south bank. Storms damaged the bridge once again during the night.51
On 2 October the first (Temes and Enns) and fourth (Szamos and Leitha) monitor groups were ordered to relieve the battered third monitor group and to bring fresh munitions, coal, and diesel oil to the flotilla craft near Rjahovo. The Szamos and Leitha left the Belene Canal in late afternoon, towing one lighter loaded with fuel and another loaded with soil. They intended to launch the lighter loaded with soil in the current in the hope it would be swept against and break through the pontoon bridge. The group came under fire by Romanian batteries established on Cinghinarele Island opposite the eastern entrance of the canal, and the monitors and their tows were hit several times, the Szamos losing the barrel of one of her 7-cm guns. The Romanian artillery made it too dangerous for the Enns to tow her lighter filled with fuel until after dark, and the Temes proceeded to Lelek on her own. The Austrians concentrated in Lelek that evening, replenishing their munitions, and the damaged monitors of the third group were ordered back to Belene.
The battle over the pontoon bridge resumed on the 3d, although by now the Romanians were fighting to keep it open as a means to retreat rather than advance. Averescu had lost faith in his enterprise, especially as the news from the Transylvanian front was bad, and, according to the French liaison officer, the Romanians now thought only of holding a small bridgehead on the Bulgarian shore. All heavy and medium artillery was withdrawn back across the river. Romanian artillery made it inadvisable for the Szamos and Leitha to approach the bridge, and the Austrians resorted to the expedient of loading six mines on the patrol boat Compo, and then launching them in the channel so that the current could carry them down against the bridge. They succeeded in destroying about 50 meters of the bridge. German aircraft also returned in the afternoon to inflict additional damage. The Austrians wanted to destroy the bridge once and for all and planned an operation to take place after dark. Covered by the Temes and Enns, the patrol boat Viza and armed steamer Balaton were to bring two empty lighters up to the bridge. The lighters would be flooded to the correct depth and along with a dozen mines let loose in the current. The operation was partially successful. The Austrians later found one lighter had grounded but the other had apparently torn away another section of the bridge and drifted all the way downstream to the log boom at Kalimok where it lodged. By this time it did not matter; during the night the remnants of the Romanian force escaped as best they could across the Danube.52 Averescu’s bold attempt to strike at the rear of Mackensen’s army had ended in complete failure.53
The monitors and patrol boats that had countered the Romanian assault did not linger in the vicinity of the partially destroyed bridge, and on the report, which turned out to be false, that enemy river forces were seen near Tutrakan, pulled back to Lelek, leaving only patrols on watch. The Austrians realized that the combined Russian and
Romanian force was potentially superior and could only be opposed from behind their own defensive minefields. Averescu’s neglect to call in the Romanian flotilla before the operation is generally considered one of his many faults, but the minefields and barricades laid by each side tended to keep the opposing river flotillas apart.
The Romanians may not have had any warships to oppose the Austrians and Germans upstream from the Kalimok barricade, but while the battle was taking place around Rjahovo, they were able to mine about two-thirds of the channel in the Danube below the eastern entrance to the Belene Canal. The Romanians under cover of their batteries on the Island of Cinghinarele expanded their minefields on the night of 4–5 October, blocking the approach to the Bulgarian shore. The minefields threatened to cut off the Austrian and German force, which had been at Rjahovo from its base, for the fields would have been difficult to sweep when covered by the Romanian batteries on Cinghinarele. The Austrians and Germans were therefore forced to execute a combined operation the night of 7–8 October. The second monitor group, the Sava and Inn, patrol boat Compo, and German gunboat Weichsel, along with German artillery brought over to Persina Island, covered the landing. A German Landsturm company and an Austrian Pioneer company were ferried over to Cinghinarele and succeeded in capturing it, while Austrian and German river minesweeping forces proceeded to clear a path through the Romanian minefields.54
The Romanian high command was anxious to isolate and destroy the Austrian Danube Flotilla and asked the commander of the Romanian fleet, Rear Admiral Balescu, to report to King Ferdinand on the subject. Balescu concluded that any project would probably fail because sufficient matériel was not available. Capitaine de frégate de Belloy, the French naval attaché and the French naval mission—which consisted of 4 officers and 31 ratings, all specialists—were anxious to at least try something, and the attaché suggested he and a representative of the much larger Russian detachment (47 officers and 1,800 men) operating on the Danube undertake a reconnaissance from the Romanian shore of the Austrian base at Persina. King Ferdinand agreed, and Belloy and Captain Zarine, head of the Russian detachment, made a brief reconnaissance and prepared a joint report. The plan was, roughly, to restrict the Austrian flotilla’s freedom of maneuver by establishing “systematic barrages,” first to the east and then to the west of the Belene Canal. The “systematic barrage” would consist of an ensemble of lines of mines, defended by artillery and machine guns, illuminated by searchlight projectors, and possibly supplemented by torpedoes and torpedo tubes mounted on shore and sunken lighters. They might eventually try offensive action against the Austrian monitors by bringing up heavy artillery to shell the anchorage, but the guns would have to be very long range, because the marshy ground on the Romanian shore prevented batteries from being established close to the river.
The French and the Russians doubted the ability of Balescu or the Romanians to implement the ambitious project and proposed that Captain Zarine be given command. But before the project could get very far, the Romanian defeats on the Transylvanian front and in the Dobrudja caused the Russian high command to order the Russian detachments on the Danube back to Reni. The Russians feared losing their specialists and matériel and shortly afterward recalled Zarine to take command of the river forces in the Reni-Galatz sector. The French naval mission could do little more than devise an alternate plan dividing the length of the Danube into sectors where naval observation posts, protected by cavalry and infantry, would be established and linked by telephone to central command posts coordinating artillery fire in the sector.55 These efforts were overtaken by events.
The tempo of river operations declined while the issue of the campaign was decided on land, although on 9 and 13 November the Austrians raided Giurgiu again to carry off more lighters before the Romanians could destroy them. The land campaign also dictated the next important river operation. On 10 November Falkenhayn began his offensive against the Romanian positions in the mountains, anxious to reach a decision before the onset of winter weather brought the campaign to a standstill. Mackensen then shifted forces from the Dobrudja to the Danube front for a crossing of the Danube in order to attack the Romanians from the south. The Danube Flotilla was placed under the command of the Svistov sector commander, Generalmajor von der Goltz, for the operation. The Danube army—consisting of one German and two Bulgarian divisions, a Turkish brigade, a German-Bulgarian cavalry division, German heavy guns and howitzers, and Austro-Hungarian pioneers—crossed the Danube on 23 November in three echelons. The assault companies were rowed in pontoons by Austro-Hungarian pioneers or sailors, or else towed by German motorboats and, in some cases, paddle steamers and ferries. The main crossings were east and west of Svistov, directed against Zimnicea. The western group, the German 217th Infantry Division, set out from the Belene Canal and crossed to the Romanian shore east of Cinghinarele Island. The infantry, cavalry, and artillery followed in lighters, grouped in fours and towed by paddle steamers. The two Bulgarian divisions crossed to the east of Svistov. As a diversion, motorboats carried a German Landsturm battalion across the Danube from Somovit to the Island of Kalnobet and against the Romanian fortifications at Izlazu. Once the initial bridgeheads had been secured, the Austrians brought up the sections of their mobile bridge, which they had quietly positioned in the Belene Canal before the start of hostilities. The monitors and other Austrian and German craft of the Danube Flotilla were deployed to cover the crossing of the three echelons and later to protect the mobile bridge, which was completed on the 24th. The crossings, although hampered by fog, were successful.56
The campaign moved to its conclusion, although not without heavy fighting. On the 26th Falkenhayn’s forces broke through the Vulkan pass, and by the 5th of December German armies had entered the Romanian capital of Bucharest. The Romanian government moved to Jassy in Moldavia, and eventually Romanian and Russian troops were able to establish a line along the lower Sereth River. The onset of winter and the exhaustion of troops and supplies brought the advance of the Central Powers to a halt. The majority of Romanian territory was in their hands, although British agents had worked feverishly to sabotage many of the oil fields in advance of the German army. The ships of the Danube Flotilla were occupied with the not inconsiderable task of clearing the river of mines, booms, and other obstacles, as well as salvaging lighters and steamers in the Romanian ports after they were captured. Once the channels downstream from Orsova were open, the Germans established a small naval presence with the Imperial German Danube Half-Flotilla. This, as opposed to the motorboat corps, which was army, was a naval force consisting of the former Bayerischen Lloyd paddle steamers Save and Maritza, each armed with two 5-cm, quick-firing guns and two machine guns. The steamers were used primarily for hydrographic work on the Danube, restoring buoys and lights to mark the channel and later assisting in anti-aircraft defense at Braila. The former motorboat corps was converted into the Deutsche Donauwachtflottille, with launches and motorboats distributed along the reaches of the Danube for police service.57
The river front was substantially unaltered for the remainder of the campaign in 1917. The Central Powers held Braila, Isaccea, and Tulcea with the bulk of the Danube Flotilla anchored in Harsova and Braila. The Romanians and Russians clung to Galatz, Reni, Ismaila, and Sulina, along with most of the Danube delta below Tulcea. Galatz and Reni were virtually in the front line, and all floating matériel was evacuated. Tulcea was a key position, for its possession by the Central Powers blocked Russian and Romanian use of the Sulina Channel, the best of the arms of the Danube through the delta. The French naval mission hoped, in vain, for a Russian offensive to retake Tulcea. The Danube itself formed the main line of defense in much of the region; the amount of dry land suitable for troop movements or water suitable for navigation in the delta varied greatly according to the season.
The Romanian and Russian naval forces were deployed in the Kilia and Sulina arm of the Danube and adapted to the local situation. The French naval mission arranged for t
he Russians to mount 150-mm cannons in six self-propelled barges. The Russians, in addition to the three Donetz-class gunboats, had another six lighters with 200-mm or 150-mm cannons, whereas the Romanians, in addition to their four monitors, had two lighters with 120-mm cannons.58 The lighters were well suited for conditions in this region, and they were similar to the armed lighters used by the Italians in the Adriatic lagoons along the maritime flank of the Italian front. For most of 1917 there was a little known and very singular type of war here among the reeds, canals, lakes, and marshes of the maritime Danube and its delta, marked by extensive mining and small sorties and raids.59
There is no space to go into operations in Romania during 1917 in detail, but the Romanian army in Moldavia was reorganized by a French military mission under General Berthelot and emerged as a much smaller but far more efficient force.60 The Romanians proved strong enough to stop an ill-advised German offensive in August with a successful counterattack in what is known to Romanian historians as the Battle of Marasesti. But any advantage gained by the Entente in Romania was more than nullified by the gradual dissolution of the Russian army following the Russian Revolution. Shortly after the Bolshevik seizure of power, the Romanians were compelled to conclude an armistice with the Central Powers at Foscani on 9 December 1917, followed by the preliminary Peace of Buftea, 5 March 1918, and the formal peace, the Treaty of Bucharest, 7 May 1918.
A Naval History of World War I Page 49