Armed merchantman
An armed merchantman is a merchant ship equipped with guns, usually for defensive purposes, either by design or after the fact. In the days of sail, piracy and privateers, many merchantmen would be routinely armed, especially those engaging in long distance and high value trade. In more modern times, auxiliary cruisers were used offensively as merchant raiders to disrupt trade chiefly during both World War I and World War II, particularly by Germany. While armed merchantmen are clearly inferior to purpose-built warships, sometimes they have scored successes in combat against them. Examples include East Indiamen mimicking ships  of the line and chasing off regular French warships in the Battle of Pulo Aura in 1804, and the sinking the Australian light cruiser in their battle in 1941, although "Kormoran" was also destroyed and had to be scuttled. Pre-20th century. East Indiamen of various European countries were heavily armed for their long journeys to the Far East. In particularly dangerous times, such as when the home countries were at war, a convoy system would be used whereby the ships were escorted by a warship. However, many East Indiamen also travelled on their own, and therefore were heavily armed in  order to defend themselves against pirates and privateers. They also defended themselves against warships, scoring signal victories at the Battle of Pulo Aura and the action of 4 August 1800. The British Royal Navy purchased several that it converted to ships of the line. Development of auxiliary cruisers. In 1856, privateering (or seizure of a belligerent country's merchant ships as a private enterprise) lost international sanction under the Declaration of Paris. From 1861 to 1865 European countries built high-speed ships to run the Union Blockade during the American Civil War. Some of these were armed and served as  Confederate States Navy raiders. Russia purchased three ships in 1878 of armed with guns for use as auxiliary cruisers for a Russian Volunteer Fleet. Germany and the United Kingdom responded to the precedent by asking their shipping companies to design fast steamers with provision for mounting guns in time of war. In 1890 German and British shipyards built new civilian ships designed for wartime conversion, and France, Italy, Japan, Austria-Hungary, and the United States made similar agreements with their shipyards. In 1892 Russia likewise built two more auxiliary cruisers. In 1895 the Imperial German Navy mobilized the provisional auxiliary  cruiser "Normannia" for a 15-day trial armed with eight 6-inch guns, two guns, six guns, and two torpedo boats. 20th century. In both World Wars, both Germany and the United Kingdom used auxiliary cruisers. While the British used armed passenger liners defensively for protecting their shipping, the German approach was to use them offensively to attack enemy shipping. Armed merchant cruisers. The armed merchant cruisers (AMC) of the British Royal Navy were employed for convoy protection against enemy warships. They ultimately proved to have limited value and many, particularly ocean liners, were later converted into troopships, a role  for which they were more suited. Documentary evidence quoted by the BBC researched from the early stages of the First World War suggests that the express liners had greater speed than most warships (few warships of the period could exceed 21 knots), which made them suitable as AMCs. The downside proved to be their high fuel consumption; using them in a purely AMC role would have burned through the Admiralty reserve supplies of steam coal in less than three months. The ships were vulnerable to enemy fire because they lacked warship armour, and they used local control of guns rather  than director fire-control systems, which reduced their effective fire power. A famous AMC of World War I was the British which, after a battle that caused heavy damage on both sides, sank the German auxiliary cruiser near the Brazilian island of Trinidade in 1914. By coincidence, "Cap Trafalgar" was disguised as "Carmania". In World War II, , the sole escort for convoy HX 84 in November 1940, stood off the pocket battleship , when the German ship attacked the convoy. Though she was sunk alongside five vessels, this enabled the rest of the convoy to escape. Her master, Acting Captain Edward  Fegen was awarded the Victoria Cross posthumously for his actions. Another famous action involving an armed merchant cruiser was the November 1939 battle between and the German battlecruisers and . Outgunned, the "Rawalpindi" was quickly sunk. Auxiliary cruisers. Both the Spanish and United States Navies used auxiliary cruisers during the Spanish–American War of 1898. In World War I, too, American auxiliary cruisers fought several engagements with German U-boats. The German practice was to arm merchantmen with hidden weapons and use them as commerce raiders. An auxiliary cruiser, "Hilfskreuzer" or "Handels-Stör-Kreuzer" (HSK), usually approached her target under a  false flag with guns concealed, and sometimes with her appearance altered with fake funnels and masts and often a fake paint scheme. The victim was thus engaged at point-blank range and had no chance to escape. In World War I, the Imperial German Navy initially used fast passenger ships, such as past holders of the Blue Riband for fastest North Atlantic crossings, but they made obvious and easy targets because of their very familiar silhouettes. The Germans, therefore, soon moved on to using captured and refitted Allied vessels, but principally modified transport ships. These were slower, but less recognizable . In both world wars, these ships were vulnerable to attack, and were withdrawn before the war ended. Many were sunk after being caught by regular warships – an unequal battle, since auxiliary cruisers had poor fire control and no armor. There were, however, a few success stories. was a former passenger liner that sank two freighters in 1914 before being caught by . Her sister ship, , had a legendary journey, sinking or capturing a total of 15 ships in 1914 and 1915, before finally running out of supplies and having to put into port in Virginia, where the Americans interned her and  eventually converted her into the United States Navy troop transport USS "Von Steuben". The most famous German commerce raider of World War I probably was , a sailing ship under the command of the legendary Count Felix von Luckner. However, both and were each much more successful than "Seeadler". In World War II, Nazi Germany's "Kriegsmarine" operated ten very successful auxiliary cruisers, ranging in tonnage from 3,860 to 9,400; typically these vessels were equipped with: To preserve their cover, these ships flew the flags of neutral or occasionally Allied nations. They were refueled and provisioned from special supply ships, from  Japanese island bases, or simply from prizes they had taken. To counter the effectiveness of these disguises, the Allies introduced the check-mate system in 1942 to identify individual ships on a one-by-one basis with the Admiralty in London. In one incident, the German (ex-merchantman "Steiermark") managed to surprise and sink the Australian light cruiser , which approached too close, though "Kormoran" was also sunk in the engagement. This was the only occasion in history when an armed merchantman managed to sink a modern warship; in most cases, auxiliary cruiser raiders tried to avoid confrontation with warships. "Kormoran"s  attack upon "Sydney" was motivated by desperation. However, she was not the most successful German raider of World War II (both and scored higher kill tonnages). Another, , was also sunk in a mutually destructive engagement with the American Liberty ship . The only encounters between Allied and Axis auxiliary cruisers in World War II were all with the raider . This small vessel, which captured or sank 22 merchantmen, encountered three British AMCs in her career, defeating HMS "Alcantara" and and later sinking HMS "Voltaire". During World War II, German auxiliary cruisers are believed to have either sunk or captured some of  Allied shipping. Compare to the Q-ship, which was a disguised merchantman for anti-submarine operations. Others. The CAM ship (from catapult armed merchantman) was a British merchantman fitted with a catapult that could launch, but not recover, a single fighter aircraft. The merchant aircraft carrier or "MAC" was a British or Dutch cargo ship with a flight deck that could carry a small number of aircraft. CAM and MAC ships remained as civilian ships operated by civilian crews, with Fleet Air Arm or Royal Netherlands Navy "air parties". 21st century. Despite a rise in modern piracy, it was up  until the early 2010s very unusual for modern merchant ships to be armed, save for maybe a number of small arms and the use of the ship's fire hoses to repel boarders. One notable exception to this were the ships of Pacific Nuclear Transport Limited, which are used to transport spent nuclear fuel and reprocessed uranium on behalf of British Nuclear Fuels Limited. Transporting enough fissile material between them to produce 50–60 nuclear weapons, these ships, beginning with the "Pacific Pintail" and "Pacific Teal", became armed in 1999 to avoid the cost of a Royal Navy escort. Travelling together  in convoy during these ships' intermittent voyages, they have an onboard escort of armed police from the UKAEAC and its successors and are equipped with two or three autocannons. Another exception were various ships of the Soviet Union's Merchant Marine (MORFLOT) during the Cold War (MORFLOT often operated as an adjunct to Soviet foreign and military policy, both overtly and otherwise). In 2007, facing a chronic shortage of naval vessels the Cuban Navy placed into service the "Rio Damuji" class of frigates, which are large fishing trawlers converted into warships. In April 2010, it was reported that a Russian  company was offering a version of the 3M-54 Klub missile that could be disguised and launched from a shipping container, in theory enabling any cargo ship to be armed with an anti-ship missile. This type of missile was allegedly capable of disabling or even sinking an aircraft carrier, but "it's not known how many of them would have to hit a carrier to knock it out of action, much less sink it." During the 2011 Libyan civil war, forces loyal to Gaddafi armed several merchant vessels and attempted to use them to blockade the port of Misrata. In  October 2011, British Prime Minister David Cameron announced that British merchant shipping passing through areas known for piracy were permitted to carry firearms. Ship list. Since the late 19th century various navies have used armed merchant ships in the role of auxiliary cruisers, also called armed merchant cruisers. Significant use of this type of ship was made by Britain and Germany in both World Wars. Some of the ships used in this role include: