A convoy is a group of vehicles motor vehicles or ships, traveling together for mutual support and protection. A convoy is organized with armed defensive support, it may be used in a non-military sense, for example when driving through remote areas. Arriving at the scene of a major emergency with a well-ordered unit and intact command structure can be another motivation. Naval convoys have been in use for centuries, with examples of merchant ships traveling under naval protection dating to the 12th century; the use of organized naval convoys dates from when ships began to be separated into specialist classes and national navies were established. By the French Revolutionary Wars of the late 18th century, effective naval convoy tactics had been developed to ward off pirates and privateers; some convoys contained several hundred merchant ships. The most enduring system of convoys were the Spanish treasure fleets, that sailed from the 1520s until 1790; when merchant ships sailed independently, a privateer could cruise a shipping lane and capture ships as they passed.
Ships sailing in convoy presented a much smaller target: a convoy was as hard to find as a single ship. If the privateer found a convoy and the wind was favourable for an attack, it could still hope to capture only a handful of ships before the rest managed to escape, a small escort of warships could thwart it; as a result of the convoy system's effectiveness, wartime insurance premiums were lower for ships that sailed in convoys. Many naval battles in the Age of Sail were fought around convoys, including: The Battle of Portland The Battle of Ushant The Battle of Dogger Bank The Glorious First of June The Battle of Pulo Aura By the end of the Napoleonic Wars the Royal Navy had in place a sophisticated convoy system to protect merchant ships. Losses of ships travelling out of convoy however were so high that no merchant ship was allowed to sail unescorted. In the early 20th century, the dreadnought changed the balance of power in convoy battles. Steaming faster than merchant ships and firing at long ranges, a single battleship could destroy many ships in a convoy before the others could scatter over the horizon.
To protect a convoy against a capital ship required providing it with an escort of another capital ship, at high opportunity cost. Battleships were the main reason that the British Admiralty did not adopt convoy tactics at the start of the first Battle of the Atlantic in World War I, but the German capital ships had been bottled up in the North Sea, the main threat to shipping came from U-boats. From a tactical point of view, World War I–era submarines were similar to privateers in the age of sail; these submarines were only a little faster than the merchant ships they were attacking, capable of sinking only a small number of vessels in a convoy because of their limited supply of torpedoes and shells. The Admiralty took a long time to respond to this change in the tactical position, in April 1917 convoys were trialled, before being introduced in the Atlantic in September 1917. Other arguments against convoys were raised; the primary issue was the loss of productivity, as merchant shipping in convoy has to travel at the speed of the slowest vessel in the convoy and spent a considerable amount of time in ports waiting for the next convoy to depart.
Further, large convoys were thought to overload port resources. Actual analysis of shipping losses in World War I disproved all these arguments, at least so far as they applied to transatlantic and other long-distance traffic. Ships sailing in convoys were far less to be sunk when not provided with an escort; the loss of productivity due to convoy delays was small compared with the loss of productivity due to ships being sunk. Ports could deal more with convoys because they tended to arrive on schedule and so loading and unloading could be planned. In his book On the Psychology of Military Incompetence, Norman Dixon suggested that the hostility towards convoys in the naval establishment were in part caused by a perception of convoys as effeminating, due to warships having to care for civilian merchant ships. Convoy duty exposes the escorting warships to the sometimes hazardous conditions of the North Atlantic, with only rare occurrences of visible achievement; the British adopted a convoy system voluntary and compulsory for all merchant ships, the moment that World War II was declared.
Each convoy consisted of between 30 and 70 unarmed merchant ships. Canadian, American, supplies were vital for Britain to continue its war effort; the course of the Battle of the Atlantic was a long struggle as the Germans developed anti-convoy tactics and the British developed counter-tactics to thwart the Germans. The capability of a armed warship against a convoy was illustrated by the fate of Convoy HX 84. On November 5, 1940, the German heavy cruiser Admiral Scheer encountered the convoy. Maiden, Kenbame Head and Fresno were sunk, other ships were damaged. Only the sacrifice of the Armed Merchant Cruiser HMS Jervis Bay and failing light allowed the rest of the convoy to escape; the deterrence value of a battleship in protecting a convoy was dramatically illustrated when the German light battleships Scharnhorst and Gneisenau, mounting 11 in guns, came upon an eastbound British convoy in the North Atlantic on February 8, 1941. When the Germans detected the slow but well-protected battleship HMS Ramillies escorting the convoy, they f
Algiers is the capital and largest city of Algeria. In 2011, the city's population was estimated to be around 3,500,000. An estimate puts the population of the larger metropolitan city to be around 5,000,000. Algiers is located in the north-central portion of Algeria. Algiers is situated on the west side of a bay of the Mediterranean Sea; the modern part of the city is built on the level ground by the seashore. The casbah and the two quays form a triangle; the city's name is derived via French and Catalan Alger from the Arabic name Al-Jazā’ir, "The Islands". This name refers to the four former islands which lay off the city's coast before becoming part of the mainland in 1525. Al-Jazā’ir is itself a truncated form of the city's older name Jaza'ir Bani Mazghana, "The Islands of the Sons of Mazghana", used by early medieval geographers such as al-Idrisi and Yaqut al-Hamawi. In antiquity, the Greeks knew the town as Ikosion, Latinized as Icosium under Roman rule; the Greeks explained the name as coming from their word for "twenty" because it had been founded by 20 companions of Hercules when he visited the Atlas Mountains during his labors.
In fact, the name transcribed the Punic name ʿWYKSM, "Seagull Island", again named after the site's former islands. Algiers is known as El-Behdja or "Algiers the White" for its whitewashed buildings, seen rising from the sea. A small Phoenician colony on Algiers's former islands was established and taken over by the Carthaginians sometime before the 3rd century BC. After the Punic Wars, the Romans took over administration of the town, which they called Icosium, its ruins now form part of the modern city's marine quarter, with the Rue de la Marine following a former Roman road. Roman cemeteries existed near Bab Azoun; the city was given Latin rights by the emperor Vespasian. The bishops of Icosium are mentioned as late as the 5th century, but the ancient town fell into obscurity during the Muslim conquest of North Africa; the present city was founded in 944 by Bologhine ibn Ziri, the founder of the Berber Zirid–Sanhaja dynasty. He had earlier built a Sanhaja center at Ashir, just south of Algiers.
Although his Zirid dynasty was overthrown by Roger II of Sicily in 1148, the Zirids had lost control of Algiers to their cousins the Hammadids in 1014. The city was wrested from the Hammadids by the Almohads in 1159, in the 13th century came under the dominion of the Ziyanid sultans of Tlemcen. Nominally part of the sultanate of Tlemcen, Algiers had a large measure of independence under amirs of its own due to Oran being the chief seaport of the Ziyanids; the Peñón of Algiers, an islet in front of Algiers harbour had been occupied by the Spaniards as early as 1302. Thereafter, a considerable amount of trade began to flow between Spain. However, Algiers continued to be of comparatively little importance until after the expulsion of the Moors from Spain, many of whom sought asylum in the city. In 1510, following their occupation of Oran and other towns on the coast of Africa, the Spaniards fortified the islet of Peñon and imposed a levy intended to suppress corsair activity. In 1516, the amir of Algiers, Selim b.
Teumi, invited the corsair brothers Aruj and Hayreddin Barbarossa to expel the Spaniards. Aruj came to Algiers, ordered the assassination of Selim, seized the town and ousted the Spanish in the Capture of Algiers. Hayreddin, succeeding Aruj after the latter was killed in battle against the Spaniards in the Fall of Tlemcen, was the founder of the pashaluk, which subsequently became the beylik, of Algeria. Barbarossa lost Algiers in 1524 but regained it with the Capture of Algiers, formally invited the Sultan Suleiman the Magnificent to accept sovereignty over the territory and to annex Algiers to the Ottoman Empire. Algiers from this time became the chief seat of the Barbary pirates. In October 1541 in the Algiers expedition, the King of Spain and Holy Roman Emperor Charles V sought to capture the city, but a storm destroyed a great number of his ships, his army of some 30,000, chiefly made up of Spaniards, was defeated by the Algerians under their Pasha, Hassan. Formally part of the Ottoman Empire but free from Ottoman control, starting in the 16th century Algiers turned to piracy and ransoming.
Due to its location on the periphery of both the Ottoman and European economic spheres, depending for its existence on a Mediterranean, controlled by European shipping, backed by European navies, piracy became the primary economic activity. Repeated attempts were made by various nations to subdue the pirates that disturbed shipping in the western Mediterranean and engaged in slave raids as far north as Iceland; the United States fought two wars over Algiers' attacks on shipping. Among the notable people held for ransom was the future Spanish novelist Miguel de Cervantes, captive in Algiers five years, who wrote two plays set in Algiers of the period; the primary source for knowledge of Algiers of this period, since there are no contemporary local sources, is the Topografía e historia general de Argel, published by Diego de Haedo, but whose authorship is disputed. This work describes in detail the city, the behavior of its inhabitants, its military defenses, with the unsuccessful hope of facilitating an attack by Spain so as to end the piracy.
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, any vessel. Naval mines can be used offensively, to hamper enemy shipping movements or lock vessels into a harbour. Mines can be laid in many ways: by purpose-built minelayers, refitted ships, submarines, or aircraft—and by dropping them into a harbour by hand, they can be inexpensive: some variants can cost as little as US$2000, though more sophisticated mines can cost millions of dollars, be equipped with several kinds of sensors, deliver a warhead by rocket or torpedo. 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 between 0.5% and 10% of the cost of removing it, it can take up to 200 times as long to clear a minefield as to lay 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, estuaries and oceans, but they can 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 defended areas, or keeping them away from sensitive ones. Minefields designed for psychological effect are placed on trade routes and are used to stop shipping from reaching an enemy nation, they are 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, to make it easier for civil shipping to avoid the mines.
The warnings do not have to be specific. Precursors to naval mines were first invented by Chinese innovators of Imperial China and were described in thorough detail by the early Ming dynasty artillery officer Jiao Yu, in his 14th century military treatise known as the Huolongjing. Chinese records tell of naval explosives in the 16th century, used to fight against Japanese pirates; this kind of naval mine was loaded in a wooden box, sealed with putty. General Qi Jiguang made several timed, to harass Japanese pirate ships; the Tiangong Kaiwu treatise, written by Song Yingxing in 1637 AD, describes naval mines with a rip cord pulled by hidden ambushers located on the nearby shore who rotated a steel wheellock flint mechanism to produce sparks and ignite the fuse of the naval mine. Although this is the rotating steel wheellock's 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, who presented his design to Queen Elizabeth I of England in 1574.
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 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, floated toward the enemy, detonated by a sparking mechanism if it struck a ship. It was used on the Delaware River as a drift mine. In 1812 Russian engineer Pavel Shilling exploded an underwater mine using an electrical circuit. In 1842 Samuel Colt used an electric detonator to destroy a moving vessel to demonstrate an underwater mine of his own design to the United States Navy and President John Tyler. However, opposition from former President John Quincy Adams scuttled the project as "not fair and honest warfare." In 1854, during the unsuccessful attempt of the Anglo-French fleet to seize the Kronstadt fortress, British steamships HMS Merlin, HMS Vulture and HMS Firefly suffered damage due to the underwater explosions of Russian naval mines.
Russian naval specialists set more than 1500 naval mines, or infernal machines, designed by Moritz von Jacobi and by Immanuel Nobel, in the Gulf of Finland during the Crimean War of 1853-1856. The mining of Vulcan led to the world's 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 galvanic cell which powered it from the shore, the power of its explosive charge was equal to 14 kilograms of black powder. In the summer of 1853, the production of the mine was approved by the Committee for Mines of the Ministry of War of the Russian Empire. In 1854, 60 Jacobi mines were laid in the vicinity of the Forts Pavel and Alexander, to deter the British Baltic Fleet from attacking them, it phased out its direct competitor the Nobel mine on the insistence of Admiral Fyodor Litke. The Nobel mines were bought from Swedish industrialist Immanuel Nobel who had entered into collusion with Russian head of navy Alexander Sergeyevich Menshikov.
Despite their high cost t
Sicily is the largest island in the Mediterranean Sea and one of the 20 regions of Italy. It is one of the five Italian autonomous regions, in Southern Italy along with surrounding minor islands referred to as Regione Siciliana. Sicily is located in the central Mediterranean Sea, south of the Italian Peninsula, from which it is separated by the narrow Strait of Messina, its most prominent landmark is Mount Etna, the tallest active volcano in Europe, one of the most active in the world 3,329 m high. The island has a typical Mediterranean climate; the earliest archaeological evidence of human activity on the island dates from as early as 12,000 BC. By around 750 BC, Sicily had three Phoenician and a dozen Greek colonies and, for the next 600 years, it was the site of the Sicilian Wars and the Punic Wars. After the fall of the Roman Empire in the 5th century AD, Sicily was ruled during the Early Middle Ages by the Vandals, the Ostrogoths, the Byzantine Empire, the Emirate of Sicily; the Norman conquest of southern Italy led to the creation of the Kingdom of Sicily, subsequently ruled by the Hohenstaufen, the Capetian House of Anjou and the House of Habsburg.
It was unified under the House of Bourbon with the Kingdom of Naples as the Kingdom of the Two Sicilies. It became part of Italy in 1860 following the Expedition of the Thousand, a revolt led by Giuseppe Garibaldi during the Italian unification, a plebiscite. Sicily was given special status as an autonomous region on 15th May 1946, 18 days before the Italian constitutional referendum of 1946. Albeit, much of the autonomy still remains unapplied financial autonomy, because the autonomy-activating laws have been deferred to be approved by the parithetic committee, since 1946. Sicily has a rich and unique culture with regard to the arts, literature and architecture, it is home to important archaeological and ancient sites, such as the Necropolis of Pantalica, the Valley of the Temples and Selinunte. Sicily has a triangular shape, earning it the name Trinacria. To the east, it is separated from the Italian mainland by the Strait of Messina, about 3 km wide in the north, about 16 km wide in the southern part.
The northern and southern coasts are each about 280 km long measured as a straight line, while the eastern coast measures around 180 km. The total area of the island is 25,711 km2, while the Autonomous Region of Sicily has an area of 27,708 km2; the terrain of inland Sicily is hilly and is intensively cultivated wherever possible. Along the northern coast, the mountain ranges of Madonie, 2,000 m, Nebrodi, 1,800 m, Peloritani, 1,300 m, are an extension of the mainland Apennines; the cone of Mount Etna dominates the eastern coast. In the southeast lie the lower Hyblaean Mountains, 1,000 m; the mines of the Enna and Caltanissetta districts were part of a leading sulphur-producing area throughout the 19th century, but have declined since the 1950s. Sicily and its surrounding small islands have some active volcanoes. Mount Etna is the largest active volcano in Europe and still casts black ash over the island with its ever-present eruptions, it stands 3,329 metres high, though this varies with summit eruptions.
It is the highest mountain in Italy south of the Alps. Etna covers an area of 1,190 km2 with a basal circumference of 140 km; this makes it by far the largest of the three active volcanoes in Italy, being about two and a half times the height of the next largest, Mount Vesuvius. In Greek mythology, the deadly monster Typhon was trapped under the mountain by Zeus, the god of the sky. Mount Etna is regarded as a cultural symbol and icon of Sicily; the Aeolian Islands in the Tyrrhenian Sea, to the northeast of mainland Sicily form a volcanic complex, include Stromboli. The three volcanoes of Vulcano and Lipari are currently active, although the latter is dormant. Off the southern coast of Sicily, the underwater volcano of Ferdinandea, part of the larger Empedocles volcano, last erupted in 1831, it is located between the island of Pantelleria. The autonomous region includes several neighbouring islands: the Aegadian Islands, the Aeolian Islands and Lampedusa; the island is drained by several rivers, most of which flow through the central area and enter the sea at the south of the island.
The Salso flows through parts of Enna and Caltanissetta before entering the Mediterranean Sea at the port of Licata. To the east, the Alcantara flows through the province of Messina and enters the sea at Giardini Naxos, the Simeto, which flows into the Ionian Sea south of Catania. Other important rivers on the island are the Platani in the southwest. Sicily has a typical Mediterranean climate with mild and wet winters and hot, dry summers with changeable intermediate seasons. On the coasts the south-western, the climate is affected by the African currents and summers can be scorching. Sicily is seen as an island of warm winters but above all along the Tyrrhenian coast and in the inland areas, winters can be cold, with typical continental climate. Snow falls in abundance above 900–1000 metres, but stronger cold waves can carry it in the hills and in coastal cities on the northern coast of the island; the interi
Ship commissioning is the act or ceremony of placing a ship in active service, may be regarded as a particular application of the general concepts and practices of project commissioning. The term is most applied to the placing of a warship in active duty with its country's military forces; the ceremonies involved are rooted in centuries old naval tradition. Ship naming and launching endow a ship hull with her identity, but many milestones remain before she is completed and considered ready to be designated a commissioned ship; the engineering plant and electronic systems and multitudinous other equipment required to transform the new hull into an operating and habitable warship are installed and tested. The prospective commanding officer, ship's officers, the petty officers, seamen who will form the crew report for training and intensive familiarization with their new ship. Prior to commissioning, the new ship undergoes sea trials to identify any deficiencies needing correction; the preparation and readiness time between christening-launching and commissioning may be as much as three years for a nuclear powered aircraft carrier to as brief as twenty days for a World War II landing ship.
USS Monitor, of American Civil War fame, was commissioned less than three weeks after launch. Regardless of the type of ship in question, a vessel's journey towards commissioning in its nation's navy begins with a process known as sea trials. Sea trials take place some years after a vessel was laid down, mark the interim step between the completion of a ship's construction and its official acceptance for service with its nation's navy. Sea trials begin when the ship in question is floated out of its dry dock, at which time the initial crew for a ship will assume command of the vessel in question; the ship is sailed in littoral waters for the purpose of testing the design and other ship specific systems to ensure that they work properly and can handle the equipment that they will be using in the coming years. Tests done during this phase can include launching missiles from missile magazines, firing the ship's gun, conducting basic flight tests with rotary and fixed-wing aircraft that will be assigned to the ship in the future, various tests of the electronic and propulsion equipment.
During this phase of testing problems arise relating to the state of the equipment on the ship in question, which can result in the ship returning to the builder's shipyard to address the concerns in question. In addition to problems with a ship's arms and equipment, the sea trial phase a ship undergoes prior to commissioning can identify issues with the ship's design that may need to be addressed before it can be accepted into service with its nation's navy. During her sea trials in 1999 French Naval officials determined that the French aircraft carrier Charles de Gaulle was too short to safely operate the E2C Hawkeye, resulting in her return to the builder's shipyard for enlargement. After a ship has cleared its sea trial period, it will be accepted into service with its nation's navy. At this point, the ship in question will undergo a process of degaussing and/or deperming, which will vastly reduce the ship in question's magnetic signature. Once a ship's sea trials are completed plans for the actual commissioning ceremony will take shape.
Depending on the naval traditions of the nation in question, the commissioning ceremony may be an elaborately planned event with guests, the ship's future crew, other persons of interest in attendance, or the nation in question may forgo a ceremony and instead administratively place the ship in commission. At a minimum, on the day on which the ship in question is to be commissioned the crew will report for duty aboard the ship and the commanding officer will read through the orders given for the ship and its personnel. If the ship's ceremony is a public affair the Captain may make a speech to the audience, along with other VIPs as the ceremony dictates. Religious ceremonies, such as blessing the ship or the singing of traditional hymns or songs, may occur. Once a ship has been commissioned its final step toward becoming an active unit of the navy it now serves is to report to its home port and load or accept any remaining equipment. To decommission a ship is to terminate its career in service in the armed forces of a nation.
Unlike wartime ship losses, in which a vessel lost to enemy action is said to be struck, decommissioning confers that the ship has reached the end of its usable life and is being retired from a given country's navy. Depending on the naval traditions of the country in question, a ceremony commemorating the decommissioning of the ship in question may take place, or the vessel may be removed administratively with little to no fanfare; the term "paid off" is alternatively used in British Commonwealth contexts, originating in the age-of-sail practice of ending an officer's commission and paying crew wages once the ship completed its voyage. Ship decommissioning occurs some years after the ship was commissioned and is intended to serve as a means by which a vessel that has become too old or too obsolete can be retired with honor from the operating country's armed force. Decommissioning of the vessel may occur due to treaty agreements or for safety reasons (such as a ship's nuclear reactor and assoc
The Clemson class was a series of 156 destroyers which served with the United States Navy from after World War I through World War II. The Clemson-class ships were commissioned by the United States Navy from 1919 to 1922, built by Newport News Shipbuilding & Dry Dock Company, New York Shipbuilding Corporation, William Cramp & Sons, Bethlehem Steel Corporation, Mare Island Naval Shipyard, Norfolk Naval Shipyard and Bath Iron Works, some quite rapidly; the Clemson class was a minor redesign of the Wickes class for greater fuel capacity and was the last pre-World War II class of flush-decker destroyers to be built for the United States. Until the Fletcher-class destroyer, the Clemsons were the most numerous class of destroyers commissioned in the United States Navy and were known colloquially as "flush-deckers", "four-stackers" or "four-pipers"; as built, the Clemson class would be a straightforward expansion of the Wickes-class destroyers. While the Wickes class had given good service there was a desire to build a class more tailored towards the anti-submarine role, as such several design studies were completed about increasing the ships' range.
These designs included a reduction in speed to between 26–28 knots by eliminating two boilers, freeing up displacement for depth charges and more fuel. This proposal foreshadowed the destroyer escorts of World War II. Upgrading the gun armament from 4-inch to 5-inch guns was considered, but only five ships were armed with 5-inch guns. In addition, the tapered stern of the Wickes-class destroyers resulted in a large turning radius and a correction to this defect was sought, although this was not corrected in the final design. In the end the General Board decided the 35 knots speed be retained so as to allow the Clemson class to be used as a fleet escort; the pressing need for destroyers overruled any change that would slow production compared to the proceeding Wickes class. Wing tanks for fuel oil were installed on either side of the ships to increase the operational range; this design choice meant the fuel oil would be stored above the waterline and create additional vulnerability, but the Navy felt a 4,900-nautical-mile range was worth the risk.
Additional improvements included provisions for 5-inch guns to be installed at a date, an enlarged rudder to help reduce the turn radius, an additional 3-inch anti-aircraft gun on the after deck-house. The class resulted from a General Board recommendation for further destroyers to combat the submarine threat, culminating in a total of 267 Wickes- and Clemson-class destroyers completed. However, the design of the ships remained optimized for operation with the battleship fleet; the main armament was the same as the Wickes class: four 4-inch /50 caliber guns and twelve 21-inch torpedo tubes. The Mark 8 torpedo was equipped, remained the standard torpedo for this class, as 600 Mark 8 torpedoes were issued to the British in 1940 as part of the Destroyers for Bases Agreement. Although the design provided for two anti-aircraft guns, most ships carried a single 3-inch /23 caliber AA gun on the aft deckhouse. A frequent modification was replacing the aft 4-inch gun with the 3-inch gun to make more room for the depth charge tracks.
Anti-submarine armament was added after construction. Two depth charge tracks were provided aft, along with a Y-gun depth charge projector forward of the aft deckhouse. Despite the provision for 5-inch guns, only seven ships were built with an increased gun armament. USS Hovey and USS Long had twin 4-inch/50 mounts for a total of eight guns, while DD 231–235 had four 5-inch /51 caliber guns in place of the 4-inch guns; as with the preceding Wickes class, the fleet found that the tapered cruiser stern, which made for a nice depth charge deployment feature, dug into the water and increased the turning radius, thus hampering anti-submarine work. While an increased rudder size helped, the answer would be in a redesigned stern, but this was not implemented, they were reported to be prone to heavy rolling in light load conditions. The flush deck gave the hull great strength but this made the deck wet. 156 Clemson class destroyers were built, with an additional six cancelled. Fourteen ships of the class were involved in the Honda Point Disaster in 1923, of which seven were lost.
Many never saw wartime service, as a significant number were decommissioned in 1930 and scrapped as part of the London Naval Treaty. About 40 Clemson-class destroyers with Yarrow boilers were scrapped or otherwise disposed of in 1930–31, as these boilers wore out in service. Flush-deckers in reserve were commissioned as replacements. In 1936 only some 169 of the flush deck destroyers would be left, four Caldwell class and the rest Wickes and Clemson class. In 1937 four Clemson class were converted to destroyer minelayers, joining several Wickes-class ships in this role. Nineteen were transferred to the Royal Navy in 1940 as part of the Destroyers for Bases Agreement, where they became part of the Town class. Others were upgraded or converted to high-speed transports, high-speed minesweepers, destroyer minelayers, or seaplane tenders and served through World War II. Four Wickes-class DM conversions and the four Clemson-class DM conversions survived to serve in World War II. Most ships remaining in service during World War II were rearmed with dual-purpose 3-inch/50 caliber guns to provide better anti-aircraft protection.
The AVD seaplane tender conversions received two guns.
Ceremonial ship launching
Ceremonial ship launching is the process of transferring a vessel to the water. It is a naval tradition in many cultures, it has been observed as a solemn blessing. Ship launching imposes stresses on the ship not met during normal operation, in addition to the size and weight of the vessel, it represents a considerable engineering challenge as well as a public spectacle; the process involves many traditions intended to invite good luck, such as christening by breaking a sacrificial bottle of champagne over the bow as the ship is named aloud and launched. There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching"; the oldest, most familiar, most used is the end-on launch, in which the vessel slides down an inclined slipway stern first. With the side launch, the ship enters the water broadside; this method came into use in the 19th-century on inland waters and lakes, was more adopted during World War II. The third method is float-out, used for ships that are built in basins or dry docks and floated by admitting water into the dock.
If launched in a restrictive waterway drag chains are used to slow the ship speed to prevent it striking the opposite bank. Ways are arranged perpendicular to the shore line and the ship is built with its stern facing the water. Where the launch takes place into a narrow river, the building slips may be at a shallow angle rather than perpendicular though this requires a longer slipway when launching. Modern slipways take the form of a reinforced concrete mat of sufficient strength to support the vessel, with two "barricades" that extend well below the water level taking into account tidal variations; the barricades support the two launch ways. The vessel is built upon temporary cribbing, arranged to give access to the hull's outer bottom and to allow the launchways to be erected under the complete hull; when it is time to prepare for launching, a pair of standing ways is erected under the hull and out onto the barricades. The surface of the ways is greased. A pair of sliding ways is placed on top, under the hull, a launch cradle with bow and stern poppets is erected on these sliding ways.
The weight of the hull is transferred from the build cribbing onto the launch cradle. Provision is made to hold the vessel in place and release it at the appropriate moment in the launching ceremony. On launching, the vessel slides backwards down the slipway on the ways; some slipways is launched sideways. This is done where the limitations of the water channel would not allow lengthwise launching, but occupies a much greater length of shore; the Great Eastern designed by Brunel was built this way as were many landing craft during World War II. This method requires many more sets of ways to support the weight of the ship. Sometimes ships are launched using a series of inflated tubes underneath the hull, which deflate to cause a downward slope into the water; this procedure has the advantages of requiring less permanent infrastructure and cost. The airbags provide support to the hull of the ship and aid its launching motion into the water, thus this method is arguably safer than other options such as sideways launching.
These airbags are cylindrical in shape with hemispherical heads at both ends. The Xiao Qinghe shipyard launched a tank barge with marine airbags on January 20, 1981, the first known use of marine airbags. A Babylonian narrative dating from the 3rd millennium BC describes the completion of a ship: Openings to the water I stopped. Egyptians and Romans called on their gods to protect seamen. Favor was evoked from the monarch of the seas—Poseidon in Greek mythology, Neptune in Roman mythology. Ship launching participants in ancient Greece wreathed their heads with olive branches, drank wine to honor the gods, poured water on the new vessel as a symbol of blessing. Shrines were carried on board Greek and Roman ships, this practice extended into the Middle Ages; the shrine was placed at the quarterdeck, an area which continues to have special ceremonial significance. Different peoples and cultures shaped the religious ceremonies surrounding a ship launching. Jews and Christians customarily used wine and water as they called upon God to safeguard them at sea.
Intercession of the saints and the blessing of the church were asked by Christians. Ship launchings in the Ottoman Empire were accompanied by prayers to Allah, the sacrifice of sheep, appropriate feasting. Chaplain Henry Teonge of Britain's Royal Navy left an interesting account of a warship launch, a "briganteen of 23 oars," by the Knights of Malta in 1675: Two friars and an attendant went into the vessel, kneeling down prayed halfe an houre, layd their hands on every mast, other places of the vessel, sprinkled her all over with holy water, they came out and hoysted a pendent to signify she was a man of war. The liturgical aspects of ship christenings, or baptisms, continued in Catholic countries, while the Reformation seems to have put a stop to them for a time in Protestant Europe. By the 17th century, for example, English launchings were secular affairs; the christening party for the launch of the