Battle of the Gulf of Riga

The Battle of the Gulf of Riga was the largest operation of the German fleet in the Baltic Sea in 1915. In August the Germans brought over from the North Sea a large part of the High Seas Fleet and twice tried to break through the Russian mine barrages in the Irben Strait, at the entrance to the Gulf of Riga. The first attempt, on 8 August, stalled on the mines. The second, begun on 16 August, succeeded: on 19 August two German dreadnoughts entered the gulf and sank a Russian gunboat. The same day a British submarine torpedoed the battlecruiser Moltke in the open sea. The Germans did not achieve their main aims, the destruction of the Russian ships in the gulf and the mining of the passage to the north. On 21 August they left the gulf, and the Russians kept control of it.

Name and dates

Polish and Western literature speaks of the Battle of the Gulf of Riga, Russian literature of the defence of the Gulf of Riga or the Irben operation, and the German official history of the “break-in into the Gulf of Riga” (Einbruch in den Rigabusen). We date the battle from 8 August 1915, when German minesweepers first began clearing the Irben Strait, to 21 August, when the last German ships left the strait. Russian sources, which used the Julian calendar, date it the same way, that is from 26 July to 8 August. Some works end the battle on 19 or 20 August. Between the two attempts, from 10 to 15 August, there were only skirmishes and shelling of the coast.

Background

In the summer of 1915 the German Army of the Niemen, advancing in Courland, occupied the western part of the country with the coast from Libau to Windau, and on 1 August entered Mitau. The left wing of the German front rested on the shore of the Gulf of Riga. From then on Russian gunboats and destroyers shelled German positions on the coast from the sea. The gulf, screened to the west by the island of Saaremaa, or Ösel, had only two entrances: the wide but shallow and mined Irben Strait on the Courland side, and the narrow passage through the Moon Sound in the north, through which the Russians could bring ships from the Gulf of Finland. The first German attempts to sweep the strait at the beginning of June had been repulsed.

Prince Henry of Prussia, the Emperor’s brother, who commanded in the Baltic, wanted to force his way into the gulf, destroy the Russian ships there and close the Moon Sound with mines. Originally the operation was to support an army offensive on Riga. By the beginning of August, however, it was already clear that the army would not attack Riga for the time being. On 10 August the Chief of the General Staff, Erich von Falkenhayn, confirmed explicitly that no land attack on Riga was planned. Grand Admiral Alfred von Tirpitz regarded an independent raid by the fleet as a risk with no prospect of real success. Prince Henry and Emperor Wilhelm II nevertheless wanted to carry out the operation, partly to raise the fleet’s morale and in the hope that the main Russian forces would come out of the Gulf of Finland. The Germans also already knew that the old Russian battleship Slava had arrived in the Gulf of Riga, and her destruction became one of the aims.

The forces assigned to the operation far exceeded the whole Russian Baltic Fleet. The actual break-in was led by Vice-Admiral Ehrhard Schmidt, commander of the IV Squadron, made up of older battleships. He had at his disposal cruisers, three torpedo-boat flotillas, several minesweeping divisions, the minelayer Deutschland and three blockships to be sunk in the harbour entrance at Pernau. On the open-sea side he was covered by Vice-Admiral Franz von Hipper with the eight dreadnoughts of the I Squadron and three battlecruisers: Seydlitz, Moltke and Von der Tann. He was to destroy the Russian fleet if it came out of the Gulf of Finland.

The Russians defended the gulf with light forces under Captain Pyotr Trukhachev. He had the Slava, four gunboats, among them Sivuch and Koreets, a dozen or so destroyers, including the modern Novik, the minelayer Amur, several submarines and seaplanes from a base on Saaremaa. The most important thing, however, was the position itself: several lines of mines in the Irben Strait, according to Russian figures up to 2,500 mines in all, backed by coastal batteries. At sea off the gulf two British submarines were also waiting, E1 and E9, which had broken through into the Baltic in the autumn of 1914 and since July had commanded German respect after torpedoing the cruiser Prinz Adalbert.

Course

First attempt, 8 August

On 8 August at about 4 a.m. German minesweepers began clearing the central passage through the Irben Strait. They were covered by the battleships Braunschweig and Elsass and by cruisers. At a quarter past five the minesweeper T 52 was blown up by a mine, and shortly afterwards mines damaged the cruiser Thetis and the torpedo boat S 144, which had to be escorted back to Libau. Russian gunboats, destroyers and seaplanes tried several times to disrupt the sweeping, but withdrew under the fire of the German battleships. At about 10.30 a.m. the Slava came up. The German battleships opened fire on her at a range of about 16 kilometres and the Russian ship quickly withdrew. The passage through the first barrage was ready only after 11 a.m., after six hours’ work, and two miles further on the minesweepers ran into the next one. After 1 p.m. the minesweeper T 58 sank on it.

Vice-Admiral Schmidt concluded that he would not manage to enter the gulf and lay mines in the Moon Sound before dark, and his coal stocks did not allow him to wait until morning. At about 1.45 p.m. he broke off the operation. In his report he wrote that the mine defence was “very strong” and that a renewed attempt made sense only with a much larger number of minesweepers. On 10 August German cruisers shelled Russian destroyers and seaplane hangars on the Sõrve peninsula, and the Von der Tann exchanged fire with the batteries on the Finnish island of Utö. After several days of disputes between the Baltic command, the Admiralty in Berlin and Tirpitz, the Emperor agreed to a second attempt. The Russians made use of the pause: the minelayer Amur and destroyers laid several hundred new mines in the strait.

Second attempt, 16–18 August

For the second attempt Schmidt took, instead of the old battleships, two dreadnoughts, Posen and Nassau, which could better withstand mine and torpedo explosions, and more minesweepers. On the morning of 16 August the minesweepers this time entered by the southern passage, along the Courland coast. At about 1.30 p.m. the minesweeper T 46 broke in two on a mine and sank, and of her crew of 25 only eight men were saved. In the afternoon the Slava twice came up to shell the minesweepers. The Russians artificially heeled her by flooding compartments on one side to increase the range of her guns, but the German dreadnoughts still had the longer reach and forced her to withdraw.

In the evening Schmidt sent two modern torpedo boats, V 99 and V 100, into the gulf to find and torpedo the Slava during the night. They did not find her. After several brief clashes with Russian destroyers, towards dawn on 17 August, they ran into the Novik. The Russian destroyer, more heavily armed, quickly gained the upper hand in the gunfight. The burning V 99 tried to escape through the minefields, struck two mines and had to be beached on the Courland coast near Mikhaylovsk (Pissen), where her crew abandoned her. Twenty-one men were killed. On the morning of 17 August the Slava again approached the minesweepers and took three heavy hits from the Posen and Nassau. She did not lose her fighting capacity, but Trukhachev withdrew her and most of the ships towards the Moon Sound. On 17 and 18 August the minesweepers cut through the last barrages, including an anti-submarine net studded with small mines.

In the gulf, 19–20 August

On the morning of 19 August the German force entered the Gulf of Riga. The same morning, in the open sea west of Saaremaa, the British submarine E1 under Noel Laurence torpedoed the battlecruiser Moltke, which was covering the operation. The ship did not sink, but Hipper sent her back to Danzig. German cruisers reconnoitred the gulf as far as Arensburg on Saaremaa and Pernau, but found hardly any Russian ships. In the evening, off the island of Kihnu, the cruiser Augsburg with two torpedo boats intercepted two Russian gunboats, Sivuch and Koreets, which were sailing from the mouth of the Dvina, where they had been laying mines, towards the Moon Sound. The Sivuch, commanded by Lieutenant-Commander Pyotr Cherkasov, fought to the end, until she was finished off by the Posen and Nassau. She capsized and sank in flames. The Germans picked up two officers and 48 sailors, several of whom died of their wounds. The Koreets escaped in the darkness, ran aground in shallow water and was blown up by her own crew the next day. During the night the German torpedo boat S 31 sank on a mine.

On the morning of 20 August German torpedo boats brought three old ships into the harbour of Pernau and scuttled them in the entrance channel under the fire of Russian field batteries. The Russians expected a landing and themselves set fire to some of the warehouses in the town. News then spread in Russia and in the Entente countries of a German landing repulsed at Pernau, which was even repeated by the British official history. German sources do not confirm that any landing attempt took place.

Withdrawal, 20–21 August

The same morning Schmidt gave up mining the Moon Sound. In the confined, mined waters and in poor visibility his ships had little freedom of manoeuvre, and one of the torpedo boats reported a submarine in the path of the battleships. Schmidt concluded that an unguarded barrage would hold up the Russians for a few days at most, since the Germans were going to leave the gulf anyway. The minesweepers were exhausted, and Hipper’s covering force was short of coal. On the afternoon of 20 August the German ships left the gulf, and on 21 August, after recovering the buoys marking the passage and blowing up the wreck of V 99, they left the Irben Strait. That evening the covering force was also dispersed. The ships of the High Seas Fleet returned to the North Sea.

Losses

According to the German official history the Germans lost two torpedo boats, V 99 and S 31, and three minesweepers, T 46, T 52 and T 58, to mines. The cruiser Thetis, the torpedo boat S 144 and the minesweeper T 77 were damaged by mines, and the Moltke by a torpedo. Sixty-five men were killed or missing. The Russians lost the gunboats Sivuch and Koreets. The Slava, the gunboat Grozyashchiy and several destroyers were damaged. The Russian historian Dmitry Kozlov estimates Russian losses in killed, wounded and captured at about 150 men, most of them from the crew of the Sivuch.

Significance

The Russians and their allies regarded the defence of the Gulf of Riga as a victory. The German fleet had indeed broken through barrages considered impassable, but it did not destroy the Slava, did not mine the Moon Sound, and two weeks’ effort by half the German fleet produced the sinking of two old gunboats. Most of the German losses were caused by mines. Russian ships returned to the gulf almost immediately and went on supporting with their guns the defence of Riga, which was held by the newly formed 12th Army. In September the German Admiralty Staff admitted that the operation as a whole could not be considered a success.

The raid nevertheless had indirect effects. The Russian high command, alarmed by rumours of a landing at Pernau, ordered the coastal defences of Livonia and Estonia strengthened and the number of guns at the mouth of the Dvina increased. The Baltic Fleet used up huge quantities of mines in rebuilding the barrages and in the following months concentrated even more on defence. The Germans returned to the Gulf of Riga only in October 1917, during Operation Albion, when together with the army they seized the islands at its entrance. Riga remained in Russian hands until September 1917.