1.
Reichsmarine
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The Reichsmarine was the name of the German Navy during the Weimar Republic and first two years of Nazi Germany. It was the branch of the Reichswehr, existing from 1919 to 1935. In 1935, it known as the Kriegsmarine, a branch of the Wehrmacht. Many of the administrative and organizational tenets of the Reichsmarine were then carried over into the organization of the Kriegsmarine, the Vorläufige Reichsmarine was formed after the end of World War I from the Imperial German Navy. Replacements for the battleships were restricted to a maximum size of 10,000 tons. The Reichsmarine was considered the naval force of the Reichswehrministerium which was headed by a civilian minister appointed by the government of the Weimar Republic. The senior most naval officer was known until 1920 as the Chef der Admiralität, the naval commander oversaw a headquarters office known as the Marinekommandiertenabteilung which was headquartered in Berlin. The Naval Command also maintained a headquarters office and a naval archives. During the 1920s, the German flagship was the SMS Schleswig-Holstein with two officers serving as fleet commander, Vizeadmiral Hans Zenker and Konrad Mommsen, between 1923 and 1927. The fleet commander position was left vacant, but the flag staff remained. The purpose of fleet command was to oversee the four major type commanders of German naval vessels and these commands were in turn responsible for the administration of various German ship classes to include equipment development, vessel deployments, and personnel assignment. Once at sea, operational control of the vessels switched to the commanders of the two main Naval Sea Stations, the Reichsmarine did not maintain traditional at-sea fleets, but instead assigned two geographical areas which oversaw all vessels operationally deployed in the North and Baltic Seas. Each naval station maintained a staff, general naval inspectorate, training department, artillery arsenal inspector. The naval stations also served as an officer for the commanders of the various German navy ports. The restrictions were intended to prevent the German Navy from becoming a threat to the Allied powers, Germany was only allowed six battleships, six cruisers, twelve destroyers, and twelve torpedo boats. The Reichsmarine tried to meet the arms restrictions with secret armament and technical innovations such as the introduction of the pocket battleship
2.
Kriegsmarine
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The Kriegsmarine was the navy of Nazi Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire and the inter-war Reichsmarine, the Kriegsmarine was one of three official branches—along with the Heer and the Luftwaffe —of the Wehrmacht, the armed forces of Nazi Germany. The Kriegsmarine grew rapidly during German naval rearmament in the 1930s, Kriegsmarine ships were deployed to the waters around Spain during the Spanish Civil War, under the guise of enforcing non-intervention, but in reality supporting the Franco side of the war. In January 1939 Plan Z was ordered, calling for naval parity with the Royal Navy by 1944, however, when World War II broke out in September 1939, Plan Z was shelved in favour of building submarines and prioritizing land and air forces. The Commander-in-Chief of the Kriegsmarine was Adolf Hitler, who exercised his authority through the Oberkommando der Marine, the Kriegsmarines most famous ships were the U-boats, most of which were constructed after Plan Z was abandoned at the beginning of World War II. However, the adoption of convoy escorts, especially in the Atlantic, after the Second World War, the Kriegsmarines remaining ships were divided up amongst the Allied powers and were used for various purposes including minesweeping. Adolf Hitler was the Commander-in-Chief of all German armed forces, including the Kriegsmarine and his authority was exercised through the Oberkommando der Marine, or OKM, with a Commander-in-Chief, a Chief of Naval General Staff and a Chief of Naval Operations. The first Commander-in-Chief of the OKM was Erich Raeder who was the Commander-in-Chief of the Reichsmarine when it was renamed and reorganized in 1935, Raeder held the post until falling out with Hitler after the German failure in the Battle of the Barents Sea. He was replaced by Karl Dönitz on 30 January 1943 who held the command until he was appointed President of Germany upon Hitlers suicide in April 1945, hans-Georg von Friedeburg was then Commander-in-Chief of the OKM for the short period of time until Germany surrendered in May 1945. Subordinate to these were regional, squadron and temporary flotilla commands, regional commands covered significant naval regions and were themselves sub-divided, as necessary. They were commanded by a Generaladmiral or an Admiral, there was a Marineoberkommando for the Baltic Fleet, Nord, Nordsee, Norwegen, Ost/Ostsee, Süd and West. The Kriegsmarine used a form of encoding called Gradnetzmeldeverfahren to denote regions on a map, each squadron also had a command structure with its own Flag Officer. The commands were Battleships, Cruisers, Destroyers, Submarines, Torpedo Boats, Minesweepers, Reconnaissance Forces, Naval Security Forces, Big Guns and Hand Guns, major naval operations were commanded by a Flottenchef. The Flottenchef controlled a flotilla and organized its actions during the operation, the commands were, by their nature, temporary. As a result the German surface fleet was plagued by design flaws throughout the war, military aircraft were also banned, so Germany could have no naval aviation. Under the treaty Germany could only build new ships to replace old ones, All the ships allowed and personnel were taken over from the Kaiserliche Marine, renamed Reichsmarine. From the outset, Germany worked to circumvent the restrictions of the Treaty of Versailles. The launching of the first pocket battleship, Deutschland in 1931 was a step in the formation of a modern German fleet, modern destroyers and light cruisers were also built
3.
German cruiser Emden
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Emden was a light cruiser built by the Reichsmarine in the early 1920s. She was the ship of her class and was the first large warship built in Germany after the end of World War I. She was built at the Reichsmarinewerft in Wilhelmshaven, her keel was laid in December 1921, Emden was commissioned into the German fleet in October 1925. Her design was informed by the restrictions of the Treaty of Versailles. She was armed with a battery of surplus 15 cm guns left over from World War I, mounted in single gun turrets. She had a top speed of 29 knots, Emden spent the majority of her career as a training ship, in the inter-war period, she conducted several world cruises to train naval cadets. At the outbreak of war, she laid minefields off the German coast and was damaged by a British bomber that crashed into her and she participated in the invasion of Norway in April 1940, and then resumed training duties in the Baltic Sea. These lasted with interruptions until September 1944, when she was deployed to Norway to serve as the flagship of the minelaying forces there. In January 1945, she carried the remains of Paul von Hindenburg from East Prussia to Pillau. While undergoing repairs in Kiel, Emden was badly damaged by British bombers, the wreck was ultimately broken up in 1949. According to Article 181 of the Treaty of Versailles, the treaty that ended World War I, Article 190 limited new cruiser designs to 6,000 long tons and prohibited new construction until the vessel to be replaced was at least twenty years old. Design work on the first new cruiser, ordered as Ersatz Niobe. The ship was intended for overseas service, so the designers placed emphasis on a large cruising radius and capacious crew accommodation spaces. The designers wanted to use a battery of eight 15-centimeter guns in four dual mounts. This arrangement placed four guns amidships, which reduced the power of her broadside, as only six guns could fire on either side, as opposed to eight. The ship was based on designs from late in World War I, primarily due to personnel shortages in the design staff. Emden was laid down at the Reichsmarinewerft in Wilhelmshaven on 8 December 1921 and she was commissioned into the fleet nine months later, on 15 October 1925. Emden was 150.5 meters long at the waterline and 155.1 m long overall
4.
Leipzig-class cruiser
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The ships were improvements over the preceding Königsberg-class cruisers, being slightly larger, with a more efficient arrangement of the main battery and improved armor protection. Leipzig was built between 1928 and 1931, and Nürnberg followed between 1934 and 1935, both ships participated in the non-intervention patrols during the Spanish Civil War in 1936 and 1937. After the outbreak of World War II, they were used in a variety of roles, including as minelayers, on 13 December 1939, both ships were torpedoed by the British submarine HMS Salmon. They were thereafter used in roles, primarily as training ships. Leipzig provided some support to German Army troops fighting on the Eastern Front. Both ships survived the war, though Leipzig was in poor condition following an accidental collision with the heavy cruiser Prinz Eugen late in the war. Leipzig was therefore used as a ship before being scuttled in 1946. The two ships of the Leipzig class were not identical, prompting some naval historians to classify them as separate designs, of the two, Nürnberg was larger. Leipzig was 165.8 meters long at the waterline and 177 m long overall and she had a beam of 16.3 m and a maximum draft of 5.69 m forward. She displaced 6,820 metric tons as designed and 8,100 metric tons at combat load. Nürnberg was slightly longer, at 170 m at the waterline and 181.3 m overall and her beam was identical to Leipzig, but her draft was slightly greater, at 5.74 m forward. She displaced 8,060 metric tons as designed and 9,040 metric tons at combat load. The ships hulls were divided into fourteen watertight compartments and had double bottoms that ran for 83 percent of the length of their keels, both vessels had side bulges and bulbous bows. They were constructed with steel frames, and were more than 90 percent welded in order to save weight. Nürnberg had a large, blocky forward superstructure, while Leipzigs superstructure resembled that of the preceding Königsberg class, Nürnberg also had a large searchlight platform fitted on the funnel, while Leipzig did not. Leipzig initially had a crew of 26 officers and 508 enlisted men, later in her career, the crew grew to 30 officers and 628 sailors and then again to 24 officers and 826 sailors. She could also accommodate a staff of 6 officers and 20 enlisted men when she was serving as a flagship. Nürnbergs crew started as 25 officers and 648 ratings, and over the course of her career swelled to 26 officers and 870 enlisted men, the ships carried two picket boats, two barges, two launches, and two cutters
5.
Knot (unit)
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The knot is a unit of speed equal to one nautical mile per hour, approximately 1.151 mph. The ISO Standard symbol for the knot is kn, the same symbol is preferred by the IEEE, kt is also common. The knot is a unit that is accepted for use with the SI. Etymologically, the term derives from counting the number of knots in the line that unspooled from the reel of a log in a specific time. 1 international knot =1 nautical mile per hour,1.852 kilometres per hour,0.514 metres per second,1.151 miles per hour,20.254 inches per second,1852 m is the length of the internationally agreed nautical mile. The US adopted the definition in 1954, having previously used the US nautical mile. The UK adopted the international nautical mile definition in 1970, having used the UK Admiralty nautical mile. The speeds of vessels relative to the fluids in which they travel are measured in knots, for consistency, the speeds of navigational fluids are also measured in knots. Thus, speed over the ground and rate of progress towards a distant point are given in knots. Until the mid-19th century, vessel speed at sea was measured using a chip log, the chip log was cast over the stern of the moving vessel and the line allowed to pay out. Knots placed at a distance of 8 fathoms -47 feet 3 inches from each other, passed through a sailors fingers, the knot count would be reported and used in the sailing masters dead reckoning and navigation. This method gives a value for the knot of 20.25 in/s, the difference from the modern definition is less than 0. 02%. On a chart of the North Atlantic, the scale varies by a factor of two from Florida to Greenland, a single graphic scale, of the sort on many maps, would therefore be useless on such a chart. Recent British Admiralty charts have a latitude scale down the middle to make this even easier, speed is sometimes incorrectly expressed as knots per hour, which is in fact a measure of acceleration. Prior to 1969, airworthiness standards for aircraft in the United States Federal Aviation Regulations specified that distances were to be in statute miles. In 1969, these standards were amended to specify that distances were to be in nautical miles. At 11000 m, an airspeed of 300 kn may correspond to a true airspeed of 500 kn in standard conditions. Beaufort scale Hull speed, which deals with theoretical estimates of maximum speed of displacement hulls Knot count Knotted cord Metre per second Orders of magnitude Rope Kemp
6.
Nautical mile
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A nautical mile is a unit of measurement defined as exactly 1852 meters. Historically, it was defined as one minute of latitude, which is equivalent to one sixtieth of a degree of latitude. Today it is an SI derived unit, being rounded to a number of meters. The derived unit of speed is the knot, defined as one mile per hour. The geographical mile is the length of one minute of longitude along the Equator, there is no internationally agreed symbol. M is used as the abbreviation for the mile by the International Hydrographic Organization and by the International Bureau of Weights. NM is used by the International Civil Aviation Organization, nm is used by the U. S. National Oceanic and Atmospheric Administration. Nmi is used by the Institute of Electrical and Electronics Engineers, the word mile is from the Latin word for a thousand paces, mīlia. In 1617 the Dutch scientist Snell assessed the circumference of the Earth at 24,630 Roman miles, around that time British mathematician Edmund Gunter improved navigational tools including a new quadrant to determine latitude at sea. He reasoned that the lines of latitude could be used as the basis for a unit of measurement for distance, as one degree is 1/360 of a circle, one minute of arc is 1/21600 of a circle. These sexagesimal units originated in Babylonian astronomy, Gunter used Snells circumference to define a nautical mile as 6,080 feet, the length of one minute of arc at 48 degrees latitude.3 metres. Other countries measure the minute of arc at 45 degrees latitude, in 1929, the international nautical mile was defined by the First International Extraordinary Hydrographic Conference in Monaco as 1,852 meters. Imperial units and United States customary units used a definition of the nautical mile based on the Clarke Spheroid, the United States nautical mile was defined as 6,080.20 feet based in the Mendenhall Order foot of 1893. It was abandoned in favour of the nautical mile in 1954.181 meters. It was abandoned in 1970 and, legally, references to the unit are now converted to 1,853 meters. Conversion of units Orders of magnitude
7.
15 cm SK C/25
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The 15 cm SK C/25 was a German medium-caliber naval gun used during the Second World War. It served as the armament for the K- and Leipzig-class cruiser. No surplus weapons of this appear to have been used as coast-defense guns. This gun was the most powerful of the Kriegsmarines 15 centimetres guns and was designed with a barrel, jacket. LC/25 triple-gun mount was the mount used for this gun in the Kriegsmarine. The mount weighed between 136. 91–147.15 tonnes, depending on its thickness, the Nürnbergs mounts had between 20–80 mm of armor while the other ships had 20–30 mm. Each mount was designed for full 360° of traverse, but was limited to less than that by the ships superstructure. The electrically powered hydraulic pumps had a maximum elevating speed of 8° per second, the maximum firing cycle was 7.5 seconds, or 8 rounds per minute, despite being hand-loaded and rammed. Ammunition was supplied by three hoists, one between the left and center guns and the two between center and right guns at the rear of the mount. The SK C/25 had a number of different shells available, naval Weapons of World War Two. Weapons of the Third Reich, An Encyclopedic Survey of All Small Arms, Artillery, hogg, Ian V. German Artillery of World War Two. Der Atlantikwall, Bauten der deutschen Küstenbefestigungen 1940-1945, a Dictionary on Modern Fortification, An Illustrated Lexicon on European Fortification in the Period 1800-1945
8.
8.8 cm SK L/45 naval gun
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The 8.8 cm SK L/45 (SK - Schnelladekanone L - Länge was a German naval gun that was used in World War I and World War II on a variety of mounts. The 8.8 cm SK L/45 gun weighed 2.5 metric tons and had a length of about 4 meters. It used a sliding block, or wedge, as it is sometimes referred to. During World War I, the SK L/45 was used as boat guns on all Imperial German Navy dreadnoughts and as main guns on torpedo boats. The SK L/45 was also used to some of the 8.8 cm SK L/35 anti-torpedo boat guns on pre-dreadnought battleships. During the 1930s surviving SK L/45 guns were modified to use the ammunition as the 8.8 cm SK C/30 naval gun and had similar performance. Fixed type ammunition with and without tracer, which weighed 15 kg, naval Weapons of World War Two. Weapons of the Third Reich, An Encyclopedic Survey of All Small Arms, Artillery, hogg, Ian V. German Artillery of World War Two. Der Atlantikwall, Bauten der deutschen Küstenbefestigungen 1940-1945, a Dictionary on Modern Fortification, An Illustrated Lexicon on European Fortification in the Period 1800-1945
9.
Torpedo
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Historically, it was called an automotive, automobile, locomotive or fish torpedo, colloquially called a fish. The term torpedo was originally employed for a variety of devices, from about 1900, torpedo has been used strictly to designate an underwater self-propelled weapon. Todays torpedoes can be divided into lightweight and heavyweight classes, and into straight-running, autonomous homers and they can be launched from a variety of platforms. The word torpedo comes from the name of a genus of rays in the order Torpediniformes. In naval usage, the American Robert Fulton introduced the name to refer to a gunpowder charge used by his French submarine Nautilus to demonstrate that it could sink warships. The concept of a torpedo existed many centuries before it was successfully developed. In 1275, Hasan al-Rammah described. an egg which moves itself, in modern language, a torpedo is an underwater self-propelled explosive, —but historically, the term also applied to primitive naval mines. These were used on an ad hoc basis during the modern period up to the late 19th century. An early submarine, the Turtle, attempted to lay a bomb with a fuse on the hull of HMS Eagle during the American Revolutionary War. In the early 1800s, the American inventor Robert Fulton, while in France and he coined the term torpedo in reference to the explosive charges he outfitted his submarine Nautilus. However, both the French and the Dutch governments were uninterested in the submarine, Fulton then concentrated on developing the torpedo independent of a submarine deployment. However, the British government refused to purchase the invention, stating they did not wish to introduce into naval warfare a system that would give advantage to weaker maritime nations. Fulton carried out a demonstration for the US government on 20 July 1807. Further development languished as Fulton focused on his steam-boat matters, during the War of 1812, torpedoes were employed in attempts to destroy British vessels and protect American harbors. In fact a submarine deployed torpedo was used in an attempt to destroy HMS Ramillies while in New Londons harbor. Hardy to warn the Americans to cease efforts with the use of any boat in this cruel and unheard-of warfare. Torpedoes were used by the Russian Empire during the Crimean War in 1855 against British warships in the Gulf of Finland and they used an early form of chemical detonator. During the American Civil War, the torpedo was used for what is today called a contact mine
10.
Naval mine
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A naval mine is a self-contained explosive device placed in water to damage or destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, Naval mines can be used offensively—to hamper enemy shipping movements or lock vessels into a harbour, or defensively—to protect friendly vessels and create safe zones. Mines can be laid in many ways, by purpose-built minelayers, refitted ships, submarines and their flexibility and cost-effectiveness make mines attractive to the less powerful belligerent in asymmetric warfare. The cost of producing and laying a mine is usually anywhere from 0. 5% to 10% of the cost of removing it, parts of some World War II naval minefields still exist because they are too extensive and expensive to clear. It is possible for some of these 1940s-era mines to remain dangerous for many years to come, Mines have been employed as offensive or defensive weapons in rivers, lakes, estuaries, seas, and oceans, but they can also be used as tools of psychological warfare. Offensive mines are placed in enemy waters, outside harbours and across important shipping routes with the aim of sinking both merchant and military vessels. Defensive minefields safeguard key stretches of coast from enemy ships and submarines, forcing them into more easily defended areas, minefields designed for psychological effect are usually placed on trade routes and are used to stop shipping from reaching an enemy nation. They are often spread thinly, to create an impression of minefields existing across large areas, a single mine inserted strategically on a shipping route can stop maritime movements for days while the entire area is swept. International law requires nations to declare when they mine an area, the warnings do not have to be specific, for example, during World War II, Britain declared simply that it had mined the English Channel, North Sea, and French coast. Chinese records tell of naval explosives in the 16th century, used to fight against Japanese pirates and this kind of naval mine was loaded in a wooden box, sealed with putty. General Qi Jiguang made several timed, drifting explosives, to harass Japanese pirate ships, although this is the rotating steel wheellocks first use in naval mines, Jiao Yu had described their use for land mines back in the 14th century. The first plan for a sea mine in the West was by Ralph Rabbards, the Dutch inventor Cornelius Drebbel was employed in the Office of Ordnance by King Charles I of England to make weapons, including a floating petard which proved a failure. Weapons of this type were apparently tried by the English at the Siege of La Rochelle in 1627, American David Bushnell developed the first American naval mine for use against the British in the American War of Independence. It was a watertight keg filled with gunpowder that was floated toward the enemy and it was used on the Delaware River as a drift mine. In 1812 Russian engineer Pavel Shilling exploded a mine using an electrical circuit. Russian naval specialists set more than 1500 naval mines, or infernal machines, designed by Moritz von Jacobi and by Immanuel Nobel, the mining of Vulcan led to the worlds first minesweeping operation. During the next 72 hours,33 mines were swept, the Jacobi mine was designed by German born, Russian engineer Jacobi, in 1853. The mine was tied to the sea bottom by an anchor, a cable connected it to a cell which powered it from the shore
11.
Armor belt
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Belt armor is a layer of heavy metal armor plated onto or within the outer hulls of warships, typically on battleships, battlecruisers and cruisers, and aircraft carriers. The belt armor is designed to prevent projectiles from penetrating to the heart of a warship, typically, the main armor belt covers the warship from its main deck down to some distance below the waterline. If, instead of forming the hull, the armor belt is built inside the hull, it is installed at a sloped angle for improved protection. Furthermore, the spaces around the main belt in some designs were filled with storage tanks that could contain fuel oil, seawater. The liquids in these tanks absorb or scatter much of the force of warheads. To deal with the leakage from the tanks and incoming seawater and this multilayer design is featured in the cross-sectional drawings of Tirpitz and King George V. In combat, a warship can be seriously damaged underwater not only by torpedoes, to improve protection against both shells and torpedoes, an air space can be added between the armor belt and the hull to increase the buoyancy of the warship. Some kinds of naval warships have belt armor thinner than actually necessary for protection against projectiles and this is common especially with battlecruisers, battleships, and aircraft carriers to reduce their weight, thus increasing their acceleration and speed. Another possible reason is to meet treaty restrictions on ship displacement, one such method is all-or-nothing armoring, where belt armor is stripped from areas deemed non-vital to the functioning of the ship in battle. Agility gained from such processes are an asset to offensive warships that seek to quickly bring their heavy striking power to the enemy. In carriers, the maneuverability is exploited when deploying and recovering aircraft, since planes take off and land most easily when flying into the wind, the aircraft carrier steams rapidly into the wind in both maneuvers, making take-off and landing safer and easier. S. Comparison of WW2 battleship armor schemes Torpedo belt Protected cruiser Armored cruiser
12.
Deck (ship)
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A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary or upper deck is the structure that forms the roof of the hull, strengthening it. Decks for some purposes have specific names, the main purpose of the upper or primary deck is structural, and only secondarily to provide weather-tightness and support people and equipment. The deck serves as the lid to the box girder which is the hull. It resists tension, compression, and racking forces, the decks scantling is usually the same as the topsides, or might be heavier if the deck is expected to carry heavier loads. The deck will be reinforced around deck fittings such as the capstan, cleats, on ships with more than one level, deck refers to the level itself. The actual floor surface is called the sole, the term refers to a structural member tying the ships frames or ribs together over the keel. In modern ships, the decks are usually numbered from the primary deck. So the first deck below the deck will be #2. Some merchant ships may alternatively designate decks below the deck, usually machinery spaces, by numbers. Ships may also call decks by common names, or may invent fanciful and romantic names for a deck or area of that specific ship. Equipment mounted on deck, such as the wheel, binnacle, fife rails. Eastern designs developed earlier, with efficient middle decks and minimalist fore, in vessels having more than one deck there are various naming conventions, numerically, alphabetically, etc. However, there are various common historical names and types of decks,01 level is the term used in naval services to refer to the deck above the main deck. The next higher decks are referred to as the 02 level, the 03 level, afterdeck an open deck area toward the stern-aft. Berth deck, A deck next below the gun deck, where the hammocks of the crew are slung, Boat deck, Especially on ships with sponsons, the deck area where lifeboats or the ships gig are stored. Boiler deck, The passenger deck above the vessels boilers, may also refer to the deck of a bridge. Flight deck, A deck from which aircraft take off or land, flush deck, Any continuous unbroken deck from stem to stern
13.
Conning tower
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A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can conn the vessel, i. e. give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility of the entirety of the ship itself and of ocean conditions, the verb “conn” probably stems from the verb “conduct” rather than from another plausible precedent, the verb “control”. On surface ships, the tower was a feature of all battleships. Located at the front end of the superstructure, the tower was a heavily armored cylinder. At all other times than during battles, the ship would be navigated from the bridge instead, conning towers were used by the French on their floating batteries at the Battle of Kinburn. They were then fitted to the first ironclad the French battleship La Gloire, the first Royal Navy conning tower appeared on HMS Warrior which had 3 inches of armour. The King George V class, in contrast to the Nelson class had comparatively light conning tower protection with 4.5 inch sides,3 inch front and rear, and 2 inch roof and deck. The RNs analysis of World War I combat revealed that command personnel were unlikely to utilize an armoured conning tower, older RN battleships that were reconstructed with new superstructures, had their heavily armoured conning towers removed and replaced with much lighter structures. These new conning towers were placed much higher in the ship. Even in the United States Navy, battleship captains and admirals preferred to use the unarmoured bridge positions during combat. The USN had mixed opinions of the tower, pointing out that its weight, high above the ships center of gravity. Beginning in the late 1930s, as radar surpassed visual sighting as the method of detecting other ships, battleships began reducing or eliminating the conning tower. By the end of World War II, US ships were designed with expanded weather bridges enclosing the armored conning towers. With the demise of battleships after World War II, along with the advent of missiles and nuclear weapons during the Cold War, modern warships no longer feature conning towers. It should not be confused with the control room, which was directly below it in the main pressure hull, or the bridge. As improvements in technology allowed the periscopes to be made longer it became unnecessary to raise the station above the main pressure hull. The USS Triton was the last American submarine to have a conning tower, the additional conning tower pressure hull was eliminated and its functions were added to the command and control center. Thus it is incorrect to refer to the sail of a submarine as a conning tower
14.
Light cruiser
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A light cruiser is a type of small- or medium-sized warship. The term is a shortening of the light armored cruiser, describing a small ship that carried armor in the same way as an armored cruiser. Prior to this smaller cruisers had been of the protected cruiser model, the first small steam-powered cruisers were built for the British Royal Navy with HMS Mercury launched in 1878. Such second and third class protected cruisers evolved, gradually becoming faster, better armed, germany took a lead in small cruiser design in the 1890s, building a class of fast cruisers—the Gazelle class—copied by other nations. Such vessels were powered by coal-fired boilers and reciprocating steam engines, the adoption of oil-fired water-tube boilers and steam turbine engines meant that older small cruisers rapidly became obsolete. Furthermore, new construction could not rely on the protection of coal bunkers, the British Bristol group of Town-class cruisers were a departure from previous designs, with turbine propulsion, mixed coal and oil firing and a 2-inch protective armoured belt as well as deck. Thus, by definition, they were armoured cruisers, despite displacing only 4,800 tons, the first true modern light cruisers were the Arethusa class which had all oil-firing and used lightweight destroyer-type machinery to make 29 knots. 1-inch to 5. 9-inch guns. Cruiser construction in Britain continued uninterrupted until Admiral Jacky Fishers appointment as First Sea Lord in 1904, the group of 21 Town-class cruisers begun in 1910 proved excellent in scouting in all types of weather and could carry enough fuel and ammunition to guard the shipping lanes. The Arethusa class, launched three years later, was also successful, British designers continued enlarging and refining subsequent cruiser designs throughout the war. The Germans built a number of cruisers in the belief that they were good multi-purpose vessels. However, the Germans were very late in adapting 5. 9-inch guns, with the Pillau and Wiesbaden-class cruisers the Germans followed the British example of heavier guns. Earlier German light cruisers were in competition with a series of British scout cruisers which had a speed of 25 knots. The Germans completed the last two of their Bremen-class cruisers in 1906 and 1907 and followed them up with four Königsberg-class and these last two classes, larger and faster than the Bremens, were armed the same and carried less deck armor. Other major powers concentrated on construction and built few cruisers. The United States, Italy, and Austria-Hungary each built only a handful of scout cruisers while Japan and Spain added a few based on British designs. The United States resumed building light cruisers in 1918, largely because the ships it then had in service had become obsolete, the first of these, the ten Omaha-class ships, displaced 7,050 tons and were armed with twelve 6-inch guns. Eight of these guns were mounted in casemates at the bow and stern. Fast and maneuverable, they were well-liked as seaboats despite being very wet in rough weather, the term light cruiser was given a definition by the London Naval Treaty of 1930
15.
German cruiser Karlsruhe
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Karlsruhe was a light cruiser, the second member of the Königsberg class, and was operated between 1929 and April 1940, including service in World War II. She was operated by two German navies, the Reichsmarine and the Kriegsmarine and she had two sister ships, Königsberg and Köln. Karlsruhe was built by the Deutsche Werke shipyard in Kiel, she was laid down in July 1926, launched in August 1927 and she was armed with a main battery of nine 15 cm SK C/25 guns in three triple turrets and had a top speed of 32 knots. Like her sisters, Karlsruhe served as a training cruiser for naval cadets throughout the 1930s, during the Spanish Civil War, she joined the non-intervention patrols off the Spanish coast. She landed troops at Kristiansand, and while returning to Germany, she was attacked by the British submarine HMS Truant, unable to return to port, Karlsruhe was scuttled by one of the escorting torpedo boats. Karlsruhe was 174 meters long overall and had a beam of 15.2 m and she displaced 7,700 long tons at full combat load. Her propulsion system consisted of four turbines and a pair of 10-cylinder four-stroke diesel engines. Steam for the turbines was provided by six Marine-type double-ended oil-fired boilers, the ships propulsion system provided a top speed of 32 knots and a range of approximately 5,700 nautical miles at 19 knots. Karlsruhe had a crew of 21 officers and 493 enlisted men, the ship was armed with nine 15 cm SK C/25 guns mounted in three triple gun turrets. One was located forward, and two were placed in a superfiring pair aft, the rear gun turrets were offset to increase their arc of fire. They were supplied with 1,080 rounds of ammunition, for 120 shells per gun, the ship was also equipped with two 8.8 cm SK L/45 anti-aircraft guns in single mounts, they had 400 rounds of ammunition each. Karlsruhe also carried four triple torpedo tube mounts located amidships, they were supplied with twenty-four 50 cm torpedoes and she was also capable of carrying 120 naval mines. The ship was protected by a deck that was 40 mm thick amidships. The conning tower had 100 mm thick sides, the new cruiser was ordered as Cruiser C and given the temporary name Ersatz Medusa as a replacement for the old cruiser Medusa. Construction of Karlsruhe began on 27 July 1926 with her keel laying at the Deutsche Werke shipyard in Kiel and she was launched on 20 August 1927, and she was commissioned into the Reichsmarine on 6 November 1929. Karlsruhe completed sea trials in the Baltic Sea after entering service, in May 1930, she departed on her first overseas training cruise, to Africa and South America. After returning to Germany, she was modernized late in the year, her foremast was shortened, over the next five years, she embarked on four more world cruises for naval cadets, traveling as far as Japan. Between each cruise, she conducted exercises with the rest of the fleet in German waters, günther Lütjens served as the ships commander from September 1934 to September 1935
16.
Torpedo tube
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A torpedo tube is a cylinder shaped device for launching torpedoes. There are two types of torpedo tube, underwater tubes fitted to submarines and some surface ships. Thus a submarine torpedo tube operates on the principle of an airlock, the diagram on the right illustrates the operation of a submarine torpedo tube. The diagram is somewhat simplified but does show the working of a torpedo launch. A torpedo tube has a number of interlocks for safety reasons. For example, an interlock prevents the door and muzzle door from opening at the same time. The submarine torpedo launch sequence is, in simplified form, Open the breech door in the torpedo room, load the torpedo into the tube. Hook up the connection and the torpedo power cable. Shut and lock the breech door, turn on power to the torpedo. A minimum amount of time is required for torpedo warmup, fire control programs are uploaded to the torpedo. This may be manually or automatically, from sea or from tanks. The tube must be vented during this process to allow for complete filling, Open the equalizing valve to equalize pressure in the tube with ambient sea pressure. If the tube is set up for Impulse Mode the slide valve will open with the muzzle door, if Swim Out Mode is selected, the slide valve remains closed. The slide valve allows water from the pump to enter the tube. Modern torpedoes have a safety mechanism that prevents activation of the torpedo unless the torpedo senses the required amount of G-force, the power cable is severed at launch. However, if a wire is used, it remains connected through a drum of wire in the tube. Torpedo propulsion systems vary but electric torpedoes swim out of the tube on their own and are of a smaller diameter,21 weapons with fuel-burning engines usually start outside of the tube. Once outside the tube the torpedo begins its run toward the target as programmed by the control system
17.
Non-intervention in the Spanish Civil War
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Primarily arranged by the French and British governments, important members of the committee also included the Soviet Union, Fascist Italy and Nazi Germany. Ultimately, the committee had the support of 27 nations, the subject of volunteers was also much discussed, with little result, although agreements were signed late on in the war, these were made outside the Committee. Efforts to stem the flow of war materials to Spain were largely unsuccessful, Nazi Germany, Italy, and the Soviet Union consistently broke the agreement they had signed, France occasionally so. Britain remained largely faithful to it, non-intervention, and with it the Non-Intervention Agreement, had been proposed in a joint diplomatic initiative by the governments of France and the United Kingdom. On 3 August 1936, Charles de Chambrun, French ambassador to Italy, presented the French governments non-intervention plan, the British, however, accepted the plan in principle immediately. The following day, it was put to Konstantin von Neurath, the German position was that such a declaration was not needed, but discussions could be held on preventing the spread of the war to the rest of Europe, so long as the USSR was present. It was mentioned at the meeting of the French with Neurath that both countries were already supplying the parties in the war, France the Republicans and Germany the Nationalists, a similar approach was made by the French to the Soviet Union. On 6 August, Ciano confirmed Italian support in principle, on 7 August 1936, France unilaterally declared non-intervention. Draft declarations had been put to the German and Italian governments, the Portuguese Foreign Minister, Armindo Monteiro, was also asked to accept, but held his hand. However, collections for food, clothing and medical supplies to the Spanish Republicans continued, on 9 August, the Germans informed the British that no war materials had been sent from Germany and none will, which was blatantly false. During the blockade of the Strait of Gibraltar by the Spanish Republican Navy one German Junkers was captured when it came down in Republican territory and its release would be required before Germany signed the Non-Intervention Pact. Portugal accepted the pact on 13 August, unless her border was threatened by the war, the Labour Party would reject non-intervention in October 1937. The British Trades Union Congress was split, a report called the Commission of Inquiry into Alleged Breaches of the Non-Intervention Agreement in Spain was drawn up in London, sponsored by Comintern, and headed by respectable figures. Both the British and French governments were aware of the First World War, France was reliant on British support in general. Léon Blum, the French prime minister, believed that support for the Republic would have led to a fascist takeover in France, on 5 August 1936, the United States had made it known that it would follow a policy of non-intervention, but did not announce it officially. This isolationism on the Spanish war would later be identified as disastrous by Under-Secretary of State Sumner Welles, five days later, the Glenn L. Martin Company enquired whether the government would allow the sale of eight bombers to the Spanish Republican Air Force, the response was negative. It also confirmed it would not take part in several mediation attempts, mexico soon became the first nation to openly support the Republicans. On 15 August, the United Kingdom banned exports of war material to Spain, Neurath also agreed to the pact, and suggested that volunteers be included
18.
Spanish Civil War
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Ultimately, the Nationalists won, and Franco then ruled Spain for the next 36 years, from April 1939 until his death in November 1975. Sanjurjo was killed in an accident while attempting to return from exile in Portugal. The coup was supported by units in the Spanish protectorate in Morocco, Pamplona, Burgos, Zaragoza, Valladolid, Cádiz, Córdoba. However, rebelling units in some important cities—such as Madrid, Barcelona, Valencia, Bilbao, and Málaga—did not gain control, Spain was thus left militarily and politically divided. The Nationalists and the Republican government fought for control of the country, the Nationalist forces received munitions and soldiers from Nazi Germany and Fascist Italy, while the Republican side received support from the Communist Soviet Union and leftist populist Mexico. Other countries, such as the United Kingdom and France, operated a policy of non-intervention. The Nationalists advanced from their strongholds in the south and west and they also besieged Madrid and the area to its south and west for much of the war. Those associated with the losing Republicans were persecuted by the victorious Nationalists, with the establishment of a dictatorship led by General Franco in the aftermath of the war, all right-wing parties were fused into the structure of the Franco regime. The war became notable for the passion and political division it inspired, organized purges occurred in territory captured by Francos forces to consolidate the future regime. A significant number of killings took place in areas controlled by the Republicans, the extent to which Republican authorities took part in killings in Republican territory varied. The 19th century was a turbulent time for Spain and those in favour of reforming Spains government vied for political power with conservatives, who tried to prevent reforms from taking place. Some liberals, in a tradition that had started with the Spanish Constitution of 1812, sought to limit the power of the monarchy of Spain, the reforms of 1812 did not last after King Ferdinand VII dissolved the Constitution and ended the Trienio Liberal government. Twelve successful coups were carried out between 1814 and 1874, until the 1850s, the economy of Spain was primarily based on agriculture. There was little development of an industrial or commercial class. The land-based oligarchy remained powerful, a number of people held large estates called latifundia as well as all the important government positions. In 1868 popular uprisings led to the overthrow of Queen Isabella II of the House of Bourbon, two distinct factors led to the uprisings, a series of urban riots and a liberal movement within the middle classes and the military concerned with the ultra-conservatism of the monarchy. In 1873 Isabellas replacement, King Amadeo I of the House of Savoy, abdicated owing to increasing pressure. After the restoration of the Bourbons in December 1874, Carlists and Anarchists emerged in opposition to the monarchy, alejandro Lerroux, Spanish politician and leader of the Radical Republican Party, helped bring republicanism to the fore in Catalonia, where poverty was particularly acute
19.
World War II
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World War II, also known as the Second World War, was a global war that lasted from 1939 to 1945, although related conflicts began earlier. It involved the vast majority of the worlds countries—including all of the great powers—eventually forming two opposing alliances, the Allies and the Axis. It was the most widespread war in history, and directly involved more than 100 million people from over 30 countries. Marked by mass deaths of civilians, including the Holocaust and the bombing of industrial and population centres. These made World War II the deadliest conflict in human history, from late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, and formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Poland, Finland, Romania and the Baltic states. In December 1941, Japan attacked the United States and European colonies in the Pacific Ocean, and quickly conquered much of the Western Pacific. The Axis advance halted in 1942 when Japan lost the critical Battle of Midway, near Hawaii, in 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained all of its territorial losses and invaded Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in South Central China and Burma, while the Allies crippled the Japanese Navy, thus ended the war in Asia, cementing the total victory of the Allies. World War II altered the political alignment and social structure of the world, the United Nations was established to foster international co-operation and prevent future conflicts. The victorious great powers—the United States, the Soviet Union, China, the United Kingdom, the Soviet Union and the United States emerged as rival superpowers, setting the stage for the Cold War, which lasted for the next 46 years. Meanwhile, the influence of European great powers waned, while the decolonisation of Asia, most countries whose industries had been damaged moved towards economic recovery. Political integration, especially in Europe, emerged as an effort to end pre-war enmities, the start of the war in Europe is generally held to be 1 September 1939, beginning with the German invasion of Poland, Britain and France declared war on Germany two days later. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or even the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred simultaneously and this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935. The British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the forces of Mongolia and the Soviet Union from May to September 1939, the exact date of the wars end is also not universally agreed upon. It was generally accepted at the time that the war ended with the armistice of 14 August 1945, rather than the formal surrender of Japan
20.
North Sea
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The North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia, Germany, the Netherlands, Belgium, and France. An epeiric sea on the European continental shelf, it connects to the ocean through the English Channel in the south and it is more than 970 kilometres long and 580 kilometres wide, with an area of around 570,000 square kilometres. The North Sea has long been the site of important European shipping lanes as well as a major fishery, the North Sea was the centre of the Vikings rise. Subsequently, the Hanseatic League, the Netherlands, and the British each sought to dominate the North Sea and thus the access to the markets, as Germanys only outlet to the ocean, the North Sea continued to be strategically important through both World Wars. The coast of the North Sea presents a diversity of geological and geographical features, in the north, deep fjords and sheer cliffs mark the Norwegian and Scottish coastlines, whereas in the south it consists primarily of sandy beaches and wide mudflats. Due to the population, heavy industrialization, and intense use of the sea and area surrounding it. In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean, in the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively. In the north it is bordered by the Shetland Islands, and connects with the Norwegian Sea, the North Sea is more than 970 kilometres long and 580 kilometres wide, with an area of 570,000 square kilometres and a volume of 54,000 cubic kilometres. Around the edges of the North Sea are sizeable islands and archipelagos, including Shetland, Orkney, the North Sea receives freshwater from a number of European continental watersheds, as well as the British Isles. A large part of the European drainage basin empties into the North Sea including water from the Baltic Sea, the largest and most important rivers flowing into the North Sea are the Elbe and the Rhine – Meuse watershed. Around 185 million people live in the catchment area of the rivers discharging into the North Sea encompassing some highly industrialized areas, for the most part, the sea lies on the European continental shelf with a mean depth of 90 metres. The only exception is the Norwegian trench, which extends parallel to the Norwegian shoreline from Oslo to a north of Bergen. It is between 20 and 30 kilometres wide and has a depth of 725 metres. The Dogger Bank, a vast moraine, or accumulation of unconsolidated glacial debris and this feature has produced the finest fishing location of the North Sea. The Long Forties and the Broad Fourteens are large areas with uniform depth in fathoms. These great banks and others make the North Sea particularly hazardous to navigate, the Devils Hole lies 200 miles east of Dundee, Scotland. The feature is a series of trenches between 20 and 30 kilometres long,1 and 2 kilometres wide and up to 230 metres deep. Other areas which are less deep are Cleaver Bank, Fisher Bank, the International Hydrographic Organization defines the limits of the North Sea as follows, On the Southwest
21.
Bergen
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Bergen, historically Bjørgvin, is a city and municipality in Hordaland on the west coast of Norway. At the end of the first quarter of 2016, the population was 278,121. Bergen is the second-largest city in Norway, the municipality covers 465 square kilometres and is on the peninsula of Bergenshalvøyen. The city centre and northern neighbourhoods are on Byfjorden, the city fjord, many of the extra-municipal suburbs are on islands. Bergen is the centre of Hordaland and consists of eight boroughs—Arna, Bergenhus, Fana, Fyllingsdalen, Laksevåg, Ytrebygda, Årstad. Trading in Bergen may have started as early as the 1020s, according to tradition, the city was founded in 1070 by king Olav Kyrre, its name was Bjørgvin, the green meadow among the mountains. It served as Norways capital in the 13th century, and from the end of the 13th century became a city of the Hanseatic League. Until 1789, Bergen enjoyed exclusive rights to trade between Northern Norway and abroad and it was the largest city in Norway until the 1830s when it was surpassed by the capital. What remains of the quays, Bryggen, is a World Heritage Site, the city was hit by numerous fires over the years. The Bergen School of Meteorology was developed at the Geophysical Institute beginning in 1917, the Norwegian School of Economics was founded in 1936, from 1831 to 1972, Bergen was its own county. In 1972 the municipality absorbed four surrounding municipalities and became a part of Hordaland county, the city is an international centre for aquaculture, shipping, offshore petroleum industry and subsea technology, and a national centre for higher education, media, tourism and finance. Bergen Port is Norways busiest in both freight and passengers with over 300 cruise ship calls a year bringing nearly a half a million passengers to Bergen, almost half of the passengers are German or British. The citys main team is SK Brann and the citys unique tradition is the buekorps. Natives speak the distinct Bergensk dialect, the city features Bergen Airport, Flesland, Bergen Light Rail, and is the terminus of the Bergen Line. Four large bridges connect Bergen to its suburban municipalities, Bergen is well known for having a mild winter climate, though with a lot of precipitation. In December - March, the difference between Bergen and Oslo can be up to 30 degrees Celsius, despite the fact that both cities are at approximately 60 degrees North. The Gulf Stream keeps the sea relatively warm, considering the latitude, the city of Bergen was traditionally thought to have been founded by king Olav Kyrre, son of Harald Hardråde in 1070 AD, four years after the Viking Age ended with the Battle of Hastings. Modern research has, however, discovered that a settlement was established already during the 1020s or 1030s
22.
Submarine
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A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability, the term most commonly refers to a large, crewed vessel. It is also used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine. The noun submarine evolved as a form of submarine boat, by naval tradition, submarines are usually referred to as boats rather than as ships. Although experimental submarines had been built before, submarine design took off during the 19th century, Submarines were first widely used during World War I, and now figure in many navies large and small. Civilian uses for submarines include marine science, salvage, exploration and facility inspection, Submarines can also be modified to perform more specialized functions such as search-and-rescue missions or undersea cable repair. Submarines are also used in tourism, and for undersea archaeology, most large submarines consist of a cylindrical body with hemispherical ends and a vertical structure, usually located amidships, which houses communications and sensing devices as well as periscopes. In modern submarines, this structure is the sail in American usage, a conning tower was a feature of earlier designs, a separate pressure hull above the main body of the boat that allowed the use of shorter periscopes. There is a propeller at the rear, and various hydrodynamic control fins, smaller, deep-diving and specialty submarines may deviate significantly from this traditional layout. Submarines use diving planes and also change the amount of water, Submarines have one of the widest ranges of types and capabilities of any vessel. Submarines can work at greater depths than are survivable or practical for human divers, modern deep-diving submarines derive from the bathyscaphe, which in turn evolved from the diving bell. In 1578, the English mathematician William Bourne recorded in his book Inventions or Devises one of the first plans for an underwater navigation vehicle and its unclear whether he ever carried out his idea. The first submersible of whose construction there exists reliable information was designed and built in 1620 by Cornelis Drebbel and it was propelled by means of oars. By the mid-18th century, over a dozen patents for submarines/submersible boats had been granted in England, in 1747, Nathaniel Symons patented and built the first known working example of the use of a ballast tank for submersion. His design used leather bags that could fill with water to submerge the craft, a mechanism was used to twist the water out of the bags and cause the boat to resurface. In 1749, the Gentlemens Magazine reported that a design had initially been proposed by Giovanni Borelli in 1680. By this point of development, further improvement in design stagnated for over a century, until new industrial technologies for propulsion. The first military submarine was the Turtle, a hand-powered acorn-shaped device designed by the American David Bushnell to accommodate a single person and it was the first verified submarine capable of independent underwater operation and movement, and the first to use screws for propulsion
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HMS Truant
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HMS Truant was a T-class submarine of the Royal Navy. She was laid down by Vickers Armstrong, Barrow and launched on 5 May 1939, Truant had a relatively active career serving in the main naval theatres of war - Home waters, the Mediterranean and the Pacific Far East. Truants first major victory came when she torpedoed and damaged the German light cruiser Karlsruhe off Kristiansand, Norway, Karlsruhe had to be scuttled with two torpedoes by the German torpedo boat Greif. Truant later attacked the British merchant Alster, unaware that it had recently captured from the Germans. She also intercepted the German merchant Tropic Sea, Tropic Sea had formerly been in Norwegian service, but had been captured by the German armed merchant cruiser Orion in the South Pacific. As well as 8,000 tons of wheat, she had on board the captain and 22 survivors of the British SS Haxby, Tropic Sea was scuttled by the German prize crew in the Bay of Biscay. Truant embarked the captain and survivors of Haxby, and the master of Tropic Sea, the majority of the Norwegians were rescued by British flying boats. Truant had an escape, when she was attacked by the River-class submarine Clyde. Truant also damaged the small Italian tanker Prometeo and the Italian torpedo boat Alcione and she also unsuccessfully attacked the Italian merchant vessels Utilitas, Silvia Tripcovich, Bainsizza and Arborea, the small Italian tanker Labor and the German merchantman Bellona. Truant was assigned to operate in the Far East, against Japanese shipping in 1942 and she torpedoed and sank the Japanese merchant cargo ships Yae Maru and Shunsei Maru and the Japanese army cargo ship Tamon Maru No.1. She also attacked the Japanese light cruiser Nagara, but the torpedoes missed their target and she was also prominent at the Battle of Badung Strait. Truant survived the war and was sold to be broken up for scrap on 19 December 1945 and she was wrecked in December 1946 whilst en route to the shipbreakers. Lost Patrols, Submarine Wrecks of the English Channel, Ships of the Royal Navy, The Complete Record of all Fighting Ships of the Royal Navy. Janes Submarines, War Beneath the Waves from 1776 to the Present Day, IWM Interview with Christopher Hutchinson, who commanded HMS Truant during the Norwegian campaign
24.
Flettner Fl 282
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The Flettner Fl 282 Kolibri is a single-seat intermeshing rotor helicopter, or synchropter, produced by Anton Flettner of Germany. According to Yves Le Bec, the Flettner Fl 282 was the worlds first series production helicopter, the Fl 282 Kolibri was an improved version of the Flettner Fl 265 announced in July 1940, which pioneered the same intermeshing rotor configuration that the Kolibri used. The Fl 282s fuselage was constructed from steel tube covered with doped fabric, the German Navy was impressed with the Kolibri and wanted to evaluate it for submarine spotting duties, ordering an initial 15 examples, to be followed by 30 production models. Flight testing of the first two prototypes was carried out through 1941, including repeated takeoffs and landings from a pad mounted on the German cruiser Köln, the first two A series prototypes had enclosed cockpits, all subsequent examples had open cockpits and were designated B series. In case of a failure, the switch from helicopter to autorotation was automatic. Three-bladed rotors were installed on a test bed and found smoother than the vibrating 2-blade rotor, the hover efficiency was 0.72 whereas for modern helicopters it is around 60%. After the war, Anton Flettner emigrated to the United States and became the designer for Kaman Aircraft. Intermeshing rotors have become noted with Kaman helicopters, which continues this concept with the Kaman K-MAX, intended roles of Fl 282 included ferrying items between ships and reconnaissance. However, as the war progressed, the Luftwaffe began considering converting the Fl 282 for battlefield use. Until this time the craft had flown by a single pilot. Later the B-2 proved a useful artillery spotting aircraft and a unit was established in 1945 comprising three Fl 282 and three Fa 223 helicopters. Good handling in bad weather led the German Air Ministry to issue a contract in 1944 to BMW to produce 1,000 units, however, the companys Munich plant was destroyed by Allied bombing raids after producing just 24 machines. Towards the end of World War II most of the surviving Fl 282s were stationed at Rangsdorf, in their role as artillery spotters, Fl 282A-1 Single-seat naval reconnaissance type, for operation from cruisers and other warships. Tested in the Baltic, Mediterranean and Aegean Seas, Fl 282A-2 Single-seat reconnaissance type for submarines equipped with special deck hangar, project only. S. Fl 282 V-1028368 Midland Air Museum, Coventry, England, partial aircraft, frame with rotor head & wheels. Fl 282 V-23 was at one time to be found at the National Museum of the United States Air Force, Dayton, Ohio. Data from General characteristics Crew,1 Length,6.56 m Height,2.2 m Empty weight,760 kg Max takeoff weight,1,000 kg Powerplant,1 × Bramo Sh. 14A 7-cyl
25.
Helicopter
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A helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and these attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL aircraft cannot perform. English language nicknames for helicopter include chopper, copter, helo, heli, Helicopters were developed and built during the first half-century of flight, with the Focke-Wulf Fw 61 being the first operational helicopter in 1936. Some helicopters reached limited production, but it was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production, with 131 aircraft built. Though most earlier designs used more than one rotor, it is the single main rotor with anti-torque tail rotor configuration that has become the most common helicopter configuration. Tandem rotor helicopters are also in use due to their greater payload capacity. Coaxial helicopters, tiltrotor aircraft, and compound helicopters are all flying today, quadcopter helicopters pioneered as early as 1907 in France, and other types of multicopter have been developed for specialized applications such as unmanned drones. The earliest references for vertical flight came from China, since around 400 BC, Chinese children have played with bamboo flying toys. This bamboo-copter is spun by rolling a stick attached to a rotor, the spinning creates lift, and the toy flies when released. The 4th-century AD Daoist book Baopuzi by Ge Hong reportedly describes some of the ideas inherent to rotary wing aircraft, designs similar to the Chinese helicopter toy appeared in Renaissance paintings and other works. In the 18th and early 19th centuries Western scientists developed flying machines based on the Chinese toy. It was not until the early 1480s, when Leonardo da Vinci created a design for a machine that could be described as an aerial screw, that any recorded advancement was made towards vertical flight. His notes suggested that he built flying models, but there were no indications for any provision to stop the rotor from making the craft rotate. As scientific knowledge increased and became accepted, people continued to pursue the idea of vertical flight. In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by a spring device. It was powered by a spring, and was suggested as a method to lift meteorological instruments. Sir George Cayley, influenced by a fascination with the Chinese flying top, developed a model of feathers, similar to that of Launoy and Bienvenu. By the end of the century, he had progressed to using sheets of tin for rotor blades and his writings on his experiments and models would become influential on future aviation pioneers
26.
Operation Barbarossa
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Operation Barbarossa was the code name for Nazi Germanys invasion of the Soviet Union during World War II, which was launched on Sunday 22 June 1941. In the two leading up to the invasion, the two countries signed political and economic pacts for strategic purposes. Nevertheless, the German High Command began planning an invasion of the Soviet Union in July 1940, over the course of the operation, about four million Axis personnel invaded the western Soviet Union along a 2, 900-kilometer front, the largest invasion force in the history of warfare. In addition to troops, the Wehrmacht employed some 600,000 motor vehicles, the offensive marked an escalation of the war, both geographically and in the formation of the Allied coalition. Despite their successes, the German offensive stalled in the Battle of Moscow and was pushed back by the Soviet winter counteroffensive. The Red Army repelled the Wehrmachts strongest blows and forced the unprepared Germans into a war of attrition, the Wehrmacht would never again mount a simultaneous offensive along the entire strategic Soviet–Axis front. The failure of the operation drove Hitler to demand further operations of limited scope inside the Soviet Union, such as Case Blue. The failure of Operation Barbarossa proved a point in the fortunes of the Third Reich. Most importantly, the operation opened up the Eastern Front, in more forces were committed than in any other theater of war in world history. The German armies captured 5,000,000 Soviet prisoners of war who were not granted protections stipulated in the Geneva Conventions, a majority of them never returned alive. The Nazis deliberately starved 3.1 million of the prisoners to death as part of a Hunger Plan that aimed to reduce the population of Eastern Europe, over a million Soviet Jews were murdered by Einsatzgruppen death squads and gassing as part of the Holocaust. On 10 February 1939, Hitler told his commanders that the next war would be purely a war of Weltanschauungen. Totally a peoples war, a racial war, on 23 November, once World War II had already started, Hitler declared that racial war has broken out and this war shall determine who shall govern Europe, and with it, the world. The racial policy of Nazi Germany viewed the Soviet Union as populated by non-Aryan Untermenschen, Hitler claimed in Mein Kampf that Germanys destiny was to turn to the East as it did six hundred years ago. Accordingly, it was stated Nazi policy to kill, deport, or enslave the majority of Russian and other Slavic populations and repopulate the land with Germanic peoples, under the Generalplan Ost. Likening the Soviets to the forces of Genghis Khan, Hitler told Croatian military leader Slavko Kvaternik that the Mongolian race threatened Europe. Following the invasion, Wehrmacht officers told their soldiers to target people who were described as Jewish Bolshevik subhumans, the Mongol hordes, the Asiatic flood, German army commanders cast the Jews as the major cause behind the partisan struggle. The main guideline policy for German troops was Where theres a partisan, theres a Jew, many German troops viewed the war in Nazi terms and regarded their Soviet enemies as sub-human
27.
Wilhelmshaven
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Wilhelmshaven is a coastal town in Lower Saxony, Germany. It is situated on the side of the Jade Bight. Wilhelmshaven is the centre of the JadeBay business region, the adjacent Lower Saxony Wadden Sea National Park provides the basis for the major tourism industry in the region. The Siebethsburg castle, built before 1383, operated as a pirate stronghold, four centuries later, the Kingdom of Prussia planned a fleet and a harbour on the North Sea.13 square kilometres of its territory at the Jade Bight to Prussia. In 1869 King William I of Prussia founded the town as an exclave of the Province of Hanover, all the hinterland of the city remained as part of the Duchy of Oldenburg. A shipbuilding yard developed at Wilhelmshaven, the Kaiserliche Werft Wilhelmshaven, on 30 June 1934 the pocket battleship Admiral Graf Spee was launched at Wilhelmshaven. In 1937 Wilhelmshaven and Rüstringen merged and the city, named Wilhelmshaven. In World War II, Allied bombing destroyed two thirds of the towns buildings, on 28 April 1945, the Canadian First Army captured Emden and Wilhelmshaven, Germany, and took the surrender of the entire garrison, including some 200 ships of the Kriegsmarine. The Poles remained as part of the occupation forces until 1947. During World War II Alter Banter Weg functioned as a subcamp of the Neuengamme concentration camp, in 1947 the city council decided to seek a new emblem for the city. Between 1947 and 1972 Wilhelmshaven was the home of PRINCE RUPERT SCHOOL, the school relocated to Rinteln in 1972. There is an association of former Wilhelmshaven pupils called The Wilhelmshaven Association. Wilhelmshaven is Germanys only deep-water port, and its largest naval base, the benefits of the deep shipping channel were already recognised at the end of the 1950s with the construction of the first oil tanker jetty. Wilhelmshaven has been the most important German import terminal for crude oil ever since, pipelines from here supply refineries in the Rhine-Ruhr region and Hamburg. Other major business operations followed, and constructed jetties for crude oil and oil products, coal, the JadeWeserPort – Container Terminal Wilhelmshaven and the development of the neighbouring Freight Village provide prospects for employment in areas such as logistics and distribution. Another element of the Wilhelmshaven energy hub programme is the chemical industry, the German defence forces together with the public sector, are the main pillars of the local employment market. The Jadestadion, the stadium of Regionalliga Nord club SV Wilhelmshaven Aquarium Wilhelmshaven, located on the Helgolandkai – a view of the oceans, the Botanischer Garten der Stadt Wilhelmshaven, a municipal botanical garden. UNESCO World Heritage Site Wadden Sea Visitor center, the large permanent interactive exhibition provides insight into the wadden sea environment
28.
Waterline length
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The waterline length is the length of a ship or boat at the point where it sits in the water. It excludes the length of the boat, such as features that are out of the water. Most boats rise outwards at the bow and stern, so a boat may be quite a bit longer than its waterline length. In a ship with raked stems, naturally the waterline length changes as the draft of the ship changes. Length at the waterline is often abbreviated as lwl, w/l and this measure is essential in determining a lot of properties of a vessel, such as how much water it displaces, where the bow and stern waves are, hull speed, amount of bottom-paint needed, etc. In sailing boats, longer waterline length will usually enable a greater speed, because it allows greater sail area. Higher beam and draft causes higher resistance against the water and this maximum speed, also known as theoretical hull speed, can be calculated using the formula x 1.34. Length overall Length between perpendiculars Hayler, William B, keever, John M. American Merchant Seamans Manual. Turpin, Edward A. McEwen, William A
29.
Length overall
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Length overall, often abbreviated as is the maximum length of a vessels hull measured parallel to the waterline. This length is important while docking the ship and it is the most commonly used way of expressing the size of a ship, and is also used for calculating the cost of a marina berth. LOA is usually measured on the hull alone, for sailing ships, this may exclude the bowsprit and other fittings added to the hull. This is how some racing boats and tall ships use the term LOA, however, other sources may include bowsprits in LOA. Sparred length, Total length including bowsprit, Mooring length and LOA including bowsprit are other expressions that might indicate the length of a sailing ship. Often used to distinguish between the length of a vessel including projections from the length of the hull itself, the Length on Deck or LOD is often reported and this is especially useful for smaller sailing vessels, as their LOA can be significantly different from their LOD. In ISO8666 for small boats, there is a definition of LOH and this may be shorter than a vessels LOA, because it excludes other parts attached to the hull, such as bowsprits. Another measure of length is LWL which is useful in assessing a vessels performance. In some cases LWL can be shorter than LOA. Overall length in cartridges The National Register of Historic Vessels Length between perpendiculars Hayler, William B, keever, John M. American Merchant Seamans Manual. Turpin, Edward A. McEwen, William A
30.
Beam (nautical)
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The beam of a ship is its width at the widest point as measured at the ships nominal waterline. The beam is a bearing projected at right-angles from the fore and aft line, Beam may also be used to define the maximum width of a ships hull, or maximum width plus superstructure overhangs. Typical length-to-beam ratios for small sailboats are from 2,1 to 5,1, large ships have widely varying beam ratios, some as large as 20,1. Rowing shells designed for racing may have length to beam ratios as high as 30,1. The beam of many vessels can be calculated using the following formula. Some examples, For a standard 27 ft yacht, the root of 27 is 3,3 squared is 9 plus 1 =10. The beam of many 27 ft monohulls is 10 ft, for a Volvo Open 70 yacht,70.5 to the power of 2/3 =17 plus 1 =18. The beam is often around 18 ft, for a 741 ft long ship, the cube root is 9, and 9 squared is 81, plus 1. The beam will usually be around 82 ft, e. g. Seawaymax, as catamarans have more than one hull, there is a different beam calculation for this kind of vessel. BOC stands for Beam On Centerline and this term in typically used in conjunction with LOA. The ratio of LOA/BOC is used to estimate the stability of multihull vessels, the lower the ratio the greater the boats stability. The BOC for vessels is measured as follows, For a catamaran, carlin – similar to a beam, except running in a fore and aft direction. Keever, John M. American Merchant Seamans Manual, turpin, Edward A. McEwen, William A
31.
Draft (hull)
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Draft determines the minimum depth of water a ship or boat can safely navigate. The draft can also be used to determine the weight of the cargo on board by calculating the displacement of water. A table made by the shows the water displacement for each draft. The density of the water and the content of the bunkers has to be taken into account. The closely related term trim is defined as the difference between the forward and aft drafts, the draft aft is measured in the perpendicular of the stern. The draft forward is measured in the perpendicular of the bow, the scale may use traditional English units or metric units. If the English system is used, the bottom of each marking is the draft in feet, in metric marking schemes, the bottom of each draft mark is the draft in decimeters and each mark is one decimeter high. Larger ships try to maintain a water draft when they are light, in order to make a better sea crossing. In order to achieve this they use sailing ballasts to stabilize the ship, the water draft of a large ship has little direct link with its stability because stability depends solely on the respective positions of the metacenter of the hull and the center of gravity. It is also however, that a light ship has quite high stability which can lead to implying too much rolling of the ship. A fully laden ship can have either a strong or weak stability, the draft of ships can be increased when the ship is in motion in shallow water, a phenomenon known as squat. Draft is a significant factor limiting navigable waterways, especially for large vessels, of course this includes many shallow coastal waters and reefs, but also some major shipping lanes. Panamax class ships—the largest ships able to transit the Panama Canal—do have a limit but are usually limited by beam, or sometimes length overall. However, in the much wider Suez Canal, the factor for Suezmax ships is draft. Some supertankers are able to transit the Suez Canal when unladen or partially laden, canals are not the only draft-limited shipping lanes. A Malaccamax ship has the deepest draft able to transit the very busy, there are only a few ships of this size. A small draft allows pleasure boats to navigate through shallower water and this makes it possible for these boats to access smaller ports, to travel along rivers and even to beach the boat. A large draft ensures a level of stability in strong wind
32.
Tonne
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The SI symbol for the tonne is t, adopted at the same time as the unit itself in 1879. Its use is also official, for the metric ton, within the United States, having been adopted by the US National Institute of Standards and it is a symbol, not an abbreviation, and should not be followed by a period. Informal and non-approved symbols or abbreviations include T, mT, MT, in French and all English-speaking countries that are predominantly metric, tonne is the correct spelling. Before metrication in the UK the unit used for most purposes was the Imperial ton of 2,240 pounds avoirdupois, equivalent to 1,016 kg, differing by just 1. 6% from the tonne. Ton and tonne are both derived from a Germanic word in use in the North Sea area since the Middle Ages to designate a large cask. A full tun, standing about a high, could easily weigh a tonne. An English tun of wine weighs roughly a tonne,954 kg if full of water, in the United States, the unit was originally referred to using the French words millier or tonneau, but these terms are now obsolete. The Imperial and US customary units comparable to the tonne are both spelled ton in English, though they differ in mass, one tonne is equivalent to, Metric/SI,1 megagram. Equal to 1000000 grams or 1000 kilograms, megagram, Mg, is the official SI unit. Mg is distinct from mg, milligram, pounds, Exactly 1000/0. 453 592 37 lb, or approximately 2204.622622 lb. US/Short tons, Exactly 1/0. 907 184 74 short tons, or approximately 1.102311311 ST. One short ton is exactly 0.90718474 t, imperial/Long tons, Exactly 1/1. 016 046 9088 long tons, or approximately 0.9842065276 LT. One long ton is exactly 1.0160469088 t, for multiples of the tonne, it is more usual to speak of thousands or millions of tonnes. Kilotonne, megatonne, and gigatonne are more used for the energy of nuclear explosions and other events. When used in context, there is little need to distinguish between metric and other tons, and the unit is spelt either as ton or tonne with the relevant prefix attached. *The equivalent units columns use the short scale large-number naming system used in most English-language countries. †Values in the equivalent short and long tons columns are rounded to five significant figures, ǂThough non-standard, the symbol kt is also sometimes used for knot, a unit of speed for sea-going vessels, and should not be confused with kilotonne. A metric ton unit can mean 10 kilograms within metal trading and it traditionally referred to a metric ton of ore containing 1% of metal. In the case of uranium, the acronym MTU is sometimes considered to be metric ton of uranium, in the petroleum industry the tonne of oil equivalent is a unit of energy, the amount of energy released by burning one tonne of crude oil, approximately 42 GJ
33.
Displacement (ship)
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The displacement or displacement tonnage of a ship is the ships weight. The name reflects the fact that it is measured indirectly, by first calculating the volume of water displaced by the ship, by Archimedes principle, this is also the weight of the ship. Displacement should not be confused with other measurements of volume or capacity typically used for vessels such as net tonnage, gross tonnage. The process of determining a vessels displacement begins with measuring its draft This is accomplished by means of its draft marks, a merchant vessel has three matching sets, one mark each on the port and starboard sides forward, midships, and astern. These marks allow a ships displacement to be determined to an accuracy of 0. 5%, the draft observed at each set of marks is averaged to find a mean draft. The ships hydrostatic tables show the corresponding volume displaced, to calculate the weight of the displaced water, it is necessary to know its density. Seawater is more dense than water, so a ship will ride higher in salt water than in fresh. The density of water varies with temperature. Devices akin to slide rules have been available since the 1950s to aid in these calculations and it is done today with computers. Displacement is usually measured in units of tonnes or long tons and these bring the ship down to its load draft, colloquially known as the waterline. Full load displacement and loaded displacement have almost identical definitions, full load is defined as the displacement of a vessel when floating at its greatest allowable draft as established by classification societies. Warships have arbitrary full load condition established, deep load condition means full ammunition and stores, with most available fuel capacity used. Light displacement is defined as the weight of the ship excluding cargo, fuel, water, ballast, stores, passengers, crew, normal displacement is the ships displacement with all outfit, and two-thirds supply of stores, ammunition, etc. on board. Standard displacement, also known as Washington displacement, is a term defined by the Washington Naval Treaty of 1922. Naval architecture Hull Hydrodynamics Tonnage Dear, I. C. B, oxford Companion to Ships and the Sea. George, William E. Stability & Trim for the Ships Officer, turpin, Edward A. McEwen, William A. Trim and Stability Information for Drydocking Calculations, conference on the Limitation of Armament,1922. Papers Relating to the Foreign Relations of the United States,1922, proceedings of the United States Naval Institute
34.
Washington Naval Treaty
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It limited the construction of battleships, battlecruisers and aircraft carriers by the signatories. The numbers of categories of warships, including cruisers, destroyers and submarines, were not limited by the treaty. The naval treaty was concluded on February 6,1922, ratifications of that treaty were exchanged in Washington on August 17,1923, and it was registered in League of Nations Treaty Series on April 16,1924. Subsequent to the treaty, other arms limitation conferences sought to increase limitations of warship building. The terms of the Washington treaty were modified by the London Naval Treaty of 1930, by the mid-1930s, Japan and Italy renounced the treaties, making naval arms limitation an increasingly untenable position for the other signatories. Immediately after World War I, the United Kingdom had the worlds largest and most powerful navy, followed by the United States, the three nations had been allied for World War I, but a naval arms race seemed likely for the next few years. The arms race began in the United States, president Woodrow Wilsons administration announced successive plans for the expansion of the US Navy from 1916 to 1919 that would have resulted in a massive fleet of 50 modern battleships. At the time, it was engaged in building six battleships, the Japanese started work on four battleships and four battlecruisers, all much larger and more powerful than those of the classes preceding. The 1921 British Naval Estimates planned four battleships and four battlecruisers, the U. S. public was largely unwelcoming of the new arms race. Britain could also ill afford any resumption of construction, given the exorbitant price of naval construction. In late 1921, the US government became aware that Britain was planning a conference to discuss the situation in the Pacific. To forestall the conference and satisfy domestic pressure for a disarmament conference. At the first plenary session held November 21,1921, US Secretary of State Charles Evans Hughes presented his countrys proposals, Hughes provided a dramatic beginning for the conference by stating with resolve, The way to disarm is to disarm. The ambitious slogan received enthusiastic public endorsement and likely shortened the conference while helping ensure his proposals were largely adopted and he subsequently proposed the following, A ten-year pause or holiday in the construction of capital ships, including the immediate suspension of all capital ship building. The scrapping of existing or planned capital ships to give a 5,5,3,1.75,1.75 ratio of tonnage with Britain, ongoing limits of both capital ship tonnage and the tonnage of secondary vessels with the 5,5,3 ratio. The proposals regarding capital ships were largely accepted by the British delegation and it would no longer be possible for Britain to have adequate fleets in the North Sea, the Mediterranean, and the Far East simultaneously. The facts provoked outrage from parts of the Royal Navy, nevertheless, there was huge pressure on Britain to agree. The risk of war with the United States was increasingly regarded as merely theoretical, Naval spending was unpopular in both Britain and its dominions
35.
Welding
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In addition to melting the base metal, a filler material is typically added to the joint to form a pool of molten material that cools to form a joint that is usually stronger than the base material. Pressure may also be used in conjunction with heat, or by itself, although less common, there are also solid state welding processes such as friction welding or shielded active gas welding in which metal does not melt. Some of the best known welding methods include, Oxy-fuel welding - also known as oxyacetylene welding or oxy welding, uses fuel gases and oxygen to weld and cut metals. Shielded metal arc welding – also known as stick welding or electric welding, the electrode holder holds the electrode as it slowly melts away. Slag protects the weld puddle from atmospheric contamination, gas tungsten arc welding – also known as TIG, uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from contamination by an inert shielding gas such as argon or helium. Flux-cored arc welding – almost identical to MIG welding except it uses a special tubular wire filled with flux, it can be used with or without shielding gas, submerged arc welding – uses an automatically fed consumable electrode and a blanket of granular fusible flux. The molten weld and the arc zone are protected from contamination by being submerged under the flux blanket. Electroslag welding – a highly productive, single pass welding process for thicker materials between 1 inch and 12 inches in a vertical or close to vertical position. Electric resistance welding - a welding process that produces coalescence of laying surfaces where heat to form the weld is generated by the resistance of the material. In general, an efficient method, but limited to relatively thin material, many different energy sources can be used for welding, including a gas flame, an electric arc, a laser, an electron beam, friction, and ultrasound. While often a process, welding may be performed in many different environments, including in open air, under water. Welding is an undertaking and precautions are required to avoid burns, electric shock, vision damage, inhalation of poisonous gases and fumes. Until the end of the 19th century, the welding process was forge welding. Arc welding and oxyfuel welding were among the first processes to develop late in the century, Welding technology advanced quickly during the early 20th century as the world wars drove the demand for reliable and inexpensive joining methods. Developments continued with the invention of laser welding, electron beam welding, magnetic pulse welding. Today, the continues to advance. Robot welding is commonplace in industrial settings, and researchers continue to develop new welding methods, the history of joining metals goes back several millennia
36.
Rivet
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A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a cylindrical shaft with a head on one end. The end opposite to the head is called the tail. On installation the rivet is placed in a punched or drilled hole, in other words, pounding creates a new head on the other end by smashing the tail material flatter, resulting in a rivet that is roughly a dumbbell shape. To distinguish between the two ends of the rivet, the head is called the factory head and the deformed end is called the shop head or buck-tail. Because there is effectively a head on each end of a rivet, it can support tension loads, however. Bolts and screws are better suited for tension applications, solid rivets consist simply of a shaft and head that are deformed with a hammer or rivet gun. A rivet compression or crimping tool can also deform this type of rivet and this tool is mainly used on rivets close to the edge of the fastened material, since the tool is limited by the depth of its frame. A rivet compression tool does not require two people, and is generally the most foolproof way to solid rivets. Solid rivets are used in applications where reliability and safety count, a typical application for solid rivets can be found within the structural parts of aircraft. Hundreds of thousands of rivets are used to assemble the frame of a modern aircraft. Such rivets come with rounded or 100° countersunk heads, typical materials for aircraft rivets are aluminium alloys, titanium, and nickel-based alloys. Some aluminum alloy rivets are too hard to buck and must be softened by solution treating prior to being bucked, ice box aluminum alloy rivets harden with age, and must likewise be annealed and then kept at sub-freezing temperatures to slow the age-hardening process. Steel rivets can be found in structures such as bridges, cranes. The setting of these fasteners requires access to both sides of a structure, solid rivets are driven using a hydraulically, pneumatically, or electromagnetically driven squeezing tool or even a handheld hammer. Applications where only one side is accessible require blind rivets, high-strength bolts have largely replaced structural steel rivets. Indeed, the latest steel construction specifications published by AISC no longer covers their installation, the reason for the change is primarily due to the expense of skilled workers required to install high strength structural steel rivets. Whereas two relatively unskilled workers can install and tighten high strength bolts, it takes a minimum of four highly skilled riveters to install rivets, at a central location near the areas being riveted, a furnace was set up
37.
Ship floodability
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Floodability is the susceptibility of a ships construction to flooding. Floodability is reduced by dividing the volume of the hull into watertight compartments with decks and bulkheads, use of double bottom, and by other means. If a ships hull is divided into compartments, any flooding resulting from a breach of the hull can be contained in the compartments where the flooding occurs. In most case, the compartments are fitted with a system of automatic doors. Smaller vessels and submarines generally feature watertight hatches between compartments, which are closed manually to block water from escaping the flooded compartment. As long as the flooding is localised, this can allow a ship to retain sufficient buoyancy to remain afloat, but if numerous compartments are opened to the sea, the ship can sink regardless. If a ship is fitted with longitudinal bulkheads as well as transverse bulkheads, flooding along one side of the ship can cause a serious list, in such cases, damage control parties can intentionally flood the corresponding compartment on the other side, equalizing the list. Such techniques can work fore-and-aft as well, for example, if a flooded bow is holding the rudder, the Song Dynasty Chinese author Zhu Yu wrote of watertight compartments in his book, Pingzhou Table Talks, written from AD1111 to 1117 and published in 1119. Watertight compartments were frequently implemented in Asian ships, and had implemented in the warships of Kubla Khan. Chinese seagoing junks often had 14 crosswalls, some of which could be flooded to increase stability or for the carriage of liquids, similarly, submersibles and submarines also produce negative buoyancy by allowing compartments to flood. Alexei Krylov and Stepan Makarov worked extensively on ship floodability in the early 20th century
38.
Launch (boat)
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A launch is an open motorboat. The forward part of the launch may be covered, prior to the era of engines on small craft, a launch was the largest boat carried on a sailing vessel, powered by sail or by oars. In competitive rowing, a launch is a boat used by the coach during training. Originally a launch was the largest boat carried by a warship in the age of sail, the word comes from the Spanish lancha and Portuguese, from Malay lancharan, from lanchar. In the Age of Sail, a ship carried a variety of boats of different sizes. In addition to the launch, examples include the boat, captains gig, pinnace. Distinctions among the vessels were clear, both in design and purpose. In the age of motorized ships, these distinctions of size and purpose have largely disappeared, in the 18th century, a launch was used to set the large anchors on a ship. The launch of that era had a transom and was about 24 feet long. In 1788 Captain Bligh was set adrift in Bounty’s launch, on the River Thames the term launch is used to mean any motorised pleasure boat. The usage arises from the governing the management of the Thames and laying down the categories of boats. Motor launch was the designation for large vessels used in the Second World War by the Royal Navy and they were used for inshore work in defending the coast from submarines and carried relatively light armament, a few depth charges, a gun and a few machine guns. In competitive rowing the term launch is used to refer to any motorized boat used by the coach to follow practicing boats during workouts, RAF rescue launch Cabin cruiser Slipper launch Naphtha launch
39.
Cutter (boat)
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A cutter is typically a small, but in some cases a medium-sized, watercraft designed for speed rather than for capacity. Traditionally a cutter sailing vessel is a small single-masted boat, fore-and-aft rigged, the cutters mast may be set farther back than on a sloop. In modern usage, a cutter can be either a small- or medium-sized vessel whose occupants exercise official authority, examples are harbor pilots cutters and cutters of the U. S. Coast Guard or UK Border Force. Cutters can also be a small boat serving a one to ferry passengers or light stores between larger boats and the shore. This type of cutter may be powered by oars, sails or a motor, the cutter is one of several types of sailboats. Traditionally the sloop rig was a rig with a single mast located forward of 70% of the length of the sailplan, in this traditional definition a sloop could have multiple jibs on a fixed bowsprit. Cutters had a rig with a single mast more centrally located, which could vary from 50% to 70% of the length of the sailplan, with multiple headsails, a mast located aft of 50% would be considered a mast aft rig. Somewhere in the 1950s or 1960s there was a shift in these definitions such that a sloop only flew one headsail, in this modern idiom, a cutter is a sailing vessel with more than one head sail and one mast. Cutters carry a staysail directly in front of the mast, set from the forestay, a traditional vessel would also normally have a bowsprit to carry one or more jibs from its end via jibstay on travelers. In modern vessels the jib may be set from a permanent stay fixed to the end of a fixed bowsprit, or directly to the stem fitting of the bow itself. In these cases, that may be referred to as the forestay, and the inner one, a sloop carries only one head sail, called either the foresail or jib. These could be managed without the need for crews, winches, or complex tackles, making the cutter especially suitable for pilot, customs. For example, a pilot cutter may only have two people on board for its outward trip—the pilot to be delivered to a ship and an assistant who had to sail the cutter back to port single-handed. The cutter sailing rig became so ubiquitous for these tasks that the modern-day motorised vessels now engaged in these duties are known as cutters, the open cutter carried aboard naval vessels in the 18th Century was rowed by pairs of men sitting side-by-side on benches. The cutter, with its transom, was broader in proportion compared to the longboat, the Watermen of London used similar boats in the 18th Century often decorated as depicted in historical prints and pictures of the River Thames in the 17th & 18th Centuries. The modern Waterman’s Cutter is based on drawings of these boats and they are 34 feet long with a beam of 4 ft 6 in They can have up to six oarsmen either rowing or sculling and can carry a cox and passengers. The organisers of the Great River Race developed the modern version in the 1980s, watermen’s Cutters also compete annually in the Port of London Challenge, and the Port Admirals’ Challenge. Cutter races are also to be found at various town rowing and skiffing regattas, in addition the cutters perform the role of ceremonial Livery Barges with the canopies and armorial flags flying on special occasions
40.
Dinghy
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A dinghy is a type of small boat, often carried or towed for use as a ships boat by a larger vessel. The term is a loanword from the Bengali ḍiṅgi, Urdu ḍīngī & Hindi ḍieṁgī, dinghies usually range in length from about 2 to 6 m. Larger auxiliary vessels are generally called tenders, pinnaces or lifeboats, folding and take-down multi-piece dinghies are used where space is limited. Some newer dinghies have much greater buoyancy, giving them more carrying capacity than older boats of the same size, whaleboats are among the classic pulling boats, with a sharp bow, fine stern lines and a canoe stern. Despite being somewhat more tippy, with cargo capacity than prams, they row, motor. Prior to the introduction of fibreglass as a material, dories were more popular because their ease of assembly and, thereby. Whitehall rowboats were the water taxis of the late 1800s until the invention of the small gasoline outboard. Considered one of the most refined rowboats for harbour and lake use, dories are sharp-ended boats traditionally made of wood but now also produced in fibreglass or aluminium. They cut the water well, but their stability is low, making them feel tippy in flat water. A dory can be landed or launched through surf where a Whitehall may founder, prams are usually short with transoms at both bow and stern. Popular as tenders on sail boats with limited deck space, some inflatable boats have a rigid deck and transom which allows an engine to be used for propulsion. They row poorly and do not tow well because of their blunt bows and large wetted surface area, rigid safety dinghies are designed to row, motor, tow, and sail. In addition to their self-rescue lifeboat functionality, these serve as everyday tenders. They are extremely buoyant and/or unsinkable and have great carrying capacity relative to length, dinghy is also a term given to any small cars, trucks or suvs towed behind a motor home. On yachts shorter than 10 m, there is not enough room for a reasonably sized dinghy. A dinghy is useful to avoid the need for expensive dock or slip space, so owners of small yachts compromise by carrying a small rigid dinghy or deflated inflatable, space can be saved by storing items in containers or bags that are tied to the dinghy. Dinghies are sometimes used as lifeboats, recently self-rescue dinghies have come back into use as proactive lifeboats that can be sailed to safety, rigid dinghies for small yachts are very small, about 2 m, usually with a pram bow to get more beam in a shorter length. Larger dinghies are towed and should have reserve buoyancy, an automatic bailer, most masters prefer a tow cable long enough to put the dinghy on the back side of the swell to prevent the dinghy from ramming the transom of the yacht
41.
Capsizing
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Capsizing or keeling over is when a boat or ship is turned on its side or it is upside down in the water. The act of reversing a capsized vessel is called righting, if a capsized vessel has enough flotation to prevent sinking, it may recover on its own if the stability is such that it is not stable inverted. Vessels of this design are called self-righting, in dinghy sailing, a practical distinction can be made between being knocked down which is called a capsize, and being inverted, which is called being turtled. Small dinghies frequently capsize in the course of use and can usually be recovered by the crew. Some types of dinghy are occasionally deliberately capsized, as capsizing and righting the vessel again can be the fastest means of draining water from the boat, capsizing is an inherent part of dinghy sailing. It is not a question of if but a question of when, for those who do not want the experience, a keelboat monohull has physics on its side. But even yachts can capsize and turtle in extraordinary conditions, so design considerations are important, such events can overcome skill and experience, boats need to be appropriate for foreseeable conditions. A capsized kayak may be righted with a roll or eskimo rescue, in whitewater kayaking, capsizing occurs frequently and is accepted as an ordinary part of the sport. For sailing vessels, the ratio is a commonly published number used as a guideline for safe operation. However the only variables that go into capsize ratio are a beam and its displacement. A vessel may be designated as self-righting if it is designed to be able to then return to upright without intervention. Most small craft intended as lifeboats with rigid hulls designed since about the middle of the century are self-righting. In a storm, even large vessels may be rolled by being hit broadside by a wave or pitchpoled stem over stern in extreme waves. This is normally catastrophic for larger ships, and smaller yachts can be dismasted due to the drag as the boat is forced to roll over, among ship types, a roll-on-roll-off ship is more prone to capsizing as it has large open car decks near the waterline. If the watertight car-deck doors fail through damage or mismanagement, water entering the car-deck is subject to the surface effect. A ship that is holed may capsize, technically, this was not a capsize as her bottom was only partly exposed, rather this was a partial sinking. A vessel which capsizes without being holed may allow water to enter in places normally above the waterline, the ship may not then be able to right itself, stability and safety will be compromised even if the vessel is righted. In competitive yacht racing, a boat has certain special rights as it cannot maneuver
42.
Lee helm
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Lee helm is the tendency of a sailboat to turn away from the wind while under sail. It is the opposite of weather helm which is the tendency of a sailboat to round up into the wind, a boat with lee helm will be difficult to sail Close Hauled and tacking may be difficult. Lee helm is considered dangerous in a sailboat, while sailing, if left to its own devices a boat with lee helm will bear away from the wind, accelerate, and perform an accidental or uncontrolled gybe, perhaps repeatedly. In an uncontrolled gybe the force of the moves the sails. In a strong wind this movement will by very fast and forceful and can damage the boat, the sails, injure the crew and this tends to push the bow of the boat away from the wind. This can be due to a design, for example with the mast too far forward. A small amount of lee helm can be counteracted with the rudder, but this introduces significant drag in the water and slows the boat. A small amount of lee helm can also be cured by raking the mast backward, reducing the size of the Jib on a Sloop rigged boat, large amounts of lee helm can only be corrected by altering the placement of the mast or keel/centerboard --- a non-trivial venture. On modern US Navy surface vessels that use gas turbine or diesel propulsion, the lee helm on vessels with nuclear propulsion and conventional steam propulsion still uses a telegraph system
43.
Rudder
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A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other conveyance that moves through a fluid medium. On an aircraft the rudder is used primarily to counter adverse yaw, a rudder operates by redirecting the fluid past the hull or fuselage, thus imparting a turning or yawing motion to the craft. In basic form, a rudder is a plane or sheet of material attached with hinges to the crafts stern, tail. Often rudders are shaped so as to minimize hydrodynamic or aerodynamic drag, on simple watercraft, a tiller—essentially, a stick or pole acting as a lever arm—may be attached to the top of the rudder to allow it to be turned by a helmsman. In larger vessels, cables, pushrods, or hydraulics may be used to link rudders to steering wheels, in typical aircraft, the rudder is operated by pedals via mechanical linkages or hydraulics. Generally, a rudder is part of the apparatus of a boat or ship that is fastened outside the hull, that is denoting all different types of oars, paddles. More specifically, the gear of ancient vessels can be classified into side-rudders and stern-mounted rudders. A third term, steering oar, can denote both types, in a Mediterranean context, side-rudders are more specifically called quarter-rudders as the later term designates more exactly the place where the rudder was mounted. Stern-mounted rudders are uniformly suspended at the back of the ship in a central position. S, a steering oar was used at this time because the rudder had not yet been invented. With a single sail, a frequent movement of the oar was required to steer a straight course. The steering oar or steering board is an oar or board to control the direction of a ship or other watercraft prior to the invention of the rudder. It is normally attached to the side in larger vessels, though in smaller ones it is rarely, if ever. Rowing oars set aside for steering appeared on large Egyptian vessels long before the time of Menes, in the Old Kingdom as much as five steering oars are found on each side of passenger boats. The tiller, at first a small pin run through the stock of the steering oar, both the tiller and the introduction of an upright steering post abaft reduced the usual number of necessary steering oars to one each side. In Iran, oars mounted on the side of ships for steering are documented from the 3rd millennium BCE in artwork, wooden models, the strength of the steering oar lay in its combination of effectiveness, adaptability and simpleness. Roman quarter steering oar mounting systems survived mostly intact through the medieval period, by the first half of the 1st century AD, steering gear mounted on the stern were also quite common in Roman river and harbour craft as proved from reliefs and archaeological finds. A tomb plaque of Hadrianic age shows a harbour tug boat in Ostia with a long stern-mounted oar for better leverage, interestingly, the boat already featured a spritsail, adding to the mobility of the harbour vessel. Further attested Roman uses of stern-mounted steering oars includes barges under tow, transport ships for wine casks, also, the well-known Zwammerdam find, a large river barge at the mouth of the Rhine, featured a large steering gear mounted on the stern
