Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service upon the United States against the naval base at Pearl Harbor in Honolulu, Hawaii on Sunday morning, December 7, 1941. The attack led to the United States' formal entry into World War II the next day; the Japanese military leadership referred to the attack as the Hawaii Operation and Operation AI, as Operation Z during its planning. Japan intended the attack as a preventive action to keep the United States Pacific Fleet from interfering with its planned military actions in Southeast Asia against overseas territories of the United Kingdom, the Netherlands, the United States. Over the course of seven hours there were coordinated Japanese attacks on the U. S.-held Philippines and Wake Island and on the British Empire in Malaya and Hong Kong. Additionally, from the Japanese viewpoint, it was seen as a preemptive strike; the attack commenced at 7:48 a.m. Hawaiian Time; the base was attacked by 353 Imperial Japanese aircraft in two waves, launched from six aircraft carriers.
All eight U. S. Navy battleships were damaged, with four sunk. All but USS Arizona were raised, six were returned to service and went on to fight in the war; the Japanese sank or damaged three cruisers, three destroyers, an anti-aircraft training ship, one minelayer. 188 U. S. aircraft were destroyed. Important base installations such as the power station, dry dock, shipyard and fuel and torpedo storage facilities, as well as the submarine piers and headquarters building, were not attacked. Japanese losses were light: 29 aircraft and five midget submarines lost, 64 servicemen killed. One Japanese sailor, Kazuo Sakamaki, was captured. Japan declared war on the United States on December 8. According to historians David M. Kennedy and Lizabeth Cohen: The sneak attack aroused and united America as nothing else could have done. To the day of the blowup, a strong majority of Americans still wanted to keep out of war, but the bombs that pulverized Pearl Harbor blasted the isolationists into silence. The only thing left to do, growled isolationist Senator Wheeler, was to'lick hell out of them.'
The following day, December 8, Congress declared war on Japan. On December 11, Germany and Italy each declared war on the U. S; the U. S. responded with a declaration of war against Italy. There were numerous historical precedents for the unannounced military action by Japan, but the lack of any formal warning while peace negotiations were still ongoing, led President Franklin D. Roosevelt to proclaim December 7, 1941, "a date which will live in infamy"; because the attack happened without a declaration of war and without explicit warning, the attack on Pearl Harbor was judged in the Tokyo Trials to be a war crime. War between Japan and the United States had been a possibility that each nation had been aware of, planned for, since the 1920s; the relationship between the two countries was cordial enough. Tensions did not grow until Japan's invasion of Manchuria in 1931. Over the next decade, Japan expanded into China, leading to the Second Sino-Japanese War in 1937. Japan spent considerable effort trying to isolate China, endeavored to secure enough independent resources to attain victory on the mainland.
The "Southern Operation" was designed to assist these efforts. Starting in December 1937, events such as the Japanese attack on USS Panay, the Allison incident, the Nanking Massacre swung Western public opinion against Japan. Fearing Japanese expansion, the United States, United Kingdom, France assisted China with its loans for war supply contracts. In 1940, Japan invaded French Indochina, attempting to stymie the flow of supplies reaching China; the United States halted shipments of airplanes, machine tools, aviation gasoline to Japan, which the latter perceived as an unfriendly act. The United States did not stop oil exports, however because of the prevailing sentiment in Washington: given Japanese dependence on American oil, such an action was to be considered an extreme provocation. In mid-1940, President Franklin D. Roosevelt moved the Pacific Fleet from San Diego to Hawaii, he ordered a military buildup in the Philippines, taking both actions in the hope of discouraging Japanese aggression in the Far East.
Because the Japanese high command was certain any attack on the United Kingdom's Southeast Asian colonies, including Singapore, would bring the U. S. into the war, a devastating preventive strike appeared to be the only way to prevent American naval interference. An invasion of the Philippines was considered necessary by Japanese war planners; the U. S. War Plan Orange had envisioned defending the Philippines with an elite force of 40,000 men. By 1941, U. S. planners expected to abandon the Philippines at the outbreak of war. Late that year, Admiral Thomas C. Hart, commander of the Asiatic Fleet, was given orders to that effect; the U. S. ceased oil exports to Japan in July 1941, following the seizure of French Indochina after the Fall of France, in part because of new American restrictions on domestic oil consumption. Because of this decision, Japan proceeded with plans to take the oil-rich Dutch East Indies. On August 17, Roosevelt warned Japan that America was prepared to take opposing steps if "neighboring countries" were attacked.
The Japanese wer
Hingham is a town in metropolitan Greater Boston on the South Shore of the U. S. state of Massachusetts in northern Plymouth County. At the 2010 census, the population was 22,157. Hingham is known for its colonial location on Boston Harbor; the town was named after Hingham, Norfolk and was first settled by English colonists in 1633. The town of Hingham was dubbed "Bare Cove" by the first colonizing English in 1633, but two years was incorporated as a town under the name "Hingham." The land on which Hingham was settled was deeded to the English by the Wampanoag sachem Wompatuck in 1655. The town was within Suffolk County from its founding in 1643 until 1803, Plymouth County from 1803 to the present; the eastern part of the town split off to become Cohasset in 1770. The town was named for Hingham, a village in the English county of Norfolk, East Anglia, whence most of the first colonists came, including Abraham Lincoln's ancestor Samuel Lincoln, his first American ancestor, who came to Massachusetts in 1637.
A statue of President Lincoln adorns the area adjacent to downtown Hingham Square. Hingham was born of religious dissent. Many of the original founders were forced to flee their native village in Norfolk with both their vicars, Rev. Peter Hobart and Rev. Robert Peck, when they fell foul of the strict doctrines of Anglican England. Peck was known for what the eminent Norfolk historian Rev. Francis Blomefield called his "violent schismatical spirit." Peck lowered the chancel railing of the church, in accord with Puritan sentiment that the Anglican church of the day was too removed from its parishioners. He antagonized ecclesiastical authorities with other forbidden practices. Hobart, born in Hingham, Norfolk, in 1604 and, like Peck, a graduate of Magdalene College, sought shelter from the prevailing discipline of the high church among his fellow Puritans; the cost to those who emigrated was steep. They "sold their possessions for half their value," noted a contemporary account, "and named the place of their settlement after their natal town."
While most of the early Hingham settlers came from Hingham and other nearby villages in East Anglia, a few Hingham settlers like Anthony Eames came from the West Country of England. The early settlers of Dorchester, for instance, had come under the guidance of Rev. John White of Dorchester in Dorset, some of them moved to Hingham. Accounts from Hingham's earliest years indicate some friction between the disparate groups, culminating in a 1645 episode involving the town's "trainband", when some Hingham settlers supported Eames, others supported Bozoan Allen, a prominent early Hingham settler and Hobart ally who came from King's Lynn in Norfolk, East Anglia. Prominent East Anglian Puritans like the Hobarts and the Cushings, for instance, were used to holding sway in matters of governance; the controversy became so heated that John Winthrop and Thomas Dudley were drawn into the fray. The bitter trainband controversy dragged on for several years. A weary Eames, in his mid-fifties when the controversy began and who had served Hingham as first militia captain, a selectman, Deputy in the General Court, threw in the towel and moved to nearby Marshfield where he again served as Deputy and emerged as a leading citizen, despite his brush with the Hingham powers-that-be.
Although the town was incorporated in 1635, the colonists didn't get around to negotiating purchase from the Wampanoag, the Native American tribe in the region, until three decades later. On July 4, 1665, the tribe's chief sachem, Josiah Wompatuck, sold the township to Capt. Joshua Hobart and Ensign John Thaxter, representatives of Hingham's colonial residents. Having occupied the land for 30 years, the Englishmen felt entitled to a steep discount; the sum promised Josiah Wompatuck for the land encompassing Hingham was to be paid by two Hingham landowners: Lieut. John Smith and Deacon John Leavitt, granted 12 acres on Hingham's Turkey Hill earlier that year. Now the two men were instructed to deliver payment for their 12-acre grant to Josiah the chief Sachem; the grant to Smith and Leavitt—who together bought other large tracts from the Native Americans for themselves and their partners—was "on condition that they satisfy all the charge about the purchase of the town's land of Josiah—Indian sagamore, both the principal purchase and all the other charge that hath been about it".
With that payment the matter was considered settled. The third town clerk of Hingham was Daniel Cushing, who emigrated to Hingham from Hingham, with his father Matthew in 1638. Cushing's meticulous records of early Hingham enabled subsequent town historians to reconstruct much of early Hingham history as well as that of the early families. Cushing was rather unusual in that he included the town's gossip along with the more conventional formal record-keeping. According to the United States Census Bureau, the town has a total area of 26.3 square miles, of which 22.2 square miles is land and 4.1 square miles, or 15.58%, is water. Hingham is bordered on the east by Cohasset, Scituate, on the south by Norwell and Rockland, on the west by Weymouth, on the north by Hingham Bay and Hull. Cohasset and Weymouth are in Norfolk County. Hingham is 14 miles southeast of downtown Boston. Hingham lies along the sou
Bofors 40 mm gun
The Bofors 40 mm gun referred to as the Bofors gun, is an anti-aircraft autocannon designed in the 1930s by the Swedish arms manufacturer AB Bofors. It was one of the most popular medium-weight anti-aircraft systems during World War II, used by most of the western Allies as well some captured systems being used by the Axis powers. A small number of these weapons remain in service to this day, saw action as late as the Persian Gulf War. In the post-war era, the original design was not suitable for action against jet-powered aircraft, so Bofors introduced a new model of more power, the 40 mm L/70. In spite of sharing nothing with the original design other than the calibre and the distinctive conical flash hider, this weapon is widely known as "the Bofors". Although not as popular as the original L/60 model, the L/70 remains in service as a multi-purpose weapon for light armoured vehicles, as on the CV 90. Bofors has been part of BAE Systems AB since March 2005; the Swedish Navy purchased a number of 2-pounder Pom-Poms from Vickers as anti-aircraft guns in 1922.
The Navy approached Bofors about the development of a more capable replacement. Bofors signed a contract in late 1928. Bofors produced a gun, a smaller version of a 57 mm semi-automatic gun developed as an anti-torpedo boat weapon in the late 19th century by Finspång, their first test gun was a re-barreled Nordenfelt version of the Finspong gun, to, added a semi-automatic loading mechanism. Testing of this gun in 1929 demonstrated that a problem existed feeding the weapon in order to maintain a reasonable rate of fire. A mechanism, strong enough to handle the stresses of moving the large round was too heavy to move enough to fire rapidly. One attempt to solve this problem used zinc shell cases; this proved to leave heavy zinc deposits in the barrel, had to be abandoned. In the summer of 1930 experiments were made with a new test gun that did away with controlled feed and instead flicked the spent casing out the rear whereafter a second mechanism reloaded the gun by "throwing" a fresh round from the magazine into the open breech.
This seemed to be the solution they needed, improving firing rates to an acceptable level, the work on a prototype commenced soon after. During this period Krupp purchased a one-third share of Bofors. Krupp engineers started the process of updating the Bofors factories to use modern equipment and metallurgy, but the 40 mm project was kept secret; the prototype was completed and fired in November 1931, by the middle of the month it was firing strings of two and three rounds. Changes to the feed mechanism were all that remained, by the end of the year it was operating at 130 rounds per minute. Continued development was needed to turn it into a weapon suitable for production, completed in October 1933. Since acceptance trials had been passed the year before, this became known as the "40 mm akan M/32". Most forces referred to it as the "Bofors 40 mm L/60", although the barrel was 56.25 calibres in length, not the 60 calibres that the name implies. The gun fired a 900 g high explosive 40 × 311R shell at 2,960 ft/s.
The rate of fire was about 120 rounds per minute, which improved when the barrels were closer to the horizontal as gravity assisted the feeding from the top-mounted magazine. In practice firing rates were closer to 80–100 rpm, as the rounds were fed into the breech from four round clips which had to be replaced by hand; the maximum attainable ceiling was 7,200 m. The gun was provided with an advanced sighting system; the trainer and layer were both provided with reflector sights for aiming, while a third crew-member standing behind them "adjusted" for lead using a simple mechanical computer. Power for the sights was supplied from a 6V battery. In spite of the successful development, the Swedish Navy changed its mind and decided it needed a smaller hand-traversed weapon of 13 mm-25 mm size, tested various designs from foreign suppliers. With the 40 mm well along in development, Bofors offered a 25 mm version in 1932, selected as the Bofors 25 mm M/32; the first version of the 40 mm the Navy ordered was intended for use on submarines, where the larger calibre allowed the gun to be used for both AA and against smaller ships.
The barrel was shorter at 42 calibers long, with the effect of reducing the muzzle velocity to about 700 m/s. When not in use, the gun retracted into a watertight cylinder; the only known submarines that used this arrangement was the Sjölejonet-class boats. The guns were removed as the subs were modified with streamlined conning towers; the first order for the "real" L/60 was made by the Dutch Navy, who ordered five twin-gun mounts for the cruiser De Ruyter in August 1934. These guns were stabilized using the Hazemeyer mount, in which one set of layers aimed the gun, while a second manually stabilized the platform the gun sat on. All five mounts were operated by one fire control system. Bofors developed a towable carriage which they displayed in April 1935 at a show in Belgium; this mount allowed the gun to be fired from the carriage with no setup required, although with limited accuracy. If time was available for setup, the gunners used the tow-bar and muzzle lock as levers, raising the wheels off the ground and thereby lowering the gun onto supporting pads.
Two additional legs folded out to the sides, the platform was leveled with hand cranks. The entire setup process could be completed in under a minute. Orders for the land based versions were immediate, starting with
Harwich is a town in Essex and one of the Haven ports, located on the coast with the North Sea to the east. It is in the Tendring district. Nearby places include Felixstowe to the northeast, Ipswich to the northwest, Colchester to the southwest and Clacton-on-Sea to the south, it is the northernmost coastal town within Essex. Its position on the estuaries of the Stour and Orwell rivers and its usefulness to mariners as the only safe anchorage between the Thames and the Humber led to a long period of maritime significance, both civil and military; the town became a naval base in 1657 and was fortified, with Harwich Redoubt, Beacon Hill Battery, Bath Side Battery. Harwich is the launch point of the Mayflower which carried English Puritans to North America, is the presumed birthplace of Mayflower captain Christopher Jones. Harwich today is contiguous with Dovercourt and the two, along with Parkeston, are referred to collectively as Harwich; the town's name means "military settlement", from Old English here-wic.
The town received its charter in 1238, although there is evidence of earlier settlement – for example, a record of a chapel in 1177, some indications of a possible Roman presence. Because of its strategic position, Harwich was the target for the invasion of Britain by William of Orange on 11 November 1688. However, unfavourable winds forced his fleet to sail into the English Channel instead and land at Torbay. Due to the involvement of the Schomberg family in the invasion, Charles Louis Schomberg was made Marquess of Harwich. Writer Daniel Defoe devotes a few pages to the town in A tour thro' the Whole Island of Great Britain. Visiting in 1722, he noted its formidable fort and harbour "of a vast extent"; the town, he recounts, was known for an unusual chalybeate spring rising on Beacon Hill, which "petrified" clay, allowing it to be used to pave Harwich's streets and build its walls. The locals claimed that "the same spring is said to turn wood into iron", but Defoe put this down to the presence of "copperas" in the water.
Regarding the atmosphere of the town, he states: "Harwich is a town of hurry and business, not much of gaiety and pleasure. Harwich played an important part in the Napoleonic and more the two world wars. Of particular note: 1793-1815—Post Office Station for communication with Europe, one of embarkation and evacuation bases for expeditions to Holland in 1799, 1809 and 1813/14; the dockyard built many ships for the Navy, including HMS Conqueror which captured the French Admiral Villeneuve at the Battle of Trafalgar. The Redoubt and the now-demolished Ordnance Building date from that era. 1914-18—base for the Royal Navy's Harwich Force light cruisers and destroyers under Commodore Tyrwhitt, for British submarines. In November 1918 the German U-Boat fleet surrendered to the Royal Navy in the harbour. 1939-1945—one of main East Coast minesweeping and destroyer bases, at one period base for British and French submarines. Harwich Dockyard was established as a Royal Navy Dockyard in 1652, it ceased to operate as a Royal Dockyard in 1713.
During the various wars with France and Holland, through to 1815, the dockyard was responsible for both building and repairing numerous warships. HMS Conqueror, a 74-gun ship completed in 1801, captured the French admiral Villeneuve at Trafalgar; the yard was a semi-private concern, with the actual shipbuilding contracted to Joseph Graham, sometimes mayor of the town. During World War II parts of Harwich were again requisitioned for naval use and ships were based at HMS Badger; the Royal Navy no longer has a presence in Harwich but Harwich International Port at nearby Parkeston continues to offer regular ferry services to the Hook of Holland in the Netherlands. Many operations of the Port of Felixstowe and of Trinity House, the lighthouse authority, are managed from Harwich; the port is famous for the phrase "Harwich for the Continent", seen on road signs and in London & North Eastern Railway advertisements. At least three pairs of lighthouses have been built over recent centuries as leading lights, to help guide vessels into Harwich.
The earliest pair were wooden structures: the High Light stood on top of the old Town Gate, whilst the Low Light stood on the foreshore. Both were coal-fired. In 1818 these were replaced by stone structures, designed by John Rennie Senior, which can still be seen today, they were owned by General Rebow of Wivenhoe Park, able to charge 1d per ton on all cargo entering the port, for upkeep of the lights. In 1836 Rebow's lease on the lights was purchased by Trinity House, but in 1863 they were declared redundant due to a change the position of the channel used by ships entering and leaving the port, caused by shifting sands, they were in turn replaced by the pair of cast iron lights at nearby Dovercourt. Despite, or because of, its small size Harwich is regarded in terms of architectural heritage, the whole of the older part of the town, excluding Navyard Wharf, is a conservation area; the regular street plan with principal thoroughfares connected b
A high pressure watertube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace. In smaller boilers, additional generating tubes are separate in the furnace, while larger utility boilers rely on the water-filled tubes that make up the walls of the furnace to generate steam. High Pressure Water Tube Boiler: The heated water rises into the steam drum. Here, saturated steam is drawn off the top of the drum. In some services, the steam will reenter the furnace through a superheater to become superheated. Superheated steam is defined as steam, heated above the boiling point at a given pressure. Superheated steam is a dry gas and therefore used to drive turbines, since water droplets can damage turbine blades. Cool water at the bottom of the steam drum returns to the feedwater drum via large-bore'downcomer tubes', where it pre-heats the feedwater supply.. To increase economy of the boiler, exhaust gases are used to pre-heat the air blown into the furnace and warm the feedwater supply.
Such watertube boilers in thermal power stations are called steam generating units. The older fire-tube boiler design, in which the water surrounds the heat source and gases from combustion pass through tubes within the water space, is a much weaker structure and is used for pressures above 2.4 MPa. A significant advantage of the watertube boiler is that there is less chance of a catastrophic failure: there is not a large volume of water in the boiler nor are there large mechanical elements subject to failure. A water tube boiler was patented by Blakey of England in 1766 and was made by Dallery of France in 1780. “The ability of watertube boilers to generate superheated steam makes these boilers attractive in applications that require dry, high-pressure, high-energy steam, including steam turbine power generation”. Owing to their superb working properties, the use of watertube boilers is preferred in the following major areas: Variety of process applications in industries Chemical processing divisions Pulp and Paper manufacturing plants Refining unitsBesides, they are employed in power generation plants where large quantities of steam having high pressures i.e. 16 megapascals and high temperatures reaching up to 550 °C are required.
For example, the Ivanpah solar-power station uses two Rentech Type-D watertube boilers. Modern boilers for power generation are entirely water-tube designs, owing to their ability to operate at higher pressures. Where process steam is required for heating or as a chemical component there is still a small niche for fire-tube boilers, their ability to work at higher pressures has led to marine boilers being entirely water-tube. This change began around 1900, traced the adoption of turbines for propulsion rather than reciprocating engines – although watertube boilers were used with reciprocating engines. There has been no significant adoption of water-tube boilers for railway locomotives. A handful of experimental designs were produced, but none of these were successful or led to their widespread use. Most water-tube railway locomotives in Europe, used the Schmidt system. Most were compounds, a few uniflows; the Norfolk and Western Railway's Jawn Henry was an exception, as it used a steam turbine combined with an electric transmission.
LMS 6399 FuryRebuilt after a fatal accidentLNER 10000 "Hush hush"Using a Yarrow boiler, rather than Schmidt. Never successful and re-boilered with a conventional boiler. A more successful adoption was the use of hybrid water-tube / fire-tube systems; as the hottest part of a locomotive boiler is the firebox, it was an effective design to use a water-tube design here and a conventional fire-tube boiler as an economiser in the usual position. One famous example of this was the USA Baldwin 4-10-2 No. 60000, built in 1926. Operating as a compound at a boiler pressure of 2,400 kilopascals it covered over 160,000 kilometres successfully. After a year though, it became clear that any economies were overwhelmed by the extra costs and it was retired to become a stationary plant. A series of twelve experimental locomotives were constructed at the Baltimore and Ohio Railroad's Mt. Clare shops under the supervision of George H. Emerson, but none of them was replicated in any numbers; the only railway use of water-tube boilers in any numbers was the Brotan boiler, invented in Austria in 1902 by Johann Brotan and found in rare examples throughout Europe.
Hungary, was a keen user and had around 1,000 of them. Like the Baldwin, this combined a water-tube firebox with a fire-tube barrel; the original characteristic of the Brotan was a long steam drum running above the main barrel, making it resemble a Flaman boiler in appearance. While the traction engine was built using its locomotive boiler as its frame, other types of steam road vehicles such as lorries and cars have used a wide range of different boiler types. Road transport pioneers Goldsworthy Gurney and Walter Hancock both used water-tube boilers in their steam carriages around 1830. Most undertype wagons used water-tube boilers. Many manufacturers used variants of the vertical cross-tube boiler, including Atkinson, Clayton and Sentinel. Other types include the Clarkson'thimble tube' and the Foden O-type wagon's pistol-shaped boiler. Steam fire-engine makers such as Merryweather used water-tube boilers for their rapid
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
Oerlikon 20 mm cannon
The Oerlikon 20 mm cannon is a series of autocannons, based on an original German 20 mm Becker design that appeared early in World War I. It was produced by Oerlikon Contraves and others, with various models employed by both Allied and Axis forces during World War II, many versions still in use today. During World War I, the German industrialist Reinhold Becker developed a 20 mm caliber cannon, known now as the 20 mm Becker using the Advanced Primer Ignition blowback method of operation; this had a cyclic rate of fire of 300 rpm. It was used on a limited scale as an aircraft gun on Luftstreitkräfte warplanes, an anti-aircraft gun towards the end of that war; because the Treaty of Versailles banned further production of such weapons in Germany, the patents and design works were transferred in 1919 to the Swiss firm SEMAG based near Zürich. SEMAG continued development of the weapon, in 1924 had produced the SEMAG L, a heavier weapon that fired more powerful 20x100RB ammunition at a higher rate of fire, 350 rpm.
In 1924 SEMAG failed. The Oerlikon firm, named after the Zürich suburb of Oerlikon where it was based acquired all rights to the weapon, plus the manufacturing equipment and the employees of SEMAG. In 1927 the Oerlikon S was added to the existing product line; this fired a still larger cartridge to achieve a muzzle velocity of 830 m/s, at the cost of increased weight and a reduced rate of fire. The purpose of this development was to improve the performance of the gun as an anti-tank and anti-aircraft weapon, which required a higher muzzle velocity. An improved version known as the 1S followed in 1930. Three sizes of gun with their different ammunition and barrel length, but similar mechanisms, continued to be developed in parallel. In 1930 Oerlikon reconsidered the application of its gun in aircraft and introduced the AF and AL, designed to be used in flexible mounts, i.e. manually aimed by a gunner. The 15-round box magazine used by earlier versions of the gun was replaced by drum magazine holding 15 or 30 rounds.
In 1935 it made an important step by introducing a series of guns designed to be mounted in or on the wings of fighter aircraft. Designated with FF for Flügelfest meaning "wing-mounted", these weapons were again available in the three sizes, with designations FF, FFL and FFS; the FF fired a larger cartridge than the AF, 20x72RB, but the major improvement in these weapons was a significant increase in rate of fire. The FF weighed 24 kg and achieved a muzzle velocity of 550 to 600 m/s with a rate of fire of 520 rpm; the FFL of 30 kg fired a projectile at a muzzle velocity of 675 m/s with a rate of fire of 500 rpm. And the FFS, which weighed 39 kg, delivered a high muzzle velocity of 830 m/s at a rate of fire of 470 rpm. Apart from changes to the design of the guns for wing-mounting and remote control, larger drums were introduced as it would not be possible to exchange magazines in flight. For the FF series drum sizes of 45, 60, 75 and 100 rounds were available, but most users chose the 60-round drum.
The 1930s were a period of global re-armament, a number of foreign firms took licenses for the Oerlikon family of aircraft cannon. In France, Hispano-Suiza manufactured development of the FFS as the Hispano-Suiza HS.7 and Hispano-Suiza HS.9, for installation between the cylinder banks of its V-12 engines. In Germany, Ikaria further developed the FF gun as firing 20x80RB ammunition, and the Imperial Japanese Navy, after evaluating all three guns, ordered developments of the FF and FFL as the Type 99-1 and Type 99-2. The incorporation of the improvements of the FFS in a new anti-aircraft gun produced, in 1938, the Oerlikon SS. Oerlikon realized further improvements in rate of fire on the 1SS of 1942, the 2SS of 1945 which achieved 650 rpm. However, it was the original SS gun, adopted as anti-aircraft gun, being widely used by Allied navies during World War II; this gun used a 400-grain charge of IMR 4831 smokeless powder to propel a 2,000-grain projectile at 2,800 feet per second. The Oerlikon FF was installed as armament on some fighters of the 1930s, such as the Polish PZL P.24G.
Locally produced derivatives of the Oerlikon cannon were used much more extensively, on aircraft, on ships and on land. In the air, the Ikaria MG FF was used as armament on a number of German aircraft, of which the most famous is the Messerschmitt Bf 109; the Japanese Navy used their copy of the FF, designated the Type 99 Mark One cannon on a number of types including the Mitsubishi A6M Zero. In the war, they equipped fighters including the Zero with the Type 99 Mark Two, a version of the more powerful and faster-firing Oerlikon FFL; the French firm of Hispano-Suiza was a manufacturer of aircraft engines, it marketed the moteur-canon combination of its 12X and 12Y engines with a H. S.7 or H. S.9 cannon installed between the cylinder banks. The gun fired through the hollow propeller hub, this being elevated above the crankcase by the design of the gearing; such armament was installed on the Morane-Saulnier M. S.406 and some other types. Similar German installations of the MG FF were not successful.
The Oerlikon became best known in its naval applications. The Oerlikon was not looked upon favorably by the Royal Navy as a short-range anti-aircraft gun. All through 1937-1938 Lord Louis Mountbatten a Captain in the Royal Navy, waged a lone campaign within the Royal Navy to set up an unprejudiced trial for the Oerlikon 20 mm gun, but it was all in vain, it was not until the Commander-in-Chief of the Home Fleet, Admiral Sir Roger Backhouse, was appointed First Sea Lord tha