The Battle of Cocos was a single-ship action that occurred on 9 November 1914, after the Australian light cruiser , under the command of John Glossop, responded to an attack on a communications station at Direction Island by the German light cruiser , commanded by Karl von Müller.
After the retreat of the German East Asia Squadron from Southeast Asia, Emden had remained behind to function as a commerce raider. During a two-month period, the German cruiser captured or sank 25 civilian vessels, shelled Madras, and destroyed two Allied warships at Penang. In early November, von Müller decided to attack the communications station at Direction Island, in the Cocos (Keeling) Islands, to hamper Allied communications and frustrate the search for his ship. Around the same time, a convoy of Europe-bound transports carrying Australian and New Zealand soldiers departed from Albany, Western Australia, with escorts , HMAS Sydney, , and the .
During the night of 8–9 November, Emden reached the islands and sent a party ashore at around 06:00 to disable the wireless and cable transmission station on Direction Island. The station was able to transmit a distress call before it was shut down. Melbourne received the message and ordered Sydney to investigate. The Australian ship arrived off Direction Island at 09:15, spotting and being spotted by Emden; both ships prepared for combat. Emden opened fire at 09:40, surprising those aboard Sydney as the range was greater than British intelligence thought Emden was capable of. The German ship scored several hits, but was unable to inflict disabling damage to the Australian cruiser before Sydney opened up with her more powerful main guns. At 11:20, von Müller ordered that the heavily damaged Emden beach on North Keeling Island. The Australian warship broke off to pursue the collier , which scuttled herself, then returned to North Keeling Island at 16:00. At this point, Emdens battle ensign was still flying, and after no response to instructions to lower the ensign, Glossop ordered two salvoes shot into the beached cruiser. Sydney had orders to ascertain the status of the transmission station, but returned the next day to provide medical assistance to the Germans.
Of Emdens crew, 134 were killed and 69 wounded, compared to only 4 killed and 16 wounded aboard Sydney. The German survivors were taken aboard the Australian cruiser, with most transferred to the auxiliary cruiser on 12 November. Sydney rejoined the troop convoy in Colombo, then spent the rest of the war assigned to the North America and West Indies Station, then the British Grand Fleet. Von Müller and some of his officers were imprisoned on Malta, with the rest of the crew being sent to prisoner-of-war camps in Australia. The 50 men of the German shore party on Direction Island commandeered the schooner Ayesha and escaped, eventually reaching Constantinople. The defeat of the last German ship in the region allowed RAN warships to be deployed to other theatres, and troopships were able to sail unescorted between Australia and the Middle East until renewed raider activity in 1917.
Ships
HMAS Sydney
Sydney was a light cruiser, of the Chatham subclass. She had a standard displacement of . The cruiser was long overall and long between perpendiculars, with a beam of , and a draught of . A combined coal- and oil-fuelled boiler system allowed the ship to reach speeds over .
The cruiser's main armament consisted of eight BL 6-inch Mark XI guns in single mountings, firing shells. Secondary and anti-aircraft armament consisted of a single 3-inch quick-firing high-angle anti-aircraft gun and ten 0.303-inch machine guns (eight Lewis guns and two Maxim guns). Two 21-inch torpedo tubes were fitted, with a payload of seven torpedoes carried. Two hydraulic-release depth charge chutes were carried for anti-submarine warfare. A single 12-pounder 8 cwt field gun and four 3-pounder Hotchkiss saluting guns rounded out the armament.
Sydney was laid down by the London and Glasgow Engineering and Iron Shipbuilding Company at Glasgow, Scotland, on 11 February 1911. The ship was launched on 29 August 1912 by the wife of Admiral Sir Reginald Henderson. Sydney was completed on 26 June 1913, and commissioned into the RAN that day. At the time of the battle, Captain John Glossop was in charge of the ship, with 434 personnel aboard.
SMS Emden
Emden was a Dresden-class cruiser. The ship had a displacement of 3,364 tons at normal load, was long, had a beam of , and a draught of . The light cruiser had a maximum speed of . The ship was armed with ten SK L/40 guns in single mountings, and carried two torpedo tubes.