HMCS Windsor is a long-range hunter-killer submarine of the Royal Canadian Navy, the second submarine of the Victoria class. She is named after the city of Ontario. Built for the Royal Navy as the Upholder-class submarine HMS Unicorn she was purchased by Canada when the United Kingdom decided to move to an all-nuclear power fleet; as built the Upholder/Victoria class was designed as a replacement for the Oberon class for use as hunter-killer and training subs. The submarines, which have a single-skinned, teardrop-shaped hull, displace 2,220 long tons surfaced and 2,455 long tons submerged, they are 230 feet 7 inches long overall with a beam of 25 feet 0 inches and a draught of 17 feet 8 inches. The submarines are powered by a one shaft diesel-electric system, they are equipped with two Paxman Valenta 1600 RPS SZ diesel engines each driving a 1.4-megawatt GEC electric alternator with two 120-cell chloride batteries. The batteries have a 90-hour endurance at 3 knots; the ship is propelled by a 5,000-kilowatt GEC dual armature electric motor turning a seven-blade fixed pitch propeller.
They have a 200-long-ton diesel capacity. This gives the subs a maximum speed of 20 knots submerged, they have a range of 8,000 nautical miles at 10,000 nautical miles at snorting depth. They have a range of 8,000 nautical miles at 8 knots; the class has a reported dive depth of over 650 feet. The Upholder/Victoria class are armed with six 21-inch torpedo tubes. In British service, the submarines were equipped with 14 Tigerfish Mk 24 Mod 2 torpedoes and four UGM-84 Sub-Harpoon missiles, they could be adapted for use as a minelayer. The submarines have Type 1007 radar and Type 2040, Type 2019, Type 2007 and Type 2046 sonar installed; the hull is fitted with elastomeric acoustic tiles to reduce acoustic signature. In British service the vessels had a complement of 40 ratings. During the refit for Canadian service, the Sub-Harpoon and mine capabilities were removed and the submarines were equipped with the Lockheed Martin Librascope Submarine fire-control system to meet the operational requirements of the Canadian Navy.
Components from the fire control system of the Oberon-class submarines were installed. This gave the submarines the ability to fire the Gould Mk 48 Mod 4 torpedo. In 2014, the Government of Canada purchased 12 upgrade kits that will allow the submarines to fire the Mk 48 Mod 7AT torpedoes; these radar and sonar systems were upgraded with the installation of the BAE Type 2007 array and the Type 2046 towed array. The Canadian Towed Array Sonar has been integrated into the towed sonar suite; the Upholder-class submarines were equipped with the CK035 electro-optical search periscope and the CH085 optronic attack periscope supplied by Pilkington Optronics. After the Canadian refit, the submarines were equipped with Canadian communication equipment and electronic support measures; this included two SSE decoy launchers and the AR 900 ESM. The submarine was laid down as HMS Unicorn at Cammell Laird's Birkenhead yard on 13 March 1990, she was launched on 16 April 1992, commissioned into the Royal Navy on 25 June 1993.
She was the last ship built at Cammell Laird until construction began on HMS Queen Elizabeth in June 2010. After entering service, Unicorn operated in the Mediterranean Sea and east of Suez, the Gulf of Oman and Indian Ocean and in the Persian Gulf, she returned to Devonport and was decommissioned on 16 October 1994. Looking to discontinue the operation of diesel-electric boats, the British government offered to sell Unicorn and her sister submarines to Canada in 1993; the offer was accepted in 1998. The four boats were leased to the Canadians for US$427 million, with the lease to run for eight years. Problems were discovered with the piping welds on all four submarines, which delayed the reactivation of Unicorn and her three sisters. Unicorn was handed over to the Canadian Forces on 6 August 2001 and sailed to Canada, arriving on 19 October; the submarine was commissioned into Maritime Command as HMCS Windsor with the hull number SSK 877 on 4 October 2003. Windsor is the only Canadian submarine deployed in the Atlantic.
In April 2002, after departing for the submarine's first training mission, Windsor was forced to return to port after the discovery of a faulty seal in the communications mast. From 27–30 September 2004, Windsor took reporters and photographers from Halifax and Windsor newspapers to document life aboard a submarine. During April 2006, the submarine was involved in the naval exercise Joint Express. In 2007 the submarine entered Halifax for refit. Scheduled for completion in two years, the refit was still not complete as of early 2011. During the refit, rust was discovered which will restrict the maximum depth to which the submarine can safely dive. According to reports, due to unexpected problems, the refit suffered delays and cost overruns; these included bad welds in the hull, broken torpedo tubes, a faulty rudder and tiles on the side of the sub that continually fell off. In 2010, the Royal Canadian Navy spent $45 million on repairs to Windsor for which it had budgeted $17 million; the refit began in 2007 and was scheduled to be completed in 2009.
The submarine was relaunched on 11 April 2012. After being out of the water for five years, Windsor was lowered back into the water; the submarine was guided out of the lift area to a nearby dock where the submari
Chief of Naval Operations
The Chief of Naval Operations is the highest-ranking officer and professional head of the United States Navy. The position is a statutory office held by a four-star admiral, a military adviser and deputy to the Secretary of the Navy. In a separate capacity as a member of the Joint Chiefs of Staff the CNO is a military adviser to the National Security Council, the Homeland Security Council, the Secretary of Defense, the President; the current Chief of Naval Operations is Admiral John M. Richardson. Despite the title, the CNO does not have operational command authority over Naval forces; the CNO is an administrative position based in the Pentagon, exercises supervision of Navy organizations as the designee of the Secretary of the Navy. Operational command of naval forces falls within the purview of the Combatant Commanders who report to the Secretary of Defense; the Chief of Naval Operations is the highest-ranking officer on active duty in the U. S. Navy unless the Chairman and/or the Vice Chairman of the Joint Chiefs of Staff are naval officers.
As per 10 U. S. C. § 5035, whenever there is a vacancy for the Chief of Naval Operations or during the absence or disability of the Chief of Naval Operations, unless the President directs otherwise, the Vice Chief of Naval Operations performs the duties of the Chief of Naval Operations until a successor is appointed or the absence or disability ceases. The CNO performs all other functions prescribed under 10 U. S. C. § 5033, such as presiding over the Office of the Chief of Naval Operations, exercising supervision of Navy organizations, other duties assigned by the Secretary or higher lawful authority, or the CNO delegates those duties and responsibilities to other officers in OPNAV or in organizations below. Acting for the Secretary of the Navy, the CNO designates naval personnel and naval forces available to the commanders of Unified Combatant Commands, subject to the approval of the Secretary of Defense; the CNO is a member of the Joint Chiefs of Staff as prescribed by 10 U. S. C. § 151 and 10 U.
S. C. § 5033. Like the other members of the Joint Chiefs of Staff, the CNO is an administrative position, with no operational command authority over the United States Navy forces. Members of the Joint Chiefs of Staff, individually or collectively, in their capacity as military advisers, shall provide advice to the President, the National Security Council, or the Secretary of Defense on a particular matter when the President, the NSC, or SECDEF requests such advice. Members of the Joint Chiefs of Staff may submit to the Chairman advice or an opinion in disagreement with, or advice or an opinion in addition to, the advice presented by the Chairman to the President, NSC, or SECDEF; when performing his JCS duties, the CNO is responsible directly to the SECDEF, but keeps SECNAV informed of significant military operations affecting the duties and responsibilities of the SECNAV, unless SECDEF orders otherwise. The Chief of Naval Operations is nominated by the President for appointment and must be confirmed by the Senate.
A requirement for being Chief of Naval Operations is having significant experience in joint duty assignments, which includes at least one full tour of duty in a joint duty assignment as a flag officer. However, the president may waive those requirements if he determines that appointing the officer is necessary for the national interest. By statute, the CNO is appointed as a four-star admiral. Number One Observatory Circle, located on the northeast grounds of the United States Naval Observatory in Washington, DC, was built in 1893 for its superintendent; the Chief of Naval Operations liked the house so much that in 1923 he took over the house as his own official residence. It remained the residence of the CNO until 1974, when Congress authorized its transformation to an official residence for the Vice President; the Chief of Naval Operations resides in Quarters A in the Washington Naval Yard. The Chief of Naval Operations presides over the Navy Staff, formally known as the Office of the Chief of Naval Operations.
The Office of the Chief of Naval Operations is a statutory organization within the executive part of the Department of the Navy, its purpose is to furnish professional assistance to the Secretary of the Navy and the CNO in carrying out their responsibilities. The OPNAV organization consists of: The Chief of Naval Operations The Vice Chief of Naval Operations, the principal deputy of the Chief of Naval Operations, delegated complete authority to act for the CNO in all matters not reserved by law to the CNO; the Director of the Navy Staff. Several Deputy Chiefs of Naval Operations of either three or two-star rank, heading functional directorates. DCNO Manpower, Training, & Education/Chief of Naval Personnel DCNO Warfare Dominance/Director of the Office of Naval Intelligence DCNO Operations, Plans, & Strategy DCNO Fleet Readiness & Logistics DCNO Integration of Capabilities & Resources DCNO Warfare Systems The Master Chief Petty Officer of the Navy, appointed by the Chief of Naval Operations to serve as a spokesperson to address the issues of enlisted personnel to the highest positions in the Navy.
The Director of the Naval Nuclear Propulsion Program, a unique eight-year posting held by a 4 star admiral, created and served in by Admiral Hyman G. Rickover; the appointment as Director is both a military and civilian position as it is the head of the Naval Nuclear Propulsion Program in the Department of the Navy and deputy administrator for the Office of Naval Reactors of the National Nuclear Security Administration
U-boat is an anglicised version of the German word U-Boot, a shortening of Unterseeboot "underseaboat." While the German term refers to any submarine, the English one refers to military submarines operated by Germany in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most used in an economic warfare role and enforcing a naval blockade against enemy shipping; the primary targets of the U-boat campaigns in both wars were the merchant convoys bringing supplies from Canada and other parts of the British Empire, from the United States to the United Kingdom and to the Soviet Union and the Allied territories in the Mediterranean. German submarines destroyed Brazilian merchant ships during World War II, causing Brazil to declare war on the Axis powers in 1944. Austro-Hungarian Navy submarines were known as U-boats; the first submarine built in Germany, the three-man Brandtaucher, sank to the bottom of Kiel harbor on 1 February 1851 during a test dive.
The inventor and engineer Wilhelm Bauer had designed this vessel in 1850, Schweffel & Howaldt constructed it in Kiel. Dredging operations in 1887 rediscovered Brandtaucher. There followed in 1890 the boats WW2, built to a Nordenfelt design. In 1903 the Friedrich Krupp Germaniawerft dockyard in Kiel completed the first functional German-built submarine, which Krupp sold to Russia during the Russo-Japanese War in April 1904; the SM U-1 was a redesigned Karp-class submarine and only one was built. The Imperial German Navy commissioned it on 14 December 1906, it had a double hull, a Körting kerosene engine, a single torpedo tube. The 50%-larger SM U-2 had two torpedo tubes; the U-19 class of 1912–13 saw the first diesel engine installed in a German navy boat. At the start of World War I in 1914, Germany had 48 submarines of 13 classes in service or under construction. During that war the Imperial German Navy used SM U-1 for training. Retired in 1919, it remains on display at the Deutsches Museum in Munich.
On 5 September 1914, HMS Pathfinder was sunk by SM U-21, the first ship to have been sunk by a submarine using a self-propelled torpedo. On 22 September, U-9 under the command of Otto Weddigen sank the obsolete British warships HMS Aboukir, HMS Cressy and HMS Hogue in a single hour. In the Gallipoli Campaign in early 1915 in the eastern Mediterranean, German U-boats, notably the U-21, prevented close support of allied troops by 18 pre-Dreadnought battleships by sinking two of them. For the first few months of the war, U-boat anticommerce actions observed the "prize rules" of the time, which governed the treatment of enemy civilian ships and their occupants. On 20 October 1914, SM U-17 sank the SS Glitra, off Norway. Surface commerce raiders were proving to be ineffective, on 4 February 1915, the Kaiser assented to the declaration of a war zone in the waters around the British Isles; this was cited as a retaliation for British minefields and shipping blockades. Under the instructions given to U-boat captains, they could sink merchant ships potentially neutral ones, without warning.
In February 1915, a submarine U-6 was rammed and both periscopes were destroyed off Beachy Head by the collier SS Thordis commanded by Captain John Bell RNR after firing a torpedo. On 7 May 1915, SM U-20 sank the liner RMS Lusitania; the sinking claimed 1,198 lives, 128 of them American civilians, the attack of this unarmed civilian ship shocked the Allies. According to the ship's manifest, Lusitania was carrying military cargo, though none of this information was relayed to the citizens of Britain and the United States who thought that the ship contained no ammunition or military weaponry whatsoever and it was an act of brutal murder. Munitions that it carried were thousands of crates full of ammunition for rifles, 3-inch artillery shells, various other standard ammunition used by infantry; the sinking of the Lusitania was used as propaganda against the German Empire and caused greater support for the war effort. A widespread reaction in the U. S was not seen until the sinking of the ferry SS Sussex.
The sinking occurred in 1915 and the United States entered the war in 1917. The initial U. S. response was to threaten to sever diplomatic ties, which persuaded the Germans to issue the Sussex pledge that reimposed restrictions on U-boat activity. The U. S. reiterated its objections to German submarine warfare whenever U. S. civilians died as a result of German attacks, which prompted the Germans to reapply prize rules. This, removed the effectiveness of the U-boat fleet, the Germans sought a decisive surface action, a strategy that culminated in the Battle of Jutland. Although the Germans claimed victory at Jutland, the British Grand Fleet remained in control at sea, it was necessary to return to effective anticommerce warfare by U-boats. Vice-Admiral Reinhard Scheer, Commander in Chief of the High Seas Fleet, pressed for all-out U-boat war, convinced that a high rate of shipping losses would force Britain to seek an early peace before the United States could react effectively; the renewed German campaign was effective, sinking 1.4 million tons of shipping between October 1916 and January 1917.
Despite this, the political situation demanded greater pressure, on 31 January 1917, Germany announced that its U-boats would engage in unrestricted submarine warfare beginning 1 February. On 17 March, German submarines sank three American merchant vessels, the U. S. declared wa
Anti-submarine warfare is a branch of underwater warfare that uses surface warships, aircraft, or other submarines to find and deter, damage, or destroy enemy submarines. Successful anti-submarine warfare depends on a mix of sensor and weapon technology and experience. Sophisticated sonar equipment for first detecting classifying and tracking the target submarine is a key element of ASW. To destroy submarines, both torpedos and naval mines are used, launched from air and underwater platforms. ASW involves protecting friendly ships; the first attacks on a ship by an underwater vehicle are believed to have been during the American Revolutionary War, using what would now be called a naval mine but what was called a torpedo, though various attempts to build submarines had been made before this. The first self-propelled torpedo was launched from surface craft; the first submarine with a torpedo was Nordenfelt I built in 1884-1885, though it had been proposed earlier. By the outbreak of the Russo-Japanese War all the large navies except the German had acquired submarines.
In 1904 all still defined the submarine as an experimental vessel and did not put it into operational use. There were no means to detect submerged U-boats, attacks on them were limited at first to efforts to damage their periscopes with hammers; the Royal Navy torpedo establishment, HMS Vernon, studied explosive grapnel sweeps. A similar approach featured a string of 70 lb charges on a floating cable, fired electrically. Tried were dropping 18.5 lb hand-thrown guncotton bombs. The Lance Bomb was developed, also. Firing Lyddite shells, or using trench mortars, was tried. Use of nets to ensnare U-boats was examined, as was a destroyer, HMS Starfish, fitted with a spar torpedo. To attack at set depths, aircraft bombs were attached to lanyards. Problems with the lanyards tangling and failing to function led to the development of a chemical pellet trigger as the Type B; these were effective at a distance of around 20 ft. The best concept arose in a 1913 RN Torpedo School report, describing a device intended for countermining, a "dropping mine".
At Admiral John Jellicoe's request, the standard Mark II mine was fitted with a hydrostatic pistol preset for 45 ft firing, to be launched from a stern platform. Weighing 1,150 lb, effective at 100 ft, the "cruiser mine" was a potential hazard to the dropping ship. During the First World War, submarines were a major threat, they operated in North Sea, Black Sea and Mediterranean as well as the North Atlantic. They had been limited to calm and protected waters; the vessels used to combat them were a range of fast surface ships using guns and good luck. They relied on the fact a submarine of the day was on the surface for a range of reasons, such as charging batteries or crossing long distances; the first approach to protect warships was chainlink nets strung from the sides of battleships, as defense against torpedoes. Nets were deployed across the mouth of a harbour or naval base to stop submarines entering or to stop torpedoes of the Whitehead type fired against ships. British warships were fitted with a ram with which to sink submarines, U-15 was thus sunk in August 1914.
RN in June 1915 began operational trials of the Type D depth charge, with a 300 lb charge of TNT and a hydrostatic pistol, firing at either 40 or 80 ft, believed to be effective at a distance of 140 ft. In July 1915, the British Admiralty set up the Board of Invention and Research to evaluate suggestions from the public as well as carrying out their own investigations; some 14,000 suggestions were received about combating submarines. In December 1916, the RN set up its own Anti-Submarine Division but relations with the BIR were poor. After 1917 most ASW work was carried out by ASD. In the U. S. a Naval Consulting Board was set up in 1915 to evaluate ideas. After American entry into the war in 1917, they encouraged work on submarine detection; the U. S. National Research Council, a civilian organization, brought in British and French experts on underwater sound to a meeting with their American counterparts in June 1917. In October 1918, there was a meeting in Paris on "supersonics", a term used for echo-ranging, but the technique was still in research by the end of the war.
The first recorded sinking of a submarine by depth charge was U-68, sunk by Q-ship HMS Farnborough off Kerry, Ireland 22 March 1916. By early 1917, the Royal Navy had developed indicator loops which consisted of long lengths of cables lain on the seabed to detect the magnetic field of submarines as they passed overhead. At this stage they were used in conjunction with controlled mines which could be detonated from a shore station once a'swing' had been detected on the indicator loop galvanometer. Indicator loops used with controlled mining were known as'guard loops'. By July 1917, depth charges had developed to the extent that settings of between 50–200 ft were possible; this design would remain unchanged through
The Balao class was a successful design of United States Navy submarine used during World War II, with 120 units completed, the largest class of submarines in the United States Navy. An improvement on the earlier Gato class, the boats had slight internal differences; the most significant improvement was the use of thicker, higher yield strength steel in the pressure hull skins and frames, which increased their test depth to 400 feet. Tang achieved a depth of 612 ft during a test dive, exceeded that test depth when taking on water in the forward torpedo room while evading a destroyer; the Balaos were similar to the Gatos, except they were modified to increase test depth from 300 ft to 400 ft. In late 1941, two of the Navy's leading submarine designers, Captain Andrew McKee and Commander Armand Morgan, met to explore increasing diving depth in a redesigned Gato. A switch to a new High-Tensile Steel alloy, combined with an increase in hull thickness from 9⁄16 inch to 7⁄8 inch, would result in a test depth of 450 ft and a collapse depth of 900 ft. However, the limited capacity of the trim pump at deep depths, lack of time to design a new pump, caused Rear Admiral E. L. Cochrane, Chief of the Bureau of Ships, to limit test depth to 400 ft. Fortunately, in 1944 a redesigned Gould centrifugal pump replaced the noisy early-war pump, effective diving depth was increased.
The Balaos incorporated the sail, conning tower and periscope shears reduction efforts that were being retrofitted to the Gatos and the preceding classes in the original design, refining the reductions and reducing the sail to the smallest practical size. By the time the boats began to be launched, lessons learned from patrol reports had been worked into the design and the bridge and sail proved to be efficiently laid out, well equipped, well liked by the crews. For the masts and periscope shears, the original arrangement for both the Government and Electric Boat designs had the two tapered cone shaped periscope support shears, followed by a thin mast for the SJ surface search radar, by a thin mast for the SD air search radar. There were minor differences in how the periscopes were braced against vibration, but both designs were nearly identical. About halfway through their production run, Electric Boat altered their design, moving the SJ radar mast forward of the periscopes altered it again a few boats by enlarging the SD radar mast.
Late in the war, many Balaos built with the original design had the SD air search radar moved aft onto a thickened and taller mast. These mast arrangements, along with the tremendous variation in the gun layout as the war progressed account for the numerous exterior detail differences among the boats, to the point that at any given time no two Balaos looked alike; the propulsion of the Balao-class submarines was similar to that of the preceding Gato-class. Like their predecessors, they were true diesel-electric submarines: their four diesel engines powered electrical generators, electric motors drove the shafts. There was no direct connection between the shafts. Balao-class submarines received main engines from one of two manufacturers. Fairbanks-Morse supplied Model 38D8⅛ opposed piston engines, General Motors' Cleveland Diesel division supplied Model 16-248 and 16-278A V16 engines. Earlier Fairbanks-Morse boats received a 9-cylinder version of the Model 38D8⅛, while boats from Sand Lance onward received 10-cylinder engines.
Earlier GM boats received Model 16-248 engines, but beginning with Perch Model 16-278A engines were used. In each case, the newer engines had greater displacement than the old, but were rated at the same power. Both the F-M and GM engines were two-stroke cycle types. Two submarines and Vendace, were to receive Hooven-Owens-Rentschler diesels, which proved unreliable on previous classes, but both boats were cancelled. Two manufacturers supplied electric motors for the Balao class. Elliott Company motors were fitted to boats with Fairbanks-Morse engines. General Electric motors were fitted to boats with General Motors engines, but some Fairbanks-Morse boats received GE motors. Allis-Chalmers motors were to be used in SS-530 through SS-536, but those seven boats were cancelled before receiving names. Earlier submarines carried four high-speed electric motors, which had to be fitted with reduction gears to slow their outputs down to an appropriate speed for the shafts; this reduction gearing was noisy, made the submarine easier to detect with hydrophones.
Eighteen late Balao-class submarines received low-speed double armature motors which drove the shafts directly and were much quieter, but this improvement was not universally fitted until the succeeding Tench class. The new direct drive electric motors were designed by the Bureau of Ships' electrical division under Captain Hyman G. Rickover, were first equipped on Sea Owl. On all US World War II-built boats, as the diesel engines were not directly connected to the shafts, the electric motors drove the shafts all the time. Many targets in the Pacific War were sampans or otherwise not worth a torpedo, so the deck gun was an important weapon. Early Balaos began their service with a 4-inch /50 caliber Mk. 9 gun. Due to war experience, most were re-armed with a 5-inch /25 caliber Mk. 17 gun, similar to mounts on battleships and cruisers but built as a "wet" mount with corrosion resistant materials, with power-operated loading and aiming features removed. This conversion started in late 1943, some boats had two of these weapons beginning in late 1944.
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position. In its simplest form, it consists of an outer case with mirrors at each end set parallel to each other at a 45° angle; this form of periscope, with the addition of two simple lenses, served for observation purposes in the trenches during World War I. Military personnel use periscopes in some gun turrets and in armoured vehicles. More complex periscopes using prisms or advanced fiber optics instead of mirrors and providing magnification operate on submarines and in various fields of science; the overall design of the classical submarine periscope is simple: two telescopes pointed into each other. If the two telescopes have different individual magnification, the difference between them causes an overall magnification or reduction. Johannes Gutenberg, known for his contribution to printing technology, marketed a kind of periscope in the 1430s to enable pilgrims to see over the heads of the crowd at the vigintennial religious festival at Aachen.
Johannes Hevelius described an early periscope with lenses in 1647 in his work Selenographia, sive Lunae descriptio. Hevelius saw military applications for his invention. In 1854, Hippolyte Marié-Davy invented the first naval periscope, consisting of a vertical tube with two small mirrors fixed at each end at 45°. Simon Lake used periscopes in his submarines in 1902. Sir Howard Grubb perfected the device in World War I. Morgan Robertson claimed to have tried to patent the periscope: he described a submarine using a periscope in his fictional works. Periscopes, in some cases fixed to rifles, served in World War I to enable soldiers to see over the tops of trenches, thus avoiding exposure to enemy fire; the periscope rifle saw use during the war - this was an infantry rifle sighted by means of a periscope, so the shooter could aim fire the weapon from a safe position below the trench parapet. During World War II, artillery observers and officers used specifically-manufactured periscope binoculars with different mountings.
Some of them allowed estimating the distance to a target, as they were designed as stereoscopic rangefinders. Tanks and armoured vehicles use periscopes: they enable drivers, tank commanders, other vehicle occupants to inspect their situation through the vehicle roof. Prior to periscopes, direct vision slits were cut in the armour for occupants to see out. Periscopes permit view outside of the vehicle without needing to cut these weaker vision openings in the front and side armour, better protecting the vehicle and occupants. A protectoscope is a related periscopic vision device designed to provide a window in armoured plate, similar to a direct vision slit. A compact periscope inside the protectoscope allows the vision slit to be blanked off with spaced armoured plate; this prevents a potential ingress point for small arms fire, with only a small difference in vision height, but still requires the armour to be cut. In the context of armoured fighting vehicles, such as tanks, a periscopic vision device may be referred to as an episcope.
In this context a periscope refers to a device that can rotate to provide a wider field of view, while an episcope is fixed into position. Periscopes may be referred to by slang, e.g. "shufti-scope". An important development, the Gundlach rotary periscope, incorporated a rotating top with a selectable additional prism which reversed the view; this allowed a tank commander to obtain a 360-degree field of view without moving his seat, including rear vision by engaging the extra prism. This design, patented by Rudolf Gundlach in 1936, first saw use in the Polish 7-TP light tank; as a part of Polish–British pre-World War II military cooperation, the patent was sold to Vickers-Armstrong where it saw further development for use in British tanks, including the Crusader, Churchill and Cromwell models as the Vickers Tank Periscope MK. IV; the Gundlach-Vickers technology was shared with the American Army for use in its tanks including the Sherman, built to meet joint British and US requirements. This saw post-war controversy through legal action: "After the Second World War and a long court battle, in 1947 he, received a large payment for his periscope patent from some of its producers."The USSR copied the design and used it extensively in its tanks (including the T-34 and T-70.
The copies were based on Lend-Lease British vehicles, many parts remain interchangeable. Germany made and used copies. Periscopic sights were introduced during the Second World War. In British use, the Vickers periscope was provided with sighting lines, enabling front and rear prisms to be directly aligned to gain an accurate direction. On tanks such as the Churchill and Cromwell, a marked episcope provided a backup sighting mechanism aligned with a vane sight on the turret roof. US-built Sherman tanks and British Centurion and Charioteer tanks replaced the main telescopic sight with a true periscopic sight in the primary role; the periscopic sight was linked to the gun itself. The sights formed part of the overall periscope, providing the gunner with greater overall vision than possible with the telescopic sight. In modern use, specialised periscopes can provide night vision; the Embedded Image Periscope designed and patented by Kent Periscopes provides standard unity vision periscope functionality for normal daytime viewing of the vehicle surroundings plus
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. It is the largest and most capable navy in the world and it has been estimated that in terms of tonnage of its active battle fleet alone, it is larger than the next 13 navies combined, which includes 11 U. S. allies or partner nations. With the highest combined battle fleet tonnage and the world's largest aircraft carrier fleet, with eleven in service, two new carriers under construction. With 319,421 personnel on active duty and 99,616 in the Ready Reserve, the Navy is the third largest of the service branches, it has 282 deployable combat vessels and more than 3,700 operational aircraft as of March 2018, making it the second-largest air force in the world, after the United States Air Force. The U. S. Navy traces its origins to the Continental Navy, established during the American Revolutionary War and was disbanded as a separate entity shortly thereafter.
The U. S. Navy played a major role in the American Civil War by blockading the Confederacy and seizing control of its rivers, it played the central role in the World War II defeat of Imperial Japan. The US Navy emerged from World War II as the most powerful navy in the world; the 21st century U. S. Navy maintains a sizable global presence, deploying in strength in such areas as the Western Pacific, the Mediterranean, the Indian Ocean, it is a blue-water navy with the ability to project force onto the littoral regions of the world, engage in forward deployments during peacetime and respond to regional crises, making it a frequent actor in U. S. foreign and military policy. The Navy is administratively managed by the Department of the Navy, headed by the civilian Secretary of the Navy; the Department of the Navy is itself a division of the Department of Defense, headed by the Secretary of Defense. The Chief of Naval Operations is the most senior naval officer serving in the Department of the Navy.
The mission of the Navy is to maintain and equip combat-ready Naval forces capable of winning wars, deterring aggression and maintaining freedom of the seas. The U. S. Navy is a seaborne branch of the military of the United States; the Navy's three primary areas of responsibility: The preparation of naval forces necessary for the effective prosecution of war. The maintenance of naval aviation, including land-based naval aviation, air transport essential for naval operations, all air weapons and air techniques involved in the operations and activities of the Navy; the development of aircraft, tactics, technique and equipment of naval combat and service elements. U. S. Navy training manuals state that the mission of the U. S. Armed Forces is "to be prepared to conduct prompt and sustained combat operations in support of the national interest." As part of that establishment, the U. S. Navy's functions comprise sea control, power projection and nuclear deterrence, in addition to "sealift" duties, it follows as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, with it, everything honorable and glorious.
Naval power... is the natural defense of the United States The Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia; the rationale for establishing a national navy was debated in the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, make it easier to seek out support from foreign countries. Detractors countered that challenging the British Royal Navy the world's preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchant ships and reported the captures to the Congress. On 13 October 1775, the Continental Congress authorized the purchase of two vessels to be armed for a cruise against British merchant ships. S. Navy; the Continental Navy achieved mixed results.
In August 1785, after the Revolutionary War had drawn to a close, Congress had sold Alliance, the last ship remaining in the Continental Navy due to a lack of funds to maintain the ship or support a navy. In 1972, the Chief of Naval Operations, Admiral Elmo Zumwalt, authorized the Navy to celebrate its birthday on 13 October to honor the establishment of the Continental Navy in 1775; the United States was without a navy for nearly a decade, a state of affairs that exposed U. S. maritime merchant ships to a series of attacks by the Barbary pirates. The sole armed maritime presence between 1790 and the launching of the U. S. Navy's first warships in 1797 was the U. S. Revenue-Marine, the primary predecessor of the U. S. Coast Guard. Although the USRCS conducted operations against the pirates, their depredations far outstripped its abilities and Congress passed the Naval Act of 1794 that established a permanent standing navy on 27 March 1794; the Naval Act ordered the construction and manning of six frigates and, by October 1797, the first three were brought into service: USS United States, USS Constellation, USS Constitution.
Due to his strong posture on having a strong standing Navy during this period, John Adams is "often called the father of the American Navy". In 1798–99 the Navy was involved in an undeclared Quasi-War with France. From 18