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136-766: SMS Emden ("His Majesty's Ship Emden ") was the second and final member of the Dresden class of light cruisers built for the German Kaiserliche Marine (Imperial Navy). Named for the town of Emden , she was laid down at the Kaiserliche Werft (Imperial Dockyard) in Danzig in 1906. The hull was launched in May 1908, and completed in July 1909. She had one sister ship, Dresden . Like

272-487: A double bottom that extended for 47 percent of the length of the keel . The ships were good sea boats, but they were crank and rolled up to twenty degrees. They were also very wet at high speeds and suffered from a slight weather helm . Nevertheless, the ships turned tightly and were very maneuverable. In a hard turn, their speed fell up to 35 percent. They had a transverse metacentric height of .59 m (1 ft 11 in). Dresden and Emden had

408-467: A weed hatch over the propeller, and once the narrowboat is stationary, the hatch may be opened to give access to the propeller, enabling debris to be cleared. Yachts and river boats rarely have weed hatches; instead they may fit a rope cutter that fits around the prop shaft and rotates with the propeller. These cutters clear the debris and obviate the need for divers to attend manually to the fouling. Several forms of rope cutters are available: A cleaver

544-410: A Japanese company proposed that Emden be repaired and refloated, but an inspection by the elderly flat-iron gunboat HMAS  Protector concluded that wave damage to Emden made such an operation unfeasible. By 1919, the wreck had almost completely broken up and disappeared beneath the waves. It was eventually broken up in situ in the early 1950s by a Japanese salvage company; parts of

680-517: A Tierra in March 1915. Her engines were worn out and she had almost no coal left for her boilers; the ship's captain contacted the local Chilean authorities to have his vessel interned for the duration of the conflict. There, she was trapped by British cruisers, including her old opponent Glasgow ; the British violated Chilean neutrality and opened fire on the ship. The Germans scuttled Dresden and

816-419: A better match of angle of attack to the wake velocity over the blades. A warped helicoid is described by specifying the shape of the radial reference line and the pitch angle in terms of radial distance. The traditional propeller drawing includes four parts: a side elevation, which defines the rake, the variation of blade thickness from root to tip, a longitudinal section through the hub, and a projected outline of

952-434: A blade onto a longitudinal centreline plane. The expanded blade view shows the section shapes at their various radii, with their pitch faces drawn parallel to the base line, and thickness parallel to the axis. The outline indicated by a line connecting the leading and trailing tips of the sections depicts the expanded blade outline. The pitch diagram shows variation of pitch with radius from root to tip. The transverse view shows

1088-474: A crew of 18 officers and 343 enlisted men. They carried a number of smaller boats, including one picket boat , one barge, one cutter , two yawls , and two dinghies . Dresden ' s propulsion system consisted of two sets of Parsons steam turbines, designed to give 15,000 shaft horsepower (11,000 kW). Emden , instead, was equipped with two triple expansion engines rated at 13,500 indicated horsepower (10,100 kW). Both ships had

1224-601: A crew of 376. Most of the surviving crew, including Müller, were taken into captivity the next day. The wounded men were sent to Australia, while the uninjured were interned at a camp in Malta ; the men were returned to Germany in 1920. Mücke's landing party evaded capture. They had observed the battle, and realized that Emden would be destroyed. Mücke therefore ordered the old 97 gross register ton schooner Ayesha to be prepared for sailing. The Germans departed before Sydney reached Direction Island, and sailed to Padang in

1360-623: A cruise to the German colonies in the Central Pacific, and was stationed off Nanjing , as fighting between Qing and revolutionary forces raged there. On 26 August, rebels attacked the ship, and Emden ' s gunners immediately returned fire, silencing the attackers. Emden moved to Shanghai on 14 August. Emden spent the first half of 1914 on the normal routine of cruises in Chinese and Japanese waters without incident. During

1496-508: A ducted propeller. The cylindrical duct acts as the stator, while the tips of the blades act as the rotor. They typically provide high torque and operate at low RPMs, producing less noise. The system does not require a shaft, reducing weight. Units can be placed at various locations around the hull and operated independently, e.g., to aid in maneuvering. The absence of a shaft allows alternative rear hull designs. Twisted- toroid (ring-shaped) propellers, first invented over 120 years ago, replace

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1632-422: A flow around the propeller. A screw turning through a solid will have zero "slip"; but as a propeller screw operates in a fluid (either air or water), there will be some losses. The most efficient propellers are large-diameter, slow-turning screws, such as on large ships; the least efficient are small-diameter and fast-turning (such as on an outboard motor). Using Newton's laws of motion, one may usefully think of

1768-435: A foray to the western side of Ceylon. On 25 September, Emden sank the British merchantmen Tywerse and King Lund two days before capturing the collier Buresk , which was carrying a cargo of high-grade coal. A German prize crew went aboard Buresk which was used to support Emden ' s operations. Later that day, the German raider sank the British vessels Ryberia and Foyle . Low on fuel, Emden proceeded to

1904-400: A marine screw propeller is based on a helicoidal surface. This may form the face of the blade, or the faces of the blades may be described by offsets from this surface. The back of the blade is described by offsets from the helicoid surface in the same way that an aerofoil may be described by offsets from the chord line. The pitch surface may be a true helicoid or one having a warp to provide

2040-426: A maximum elevation of 30 degrees, which allowed them to engage targets out to 12,700 m (13,900 yd). They were supplied with 1,500 rounds of ammunition, for 150 shells per gun. The ships were also equipped with eight 5.2 cm (2 in) SK L/55 guns with 4,000 rounds of ammunition. Both ships were also equipped with a pair of 45 cm (17.7 in) torpedo tubes with five torpedoes submerged in

2176-528: A minimal superstructure , which consisted of a small conning tower and bridge structure. Her hull had a raised forecastle and quarterdeck , along with a pronounced ram bow . She was fitted with two pole masts . She had a crew of 18 officers and 343 enlisted men. Her propulsion system consisted of two triple-expansion steam engines drove a pair of screw propellers . Steam was provided by twelve coal-fired Marine-type water-tube boilers that were vented through three funnels . The propulsion system

2312-402: A propeller solution of a rod going through the underwater aft of a boat attached to a bladed propeller, though he never built it. In February 1800, Edward Shorter of London proposed using a similar propeller attached to a rod angled down temporarily deployed from the deck above the waterline and thus requiring no water seal, and intended only to assist becalmed sailing vessels. He tested it on

2448-452: A propeller with a steel shaft and aluminium blades for his 14 bis biplane . Some of his designs used a bent aluminium sheet for blades, thus creating an airfoil shape. They were heavily undercambered , and this plus the absence of lengthwise twist made them less efficient than the Wright propellers. Even so, this may have been the first use of aluminium in the construction of an airscrew. In

2584-501: A propeller's forward thrust as being a reaction proportionate to the mass of fluid sent backward per time and the speed the propeller adds to that mass, and in practice there is more loss associated with producing a fast jet than with creating a heavier, slower jet. (The same applies in aircraft, in which larger-diameter turbofan engines tend to be more efficient than earlier, smaller-diameter turbofans, and even smaller turbojets , which eject less mass at greater speeds.) The geometry of

2720-474: A range of 3,760 nmi (6,960 km; 4,330 mi) at 12 knots (22 km/h; 14 mph). Electrical power was supplied by three turbo generators that provided a total of 125 kilowatts at 110  volts . The ships were armed with ten 10.5 cm (4.1 in) SK L/40 guns in single pedestal mounts. Two were placed side by side forward on the forecastle , six were located amidships, three on either side, and two were side by side aft. The guns had

2856-416: A rubber bushing can be replaced or repaired depends upon the propeller; some cannot. Some can, but need special equipment to insert the oversized bushing for an interference fit . Others can be replaced easily. The "special equipment" usually consists of a funnel, a press and rubber lubricant (soap). If one does not have access to a lathe, an improvised funnel can be made from steel tube and car body filler; as

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2992-462: A salvo every ten seconds; Müller hoped to overwhelm Sydney with a barrage of shells before her heavier armament could take effect. Two shells hit Sydney , one of which disabled the aft fire control station; the other failed to explode. It took slightly longer for Sydney to find the range, and in the meantime, Emden turned toward Sydney in an attempt to close to torpedo range. Sydney ' s more powerful 6 in (152 mm) guns soon found

3128-494: A screw propeller with multiple blades on a conical base. He tested it in February 1826 on a manually-driven ship and successfully used it on a steamboat in 1829. His 48-ton ship Civetta reached 6 knots. This was the first successful Archimedes screw-propelled ship. His experiments were banned by police after a steam engine accident. Ressel, a forestry inspector, held an Austro-Hungarian patent for his propeller. The screw propeller

3264-468: A screw to lift water for irrigation and bailing boats, so famously that it became known as Archimedes' screw . It was probably an application of spiral movement in space (spirals were a special study of Archimedes) to a hollow segmented water-wheel used for irrigation by Egyptians for centuries. A flying toy, the bamboo-copter , was enjoyed in China beginning around 320 AD. Later, Leonardo da Vinci adopted

3400-597: A second, larger screw-propelled boat, Robert F. Stockton , and had her sailed in 1839 to the United States, where he was soon to gain fame as the designer of the U.S. Navy 's first screw-propelled warship, USS  Princeton . Apparently aware of the Royal Navy's view that screw propellers would prove unsuitable for seagoing service, Smith determined to prove this assumption wrong. In September 1837, he took his small vessel (now fitted with an iron propeller of

3536-411: A single turn) to sea, steaming from Blackwall, London to Hythe, Kent , with stops at Ramsgate , Dover and Folkestone . On the way back to London on the 25th, Smith's craft was observed making headway in stormy seas by officers of the Royal Navy. This revived Admiralty's interest and Smith was encouraged to build a full size ship to more conclusively demonstrate the technology. SS  Archimedes

3672-545: A slightly greater displacement with an additional boiler for the propulsion system to increase engine power. Like the Königsberg s, one ship— Dresden —was fitted with a steam turbine engine to compare its performance with the traditional triple-expansion engine in an otherwise-identical sister ship . All subsequent designs of German cruisers utilized turbine propulsion systems. The two Dresden -class cruisers were 117.90 meters (386 ft 10 in) long at

3808-452: A top speed of 24 knots (44 km/h; 28 mph). In both vessels, the engines were powered by twelve coal-fired Marine-type water-tube boilers . Both ships carried up to 860 metric tons (850 long tons) of coal, though their ranges were slightly different, owing to their different propulsion systems. Dresden could steam for 3,600 nautical miles (6,700 km; 4,100 mi) at 14 knots (26 km/h; 16 mph), while Emden had

3944-479: A tremendous explosion that tore the ship apart. By the time the smoke cleared, Zhemchug had already slipped beneath the waves, the masts the only parts of the ship still above water. The destruction of Zhemchug killed 81 Russian sailors and wounded 129, of whom seven later died of their injuries. The elderly French torpedo cruiser D'Iberville and the destroyer Fronde opened wildly inaccurate fire on Emden . Müller then decided to depart, owing to

4080-411: A twist in their blades to keep the angle of attack constant. Their blades were only 5% less efficient than those used 100 years later. Understanding of low-speed propeller aerodynamics was complete by the 1920s, although increased power and smaller diameters added design constraints. Alberto Santos Dumont , another early pioneer, applied the knowledge he gained from experiences with airships to make

4216-468: A veteran of the Battle of Tsushima . Zhemchug had put into Penang for boiler repairs; only one was in service, which meant that she could not get under way, nor were the ammunition hoists powered. Only five rounds of ready ammunition were permitted for each gun, with a sixth chambered. Emden pulled alongside Zhemchug at a distance of 300 yards (270 m); Müller ordered a torpedo to be fired at

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4352-510: A warm reception. She remained there until 10 October, to remove fouling . While searching for merchant ships west of Colombo, Emden picked up Hampshire ' s wireless signals again; the ship had departed for the Chagos Archipelago on 13 October. The British had captured Markomannia on 12 October, depriving Emden of a collier. On 15 October, Emden captured the British steamer Benmore off Minikoi and sank her

4488-471: A week after the battle to bury the sailors killed in the battle. Over a raiding career spanning three months and 30,000 nautical miles (56,000 km; 35,000 mi), Emden had destroyed two Entente warships and sank or captured sixteen British steamers and one Russian merchant ship, totaling 70,825  gross register tons  (GRT). Another four British ships were captured and released, and one British and one Greek ship were used as colliers. In 1915,

4624-445: Is a type of propeller design especially used for boat racing. Its leading edge is formed round, while the trailing edge is cut straight. It provides little bow lift, so that it can be used on boats that do not need much bow lift, for instance hydroplanes , that naturally have enough hydrodynamic bow lift. To compensate for the lack of bow lift, a hydrofoil may be installed on the lower unit. Hydrofoils reduce bow lift and help to get

4760-479: Is an opportunity to only change the pitch or the damaged blades. Being able to adjust pitch will allow for boaters to have better performance while in different altitudes, water sports, or cruising. Voith Schneider propellers use four untwisted straight blades turning around a vertical axis instead of helical blades and can provide thrust in any direction at any time, at the cost of higher mechanical complexity. A rim-driven thruster integrates an electric motor into

4896-628: Is on display at the Australian War Memorial in Canberra . In addition, Emden ' s bell and stern ornament were recovered from the wreck and both are currently in the collection of the Australian War Memorial. A number of other artifacts, including a damaged 10.5 cm shell case, an iron rivet from the hull, and uniforms were also recovered and are held in the Australian War Memorial. In March 1921,

5032-482: Is the tangential offset of the line of maximum thickness to a radius The propeller characteristics are commonly expressed as dimensionless ratios: Cavitation is the formation of vapor bubbles in water near a moving propeller blade in regions of very low pressure. It can occur if an attempt is made to transmit too much power through the screw, or if the propeller is operating at a very high speed. Cavitation can waste power, create vibration and wear, and cause damage to

5168-633: The Reichsmarine , also carried the Iron Cross, along with battle honors for the Indian Ocean, Penang, Cocos Islands, and Ösel , where the second Emden had engaged several Russian destroyers and torpedo boats. Three further vessels have been named for the cruiser in the post-war German Navy , two of which also carried an Iron Cross: the Köln -class frigate Emden laid down in 1959,

5304-792: The Emden ) was released, which was made about how the crew of Emden made their way back to Germany after the Battle of Cocos. After the bombardment of Madras, Emden ' s name, as "Amdan", entered the Sinhala and Tamil languages meaning "someone who is tough, manipulative and crafty." In the Malayalam language the word "Emadan" means "a big and powerful thing" or "as big as Emden". 11°50′00″S 96°49′00″E  /  11.8333°S 96.8167°E  / -11.8333; 96.8167 Dresden-class cruiser The Dresden class

5440-775: The Bremen -class frigate Emden laid down in 1979, and the Braunschweig -class corvette Emden laid down in 2020. Three of the ship's 10.5 cm guns were removed from the wreck three years after the battle. One is preserved in Hyde Park in Sydney, a second is located at the Royal Australian Navy Heritage Centre in HMAS ; Kuttabul , the main naval base in Sydney, and the third

5576-627: The Battle of Coronel in November 1914 and the Battle of the Falkland Islands the following December. She was the only German vessel to escape destruction at the latter engagement, and she remained at large for several more months. Dresden finally put into the Chilean island of Más a Tierra in March 1915 owing to worn-out engines. A pair of British cruisers violated Chilean neutrality and attacked Dresden while she lay at anchor;

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5712-535: The Cocos Islands , where he landed a contingent of sailors to destroy British facilities. There, Emden was attacked by the Australian cruiser HMAS  Sydney on 9 November 1914. The more powerful Australian ship quickly inflicted serious damage and forced Müller to run his ship aground to avoid sinking. Out of a crew of 376, 133 were killed in the battle. Most of the survivors were taken prisoner;

5848-581: The East Asia Squadron from her commissioning, and Dresden was sent to Caribbean waters in 1913. Dresden was due to return to Germany for periodic maintenance shortly before the outbreak of World War I in August 1914, but this became impossible with the onset of hostilities. She therefore operated as a commerce raider, before linking up with Vizeadmiral Maximilian von Spee 's East Asia Squadron. Dresden thereafter participated in

5984-553: The Ganges estuary, Emden caught a Norwegian merchantman, which the Germans searched; finding no contraband they released her. The Norwegians informed Müller that Entente warships were operating in the area, which persuaded him to return to the eastern coast of India. Emden stopped and released an Italian freighter, whose crew relayed news of the incident to a British vessel, which in turn informed British naval authorities in

6120-677: The July Crisis that followed the assassination of Archduke Franz Ferdinand of Austria , Emden was the only German cruiser in Qingdao; Spee's two armored cruisers , Scharnhorst and Gneisenau , were cruising in the South Pacific and Leipzig was en route to replace Nürnberg off the coast of Mexico. On 31 July, with war days away, Müller put to sea to begin commerce raiding once war had been formally declared. Two days later, on 2 August, Germany declared war on Russia, and

6256-503: The Maldives , arriving on 29 September and remaining for a day while coal stocks were replenished. The raider then cruised the routes between Aden and Australia and between Calcutta and Mauritius for two days without success. Emden steamed to Diego Garcia for engine maintenance and to rest the crew. The British garrison at Diego Garcia had not yet learned of the state of war between Britain and Germany, and so treated Emden to

6392-716: The River Thames to senior members of the British Admiralty , including Surveyor of the Navy Sir William Symonds . In spite of the boat achieving a speed of 10 miles an hour, comparable with that of existing paddle steamers , Symonds and his entourage were unimpressed. The Admiralty maintained the view that screw propulsion would be ineffective in ocean-going service, while Symonds himself believed that screw propelled ships could not be steered efficiently. Following this rejection, Ericsson built

6528-708: The commerce raider Cormoran . Emden rejoined the East Asia Squadron, then was detached for independent raiding in the Indian Ocean . The cruiser spent nearly two months operating in the region, and captured nearly two dozen ships. On 28 October 1914, Emden launched a surprise attack on Penang ; in the resulting Battle of Penang , she sank the Russian cruiser Zhemchug and the French destroyer Mousquet . Müller then took Emden to raid

6664-403: The rangefinders and caused heavy casualties amongst Emden ' s gun crews. Müller made a third attempt to close to torpedo range, but Sydney quickly turned away. Shortly after 10:00, a shell from Sydney detonated ready ammunition near the starboard No. 4 gun and started a serious fire. Emden made a fourth and final attempt to launch a torpedo attack, but Sydney was able to keep

6800-417: The vapor pressure of the water, resulting in the formation of a vapor pocket. Under such conditions, the change in pressure between the downstream surface of the blade (the "pressure side") and the suction side is limited, and eventually reduced as the extent of cavitation is increased. When most of the blade surface is covered by cavitation, the pressure difference between the pressure side and suction side of

6936-538: The Archimedean screw. In 1771, steam-engine inventor James Watt in a private letter suggested using "spiral oars" to propel boats, although he did not use them with his steam engines, or ever implement the idea. One of the first practical and applied uses of a propeller was on a submarine dubbed Turtle which was designed in New Haven, Connecticut , in 1775 by Yale student and inventor David Bushnell , with

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7072-463: The Australians ceased fire. In the course of the action, Emden scored sixteen hits on Sydney , killing three of her crew and wounding another thirteen. A fourth crewman died later from his injuries. Sydney had meanwhile fired some 670 rounds of ammunition, with around 100 hits claimed. Emden had suffered much higher casualties: 133 officers and enlisted men died, out of

7208-515: The British armored cruiser HMS  Hampshire . To maintain secrecy, Emden ' s crew rigged up a dummy funnel to impersonate a British light cruiser, then steamed up the coast of Sumatra toward the Indian Ocean. On 5 September, Emden entered the Bay of Bengal , achieving complete surprise, since the British assumed she was still with Spee's squadron. She operated on shipping routes there without success, until 10 September, when she moved to

7344-597: The Colombo– Calcutta route. There, she captured the Greek collier SS  Pontoporos , which was carrying equipment for the British. Müller took the ship into his service and agreed to pay the crew. Emden captured five more ships; troop transports Indus and Lovat and two other ships were sunk, and the fifth, a steamer named Kabinga , was used to carry the crews from the other vessels. On 13 September, Müller released Kabinga and sank two more British prizes . Off

7480-644: The Dutch East Indies. From there, they traveled to Yemen , which was then part of the Ottoman Empire , an ally of Germany. They then traveled overland to Constantinople , arriving in June 1915. There, they reported to Vizeadmiral Wilhelm Souchon , the commander of the ex-German battlecruiser Goeben . In the meantime, the British sloop Cadmus arrived at the Cocos Islands about

7616-532: The East Asia Squadron. At the end of the year, Emden won the Kaiser's Schießpreis (Shooting Prize) for excellent gunnery in the East Asia Squadron. In early December, Emden steamed to Incheon to assist the grounded German steamer Deike Rickmers . In May 1913, Korvettenkapitän (Lieutenant Commander) Karl von Müller became the ship's commanding officer; he was soon promoted to Fregattenkapitän (Commander). In mid-June, Emden went on

7752-469: The East Asia Squadron. The first, the Battle of Coronel , took place in November, and Dresden engaged the British cruiser HMS  Glasgow . The second, the Battle of the Falkland Islands , followed in December, where British battlecruisers annihilated the German squadron; Dresden was the only vessel to escape. She eluded her British pursuers for several more months, until she put into Más

7888-405: The Germans scuttled their ship to prevent her capture. Emden , meanwhile, had been detached from the East Asia Squadron to pursue an independent commerce raiding campaign in the Indian Ocean. She captured or sank numerous Entente vessels, including the steamer Ryazan , which was converted into the auxiliary cruiser Cormoran . In September 1914, Emden raided Penang and caught

8024-464: The Indian Ocean in September, Emden captured several British merchantmen along the sea lanes from India to Aden . On 22 September, the ship bombarded Madras , before resuming the hunt for merchant ships. She captured several more vessels, and then raided the port of Penang . There, Emden caught the Russian protected cruiser Zhemchug in the harbor and quickly destroyed her. As Emden

8160-519: The Navy, Sir William Barrow. Having secured the patronage of a London banker named Wright, Smith then built a 30-foot (9.1 m), 6- horsepower (4.5 kW) canal boat of six tons burthen called Francis Smith , which was fitted with his wooden propeller and demonstrated on the Paddington Canal from November 1836 to September 1837. By a fortuitous accident, the wooden propeller of two turns

8296-471: The Russian protected cruiser Zhemchug and the French destroyer Mousquet and quickly destroyed both ships. Shortly thereafter, Emden was caught by the Australian cruiser HMAS  Sydney off the Cocos Islands and forced to beach after a ferocious engagement . The 1898 Naval Law authorized the construction of thirty new light cruisers ; the program began with the Gazelle class , which

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8432-430: The Russian cruiser, then gave the order for the 10.5 cm guns to open fire. Emden quickly inflicted grievous damage on her adversary, then turned around to make another pass at Zhemchug . One of the Russian gun crews managed to get a weapon into action, but scored no hits. Müller ordered a second torpedo to be fired into the burning Zhemchug while his guns continued to batter her. The second torpedo caused

8568-632: The United States in 1909 as part of Germany's delegation to the Hudson–Fulton Celebration . She returned to North American waters in late 1913, when she was stationed off the Mexican coast to protect German nationals during the Mexican Revolution . Following the rebels' victory the following year, Dresden evacuated the former dictator Victoriano Huerta to Jamaica , where the British had granted him asylum. In need of repairs,

8704-593: The annual autumn maneuvers of the main fleet. During this period, Emden also escorted the imperial yacht Hohenzollern with Kaiser Wilhelm II aboard. Emden was decommissioned in September after completing trials. On 1 April 1910 Emden was reactivated and assigned to the Ostasiengeschwader (East Asia Squadron), based at Qingdao in Germany's Jiaozhou Bay Leased Territory in China. The concession had been seized in 1897 in retaliation for

8840-413: The attack would demonstrate his freedom of maneuver and decrease British prestige with the local population. At around 20:00 on 22 September, Emden entered the port, which was completely illuminated, despite the blackout order. Emden closed to within 3,000 yards (2,700 m) from the piers before opening fire. She set fire to two oil tanks and damaged three others, and damaged a merchant ship in

8976-419: The blade drops considerably, as does the thrust produced by the propeller. This condition is called "thrust breakdown". Operating the propeller under these conditions wastes energy, generates considerable noise, and as the vapor bubbles collapse it rapidly erodes the screw's surface due to localized shock waves against the blade surface. Tip vortex cavitation is caused by the extremely low pressures formed at

9112-431: The blade to the water at the effective angle. The innovation introduced with the screw propeller was the extension of that arc through more than 360° by attaching the blade to a rotating shaft. Propellers can have a single blade , but in practice there is nearly always more than one so as to balance the forces involved. The origin of the screw propeller starts at least as early as Archimedes (c. 287 – c. 212 BC), who used

9248-400: The blades with a-circular rings. They are significantly quieter (particularly at audible frequencies) and more efficient than traditional propellers for both air and water applications. The design distributes vortices generated by the propeller across the entire shape, causing them to dissipate faster in the atmosphere. For smaller engines, such as outboards, where the propeller is exposed to

9384-453: The bushing in the hub is overcome and the rotating propeller slips on the shaft, preventing overloading of the engine's components. After such an event the rubber bushing may be damaged. If so, it may continue to transmit reduced power at low revolutions, but may provide no power, due to reduced friction, at high revolutions. Also, the rubber bushing may perish over time leading to its failure under loads below its designed failure load. Whether

9520-566: The celebrations of the hundredth anniversary of Argentinian independence. The two ships then rounded Cape Horn ; Emden stopped in Valparaíso , Chile, while Bremen continued on to Peru. The cruise across the Pacific was delayed because of a lack of good quality coal. Emden eventually took on around 1,400 t (1,400 long tons; 1,500 short tons) of coal at the Chilean naval base at Talcahuano and departed on 24 June. The cruise

9656-600: The core of the tip vortex. The tip vortex is caused by fluid wrapping around the tip of the propeller; from the pressure side to the suction side. This video demonstrates tip vortex cavitation. Tip vortex cavitation typically occurs before suction side surface cavitation and is less damaging to the blade, since this type of cavitation doesn't collapse on the blade, but some distance downstream. Variable-pitch propellers may be either controllable ( controllable-pitch propellers ) or automatically feathering ( folding propellers ). Variable-pitch propellers have significant advantages over

9792-534: The course of construction. The primary alteration for the two Dresden -class cruisers, assigned to the 1906 fiscal year, consisted of an additional boiler for the propulsion system to increase engine power. Emden was 118.3 meters (388 ft 1 in) long overall and had a beam of 13.5 m (44 ft 3 in) and a draft of 5.53 m (18 ft 2 in) forward. She displaced 3,664 metric tons (3,606 long tons ) as designed and up to 4,268 t (4,201 long tons) at full load . The ship had

9928-608: The cruiser was scheduled to return to Germany in July 1914, but the outbreak of World War I prevented this from taking place. Instead, Dresden operated as a commerce raider in South American waters in the Atlantic in the first months of the war before moving to the Pacific Ocean in September and thereafter joining Maximilian von Spee 's East Asia Squadron . Dresden participated in two major battles with

10064-513: The design to provide motive power for ships through water. In 1693 a Frenchman by the name of Du Quet invented a screw propeller which was tried in 1693 but later abandoned. In 1752, the Academie des Sciences in Paris granted Burnelli a prize for a design of a propeller-wheel. At about the same time, the French mathematician Alexis-Jean-Pierre Paucton suggested a water propulsion system based on

10200-409: The engine at normal loads. The pin is designed to shear when the propeller is put under a load that could damage the engine. After the pin is sheared the engine is unable to provide propulsive power to the boat until a new shear pin is fitted. In larger and more modern engines, a rubber bushing transmits the torque of the drive shaft to the propeller's hub. Under a damaging load the friction of

10336-399: The filler is only subject to compressive forces it is able to do a good job. Often, the bushing can be drawn into place with nothing more complex than a couple of nuts, washers and a threaded rod. A more serious problem with this type of propeller is a "frozen-on" spline bushing, which makes propeller removal impossible. In such cases the propeller must be heated in order to deliberately destroy

10472-541: The first Royal Navy ships to have steam-powered engines and screw propellers. Both participated in Franklin's lost expedition , last seen in July 1845 near Baffin Bay . Screw propeller design stabilized in the 1880s. The Wright brothers pioneered the twisted aerofoil shape of modern aircraft propellers. They realized an air propeller was similar to a wing. They verified this using wind tunnel experiments. They introduced

10608-552: The fixed-pitch variety, namely: An advanced type of propeller used on the American Los Angeles-class submarine as well as the German Type 212 submarine is called a skewback propeller . As in the scimitar blades used on some aircraft, the blade tips of a skewback propeller are swept back against the direction of rotation. In addition, the blades are tilted rearward along the longitudinal axis, giving

10744-610: The following day, Emden captured the Russian steamer Ryazan . The Russian vessel was sent back to Qingdao, and converted into the auxiliary cruiser Cormoran . On 5 August, Spee ordered Müller to join him at Pagan Island in the Mariana Islands ; Emden left Qingdao the following day along with the auxiliary cruiser Prinz Eitel Friedrich and the collier Markomannia . The ships arrived in Pagan on 12 August. The next day, Spee learned that Japan would enter

10880-414: The government of Prussia decreed that Prussian former crew members and relatives of those serving aboard the ship during World War I were allowed to add the heritable suffix "-Emden" to their last names as recognition for their service. Other German state governments followed suit. In March 1934, Paul von Hindenburg , who was then the president , decreed that relatives of those who had been killed aboard

11016-505: The harbor. In the course of the bombardment, Emden fired 130 rounds. The following day, the British again mandated that shipping stop in the Bay of Bengal; during the first month of Emden ' s raiding career in the Indian Ocean, the value of exports there had fallen by 61.2 percent. From Madras, Müller had originally intended to rendezvous with his colliers off Simalur Island in Indonesia, but instead decided to make

11152-561: The help of clock maker, engraver, and brass foundryman Isaac Doolittle . Bushnell's brother Ezra Bushnell and ship's carpenter and clock maker Phineas Pratt constructed the hull in Saybrook, Connecticut . On the night of September 6, 1776, Sergeant Ezra Lee piloted Turtle in an attack on HMS  Eagle in New York Harbor . Turtle also has the distinction of being the first submarine used in battle. Bushnell later described

11288-441: The horizon, and thirty minutes later identified it as a warship approaching at high speed. Mücke's landing party was still ashore, and there was no time left to recover them. Sydney closed to a distance of 9,500 yards (8,700 m) before turning to a parallel course with Emden . The German cruiser opened fire first, and straddled the Australian vessel with her third salvo. Emden ' s gunners were firing rapidly, with

11424-535: The hull on the broadside . The ships were protected by an armored deck that was up to 80 mm (3.1 in) thick amidships with 50 mm (2 in) thick sloping armor on the sides. The deck was reduced to 30 mm (1.2 in) further aft and then again to 20 mm (0.79 in) toward the stern. The conning tower had 100 mm (3.9 in) thick sides, and the guns were protected by 50 mm thick shields. Dresden spent most of her career on foreign stations. After her commissioning, she visited

11560-473: The landing party, led by Hellmuth von Mücke , commandeered an old schooner and eventually returned to Germany. Emden ' s wreck was quickly destroyed by wave action, and was broken up for scrap in the 1950s. The 1898 Naval Law authorized the construction of thirty new light cruisers ; the program began with the Gazelle class , which was developed into the Bremen and Königsberg classes , both of which incorporated incremental improvements over

11696-461: The main German naval base in Asia. Müller immediately began to operate as a commerce raider, and captured one ship, the Russian steamer Ryazan . Emden was thereafter ordered to rendezvous with the rest of Spee's cruisers. She remained with the East Asia Squadron for only a few days, as Müller convinced Spee to detach Emden as an independent raider in the Indian Ocean . After arriving in

11832-537: The majority of the crew escaped to be interned in Chile for the duration of the war. The wreck remains in the harbor and was first surveyed in 2002. Following her commissioning into the fleet, Emden was assigned to the East Asia Squadron. In 1913, Korvettenkapitän (Corvette Captain) Karl von Müller became the ship's commander. At the outbreak of war, Emden was the only major German warship in Qingdao ,

11968-627: The more powerful steam turbines . The ship's main battery comprised ten 10.5 cm (4.1 in) SK L/40 guns in single pivot mounts . Two were placed side by side forward on the forecastle; six were located on the broadside , three on either side; and two were placed side by side aft. The guns could engage targets out to 12,200 m (40,000 ft), and were supplied with 1,500 rounds of ammunition, 150 per gun. The secondary armament consisted of eight 5.2 cm (2 in) SK L/55 guns , also in single mounts. She had two 45 cm (17.7 in) torpedo tubes with four torpedoes , mounted below

12104-585: The murder of German nationals in the area. Emden left Kiel on 12 April 1910, bound for Asia by way of a goodwill tour of South America. A month later, on 12 May, she stopped in Montevideo and met with the cruiser Bremen , which was assigned to the Ostamerikanischen (East American) Station. Emden and Bremen stayed in Buenos Aires from 17 to 30 May to represent Germany at

12240-563: The next day. Over the next five days, she captured Troiens , Exfort , Graycefale , Sankt Eckbert , and Chilkana . One was used as a collier, three were sunk, and the fifth was sent to port with the crews of the other vessels. On 20 October, Müller decided to move to a new area of operations. Müller planned a surprise attack on Penang in British Malaya . Emden coaled in the Nicobar Islands and departed for Penang on

12376-403: The night of 27 October, with the departure timed to arrive off the harbor at dawn. She approached the harbor entrance at 03:00 on 28 October, steaming at 18 kn (33 km/h; 21 mph), with the fourth dummy funnel erected to disguise her identity. Emden ' s lookouts quickly spotted a warship in the port with lights on; it turned out to be the Russian protected cruiser Zhemchug ,

12512-407: The nineteenth century, several theories concerning propellers were proposed. The momentum theory or disk actuator theory – a theory describing a mathematical model of an ideal propeller – was developed by W.J.M. Rankine (1865), A.G. Greenhill (1888) and R.E. Froude (1889). The propeller is modelled as an infinitely thin disc, inducing a constant velocity along the axis of rotation and creating

12648-406: The preceding Königsberg class , being slightly larger and slightly faster, but with the same primary armament of ten 10.5 cm (4.1 in) guns. Dresden and Emden were powered by steam turbines and triple expansion engines , respectively, as part of continued experiments with the new turbine technology. Both ships served extensively on foreign stations; Emden was assigned to

12784-515: The preceding Königsberg -class cruisers, Emden was armed with ten 10.5 cm (4.1 in) guns and two torpedo tubes . Emden spent the majority of her career overseas in the East Asia Squadron , based in Qingdao , in the Jiaozhou Bay Leased Territory in China. In 1913, Karl von Müller took command of the ship. At the outbreak of World War I, Emden captured a Russian steamer and converted her into

12920-654: The problem. Smith was first to take out a screw propeller patent on 31 May, while Ericsson, a gifted Swedish engineer then working in Britain, filed his patent six weeks later. Smith quickly built a small model boat to test his invention, which was demonstrated first on a pond at his Hendon farm, and later at the Royal Adelaide Gallery of Practical Science in London , where it was seen by the Secretary of

13056-447: The propeller an overall cup-shaped appearance. This design preserves thrust efficiency while reducing cavitation, and thus makes for a quiet, stealthy design. A small number of ships use propellers with winglets similar to those on some airplane wings, reducing tip vortices and improving efficiency. A modular propeller provides more control over the boat's performance. There is no need to change an entire propeller when there

13192-486: The propeller in an October 1787 letter to Thomas Jefferson : "An oar formed upon the principle of the screw was fixed in the forepart of the vessel its axis entered the vessel and being turned one way rowed the vessel forward but being turned the other way rowed it backward. It was made to be turned by the hand or foot." The brass propeller, like all the brass and moving parts on Turtle , was crafted by Issac Doolittle of New Haven. In 1785, Joseph Bramah of England proposed

13328-406: The propeller. It can occur in many ways on a propeller. The two most common types of propeller cavitation are suction side surface cavitation and tip vortex cavitation. Suction side surface cavitation forms when the propeller is operating at high rotational speeds or under heavy load (high blade lift coefficient ). The pressure on the upstream surface of the blade (the "suction side") can drop below

13464-469: The range and inflicted serious damage. The wireless compartment was destroyed and the crew for one of the forward guns was killed early in the engagement. At 09:45, Müller turned his ship toward Sydney in another attempt to reach a torpedo firing position. Five minutes later, a shell hit disabled the steering gear, and other fragments jammed the hand steering equipment. Emden could only be steered with her propellers. Sydney ' s gunfire also destroyed

13600-489: The range open. By 10:45, Emden ' s guns had largely gone silent; the superstructure had been shredded and the two rear-most funnels had been shot away, along with the foremast. Müller realized that his ship was no longer able to fight, and beached Emden on North Keeling Island to save the lives of his crew. At 11:15, Emden was run onto the reef, and the engines and boilers were flooded. Her breech blocks and torpedo aiming gear were thrown overboard to render

13736-497: The region. The result was an immediate cessation of shipping and the institution of a blackout . Vice Admiral Martyn Jerram ordered Hampshire , Yarmouth , and the Japanese protected cruiser Chikuma to search for Emden . The British armored cruiser Minotaur and the Japanese armored cruiser Ibuki were sent to patrol likely coaling stations. In late September, Müller decided to bombard Madras . Müller believed

13872-537: The rest of the East Asia Squadron, commanded by Konteradmiral (Rear Admiral) Erich Gühler . The squadron remained in Samoa until October, when the ships returned to their base at Qingdao. Emden was sent to the Yangtze River from 27 October to 19 November, which included a visit to Hankou . The ship visited Nagasaki , Japan, before returning to Qingdao on 22 December for an annual refit. The repair work

14008-403: The risk of collision with heavy objects, the propeller often includes a device that is designed to fail when overloaded; the device or the whole propeller is sacrificed so that the more expensive transmission and engine are not damaged. Typically in smaller (less than 10 hp or 7.5 kW) and older engines, a narrow shear pin through the drive shaft and propeller hub transmits the power of

14144-404: The risk of encountering superior warships. Upon leaving the harbor, he encountered a British freighter, SS  Glen Turret , loaded with ammunition, that had already stopped to pick up a harbor pilot . While preparing to take possession of the ship, Emden had to recall her boats having spotted an approaching ship. This proved to be the French destroyer Mousquet , which was unprepared and

14280-404: The rubber insert. Once the propeller is removed, the splined tube can be cut away with a grinder and a new spline bushing is then required. To prevent a recurrence of the problem, the splines can be coated with anti-seize anti-corrosion compound. In some modern propellers, a hard polymer insert called a drive sleeve replaces the rubber bushing. The splined or other non-circular cross section of

14416-498: The screw principle to drive his theoretical helicopter, sketches of which involved a large canvas screw overhead. In 1661, Toogood and Hays proposed using screws for waterjet propulsion, though not as a propeller. Robert Hooke in 1681 designed a horizontal watermill which was remarkably similar to the Kirsten-Boeing vertical axis propeller designed almost two and a half centuries later in 1928; two years later Hooke modified

14552-476: The screw-driven Rattler pulling the paddle steamer Alecto backward at 2.5 knots (4.6 km/h). The Archimedes also influenced the design of Isambard Kingdom Brunel 's SS  Great Britain in 1843, then the world's largest ship and the first screw-propelled steamship to cross the Atlantic Ocean in August 1845. HMS  Terror and HMS  Erebus were both heavily modified to become

14688-757: The ship could also apply for the suffix. A number of films have been made about Emden ' s wartime exploits, including the 1915 movies How We Beat the Emden and How We Fought the Emden and the 1928 The Exploits of the Emden , all produced in Australia. German films include the 1926 silent film Unsere Emden , footage from which was incorporated in Kreuzer Emden of 1932, and Heldentum und Todeskampf unserer Emden , produced in 1934. All three films were directed by Louis Ralph . More recently, in 2012, Die Männer der Emden (The men of

14824-457: The ship remain scattered around the area. Following the destruction of Emden , Kaiser Wilhelm II awarded the Iron Cross to the ship and announced that a new Emden would be built to honor the original cruiser. Wilhelm II ordered that the new cruiser wear a large Iron Cross on her bow to commemorate her namesake ship. The third cruiser to bear the name Emden , built in the 1920s for

14960-525: The ship went on a cruise to Japan, where she accidentally rammed a Japanese steamer during a typhoon . The collision caused damage necessitating another trip to the drydock in Qingdao. She returned to the Yangtze to protect Europeans during the Chinese Revolution that broke out on 10 October. In November, Vizeadmiral (Vice Admiral) Maximilian von Spee replaced Gühler as the commander of

15096-590: The shipping lanes between Singapore , Colombo and Aden . Emden steamed toward the Indian Ocean by way of the Molucca and Banda Seas . While seeking to coal off Jampea Island , the Dutch coastal defense ship Maarten Harpertszoon Tromp stopped Emden and asserted Dutch neutrality. Müller steamed into the Lombok Strait . There, Emden ' s radio-intercept officers picked up messages from

15232-517: The ships along with colonial police troops, ashore in mid-January 1911. By the end of February the revolt had been suppressed, and on 26 February the unprotected cruiser Condor arrived to take over the German presence in the Carolines. Emden and the other ships held a funeral the following day for those killed in the operation, before departing on 1 March for Qingdao via Guam. After arriving on 19 March, she began an annual overhaul. In mid-1911,

15368-599: The sleeve inserted between the shaft and propeller hub transmits the engine torque to the propeller, rather than friction. The polymer is weaker than the components of the propeller and engine so it fails before they do when the propeller is overloaded. This fails completely under excessive load, but can easily be replaced. Whereas the propeller on a large ship will be immersed in deep water and free of obstacles and flotsam , yachts , barges and river boats often suffer propeller fouling by debris such as weed, ropes, cables, nets and plastics. British narrowboats invariably have

15504-525: The transport ship Doncaster at Gibraltar and Malta, achieving a speed of 1.5 mph (2.4 km/h). In 1802, American lawyer and inventor John Stevens built a 25-foot (7.6 m) boat with a rotary steam engine coupled to a four-bladed propeller. The craft achieved a speed of 4 mph (6.4 km/h), but Stevens abandoned propellers due to the inherent danger in using the high-pressure steam engines. His subsequent vessels were paddle-wheeled boats. By 1827, Czech inventor Josef Ressel had invented

15640-455: The transverse projection of a blade and the developed outline of the blade. The blades are the foil section plates that develop thrust when the propeller is rotated The hub is the central part of the propeller, which connects the blades together and fixes the propeller to the shaft. This is called the boss in the UK. Rake is the angle of the blade to a radius perpendicular to the shaft. Skew

15776-492: The war on the side of the Triple Entente and had dispatched a fleet to track his squadron down. Spee decided to take the East Asia Squadron to South America, where it could attempt to break through to Germany, harassing British merchant traffic along the way. Müller suggested that one cruiser be detached for independent operations in the Indian Ocean , since the squadron would be unable to attack British shipping while it

15912-468: The war. The attack on Penang was a significant shock to the Entente powers, and caused them to delay the large convoys from Australia, since they would need more powerful escorts. After releasing the British steamer, Emden turned south to Simalur, and rendezvoused with the captured collier Buresk . Müller then decided to attack the British coaling station in the Cocos Islands ; he intended to destroy

16048-473: The waterline and 118.30 m (388 ft 1 in) long overall . They had a beam of 13.50 m (44 ft 3 in) and a draft of 5.53 m (18 ft 2 in) forward. They displaced 3,664 metric tons (3,606 long tons ) as designed and up to 4,268 t (4,201 long tons; 4,705 short tons) at full load . Their hulls were constructed with transverse and longitudinal steel frames. The hulls contained thirteen watertight compartments and had

16184-515: The waterline, and could carry fifty naval mines . The ship was protected by a curved armored deck that was up to 80 mm (3.1 in) thick. It sloped downward at the sides of the hull to provide defense against incoming fire; the sloped portion was 50 mm (2 in) thick. The conning tower had 100 mm (3.9 in) thick sides, and the guns were protected by 50 mm (2 in) thick gun shields . The contract for Emden , ordered as ersatz (replacement) SMS  Pfeil ,

16320-453: The weapons unusable, and all signal books and secret papers were burned. Sydney turned to capture the collier Buresk , whose crew scuttled her when the Australian cruiser approached. Sydney then returned to the wrecked Emden and inquired if she surrendered. The signal books had been destroyed by fire and so the Germans could not reply, and since her flag was still flying, Sydney resumed fire. The Germans quickly raised white flags and

16456-779: The wireless station there and draw away British forces searching for him in the Indian Ocean. While en route to the Cocos, Emden spent two days combing the Sunda Strait for merchant shipping without success. She steamed to the Cocos, arriving off Direction Island at 06:00 on the morning of 9 November. Since there were no British vessels in the area, Müller sent ashore a landing party led by Kapitänleutnant (First Lieutenant) Hellmuth von Mücke , Emden ' s executive officer . The party consisted of another two officers, six non-commissioned officers, and thirty-eight sailors armed with four machine guns and thirty rifles. Emden

16592-477: Was a pair of light cruisers built for the Imperial German Navy in the early part of the 20th century. The class comprised SMS  Dresden , the lead ship , and SMS  Emden . Both ships were laid down in 1906; Dresden was launched in 1907, and Emden followed in 1908. They entered service in 1908 and 1909, respectively. The design for the ships was an incremental improvement over

16728-482: Was an improvement over paddlewheels as it wasn't affected by ship motions or draft changes. John Patch , a mariner in Yarmouth, Nova Scotia developed a two-bladed, fan-shaped propeller in 1832 and publicly demonstrated it in 1833, propelling a row boat across Yarmouth Harbour and a small coastal schooner at Saint John, New Brunswick , but his patent application in the United States was rejected until 1849 because he

16864-498: Was built in 1838 by Henry Wimshurst of London, as the world's first steamship to be driven by a screw propeller . The Archimedes had considerable influence on ship development, encouraging the adoption of screw propulsion by the Royal Navy , in addition to her influence on commercial vessels. Trials with Smith's Archimedes led to a tug-of-war competition in 1845 between HMS  Rattler and HMS  Alecto with

17000-456: Was crossing the Pacific. Spee agreed, and allowed Müller to operate independently, since Emden was the fastest cruiser in the squadron. On 14 August, Emden and Markomannia left the company of the East Asia Squadron, bound for the Indian Ocean. Since the cruiser Königsberg was already operating in the western Indian Ocean around the Gulf of Aden , Müller decided he should cruise in

17136-440: Was damaged during a voyage in February 1837, and to Smith's surprise the broken propeller, which now consisted of only a single turn, doubled the boat's previous speed, from about four miles an hour to eight. Smith would subsequently file a revised patent in keeping with this accidental discovery. In the meantime, Ericsson built a 45-foot (14 m) screw-propelled steamboat, Francis B. Ogden in 1837, and demonstrated his boat on

17272-523: Was departing, she encountered and sank the French destroyer Mousquet . Emden thereafter proceeded to the Cocos Islands , where Müller intended to destroy a wireless station. The Australian cruiser HMAS  Sydney reacted to British wireless signals warning of the Germans' presence. After a fierce gunnery duel, Sydney caused serious damage to Emden and forced her to beach on North Keeling island. Most of her surviving crew, including Müller, were thereafter taken into captivity. The wreck

17408-427: Was designed to give 13,500 metric horsepower (9,900  kW ) for a top speed of 23.5 knots (43.5 km/h; 27.0 mph). Emden carried up to 860 metric tons (850 long tons) of coal, which gave a range of 3,760 nautical miles (6,960 km; 4,330 mi) at 12 knots (22 km/h; 14 mph). Emden was the last German cruiser to be equipped with triple-expansion engines; all subsequent cruisers used

17544-455: Was developed into the Bremen and Königsberg classes , both of which incorporated incremental improvements over the course of construction. The two ships of the Dresden class were ordered in the 1905–1906 construction program. Their design represented an incremental improvement over the earlier Königsberg class. They carried the same main battery of 10.5 cm (4.1 in) guns on

17680-497: Was eventually broken up in situ in the early 1950s by a Japanese salvage company, though parts of the ship remain scattered around the area. See also : List of ships of the Imperial German Navy Screw propeller The principle employed in using a screw propeller is derived from stern sculling . In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting

17816-497: Was not an American citizen. His efficient design drew praise in American scientific circles but by then he faced multiple competitors. Despite experimentation with screw propulsion before the 1830s, few of these inventions were pursued to the testing stage, and those that were proved unsatisfactory for one reason or another. In 1835, two inventors in Britain, John Ericsson and Francis Pettit Smith , began working separately on

17952-531: Was not carried out; the Sokehs Rebellion erupted on Ponape in the Carolines , which required Emden ' s presence; she departed Qingdao on 28 December, and Nürnberg left Hong Kong to join her. The two cruisers reinforced German forces at Ponape, which included the old unprotected cruiser Cormoran . The ships bombarded rebel positions and sent a landing force, which included men from

18088-542: Was placed on 6 April 1906 at the Kaiserliche Werft (Imperial Dockyard) in Danzig . Her keel was laid down on 1 November 1906. She was launched on 26 May 1908 and christened by the Oberbürgermeister (Lord Mayor) of the city of Emden , Dr. Leo Fürbringer . After fitting-out work was completed by 10 July 1909, she was commissioned into the fleet. The new cruiser began sea trials that day but interrupted them from 11 August to 5 September to participate in

18224-466: Was quickly destroyed. Emden stopped to pick up survivors and departed at around 08:00 as the other French ships were raising steam to get underway. One officer and thirty-five sailors were plucked from the water. Another French destroyer tried to follow, but lost sight of the German raider in a rainstorm. On 30 October, Emden stopped the British steamer Newburn and put the French sailors aboard after they signed statements promising not to return to

18360-504: Was used to evaluate the ship on long-distance voyages for use in future light cruiser designs. Emden encountered unusually severe weather on the trip, which included a stop at Easter Island . She anchored at Papeete , Tahiti to coal on 12 July, as the bunkers were nearly empty after crossing 4,200 nautical miles (7,800 km; 4,800 mi). The ship then proceeded to Apia in German Samoa , arriving on 22 July. There, she met

18496-608: Was using jamming , but the British wireless station was able to transmit the message "Unidentified ship off entrance." The message was received by the Australian light cruiser HMAS  Sydney , which was 52 nautical miles (96 km; 60 mi) away, escorting a convoy. Sydney immediately headed for the Cocos Islands at top speed. Emden picked up wireless messages from the then unidentified vessel approaching, but believed her to be 250 nautical miles (460 km; 290 mi) away, giving them much more time than they actually had. At 09:00, lookouts aboard Emden spotted smoke on

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