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145-424: DPVs include a range of configurations from small, easily portable scooter units with a small range and low speed, to faired or enclosed units capable of carrying several divers longer distances at higher speeds. The earliest recorded DPVs were used for military purposes during World War II and were based on torpedo technology and components. A DPV usually consists of a pressure-resistant watertight casing containing

290-408: A battery -powered electric motor , which drives a propeller . The design must ensure that the propeller cannot harm the diver, diving equipment or marine life, the vehicle cannot be accidentally started or run away from the diver, and it remains approximately neutrally buoyant while in use underwater. DPVs are useful for extending the range of an autonomous diver that is otherwise restricted by

435-400: A zinc anode, usually in the form of a cylindrical pot, with a carbon cathode in the form of a central rod. The electrolyte is ammonium chloride in the form of a paste next to the zinc anode. The remaining space between the electrolyte and carbon cathode is taken up by a second paste consisting of ammonium chloride and manganese dioxide, the latter acting as a depolariser . In some designs,

580-431: A DPV requires simultaneous depth control, buoyancy adjustment, monitoring of breathing gas, and navigation. Buoyancy control is vital for diver safety: The DPV has the capacity to dynamically compensate for poor buoyancy control by thrust vectoring while moving, but on stopping the diver may turn out to be dangerously positively or negatively buoyant if adjustments were not made to suit the changes in depth while moving. If

725-477: A Submarine Legion and complemented German Kriegsmarine U-boat operations as part of Operation Ursula . At least two Republican freighters, one Soviet and another Panamanian were either sunk or forced to run aground by Italian destroyers near the Strait of Sicily . Two light cruisers took part in the shelling of Barcelona and Valencia in 1937, resulting in the deaths of more than 30 civilians. In 1939,

870-434: A battery cannot deliver as much power. As such, in cold climates, some car owners install battery warmers, which are small electric heating pads that keep the car battery warm. A battery's capacity is the amount of electric charge it can deliver at a voltage that does not drop below the specified terminal voltage. The more electrode material contained in the cell the greater its capacity. A small cell has less capacity than

1015-403: A battery rated at 100 A·h can deliver 5 A over a 20-hour period at room temperature . The fraction of the stored charge that a battery can deliver depends on multiple factors, including battery chemistry, the rate at which the charge is delivered (current), the required terminal voltage, the storage period, ambient temperature and other factors. The higher the discharge rate, the lower

1160-421: A battery rated at 2 A·h for a 10- or 20-hour discharge would not sustain a current of 1 A for a full two hours as its stated capacity suggests. The C-rate is a measure of the rate at which a battery is being charged or discharged. It is defined as the current through the battery divided by the theoretical current draw under which the battery would deliver its nominal rated capacity in one hour. It has

1305-412: A cell maintained 1.5 volts and produced a charge of one coulomb then on complete discharge it would have performed 1.5 joules of work. In actual cells, the internal resistance increases under discharge and the open-circuit voltage also decreases under discharge. If the voltage and resistance are plotted against time, the resulting graphs typically are a curve; the shape of the curve varies according to

1450-670: A combat swimmer unit or naval Special Forces underwater, over long distances. SDVs carry a pilot, co-pilot/navigator, and combat swimmer team and their equipment, to and from maritime mission objectives on land or at sea. The pilot and co-pilot are often a part of the swimmer team. An example of a modern SDV in use today is the SEAL Delivery Vehicle used by the United States Navy SEALs and British Special Boat Service . For long-range missions, SDVs can carry their own onboard breathing gas supply to extend

1595-660: A discharge rate about 100x greater than current batteries, and smart battery packs with state-of-charge monitors and battery protection circuits that prevent damage on over-discharge. Low self-discharge (LSD) allows secondary cells to be charged prior to shipping. Lithium–sulfur batteries were used on the longest and highest solar-powered flight. Batteries of all types are manufactured in consumer and industrial grades. Costlier industrial-grade batteries may use chemistries that provide higher power-to-size ratio, have lower self-discharge and hence longer life when not in use, more resistance to leakage and, for example, ability to handle

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1740-517: A fast, light, surface boat to a submerged DPV. Started in the 1970s by Submarine Products Ltd. of Hexham, Northumberland, England, Subskimmer is now a tradename owned by Marine Specialised Technology. As DPVs get bigger they gradually merge into submarines . A wet sub is a small submarine where the crew spaces are flooded at ambient pressure and the crew must wear diving gear. Covert military operations use wet subs to deliver and retrieve operators into harbors and near-shore undetected. An example

1885-528: A fleet air arm. The High Command had reasoned that since the Italian navy would be operating solely in the Mediterranean, their vessels would never be far from an airfield and so the time and the resources needed to develop a naval air arm could be directed elsewhere. This proved problematic on a number of occasions. The Italians had the aircraft carriers Aquila and Sparviero under construction at

2030-800: A force capable of taking on the British Royal Navy , especially after the Fascist takeover. The British response to the Corfu incident left Benito Mussolini and his military advisors convinced that Italy was "imprisoned in the Mediterranean" through British bases in Gibraltar , the Suez Canal , Malta , and Cyprus . Italian naval construction was limited by the Washington Naval Conference . The 1922 treaty required

2175-525: A freshly charged nickel cadmium (NiCd) battery loses 10% of its charge in the first 24 hours, and thereafter discharges at a rate of about 10% a month. However, newer low self-discharge nickel–metal hydride (NiMH) batteries and modern lithium designs display a lower self-discharge rate (but still higher than for primary batteries). The active material on the battery plates changes chemical composition on each charge and discharge cycle; active material may be lost due to physical changes of volume, further limiting

2320-475: A gun. The acceleration breaks a capsule of electrolyte that activates the battery and powers the fuze's circuits. Reserve batteries are usually designed for a short service life (seconds or minutes) after long storage (years). A water-activated battery for oceanographic instruments or military applications becomes activated on immersion in water. On 28 February 2017, the University of Texas at Austin issued

2465-446: A large current for a sustained period. The Daniell cell , invented in 1836 by British chemist John Frederic Daniell , was the first practical source of electricity , becoming an industry standard and seeing widespread adoption as a power source for electrical telegraph networks. It consisted of a copper pot filled with a copper sulfate solution, in which was immersed an unglazed earthenware container filled with sulfuric acid and

2610-434: A larger cell with the same chemistry, although they develop the same open-circuit voltage. Capacity is usually stated in ampere-hours (A·h) (mAh for small batteries). The rated capacity of a battery is usually expressed as the product of 20 hours multiplied by the current that a new battery can consistently supply for 20 hours at 20 °C (68 °F), while remaining above a specified terminal voltage per cell. For example,

2755-539: A magazine explosion (although there were rumours of Austrian sabotage). The Austrians also sank the Italian armed merchant cruiser SS Principe Umberto on 8 June 1916. While transporting troops in the Adriatic, the ship was sunk by Austro-Hungarian U-boat U-5 with the loss of 1,926 men. It was the worst naval disaster of World War I in terms of human lives lost. In the last part of the war, the Regia Marina developed

2900-520: A marked disadvantage in numbers and equipment, superior handling by the Austrians under Admiral Wilhelm von Tegetthoff resulted in a severe defeat for Italy, which lost two armoured ships and 640 men. After the war, the Regia Marina passed through some difficult years as the naval budget was substantially reduced, thus impairing the fleet's efficiency and the pace of new construction; only in

3045-457: A molten salt as electrolyte. They operate at high temperatures and must be well insulated to retain heat. A dry cell uses a paste electrolyte, with only enough moisture to allow current to flow. Unlike a wet cell, a dry cell can operate in any orientation without spilling, as it contains no free liquid, making it suitable for portable equipment. By comparison, the first wet cells were typically fragile glass containers with lead rods hanging from

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3190-655: A naval base in the concession territory of Tientsin in China . The primary Italian vessels based in China were the mine-layer Lepanto and the gunboat Carlotto . During World War II, Italian supply ships, auxiliary cruisers and submarines operated throughout the waters of the Far East, often in disguise. The Italians also utilized Japanese-controlled port facilities such as Shanghai, China , and Kobe , Japan . Seven Italian submarines operating from France were converted by

3335-483: A nickel and a penny ) and a piece of paper towel dipped in salt water . Such a pile generates a very low voltage but, when many are stacked in series , they can replace normal batteries for a short time. Batteries are classified into primary and secondary forms: Some types of primary batteries used, for example, for telegraph circuits, were restored to operation by replacing the electrodes. Secondary batteries are not indefinitely rechargeable due to dissipation of

3480-417: A parity in naval forces between the Italian and French navies, with equality in total displacement in battleships and carriers. The treaty influenced the development of the Italian fleet over the years between the two world wars. Between the late twenties and early thirties a construction program began, focusing first on cruisers up to 10,000 tons, followed by the building of destroyers and submarines, and lastly

3625-539: A paste, made portable electrical devices practical. Batteries in vacuum tube devices historically used a wet cell for the "A" battery (to provide power to the filament) and a dry cell for the "B" battery (to provide the plate voltage). Between 2010 and 2018, annual battery demand grew by 30%, reaching a total of 180  GWh in 2018. Conservatively, the growth rate is expected to be maintained at an estimated 25%, culminating in demand reaching 2600 GWh in 2030. In addition, cost reductions are expected to further increase

3770-480: A press release about a new type of solid-state battery , developed by a team led by lithium-ion battery inventor John Goodenough , "that could lead to safer, faster-charging, longer-lasting rechargeable batteries for handheld mobile devices, electric cars and stationary energy storage". The solid-state battery is also said to have "three times the energy density", increasing its useful life in electric vehicles, for example. It should also be more ecologically sound since

3915-427: A significant reconstruction project, with only 40% of the original structures being left. The ship's guns were upgraded in main armament, going from 13 guns of 305 mm diameter, to 10 guns of 320 mm diameter. The middle turret and the vessel's central tower were eliminated. To increase speed the coal-fired boilers were replaced with modern oil-fired boilers and ten meters were added to the ship's length to improve

4060-402: A single cell. Primary (single-use or "disposable") batteries are used once and discarded , as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used for flashlights and a multitude of portable electronic devices. Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current;

4205-766: A squadron of gunboats there. These were destroyed while attempting to withdraw into the Mediterranean at the Battle of Kunfuda Bay . Before 1914, the Kingdom of Italy built six dreadnought battleships: ( Dante Alighieri as a prototype; Giulio Cesare , Conte di Cavour and Leonardo da Vinci of the Conte di Cavour class ; and Andrea Doria and Duilio of the Andrea Doria class ), but they did not participate in any major naval actions in World War I . During

4350-528: A team can be re-supplied by contact with other SDVs. In the latter usage, SDVs can stealthily plant mines and other bombs on ships or port infrastructure and then retreat to a safe distance before detonating the explosives. In addition to destroying targets, the SDV can mislead enemies as to where they are being attacked from. One type of SDV—the Mark 9 SEAL Delivery Vehicle—was also capable of firing torpedoes, giving it

4495-466: A technical disadvantage. The Italian ships relied on speed but could easily be damaged by shell or torpedo, due to their relatively thin armour, as happened in the battle of Cape Spada . The fatal and final blow to the Italian Navy was a shortage of fuel, which forced its main units to remain at anchor for most of the last year of the Italian alliance with Germany. From 10 June 1940, submarines of

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4640-596: A type of diver propulsion vehicle used as secret naval weapons in World War II . The name was commonly used to refer to the weapons that Italy, and later Britain, deployed in the Mediterranean and used to attack ships in enemy harbours. The first human torpedo was the Italian Maiale ("Pig"). In operation, it was carried by another vessel (usually a normal submarine), and launched near the target. It

4785-422: A zinc electrode. These wet cells used liquid electrolytes, which were prone to leakage and spillage if not handled correctly. Many used glass jars to hold their components, which made them fragile and potentially dangerous. These characteristics made wet cells unsuitable for portable appliances. Near the end of the nineteenth century, the invention of dry cell batteries , which replaced the liquid electrolyte with

4930-423: Is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode . The terminal marked negative is the source of electrons. When a battery is connected to an external electric load, those negatively charged electrons flow through

5075-573: Is also used as a rating on batteries to indicate the maximum current that a battery can safely deliver in a circuit. Standards for rechargeable batteries generally rate the capacity and charge cycles over a 4-hour (0.25C), 8 hour (0.125C) or longer discharge time. Types intended for special purposes, such as in a computer uninterruptible power supply , may be rated by manufacturers for discharge periods much less than one hour (1C) but may suffer from limited cycle life. In 2009 experimental lithium iron phosphate ( LiFePO 4 ) battery technology provided

5220-510: Is called the open-circuit voltage and equals the emf of the cell. Because of internal resistance, the terminal voltage of a cell that is discharging is smaller in magnitude than the open-circuit voltage and the terminal voltage of a cell that is charging exceeds the open-circuit voltage. An ideal cell has negligible internal resistance, so it would maintain a constant terminal voltage of E {\displaystyle {\mathcal {E}}} until exhausted, then dropping to zero. If such

5365-505: Is known as the "self-discharge" rate, and is due to non-current-producing "side" chemical reactions that occur within the cell even when no load is applied. The rate of side reactions is reduced for batteries stored at lower temperatures, although some can be damaged by freezing and storing in a fridge will not meaningfully prolong shelf life and risks damaging condensation. Old rechargeable batteries self-discharge more rapidly than disposable alkaline batteries, especially nickel-based batteries;

5510-886: Is largely controlled by the towing vessel, but the diver has a limited amount of control over vertical and lateral excursions. DPVs currently in service include: Swedish firm Defence Consulting Europe Aktiebolag (stock company, often abbreviated as DCE AB) has developed a family of SDV of modular design, all of them based on the same basic frame and general design principle, and current available versions include: After purchasing US submersible manufacturer Seahorse Marine, Emirate Marine Technologies of United Arab Emirates has developed four classes DPV/SDV, all of them built of glass reinforced plastic and carbon composite materials: All SDVs of former Yugoslavia were developed by Brodosplit - Brodogradilište Specijalnih Objekata d.o.o. which have been passed on to successor nations of former Yugoslavia. Battery (electricity) An electric battery

5655-539: Is lost and the battery stops producing power. Internal energy losses and limitations on the rate that ions pass through the electrolyte cause battery efficiency to vary. Above a minimum threshold, discharging at a low rate delivers more of the battery's capacity than at a higher rate. Installing batteries with varying A·h ratings changes operating time, but not device operation unless load limits are exceeded. High-drain loads such as digital cameras can reduce total capacity of rechargeable or disposable batteries. For example,

5800-540: Is no practical experience". Thus, the Italian navy entered the Second World War with a marked technical inferiority to the British Royal Navy . Albert Kesselring , overall commander of Axis forces in the Mediterranean, observed that the Italian navy was "a good weather" force, unable to operate effectively at night or in heavy seas. Two training ships were built during this period, in addition to

5945-636: Is popular in the automotive industry as a replacement for the lead–acid wet cell. The VRLA battery uses an immobilized sulfuric acid electrolyte, reducing the chance of leakage and extending shelf life . VRLA batteries immobilize the electrolyte. The two types are: Other portable rechargeable batteries include several sealed "dry cell" types, that are useful in applications such as mobile phones and laptop computers . Cells of this type (in order of increasing power density and cost) include nickel–cadmium (NiCd), nickel–zinc (NiZn), nickel–metal hydride (NiMH), and lithium-ion (Li-ion) cells. Li-ion has by far

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6090-508: Is somewhat offset by the higher efficiency of electric motors in converting electrical energy to mechanical work, compared to combustion engines. Benjamin Franklin first used the term "battery" in 1749 when he was doing experiments with electricity using a set of linked Leyden jar capacitors. Franklin grouped a number of the jars into what he described as a "battery", using the military term for weapons functioning together. By multiplying

6235-571: Is the Multi-Role Combatant Craft (MRCC). These are unpowered boards (usually rectangular) towed by a surface boat which function as diving planes . The diver holds onto the sled and may use a quick-release tether to reduce fatigue. Depth control while submerged is by adjusting the angle of attack. Sometimes known as manta-boards, after the manta ray . Towed sleds are useful for surveys and searches in good visibility in waters where there are not too many large obstacles. The route

6380-455: Is the difference in the cohesive or bond energies of the metals, oxides, or molecules undergoing the electrochemical reaction. For instance, energy can be stored in Zn or Li, which are high-energy metals because they are not stabilized by d-electron bonding, unlike transition metals . Batteries are designed so that the energetically favorable redox reaction can occur only when electrons move through

6525-489: Is the modern car battery , which can, in general, deliver a peak current of 450 amperes . Many types of electrochemical cells have been produced, with varying chemical processes and designs, including galvanic cells , electrolytic cells , fuel cells , flow cells and voltaic piles. A wet cell battery has a liquid electrolyte . Other names are flooded cell , since the liquid covers all internal parts or vented cell , since gases produced during operation can escape to

6670-409: The Regia Marina conducted experiments with Guglielmo Marconi in the use of radio communications. 1909 saw the first use of aircraft with the fleet. An Italian naval officer, Vittorio Cuniberti , was the first in 1903 to envision in a published article the all-big gun battleship design, which would be later come to be known as dreadnought . In 1911 and 1912, the Regia Marina was involved in

6815-634: The Regia Marina supported the invasion of Albania . All ground forces involved in the invasion had to cross the Adriatic Sea from mainland Italy and the crossings were accomplished without incident. On 10 June 1940, after the German invasion of France , the Kingdom of Italy declared war on France and the United Kingdom and entered World War II. Italian dictator Benito Mussolini saw

6960-866: The Regia Marina took part in the Battle of the Atlantic alongside the U-boats of Nazi Germany 's Kriegsmarine . The Italian submarines were based in Bordeaux , France at the BETASOM base. While more suited for the Mediterranean Sea than the Atlantic Ocean , the thirty-two Italian submarines that operated in the Atlantic sank 109 Allied ships for a total of 593,864 tons. The Regia Marina even planned an attack on New York Harbor with midget submarines for December 1942, but this plan

7105-570: The British when they discovered how effective this weapon could be after three Italian units successfully penetrated the harbour of Alexandria and damaged the British battleships HMS  Queen Elizabeth and HMS  Valiant , and the tanker "Sagona." The official Italian name for their craft was "Siluro a Lenta Corsa" (SLC or "Slow-running torpedo"), but the Italian operators nicknamed it "Maiale" after their inventor Teseo Tesei said that it

7250-683: The Cape of Good Hope and ultimately sailed to German occupied Bordeaux , France . One or two Italian merchant ships from the Red Sea Flotilla made it to Vichy French -controlled Madagascar . On 10 June 1941, the British launched Operation Chronometer, landing a battalion of troops from the British Indian Army at Assab , the last Italian-held harbour on the Red Sea. By 11 June, Assab had fallen. Two days later, on 13 June,

7395-741: The Daniell cell were built as open-top glass jar wet cells. Other primary wet cells are the Leclanche cell , Grove cell , Bunsen cell , Chromic acid cell , Clark cell , and Weston cell . The Leclanche cell chemistry was adapted to the first dry cells. Wet cells are still used in automobile batteries and in industry for standby power for switchgear , telecommunication or large uninterruptible power supplies , but in many places batteries with gel cells have been used instead. These applications commonly use lead–acid or nickel–cadmium cells. Molten salt batteries are primary or secondary batteries that use

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7540-655: The Danube River at Vienna , Austria , and then transported by water to Constanța , Romania . The flotilla had an active and successful campaign, based at Yalta and Feodosia . After Italy quit the war, most of the Italian vessels on the Black Sea were transferred to Nazi Germany 's Kriegsmarine . In early 1944, six MAS boats were transferred to the Royal Romanian Navy . By August 1944, they were ultimately captured by Soviet forces when Constanța

7685-766: The Italo-Turkish War against forces of the Ottoman Empire . As the majority of the Ottoman Navy stayed behind the relative safety of the Dardanelles , the Italians dominated the Mediterranean during the conflict winning victories against Ottoman light units at the battles of Preveza and Beirut . In the Red Sea the Italian forces were vastly superior to those of the Ottomans who possessed only

7830-677: The MAS boats , that, by chance, managed to sink the Austro-Hungarian battleship SMS  Szent István in the Adriatic Sea on 10 June 1918; and an early type of human torpedo (codenamed Mignatta , or "leech") carrying two men, which entered the harbour of Pola and planted two magnetic mines during the early hours of the morning which exploded sinking the Austro-Hungarian flagship SMS  Viribus Unitis , with considerable loss of life, on 1 November 1918, shortly after

7975-486: The Zamboni pile , invented in 1812, offers a very long service life without refurbishment or recharge, although it can supply very little current (nanoamps). The Oxford Electric Bell has been ringing almost continuously since 1840 on its original pair of batteries, thought to be Zamboni piles. Disposable batteries typically lose 8–20% of their original charge per year when stored at room temperature (20–30 °C). This

8120-549: The coefficient of fineness . Though the ships were improved, they still were not an equal match for the Queen Elizabeth -class battleships and the Renown -class battlecruisers, both of which carried larger guns and heavier armour. Though scientific research on tracking devices such as radar and sonar was being conducted in Italian universities and military laboratories by men such as Ugo Tiberio and Guglielmo Marconi ,

8265-435: The cruiser HMS  Neptune lost, along with the destroyer HMS  Kandahar . In addition, another destroyer was seriously damaged. All told 800 seamen were lost, and Force K, which had been effectively interdicting Axis convoys, was put out of action. This series of successes allowed the Regia Marina to achieve naval supremacy in the central Mediterranean. Coupled with an intensive bombing campaign against Malta,

8410-524: The "Battle of Mid-June") and Operation Pedestal (the "Battle of Mid-August"). All of these engagements ended favourably for the Axis. Despite this activity, the only real success of the Italian fleet was the surface attack on the Harpoon convoy, supported by Axis aerial forces. These attacks sank several Allied warships and damaged others. Only two transports of the original six in the convoy reached Malta. This

8555-408: The 1870s, under Simone Pacoret de Saint Bon 's ministry, did the situation begin to improve. In 1881, the battleship Duilio was commissioned, followed in 1882 by the battleship Enrico Dandolo ; at the time these were the most powerful warships in the world, and signalled the Italian fleet's renewed power. In 1896 the corvette Magenta completed a circumnavigation of the world. The following year

8700-465: The 1920s, such as Giovanni delle Bande Nere were built with a newly designed and relatively thin armour. This would have a decisive role in a number of naval battles, including the Battle of Cape Spada . Later classes, such as the Zara and Raimondo Montecuccoli classes, were built to a more balanced design with thicker armor. The modernization work on the four Great War era battleships turned into

8845-490: The Adriatic, which was successful with regards to surface units, but failed for the submarines, which found safe harbours and easy passage into and out of the area for the whole of the war. Considered a relatively minor part of the naval warfare of World War I , it nonetheless tied down significant forces. In December 1915, and January 1916, when the Serbian army was driven by the German foces under General von Mackensen toward

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8990-542: The Albanian coast, 138,000 Serbian infantry and 11,000 refugees were ferried across the Adriatic and landed in Italy in 87 trips by the Conte di Cavour and other shps of the Italian Navy under the command of Admiral Conz. These ships also carried 13,000 cavalrymen and 10,000 horses of the Serbian army to Corfu in 13 crossings from the Albanian port of Vallons. For most of the war the Italian navy avoided wherever possible

9135-453: The Austro-Hungarian navy. The Italian fleet lost the destroyer Turbine in 1915 to an Austro-Hungarian fleet sortie; the armoured cruiser Amalfi was sunk by Austrian submarine U-26 on 7 July 1915; the armoured cruiser Giuseppe Garibaldi , sunk by Austrian submarine U-4 on 18 July 1915, the pre-dreadnought battleship Benedetto Brin at Brindisi (27 September 1915) and the dreadnought Leonardo da Vinci at Taranto (2 August 1916) due to

9280-575: The Axis supply routes from southern Europe to North Africa were almost untouched by the Royal Navy or its allies for the next several months. The Italian fleet went on the offensive, blocking or mauling three large Allied convoys bound for Malta. This led to a number of naval engagements, including the Second Battle of Sirte in March 1942, Operation Harpoon and Operation Vigorous , (known as

9425-457: The DPV is bulky and affects precise manoeuvring at close quarters. The DPV occupies at least one hand while in use and may get in the way while performing precision work like macro photography. Since the diver is not kicking for propulsion, they will generally get colder due to lower physical activity and increased water flow. This can be compensated by appropriate thermal insulation. If the operation of

9570-416: The DPV is critical to exit from a long penetration dive, it is necessary to allow for alternative propulsion in case of a breakdown to ensure safe exit before the breathing gas runs out. Control of the DPV is additional task loading and can distract the diver from other matters. A DPV can increase the risk of a silt-out if the thrust is allowed to wash over the bottom. Human torpedoes or manned torpedoes are

9715-488: The Far East, but only two of these vessels were completed before Italy quit the war. Both of these submarines were destroyed by Allied action almost as soon as they were launched. In 1943, Italian dictator Benito Mussolini was deposed and the new Italian government agreed to an armistice with the Allies . Under the terms of this armistice, the Regia Marina had to sail its ships to an Allied port. Most sailed to Malta, but

9860-599: The Indian trawler Parvati became the last naval casualty of the East African Campaign when it struck a moored mine near Assab. In May 1942, at German request, the Regia Marina deployed four 24-ton torpedo motorboats ( Motoscafo Armato Silurante , MAS ), six CB-class midget submarines , five torpedo motorboats, and five explosive motorboats to the Black Sea . The vessels were transported overland to

10005-713: The Italian fleet was formidable, but there were a large number of older vessels, and the service suffered in general from insufficient time at sea for crew training. Italy's lack of raw materials meant that it would have great difficulty building new ships over the course of the war. Thus, the assets that it had were handled with caution by Supermarina . Allied commanders at sea had a fair degree of autonomy and discretion to fight their vessels as circumstance allowed, but Italian commanders were required to confer with their headquarters before committing their forces in an engagement that might result in their loss. That led to delays in arriving at decisions and actions being avoided even when

10150-441: The Italian vessels the ability to minimize close contact with vessels of the Royal Navy, whose crews were more experienced. In theory this would allow them to engage or break off at their own choosing, and would allow them to hit the enemy when he could not yet hit back. New guns were developed with longer ranges than their British counterparts of similar caliber. Speed was emphasized in their new construction. Italian cruisers built in

10295-429: The Italians had a clear advantage. An example occurred during " Operation Hats " in which the Regia Marina had superior forces but failed to commit them to take advantage of the opportunity. A further key disadvantage in the convoy support and interception battles that dominated the Battle of the Mediterranean was the intelligence advantage granted to the British in intercepting German Ultra and, through this,

10440-587: The Italians into " transport submarines " in order to exchange rare or irreplaceable trade goods with Japan. The submarines Alpino Bagnolini , Barbarigo , Comandante Cappellini , Giuseppe Finzi , Reginaldo Giuliani , Enrico Tazzoli , and Luigi Torelli were converted for service with the Monsun Gruppe ("Monsoon Group"). The name of Comandante Cappellini was changed to Aquila III . Twelve additional R-class blockade running transport submarines were specifically designed for trade with

10585-590: The Italians the use of the port of Berbera ; in January 1941, however, British and Commonwealth forces launched a successful counterattack in East Africa and the threat posed by the Red Sea Flotilla disappeared. Much of the Red Sea Flotilla was destroyed by hostile action during the first months of war or when the port of Massawa fell in April 1941. However, there were a few survivors. In February 1941, prior to

10730-484: The Italians. Their sea convoys were harassed day after day by the aerial and naval supremacy of the Allies. The maritime lane between Sicily and Tunisia became known as the "route of death". After years of back and forth, the Axis forces were forced to surrender in Tunisia, bringing the campaign for North Africa to a close. The Regia Marina performed well and bravely in its North African convoy duties, but remained at

10875-528: The Mediterranean alone. Similar vehicles have been made for work divers or sport divers but better streamlined as these do not have warheads; the Dolphin made on the Isle of Wight (UK) in the 1971s is an example. Some Farallon and Aquazepp scooters are torpedo-shaped with handles near the bow and a raised seat at the rear to support the diver's crotch against the slipstream. The Russian Protei-5 and Proton carry

11020-400: The Mediterranean, the four most modern of which were being re-fitted at the outbreak of the war. In addition to the six capital ships, the Italians had 19 cruisers, 59 destroyers, 67 torpedo boats, and 116 submarines. Though the Regia Marina had a number of fast new cruisers with good range in their gunnery, the older classes were lightly built and had inadequate defensive armor. Numerically

11165-475: The Royal Navy for control of the Mediterranean, there had been a lack of emphasis on the incorporation of technological advances such as radar and sonar . This meant that in night engagements or foul weather, the Italian ships were unable to detect the approach of their British adversaries. When engaged, they could only range their guns if they were able to visually locate their targets. The Regia Marina had six battleships with which to contend for control of

11310-481: The active materials, loss of electrolyte and internal corrosion. Primary batteries, or primary cells , can produce current immediately on assembly. These are most commonly used in portable devices that have low current drain, are used only intermittently, or are used well away from an alternative power source, such as in alarm and communication circuits where other electric power is only intermittently available. Disposable primary cells cannot be reliably recharged, since

11455-483: The air. Wet cells were a precursor to dry cells and are commonly used as a learning tool for electrochemistry . They can be built with common laboratory supplies, such as beakers , for demonstrations of how electrochemical cells work. A particular type of wet cell known as a concentration cell is important in understanding corrosion . Wet cells may be primary cells (non-rechargeable) or secondary cells (rechargeable). Originally, all practical primary batteries such as

11600-414: The ammonium chloride is replaced by zinc chloride . A reserve battery can be stored unassembled (unactivated and supplying no power) for a long period (perhaps years). When the battery is needed, then it is assembled (e.g., by adding electrolyte); once assembled, the battery is charged and ready to work. For example, a battery for an electronic artillery fuze might be activated by the impact of firing

11745-408: The amount of breathing gas that can be carried, the rate at which that breathing gas is consumed, which is increased by exertion and diver fatigue, and the time limits imposed by decompression obligation, which depend on the dive profile . Typical uses include cave diving and technical diving where the vehicles help move bulky equipment and make better use of the limited underwater time imposed by

11890-463: The batteries within are charged and discharged evenly. Primary batteries readily available to consumers range from tiny button cells used for electric watches, to the No. 6 cell used for signal circuits or other long duration applications. Secondary cells are made in very large sizes; very large batteries can power a submarine or stabilize an electrical grid and help level out peak loads. As of 2017 ,

12035-428: The battery be kept upright and the area be well ventilated to ensure safe dispersal of the hydrogen gas it produces during overcharging . The lead–acid battery is relatively heavy for the amount of electrical energy it can supply. Its low manufacturing cost and its high surge current levels make it common where its capacity (over approximately 10 Ah) is more important than weight and handling issues. A common application

12180-566: The battery is fully charged then overcharging is likely, damaging it. Regia Marina The Regia Marina ( Italian for 'Royal Navy'; pronounced [ˈrɛːdʒa maˈriːna] ) ( RM ) or Royal Italian Navy was the navy of the Kingdom of Italy ( Regno d'Italia ) from 1861 to 1946. In 1946, with the birth of the Italian Republic ( Repubblica Italiana ), the Regia Marina changed its name to Marina Militare ("Military Navy"). The Regia Marina

12325-659: The border in the Italian invasion of France . By contrast, the Regia Marina prepared to secure the lines of communications between Italy, Libya and the East African colonies. The Italian High Command ( Comando Supremo ) did not approve of the plan devised by the Italian Naval Headquarters ( Supermarina ) to occupy a weakly defended Malta , which proved a crucial mistake. British High Command, thinking that Malta could not be defended because of

12470-703: The capacity. The relationship between current, discharge time and capacity for a lead acid battery is approximated (over a typical range of current values) by Peukert's law : where Charged batteries (rechargeable or disposable) lose charge by internal self-discharge over time although not discharged, due to the presence of generally irreversible side reactions that consume charge carriers without producing current. The rate of self-discharge depends upon battery chemistry and construction, typically from months to years for significant loss. When batteries are recharged, additional side reactions reduce capacity for subsequent discharges. After enough recharges, in essence all capacity

12615-400: The cathode, while metal atoms are oxidized (electrons are removed) at the anode. Some cells use different electrolytes for each half-cell; then a separator is used to prevent mixing of the electrolytes while allowing ions to flow between half-cells to complete the electrical circuit. Each half-cell has an electromotive force ( emf , measured in volts) relative to a standard . The net emf of

12760-449: The cell is the difference between the emfs of its half-cells. Thus, if the electrodes have emfs E 1 {\displaystyle {\mathcal {E}}_{1}} and E 2 {\displaystyle {\mathcal {E}}_{2}} , then the net emf is E 2 − E 1 {\displaystyle {\mathcal {E}}_{2}-{\mathcal {E}}_{1}} ; in other words,

12905-644: The chemical reactions are not easily reversible and active materials may not return to their original forms. Battery manufacturers recommend against attempting to recharge primary cells. In general, these have higher energy densities than rechargeable batteries, but disposable batteries do not fare well under high-drain applications with loads under 75 ohms (75 Ω). Common types of disposable batteries include zinc–carbon batteries and alkaline batteries . Secondary batteries, also known as secondary cells , or rechargeable batteries , must be charged before first use; they are usually assembled with active materials in

13050-452: The chemistry and internal arrangement employed. The voltage developed across a cell's terminals depends on the energy release of the chemical reactions of its electrodes and electrolyte. Alkaline and zinc–carbon cells have different chemistries, but approximately the same emf of 1.5 volts; likewise NiCd and NiMH cells have different chemistries, but approximately the same emf of 1.2 volts. The high electrochemical potential changes in

13195-435: The circuit and reach to the positive terminal, thus cause a redox reaction by attracting positively charged ions, cations. Thus converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of

13340-598: The conflict for almost two years. This action , coming on the heels of the loss of the Prince of Wales and Repulse in the South China Sea, significantly weakened the surface strength of the Royal Navy, making it difficult for them to challenge Italian control of the eastern Mediterranean. On the night of 19 December, Force K , comprising three cruisers and four destroyers based at Malta , ran into an Italian minefield off Tripoli . Three cruisers struck mines, with

13485-941: The conservative Italian leadership had little interest in these new technologies, and did not use them to improve the effectiveness of the Italian vessels. This was mainly due to the influence of Admiral Domenico Cavagnari , whom Mussolini appointed as Chief of Staff of the Navy in 1933, and whom he later promoted to Secretary of the Navy. Likewise technological advancement in radio range finders and gunnery control devices for night combat were not incorporated. Regarding such devices, Cavagnari emphasized "not wanting traps in your way". Writing to Admiral Iachino, he wrote " procedere con estrema cautela nell'accettare brillanti novità tecniche che non siano ancora collaudate da una esperienza pratica sufficientemente lunga ", which can be translated to "proceed with extreme caution regarding brilliant technical innovations that have not yet been tested or with which there

13630-495: The construction of the new Littorio -class battleships; plans were also put in place to modernize the Conte di Cavour -class and Andrea Doria -class battleships. Much of these new naval units were responses to French naval constructions, as the Marine nationale was seen until the mid-1930s as the most likely enemy in a hypothetical conflict. The Regia Marina chose to build fast ships armed with longer ranged guns to give

13775-523: The control of the Mediterranean Sea as an essential prerequisite for expanding his " New Roman Empire " into Nice , Corsica , Tunis and the Balkans . Italian naval building accelerated during his tenure. Mussolini described the Mediterranean as " Mare Nostrum " (Our Sea). Before the declaration of war, Italian ground and air forces had prepared to strike at the beaten French forces across

13920-548: The decompression requirements of deep diving . Military applications include delivery of combat divers and their equipment over distances or at speeds that would be otherwise impracticable. There are accessories that can be mounted to a DPV to make it more useful, such as lights, compasses, and video cameras. Use of a DPV on deep dives can reduce the risk of hypercapnia from overexertion and high breathing rate. DPV operation requires greater situational awareness than simply swimming, as some changes can happen much faster. Operating

14065-607: The demand to as much as 3562 GWh. Important reasons for this high rate of growth of the electric battery industry include the electrification of transport, and large-scale deployment in electricity grids, supported by decarbonization initiatives. Distributed electric batteries, such as those used in battery electric vehicles ( vehicle-to-grid ), and in home energy storage , with smart metering and that are connected to smart grids for demand response , are active participants in smart power supply grids. New methods of reuse, such as echelon use of partly-used batteries, add to

14210-443: The discharged state. Rechargeable batteries are (re)charged by applying electric current, which reverses the chemical reactions that occur during discharge/use. Devices to supply the appropriate current are called chargers. The oldest form of rechargeable battery is the lead–acid battery , which are widely used in automotive and boating applications. This technology contains liquid electrolyte in an unsealed container, requiring that

14355-400: The diver attached to the top. The New Zealand made Proteus is strapped onto the diver's cylinder. The Subskimmer is a submersible rigid-hulled inflatable boat (RIB). On the surface it is powered by a petrol engine, when submerged the petrol engine is sealed and it runs on battery-electric thrusters mounted on a steerable cross-arm. It can self inflate and deflate, transforming itself from

14500-526: The diver does not control the DPV properly, a rapid ascent or descent under power can result in barotrauma or decompression sickness. High speed travel in confined spaces, or limited visibility can increase the risk of impact with the surroundings at speeds where injury and damage are more likely. Many forms of smaller marine life are very well camouflaged or hide well and are only seen by divers who move very slowly and look carefully. Fast movement and noise can frighten some fish into hiding or swimming away, and

14645-435: The diver who holds onto handles on the stern or bow . Tow-behind scooters are most efficient by placing the diver parallel to and above the propeller wash. The diver wears a harness that includes a crotch-strap with a D-ring on the front of the strap. The scooter is rigged with a tow leash that clips to the scooter with releasable metal snap. Swimmer Delivery Vehicles (SDVs) are wet subs designed to transport frogmen from

14790-554: The effort to modernize and re-equip the combat vessels of the navy. These were square rigged school ships the Regia Marina ordered in 1925. The sailing ships followed a design by Lieutenant Colonel Francesco Rotundi of the Italian Navy Engineering Corps, reminiscent of ships of the line from the Napoleonic era . The first of these two ships, Cristoforo Colombo , was put into service in 1928 and

14935-416: The electrodes. Low-capacity NiMH batteries (1,700–2,000 mA·h) can be charged some 1,000 times, whereas high-capacity NiMH batteries (above 2,500 mA·h) last about 500 cycles. NiCd batteries tend to be rated for 1,000 cycles before their internal resistance permanently increases beyond usable values. Fast charging increases component changes, shortening battery lifespan. If a charger cannot detect when

15080-424: The entire navy had been turned over to the newly founded neutral State of Slovenes, Croats and Serbs. The battleship SMS  Tegetthoff (sister of the former two) was handed over to Italy as a war prize in 1919. During the interwar years the Italian government set about modernizing the Regia Marina in a way that could enable it to reach dominance over the Mediterranean Sea. Italian naval planners also wanted

15225-506: The external part of the circuit. A battery consists of some number of voltaic cells . Each cell consists of two half-cells connected in series by a conductive electrolyte containing metal cations . One half-cell includes electrolyte and the negative electrode, the electrode to which anions (negatively charged ions) migrate; the other half-cell includes electrolyte and the positive electrode, to which cations (positively charged ions ) migrate. Cations are reduced (electrons are added) at

15370-580: The fall of Massawa, the colonial ship Eritrea and the auxiliary cruisers Ramb I and Ramb II broke out and sailed to Kobe , Japan . While Ramb I was sunk by the Royal New Zealand Navy cruiser HMNZS  Leander off the Maldives , Eritrea and Ramb II made it to Kobe. As the port of Massawa was falling, four submarines— Guglielmotti , Galileo Ferraris , Perla , and Archimede —sailed south from Massawa, rounded

15515-535: The fastest charging and energy delivery, discharging all its energy into a load in 10 to 20 seconds. In 2024 a prototype battery for electric cars that could charge from 10% to 80% in five minutes was demonstrated, and a Chinese company claimed that car batteries it had introduced charged 10% to 80% in 10.5 minutes—the fastest batteries available—compared to Tesla's 15 minutes to half-charge. Battery life (or lifetime) has two meanings for rechargeable batteries but only one for non-chargeables. It can be used to describe

15660-422: The high temperature and humidity associated with medical autoclave sterilization. Standard-format batteries are inserted into battery holder in the device that uses them. When a device does not uses standard-format batteries, they are typically combined into a custom battery pack which holds multiple batteries in addition to features such as a battery management system and battery isolator which ensure that

15805-402: The highest share of the dry cell rechargeable market. NiMH has replaced NiCd in most applications due to its higher capacity, but NiCd remains in use in power tools , two-way radios , and medical equipment . In the 2000s, developments include batteries with embedded electronics such as USBCELL , which allows charging an AA battery through a USB connector, nanoball batteries that allow for

15950-435: The island of Vis in the Adriatic Sea . That was one of the few fleet actions of the 19th century and as a major sea battle that involved ramming , it is often considered to have had a profound effect on subsequent warship design and tactics. The Italian fleet, commanded by Admiral Persano, mustered 12 ironclad and 17 wooden-hulled ships, though only one, Affondatore , was of the most modern turret ship design. Despite

16095-486: The key information on Italian convoy routes, times of departure, time of arrival, and make up of the convoy. The warships of the Regia Marina had a general reputation as being well-designed. Italian small attack craft lived up to expectations and were responsible for many successful actions in the Mediterranean. Though Italian warships lacked radar , that was partly offset in fair weather by good optical rangefinder and fire-control systems. The Italian Navy lacked

16240-429: The large-scale use of batteries to collect and store energy from the grid or a power plant and then discharge that energy at a later time to provide electricity or other grid services when needed. Grid scale energy storage (either turnkey or distributed) are important components of smart power supply grids. Batteries convert chemical energy directly to electrical energy . In many cases, the electrical energy released

16385-520: The length of time a device can run on a fully charged battery—this is also unambiguously termed "endurance". For a rechargeable battery it may also be used for the number of charge/discharge cycles possible before the cells fail to operate satisfactorily—this is also termed "lifespan". The term shelf life is used to describe how long a battery will retain its performance between manufacture and use. Available capacity of all batteries drops with decreasing temperature. In contrast to most of today's batteries,

16530-494: The long naval traditions of its constituents, especially those of Sardinia and Naples, but also suffered from some major handicaps. Firstly, it suffered from a lack of uniformity and cohesion; the Regia Marina was a heterogeneous mix of equipment, standards and practice, and even saw hostility between the officers from the various former navies. These problems were compounded by the continuation of separate officer schools at Genoa and Naples , and were not fully addressed until

16675-425: The net emf is the difference between the reduction potentials of the half-reactions . The electrical driving force or Δ V b a t {\displaystyle \displaystyle {\Delta V_{bat}}} across the terminals of a cell is known as the terminal voltage (difference) and is measured in volts . The terminal voltage of a cell that is neither charging nor discharging

16820-422: The number of holding vessels, a stronger charge could be stored, and more power would be available on discharge. Italian physicist Alessandro Volta built and described the first electrochemical battery, the voltaic pile , in 1800. This was a stack of copper and zinc plates, separated by brine-soaked paper disks, that could produce a steady current for a considerable length of time. Volta did not understand that

16965-437: The number of times the battery can be recharged. Most nickel-based batteries are partially discharged when purchased, and must be charged before first use. Newer NiMH batteries are ready to be used when purchased, and have only 15% discharge in a year. Some deterioration occurs on each charge–discharge cycle. Degradation usually occurs because electrolyte migrates away from the electrodes or because active material detaches from

17110-443: The open top and needed careful handling to avoid spillage. Lead–acid batteries did not achieve the safety and portability of the dry cell until the development of the gel battery . A common dry cell is the zinc–carbon battery , sometimes called the dry Leclanché cell , with a nominal voltage of 1.5 volts , the same as the alkaline battery (since both use the same zinc – manganese dioxide combination). A standard dry cell comprises

17255-411: The opening of a unified Naval Academy at Livorno in 1881. Secondly, unification occurred during a period of rapid advances in naval technology and tactics, as typified by the launch of Gloire by France in 1858, and later by the appearance of, and battle between, USS  Monitor and CSS  Virginia in 1862. These innovations quickly made older warships obsolete. Italy did not possess

17400-631: The original composition of the electrodes can be restored by reverse current. Examples include the lead–acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and mobile phones . Batteries come in many shapes and sizes, from miniature cells used to power hearing aids and wristwatches to, at the largest extreme, huge battery banks the size of rooms that provide standby or emergency power for telephone exchanges and computer data centers . Batteries have much lower specific energy (energy per unit mass) than common fuels such as gasoline. In automobiles, this

17545-408: The overall utility of electric batteries, reduce energy storage costs, and also reduce pollution/emission impacts due to longer lives. In echelon use of batteries, vehicle electric batteries that have their battery capacity reduced to less than 80%, usually after service of 5–8 years, are repurposed for use as backup supply or for renewable energy storage systems. Grid scale energy storage envisages

17690-492: The proximity of Regia Aeronautica air bases in Italy , Sicily , and Libya , had put little effort into bolstering the islands' defences. Thus, at the outset of the war there were only 42 anti-aircraft guns on the island and twelve Gloster Sea Gladiators , half sitting in crates at the wharf. Entering the war, the Regia Marina was operating under a number of limitations. Though significant assets were available to challenge

17835-414: The range of the swimmer's scuba equipment. SDVs are typically used to land special operations forces or plant limpet mines on the hull of enemy ships. In the former usage, they can land a combat swimmer team covertly on a hostile shore in order to conduct missions on land. After completing their mission, the team may return to the SDV to exfiltrate back to the mother-ship. For extended missions on land,

17980-440: The reactions of lithium compounds give lithium cells emfs of 3 volts or more. Almost any liquid or moist object that has enough ions to be electrically conductive can serve as the electrolyte for a cell. As a novelty or science demonstration, it is possible to insert two electrodes made of different metals into a lemon , potato, etc. and generate small amounts of electricity. A voltaic pile can be made from two coins (such as

18125-404: The ships and range their weapons at distance and at night. The better air reconnaissance skills of the Royal Navy's Fleet Air Arm and their close collaboration with surface units were other major causes of the Italian debacle. On 19 December 1941, the battleships HMS  Queen Elizabeth and HMS  Valiant were damaged by limpet mines planted by Italian frogmen , knocking both out of

18270-633: The shipyards or infrastructure to build the modern ships required, but the then Minister for the Navy, Admiral Carlo di Persano , launched a substantial programme to purchase warships from foreign yards. The new navy's baptism of fire came on 20 July 1866 at the Battle of Lissa during the Third Italian War of Independence (parallel to the Seven Weeks War ). The battle was fought against the Austrian Empire and occurred near

18415-575: The standoff ability to attack from up to 3 nautical miles (5.6 km) away. The origins of the SDV stems from the Italian human torpedoes and the British Motorised Submersible Canoe used during World War II. These are torpedo or fish-shaped vehicles for one or more divers typically sitting astride them or in hollows inside. The human torpedo was used to great effect by commando frogmen in World War II , who were able to sink more than 100,000 tons worth of ships in

18560-546: The start of the war, but neither was ever completed. Lastly, the lack of natural oil reserves and subsequent shortage of oil precluded extensive fleet operations. The Regia Marina and the Royal Navy engaged in a two-and-a-half-year struggle for control of the Mediterranean. The Regia Marina 's primary goal was to support the Axis forces in North Africa while obstructing the supply route to Alexandria and cutting off supplies to Malta. The Royal Navy's major effort

18705-447: The technology uses less expensive, earth-friendly materials such as sodium extracted from seawater. They also have much longer life. Sony has developed a biological battery that generates electricity from sugar in a way that is similar to the processes observed in living organisms. The battery generates electricity through the use of enzymes that break down carbohydrates. The sealed valve regulated lead–acid battery (VRLA battery)

18850-414: The units h . Because of internal resistance loss and the chemical processes inside the cells, a battery rarely delivers nameplate rated capacity in only one hour. Typically, maximum capacity is found at a low C-rate, and charging or discharging at a higher C-rate reduces the usable life and capacity of a battery. Manufacturers often publish datasheets with graphs showing capacity versus C-rate curves. C-rate

18995-428: The voltage was due to chemical reactions. He thought that his cells were an inexhaustible source of energy, and that the associated corrosion effects at the electrodes were a mere nuisance, rather than an unavoidable consequence of their operation, as Michael Faraday showed in 1834. Although early batteries were of great value for experimental purposes, in practice their voltages fluctuated and they could not provide

19140-492: The war, the Regia Marina spent its minor efforts in the Adriatic Sea , opposing the Austro-Hungarian Navy . The resulting Adriatic Campaign of World War I consisted mainly of Austro-Hungarian coastal bombardments of Italy's Adriatic coast, and wider-ranging German/Austro-Hungarian submarine warfare into the Mediterranean. Allied forces mainly limited themselves to blockading the Austro-Hungarian navy inside

19285-600: The world's largest battery was built in South Australia by Tesla . It can store 129 MWh. A battery in Hebei Province , China, which can store 36 MWh of electricity was built in 2013 at a cost of $ 500 million. Another large battery, composed of Ni–Cd cells, was in Fairbanks, Alaska . It covered 2,000 square metres (22,000 sq ft)—bigger than a football pitch—and weighed 1,300 tonnes. It

19430-702: Was captured. The five surviving midget submarines were transferred to the Royal Romanian Navy. The Regia Marina operated a squadron of four MAS boats on Lake Ladoga during the Continuation War (1941–1944). As part of Naval Detachment K , German, Italian, and Finnish vessels operated against Soviet gunboats, escorts and supply vessels during the Siege of Leningrad between 21 June and 21 October 1942. The Italian vessels were ultimately turned over to Finland. The Regia Marina had

19575-613: Was delayed for many reasons and was never carried out. Initially, Italian forces enjoyed considerable success in East Africa. From 10 June 1940, the Regia Marina 's Red Sea Flotilla , based at Massawa , Eritrea , posed a potential threat to Allied shipping crossing the Red Sea between the Indian Ocean and the Mediterranean Sea. This threat increased in August 1940 with the Italian conquest of British Somaliland , which allowed

19720-442: Was electrically propelled, with two crewmen in diving suits and rebreathers riding astride. They steered the torpedo at slow speed to the target, used the detachable warhead as a limpet mine and then rode the torpedo away. The nose of the torpedo was filled with pounds of TNT and would be hung under a ship's keel. The idea was successfully applied by the Italian navy ( Regia Marina ) early in World War II and then copied by

19865-442: Was established on 17 March 1861 following the proclamation of the formation of the Kingdom of Italy . Just as the Kingdom was a unification of various states in the Italian peninsula , so the Regia Marina was formed from the navies of those states, though the main constituents were the navies of the former kingdoms of Sardinia and Naples . The new Navy inherited a substantial number of ships, both sail- and steam-powered, and

20010-494: Was inflicted on the Regia Marina at Cape Matapan , where the Royal Navy and the Royal Australian Navy intercepted and destroyed three heavy cruisers ( Zara , Pola and Fiume ; all of the same class) and two Oriani -class destroyers in a night ambush, with the loss of over 2,300 seamen. The Allies had Ultra intercepts, which uncovered the Italian movements, and radar , which enabled them to locate

20155-634: Was instrumental in delivering and supplying the invasion forces through Somali and Eritrean ports. At the time of the Italian intervention in the Spanish Civil War , the Regia Marina sent naval units in support of the Italian Corps of Volunteer Troops ( Corpo Truppe Volontarie ). Approximately 58 Italian submarines took part in operations against the Spanish Republican Navy . These submarines were organized in

20300-417: Was making the noise of a pig while moored on the beach. The British versions were named " chariots ". The Motorised Submersible Canoe (MSC), nicknamed Sleeping Beauty , was built by British Special Operations Executive (SOE) during World War II as an underwater vehicle for a single frogman to perform clandestine reconnaissance or attacks against enemy vessels. The most common type of DPV tows

20445-840: Was manufactured by ABB to provide backup power in the event of a blackout. The battery can provide 40 MW of power for up to seven minutes. Sodium–sulfur batteries have been used to store wind power . A 4.4 MWh battery system that can deliver 11 MW for 25 minutes stabilizes the output of the Auwahi wind farm in Hawaii. Many important cell properties, such as voltage, energy density, flammability, available cell constructions, operating temperature range and shelf life, are dictated by battery chemistry. A battery's characteristics may vary over load cycle, over charge cycle , and over lifetime due to many factors including internal chemistry, current drain, and temperature. At low temperatures,

20590-518: Was put into service in July of that year. She is still being used to this day. In 1928, the unified command of the " Armata Navale " was abolished, and the fleet was divided in two squadrons ( Squadre navali ), one based at La Spezia and the other based at Taranto. The Regia Marina played a limited role in the invasion of Ethiopia . While the Ethiopian Empire was landlocked, the navy

20735-579: Was the only undisputed squadron-sized victory for Italian surface forces in World War II. Despite the heavy losses suffered by the merchantmen and escorting forces of convoy Pedestal, the oil and supplies brought through allowed the near starving island of Malta to continue to hold out. With Allied landings in North Africa, Operation Torch , in November 1942, the fortunes of war turned against

20880-532: Was to maintain supply to the military forces and people of Malta, and secondarily to interdict convoy shipments to North Africa. The first major action occurred on 11 November 1940 when the British aircraft carrier HMS  Illustrious launched two waves of Fairey Swordfish torpedo-bombers in a surprise raid against the Italian Fleet moored at the naval base of Taranto . The raid came in undetected, and three battleships were sunk. Another major defeat

21025-460: Was used by the Italian Navy for training until 1943. After World War II , this ship was handed over to the Soviet Union as part of war reparations and was shortly afterwards decommissioned. The second ship of the design was Amerigo Vespucci . The ship was built in 1930 at the (formerly Royal) Naval Shipyard of Castellammare di Stabia ( Naples ). She was launched on 22 February 1931, and

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