1.
Naval artillery
–
Naval artillery is artillery mounted on a warship, originally used only for naval warfare, later also for naval gunfire support against targets on land, and for anti-aircraft use. The idea of artillery dates back to the classical era. Julius Caesar indicates the use of ship-borne catapults against Britons ashore in his Commentarii de Bello Gallico, the dromons of the Byzantine Empire carried catapults and fire-throwers. From the late Middle Ages onwards, warships began to carry cannon of various calibres, the Battle of Arnemuiden, fought between England and France in 1338 at the start of the Hundred Years War, was the first recorded European naval battle using artillery. The English ship Christopher was armed with three cannons and one hand gun, by the 15th century most Mediterranean powers were utilising heavy cannon mounted on the bow or stern of a vessel and designed to bombard fortresses on shore. By mid-century some vessels also carried smaller broadside cannons for bombarding other vessels immediately prior to an attempted boarding and these small guns were anti-personnel weapons and were fired at point blank range to accompany engagement with muskets or bows. From the 1470s both the Portuguese and Venetian navies were experimenting with cannons as anti-ship weapons, in 1489 John of Portugal further contributed to the development of naval artillery by establishing the first standardized teams of trained naval gunners. The 16th century was an era of transition in naval warfare, since ancient times, war at sea had been fought much like that on land, with melee weapons and bows and arrows, but on floating wooden platforms rather than battlefields. Though the introduction of guns was a significant change, it slowly changed the dynamics of ship-to-ship combat. As guns became heavier and able to more powerful gunpowder charges, they needed to be placed lower in the ship. Although some 16th-century galleys mounted broadside cannon, they did so at the expense of rowing positions which sacrificed speed, most early cannon were still placed in the forecastle and aftercastle of a ship where they might be conveniently pointed in any direction. Early naval artillery was a weapon to deter boarders, because cannon powerful enough to damage ships were heavy enough to destabilize any ship mounting them in an elevated castle. Being a crown industry, cost considerations did not curb the pursuit of the best quality, best innovations, the crown paid wage premiums and bonuses to lure the best European artisans and gunners to advance the industry in Portugal. This made broadsides, coordinated volleys from all the guns on one side of a ship, possible for the first time in history, at least in theory. Ships, such as Mary Rose, carried a mixture of cannon of different types and sizes, many designed for land use, and using incompatible ammunition at different ranges and rates of fire. The Mary Rose, like other ships of the time, was built during a period of development of heavy artillery. The heavy armament was a mix of older-type wrought iron and cast bronze guns, the bronze guns were cast in one piece and rested on four-wheel carriages which were essentially the same as those used until the 19th century. The breech-loaders were cheaper to produce and both easier and faster to reload, but could take less powerful charges than cast bronze guns, the majority of the guns were small iron guns with short range that could be aimed and fired by a single person
2.
Coastal artillery
–
Coastal artillery is the branch of the armed forces concerned with operating anti-ship artillery or fixed gun batteries in coastal fortifications. The advent of 20th-century technologies, especially aviation, naval aviation, jet aircraft, and guided missiles, reduced the primacy of cannon, battleships. In countries where coastal artillery has not been disbanded, these forces have acquired amphibious capabilities, in littoral warfare, mobile coastal artillery armed with surface-to-surface missiles still can be used to deny the use of sea lanes. Land-based guns also benefited in most cases from the protection of walls or earth mounds. The Martello tower is an excellent example of a widely used coastal fort which mounted defensive artillery, during the 19th century China also built hundreds of coastal fortresses in an attempt to counter Western naval threats. Coastal artillery could be part of the Navy, or part of the Army, in English-speaking countries, certain coastal artillery positions were sometimes referred to as Land Batteries, distinguishing this form of artillery battery from for example floating batteries. In the United Kingdom, in the later 19th and earlier 20th Centuries, then, following the Spanish–American War and the report of the Endicott Board, U. S. harbor defenses were greatly strengthened and provided with new, rifled artillery and minefield defenses. Shortly thereafter, in 1907, Congress split the field artillery, the first decade of the 20th Century, the United States Marine Corps established the Advanced Base Force. The force was used for setting up and defending advanced bases, during the Siege of Port Arthur, Japanese forces had captured the vantage point on 203 Meter Hill overlooking Port Arthur harbor. The battleship Sevastopol, although hit 5 times by 11-inch shells, after 3 weeks, the Sevastopol was still afloat, having survived 124 torpedoes fired at her while sinking two Japanese destroyers and damaging six other vessels. The Japanese had meanwhile lost the cruiser Takasago to a mine outside the harbor, the Blücher had entered the narrow waters of the Oslofjord, carrying 1,000 soldiers and leading a German invasion fleet. The first salvo from the Norwegian defenders, fired from Oscarsborg Fortress about 1 mile distant, disabled Blüchers main battery, fire from the smaller guns swept her decks and disabled her steering, and she received several torpedo hits before the fires reached her magazines and doomed her. Singapore was defended by its famous large-caliber coastal guns, which included one battery of three 15-inch guns and one with two 15-inch guns, AP shells were designed to penetrate the hulls of heavily armoured warships and were ineffective against personnel. The Japanese defended the island of Betio in the Tarawa atoll with numerous 203 mm coastal guns, in 1943, these were knocked out early in the battle with a combined USN naval and aerial bombardment. Nazi Germany fortified its conquered territories with the Atlantic Wall, the intent was to destroy the Allied landing craft before they could unload. During the Normandy Landings in 1944, shore bombardment was given a high importance, using ships from battleships to destroyers, for example, the Canadians at Juno beach had fire support many times greater than they had had for the Dieppe Raid in 1942. In addition, there were modified landing-craft, eight Landing Craft Gun, twenty-four Landing Craft Tank carried Priest self-propelled howitzers which also fired while they were on the run-in to the beach. Similar arrangements existed at other beaches, on June 25,1944 the American battleship Texas engaged German shore batteries on the Cotentin Peninsula
3.
Railway gun
–
A railway gun, also called a railroad gun, is a large artillery piece, often surplus naval artillery, mounted on, transported by, and fired from a specially designed railway wagon. Many countries have built railway guns, but the best known are the large Krupp-built pieces used by Germany in World War I, smaller guns were often part of an armoured train. Railway guns have been rendered obsolete by advances in technology and their large size and limited mobility make them vulnerable to attack, and similar payloads can be delivered by aircraft, rocket, or missile. The design of a gun has three issues over and above those of an ordinary artillery piece to consider. The first method of traverse is to rely entirely on movement along a section of track or on a turntable with no provision to traverse the gun on its mount. The second is to traverse the rail car body on its trucks, generally this is limited to a few degrees of traverse to either side unless an elaborate foundation is built with a centre pivot and traversing rollers. The design of the foundation is the limit to the amount of traverse allowed in this latter case. The third choice is to allow the gun mount to rotate with respect to the rail car body. This usually requires the gun to be mounted on a pivot which. There are four methods to absorb the recoil force for railway guns, cradle recoil, top-carriage recoil, sliding recoil. Cradle recoil means that the gun recoils backward in its cradle and it is returned to battery, or the firing position, by either helical springs or by air in a pneumatic recuperator cylinder that is compressed by the force of recoil. This is the most common used for lighter railroad guns. Top-carriage recoil is where the gun is mounted in a carriage that moves on wheels on fixed rails. The gun and upper carriage recoil together, restrained by the hydraulic buffers. Return to battery is effected either by gravity, through the use of inclined rails and it is not well-suited to firing at high elevations because it cannot absorb much of the vertical component of the recoil force. The gun, car body and trucks all recoil together with the friction generated by the sliding on the girders absorbing the recoil force after moving only about 1 to 2 metres to the rear. The sleepers must be jacked up again to allow the gun to roll forward to its firing position and this was often done by handwheels driving gear trains attached to the wheels, or even by electric motors on more modern mounts. Almost all of type of mounts were of the non-traversing type and had to be fired from a curved section of track or turntable
4.
Soviet Union
–
The Soviet Union, officially the Union of Soviet Socialist Republics was a socialist state in Eurasia that existed from 1922 to 1991. It was nominally a union of national republics, but its government. The Soviet Union had its roots in the October Revolution of 1917 and this established the Russian Socialist Federative Soviet Republic and started the Russian Civil War between the revolutionary Reds and the counter-revolutionary Whites. In 1922, the communists were victorious, forming the Soviet Union with the unification of the Russian, Transcaucasian, Ukrainian, following Lenins death in 1924, a collective leadership and a brief power struggle, Joseph Stalin came to power in the mid-1920s. Stalin suppressed all opposition to his rule, committed the state ideology to Marxism–Leninism. As a result, the country underwent a period of rapid industrialization and collectivization which laid the foundation for its victory in World War II and postwar dominance of Eastern Europe. Shortly before World War II, Stalin signed the Molotov–Ribbentrop Pact agreeing to non-aggression with Nazi Germany, in June 1941, the Germans invaded the Soviet Union, opening the largest and bloodiest theater of war in history. Soviet war casualties accounted for the highest proportion of the conflict in the effort of acquiring the upper hand over Axis forces at battles such as Stalingrad. Soviet forces eventually captured Berlin in 1945, the territory overtaken by the Red Army became satellite states of the Eastern Bloc. The Cold War emerged by 1947 as the Soviet bloc confronted the Western states that united in the North Atlantic Treaty Organization in 1949. Following Stalins death in 1953, a period of political and economic liberalization, known as de-Stalinization and Khrushchevs Thaw, the country developed rapidly, as millions of peasants were moved into industrialized cities. The USSR took a lead in the Space Race with Sputnik 1, the first ever satellite, and Vostok 1. In the 1970s, there was a brief détente of relations with the United States, the war drained economic resources and was matched by an escalation of American military aid to Mujahideen fighters. In the mid-1980s, the last Soviet leader, Mikhail Gorbachev, sought to reform and liberalize the economy through his policies of glasnost. The goal was to preserve the Communist Party while reversing the economic stagnation, the Cold War ended during his tenure, and in 1989 Soviet satellite countries in Eastern Europe overthrew their respective communist regimes. This led to the rise of strong nationalist and separatist movements inside the USSR as well, in August 1991, a coup détat was attempted by Communist Party hardliners. It failed, with Russian President Boris Yeltsin playing a role in facing down the coup. On 25 December 1991, Gorbachev resigned and the twelve constituent republics emerged from the dissolution of the Soviet Union as independent post-Soviet states
5.
Gun barrel
–
A gun barrel is a part of firearms and artillery pieces. The hollow interior of the barrel is called the bore, a gun barrel must be able to hold in the expanding gas produced by the propellants to ensure that optimum muzzle velocity is attained by the projectile as it is being pushed out by the expanding gas. Modern small arms barrels are made of known and tested to withstand the pressures involved. Artillery pieces are made by various techniques providing reliably sufficient strength, early firearms were muzzle-loading, with powder, and then shot loaded from the muzzle, capable of only a low rate of fire. During the 19th century effective mechanical locks were invented that sealed a breech-loading weapon against the escape of propellant gases, the early Chinese, the inventors of gunpowder, used bamboo, a naturally tubular stalk, as the first barrels in gunpowder projectile weapons. Early European guns were made of iron, usually with several strengthening bands of the metal wrapped around circular wrought iron rings. The Chinese were the first to master cast-iron cannon barrels, early cannon barrels were very thick for their caliber. Bore evacuator Bore snake Cannon Muzzle Polygonal rifling Rifling Slug barrel Smoothbore
6.
Shell (projectile)
–
A shell is a payload-carrying projectile that, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot. Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used, originally, it was called a bombshell, but shell has come to be unambiguous in a military context. Words cognate with grenade are still used for an artillery or mortar projectile in some European languages, shells are usually large-calibre projectiles fired by artillery, combat vehicles, and warships. Shells usually have the shape of a cylinder topped by a nose for good aerodynamic performance, possibly with a tapering base. Solid cannonballs did not need a fuse, but hollow munitions filled with something such as gunpowder to fragment the ball, needed a fuse, percussion fuses with a spherical projectile presented a challenge because there was no way of ensuring that the impact mechanism hit the target. Therefore, shells needed a fuse that was ignited before or during firing. The earliest record of shells being used in combat was by the Republic of Venice at Jadra in 1376, shells with fuses were used at the 1421 siege of St Boniface in Corsica. These were two hollowed hemispheres of stone or bronze held together by an iron hoop, as described in their book, these hollow, gunpowder-packed shells were made of cast iron. At least since the 16th Century grenades made of ceramics or glass were in use in Central Europe, a hoard of several hundred ceramic greandes were discovered during building works in front of a bastion of the Bavarian City of Ingolstadt, Germany dated to the 17th Century. Lots of the grenades obtained their orignal blackpowder loads and igniters, most probably the grenades were intentionally dumped the moat of the bastion before the year 1723. Early powder burning fuses had to be loaded fuse down to be ignited by firing or a portfire put down the barrel to light the fuse, other shells were wrapped in bitumen cloth, which would ignite during the firing and in turn ignite a powder fuse. Nevertheless, shells came into use in the 16th Century. By the 18th Century, it was known that the fuse towards the muzzle could be lit by the flash through the windage between the shell and the barrel, the use of exploding shells from field artillery became relatively commonplace from early in the 19th century. Until the mid 19th century, shells remained as simple exploding spheres that used gunpowder and they were usually made of cast iron, but bronze, lead, brass and even glass shell casings were experimented with. The word bomb encompassed them at the time, as heard in the lyrics of The Star-Spangled Banner, typically, the thickness of the metal body was about a sixth of their diameter and they were about two thirds the weight of solid shot of the same calibre. To ensure that shells were loaded with their fuses towards the muzzle, in 1819, a committee of British artillery officers recognised that they were essential stores and in 1830 Britain standardised sabot thickness as a half inch. The sabot was also intended to reduce jamming during loading, despite the use of exploding shell, the use of smoothbore cannons, firing spherical projectiles of shot, remained the dominant artillery method until the 1850s. By the late 18th century, artillery could use canister shot to defend itself from infantry or cavalry attack and this involved loading a tin or canvas container filled with small iron or lead balls instead of the usual cannonball
7.
Soviet Navy
–
The Soviet Navy was the naval arm of the Soviet Armed Forces. The influence of the Soviet Navy played a role in the Cold War. The Soviet Navy was divided into four major fleets, the Northern, Pacific, Black Sea, the Caspian Flotilla was a smaller force operating in the land-locked Caspian Sea. Main components of the Soviet Navy included Soviet Naval Aviation, Naval Infantry, most of the Soviet Navy was reformed into the Russian Navy after the dissolution of the Soviet Union in 1991, while some elements became the basis of the Ukrainian, Azerbaijani and Georgian navies. During the revolution, sailors deserted their ships at will and generally neglected their duties, the officers were dispersed and most of the sailors left their ships. Work stopped in the shipyards, where uncompleted ships deteriorated rapidly, the Black Sea Fleet fared no better than the Baltic. The Bolshevik revolution entirely disrupted its personnel, with murders of officers. At the end of April 1918, German troops entered Crimea, the more effective ships were moved from Sevastopol to Novorossiysk where, after an ultimatum from Germany, they were scuttled by Vladimir Lenins order. The ships remaining in Sevastopol were captured by the Germans and then, after November 1918, on 1 April 1919, when Red Army forces captured Crimea, the British squadron had to withdraw, but before leaving they damaged all the remaining battleships and sank thirteen new submarines. When the White Army captured Crimea in 1919, it rescued and reconditioned a few units, at the end of the civil war, Wrangels fleet, a White fleet, moved to Bizerta in French Tunisia, where it was interned. The first ship of the navy could be considered the rebellious Imperial Russian cruiser Aurora. Sailors of the Baltic fleet supplied the fighting force of the Bolsheviks during the October Revolution, some imperial vessels continued to serve after the revolution, albeit with different names. The Soviet Navy, established as the Workers and Peasants Red Fleet by a 1918 decree of the Soviet government, was less than service-ready during the interwar years, as the countrys attentions were largely directed internally, the Navy did not have much funding or training. The greater part of the old fleet was sold by the Soviet government to Germany for scrap, in the Baltic Sea there remained only three much-neglected battleships, two cruisers, some ten destroyers, and a few submarines. Despite this state of affairs, the Baltic Fleet remained a significant naval formation, there also existed some thirty minor-waterways combat flotillas. During the 1930s, as the industrialization of the Soviet Union proceeded, approved by the Labour and Defence Council in 1926, the Naval Shipbuilding Program included plans to construct twelve submarines, the first six were to become known as the Dekabrist class. Beginning 4 November 1926, Technical Bureau Nº4, under the leadership of B. M, malinin, managed the submarine construction works at the Baltic Shipyard. In subsequent years,133 submarines were built to designs developed during Malinins management, additional developments included the formation of the Pacific Fleet in 1932 and the Northern Fleet in 1933
8.
Russian Civil War
–
The Russian Civil War was a multi-party war in the former Russian Empire immediately after the Russian Revolutions of 1917, as many factions vied to determine Russias political future. In addition, rival militant socialists and nonideological Green armies fought against both the Bolsheviks and the Whites, eight foreign nations intervened against the Red Army, notably the Allied Forces and the pro-German armies. The Red Army defeated the White Armed Forces of South Russia in Ukraine, the remains of the White forces commanded by Pyotr Nikolayevich Wrangel were beaten in Crimea and evacuated in late 1920. Lesser battles of the war continued on the periphery for two years, and minor skirmishes with the remnants of the White forces in the Far East continued well into 1923. Armed national resistance in Central Asia was not completely crushed until 1934, there were an estimated 7,000, 000–12,000,000 casualties during the war, mostly civilians. The Russian Civil War has been described by some as the greatest national catastrophe that Europe had yet seen, many pro-independence movements emerged after the break-up of the Russian Empire and fought in the war. Several parts of the former Russian Empire—Finland, Estonia, Latvia, Lithuania, the rest of the former Russian Empire was consolidated into the Soviet Union shortly afterwards. After the abdication of Tsar Nicholas II of Russia, the Russian Provisional Government was established during the February Revolution of 1917, Political commissars were appointed to each unit of the army to maintain morale and ensure loyalty. In June 1918, when it became apparent that an army composed solely of workers would be far too small. Former Tsarist officers were utilized as military specialists, sometimes their families were taken hostage in order to ensure their loyalty, at the start of the war three-quarters of the Red Army officer corps was composed of former Tsarist officers. By its end, 83% of all Red Army divisional and corps commanders were ex-Tsarist soldiers, a Ukrainian nationalist movement was active in Ukraine during the war. More significant was the emergence of an anarchist political and military movement known as the Revolutionary Insurrectionary Army of Ukraine or the Anarchist Black Army led by Nestor Makhno, some of the military forces were set up on the basis of clandestine officers organizations in the cities. The Czechoslovak Legions had been part of the Russian army and numbered around 30,000 troops by October 1917 and they had an agreement with the new Bolshevik government to be evacuated from the Eastern Front via the port of Vladivostok to France. The transport from the Eastern Front to Vladivostok slowed down in the chaos, under pressure from the Central Powers, Trotsky ordered the disarming and arrest of the legionaries, which created tensions with the Bolsheviks. The Western Allies armed and supported opponents of the Bolsheviks, hence, many of these countries expressed their support for the Whites, including the provision of troops and supplies. Winston Churchill declared that Bolshevism must be strangled in its cradle, the British and French had supported Russia during World War I on a massive scale with war materials. After the treaty, it looked like much of material would fall into the hands of the Germans. Under this pretext began allied intervention in the Russian Civil War with the United Kingdom, there were violent clashes with troops loyal to the Bolsheviks
9.
Imperial Russian Navy
–
It was expanded in the second half of the 18th century and by the early part of the 19th century had reached its peak strength, only behind the British and French fleets in terms of size. The First World War was mixed for the navy, with the Germans generally gaining the upper hand in the Baltic but the Black Sea falling under Russian control. The Russian Revolution marked the end of the Imperial Navy with its sailors fighting on both sides and its surviving ships forming the core of the Soviet Navy upon its creation in 1918. Under Tsar Mikhail I, construction of the first three-masted ship actually built within Russia was completed in 1636 and it was built in Balakhna by Danish shipbuilders from Holstein according to European design and was christened Frederick. During its maiden voyage on the Caspian Sea, Frederick sailed into a storm and was lost at sea. A boyar named Afanasy Ordin-Nashchokin founded a shipyard at Tsarevich-Dmitriev fortress, in 1661, however, Russia was once again forced to abide by the harsh terms of a treaty, this time the Peace of Cardis. Russia agreed to surrender to Sweden all captured territories, and all constructed at Tsarevich-Dmitriev were ordered destroyed. Boyar Ordin-Nashchyokin, not grieving long over defeat, turned his attention to the Volga River, with the Tsars approval, the boyar brought Dutch shipbuilding experts to the town of Dedinovo near the confluence of the Oka and Volga Rivers. Shipbuilding commenced in the winter of 1667, within two years, four vessels had been completed, one 22-gun galley, christened Орёл, and three smaller ships. The ill-fated Frederick had been a Holstein vessel, Орёл became Russias first own three-masted, European-designed sailing ship, the ship was captured in Astrakhan by rebellious Cossacks led by Stepan Razin. The Cossacks ransacked Орёл and abandoned it, half-submerged, in an estuary of the Volga, unquestionably, the most celebrated Russian explorer was Semyon Dezhnev, who, in 1648, sailed the entire length of present-day Russia by way of the Arctic Ocean. Rounding the Chukotsk Peninsula, Dezhnev passed through the Bering Sea, the creation of the regular Russian Navy took place during the reign of Peter the Great. During the Second Azov campaign of 1696 against Turkey, the Russians employed for the first time 2 warships,4 fireships,23 galleys and 1300 strugs, built on the Voronezh River. After the occupation of the Azov fortress, the Boyar Duma looked into Peters report of military campaign. This date is considered the birthday of the regular Russian Navy. During the Great Northern War of 1700-1721, the Russians built the Baltic Fleet, the construction of the oared fleet took place in 1702-1704 at several shipyards. From 1703-1723, the base of the Baltic Fleet was located in Saint Petersburg. The bases were created in Reval and in Vyborg after it was ceded from Sweden after the war of 1741-43
10.
October Revolution
–
It took place with an armed insurrection in Petrograd on 25 October 1917. During this time, urban workers began to organize into councils wherein revolutionaries criticized the provisional government and this immediately initiated the establishment of the Russian Socialist Federative Soviet Republic, the worlds first self-proclaimed socialist state. The revolution was led by the Bolsheviks, who used their influence in the Petrograd Soviet to organize the armed forces, Bolshevik Red Guards forces under the Military Revolutionary Committee began the takeover of government buildings on 24 October 1917. The following day, the Winter Palace, was captured, the long-awaited Constituent Assembly elections were held on 12 November 1917. The Bolsheviks only won 175 seats in the 715-seat legislative body, coming in second behind the Socialist Revolutionary party, the Constituent Assembly was to first meet on 28 November 1917, but its convocation was delayed until 5 January 1918 by the Bolsheviks. On its first and only day in session, the body rejected Soviet decrees on peace and land, as the revolution was not universally recognized, there followed the struggles of the Russian Civil War and the creation of the Soviet Union in 1922. At first, the event was referred to as the October coup or the Uprising of 25th, in Russian, however, переворот has a similar meaning to revolution and also means upheaval or overturn, so coup is not necessarily the correct translation. With time, the term October Revolution came into use and it is also known as the November Revolution having occurred in November according to the Gregorian Calendar. The Great October Socialist Revolution was the name for the October Revolution in the Soviet Union after the 10th anniversary of the Revolution in 1927. The February Revolution had toppled Tsar Nicolas II of Russia, however, the provisional government was weak and riven by internal dissension. It continued to wage World War I, which became increasingly unpopular, a nationwide crisis developed in Russia, affecting social, economic, and political relations. Disorder in industry and transport had intensified, and difficulties in obtaining provisions had increased, gross industrial production in 1917 had decreased by over 36% from what it had been in 1914. In the autumn, as much as 50% of all enterprises were closed down in the Urals, the Donbas, at the same time, the cost of living increased sharply. Real wages fell about 50% from what they had been in 1913, russias national debt in October 1917 had risen to 50 billion rubles. Of this, debts to foreign governments constituted more than 11 billion rubles, the country faced the threat of financial bankruptcy. In these months alone, more than a million took part in strikes. Workers established control over production and distribution in many factories and plants in a social revolution, by October 1917, there had been over 4,000 peasant uprisings against landowners. When the Provisional Government sent punitive detachments, it only enraged the peasants
11.
Glossary of British ordnance terms
–
This article explains terms used for the British Armed Forces ordnance and also ammunition. The terms may have different meanings in the military of other countries. Between decks, applies to a gun mounting in which part of the rotating mass is below the deck. This allows for a profile of turret, meaning that turrets need not be superfiring The term BL, in its general sense, stood for breech loading. The shell was loaded via the breech followed by the propellant charge, sealing the chamber to prevent escape of the propellant gases. The term BL was first used to refer to the Armstrong breechloaders, following the discontinuation of Armstrong breechloaders and the period of British rifled muzzle-loaders, British breechloaders were re-introduced in 1880. Early British Elswick breechloaders in the 1880s used a steel cup obturation method and this was quickly superseded in guns designed by the Royal Gun Factory by the French de Bange method, the basic principle of which is still in use today. In British service this became a Crossley pad with an interrupted thread screw block e. g. a Welin screw, the shell was loaded via the breech, followed by the propellant charge in a cloth bag. A single-use vent sealing tube, a type of primer not dissimilar in appearance to a rifle round, was inserted into the breech for firing the gun. For instance, Britain before World War I had both QF and BL6 inch guns and this presented difficulties for BL guns at high angles. A special cartridge was developed for BL9.2 inch guns on H. A. mountings, using multiple small fabric bags also allows the gunners to use a reduced charge if need be. The term BLC stood for BL converted and referred to a breech and breech mechanism modified from an early long-screw three- or four-motion to modern short-screw single-motion, an example is the conversion of the BL15 pounder to BLC15 pounder. Calibre radius head, the radius of a circle with the curve of the nose on its circumference. The longer and more pointed the nose, the higher the C. R. H. Typical C. R. H. for British shells leading up to World War I was two, e. g. the curve of the nose of a two C. R. H. Six-inch shell was equivalent to the curve of a circle with a radius of 12 inches, shells of four C. R. H. were soon developed in World War I, identified by an A following the shell mark number, B for six and so on. For modern streamlined shells post-World War I, two numbers were necessary to more correctly denote a shells C. R. H, for instance, the World War I6 inch 26 cwt howitzer shell was two C. R. H. The World War II Mk 2D shell was correctly described as 5/10 C. R. H, in this use it is synonymous with round
