Submarines

# How do submarines float and dive?

Sinking a Submarine (or any other vessel) is pretty easy - with enough water it'll sink straight to the bottom of the ocean real fast. The key is getting the number of surfaces to equal the number of dives.

Submarines use several systems along with fixed ballast to decrease buoyancy to submerge, or increase it to surface:

1. Main Ballast Tanks (MBT's)

2. Trim Ballast Tanks (Trim Tanks)

3. Trim/Dive Planes

4. Main Propulsion Systems

Like all vessels, submarines have fixed and variable ballast weight. Her fixed ballast, essentially just iron weights, allow the boat to remain on the surface in a positive buoyancy state, i.e., floating on the surface but mostly submerged. All pictures you see of surfaced submarines only show about a 1/4 of the actual hull above water. Variable ballast, consisting of Main and Trim Ballast tanks, as well as personnel and all supplies onboard, help the boat maintain submerged operations at fixed or variable depths as required.

A boat's fixed ballast weight is a known variable; it is the addition or removal of variable ballast that must be closely monitored. All supplies and personnel (including weapons load-out) are monitored and estimated weight is calculated so that when the MBT's are purged and filled, the crew already knows how much trim ballast water to bring in to achieve a state of Neutral Buoyancy, which is a submerged state in which the boat neither rises nor sinks. Achieving Neutral Buoyancy is also used by Scuba Divers for maintaining their own depth control.

Without knowing an estimate of pre-submergence ballast amount, too much variable ballast can sink her too far upon submerging. If you're wondering, the boat's crush depth or the bottom of the ocean is considered too far, whichever comes first.

The calculations must be continually updated during longer missions, as supplies are used and trash is put overboard via the trash tube, or exercise weapons are shot.

For anyone who is certified in SCUBA, the principles are essentially the same. A diver, using a combination of personal weight and added lead weights for fixed ballast, uses air inflated into, or deflated from, a buoyancy compensator (variable ballast) to adjust for neutral, positive, or negative buoyancy. The only difference is that divers initially make themselves negatively buoyant to get beneath the water.

Water temperature and salinity are also variables and affect variable ballast. For example, due to the cold freshwater ice of the Polar ice cap, water in the Arctic has a lower salinity level than the open ocean. Since colder temperatures affect density, and lower salinity causes less buoyancy, submerged operations under the ice must take this into account for ballasting purposes.

The Main Ballast Tanks are nothing more than large sections between the outer hull and inner hull. Submarines have 2 hulls, much like a thermos bottle; the outer Superstructure which is visible, and the inner Pressure hull, which houses the crew. The bottom of a tank has an open grate, where the top of the tank has a hydraulically activated valve. Think about a bottle without a bottom and a cork in it; if you put it in water and pull the cork the air is forced out by the water pressure - same principle. The pressure on the air inside the tank when surfaced is enormous - to dive the boat, the MBT valves are opened, and the sea pressure forces the air out of the tank through the open valve. Once the tanks are full of water, the valves are closed. As with all onboard systems, the MBT valves, which are physically located on the main deck of the Superstructure, can be opened or closed hydraulically or manually.

After submerging, the Chief of the Watch (the primary operator of the key diving and control systems for the boat) will bring in or pump out water from several Trim Ballast Tanks (used for ship leveling and minor ballast adjustments as the boat moves to specific depths) on the boat. Trimming the boat gets the boat to Neutral Buoyancy. The Chief of the Watch takes orders from the Diving Officer, who is in charge of keeping the boat at NB while submerged. The Diving Officer also gives orders to the Helmsman and Planesman (Helmsman steers, Planesman maintains depth) as necessary, and the Trim/Dive planes and ship propulsion help maintain the boat on depth until the Trim tanks can be adjusted to the new depth, if required.

From there the Dive Planes take over for moving deep or shallow. Older WW2 era submarines used Bow Dive Planes, which were located at the bow of the boat. When the Teardrop Hull shape used today was developed, the Dive Planes were moved to the Fairwater, which is the superstructure above the hull that houses the periscopes and other masts. It is often incorrectly called a Conning Tower, which is a holdover from the older Fleet type submarines of WWI and WWII. The boat was controlled (conned) by the CO from an area above the main control room where the helm and planesmen and other crew were during an attack. The correct term for submarines with dive planes on the Fairwater is Fairwater Planes. For planes on the bow, they are called Bow Dive Planes, or simply Bow Planes.

Fairwater Planes have their problems though. In rough water, if the boat is at Periscope Depth, and is inadvertently sucked to the surface by a large enough wave, the boat can lose its depth control ability very quickly. If in a tactical situation, it makes it even more dicey if non-discovery is imperative. For this reason. the new Seawolf and Virginia class boats have gone back to Bow Planes, which give the boat depth control whether the sail is out of the water or not. A boat with a broached sail and bow planes can dive much faster than one with Fairwater planes can, since the latter must rely on bringing on more trim ballast to submerge when the primary control surfaces are out of the water.

There are 2 primary methods of surfacing a boat - an "Emergency Blow", used in emergency situations to surface rapidly, and a "Low Pressure Blow".

During an EB, compressed air stored in tanks (outside the pressure hull in the MBT's) is released rapidly into the Main Ballast Tanks to expel water and thus create Positive Buoyancy. The other method is a Low Pressure Blow, using the boat's onboard Low Pressure Blower (essentially a large fan blower) to slowly blow air into the MBT's. This is only used near the surface at Periscope Depth, as it requires the Snorkel Mast to be raised. Utilizing the LPB saves vital compressed air, which is used for emergency systems and weapon ejection. A Low Pressure Blow is the most common method of surfacing a Submarine in a non-emergency situation. The backup Diesel Generator exhaust can also be used in place of the LPB if needed, though the ship's ventilation system must be rigged to pipe the exhaust to the ballast tanks.

If you've seen pictures or film of a boat's bow coming out of the water at a steep angle at high speed, that's the result of an emergency blow at deep depth. It takes about 90 seconds from Test Depth to broach the surface, with the engines pushing the boat at full or flank speed. It's a hell of ride, and one that we all looked forward to as we didn't get to do it often, just for drills or certifications. Once the boat broaches, it sinks back down to about PD, and the LPB is used to fully surface the boat.

It is important to also note that the boat's propulsion type (Diesel-Electric or Nuclear) plays a big role in keeping the boat on course and depth. Without functional propulsion, any major casualty is next to impossible to deal with. It is this fact that is believed to be at the heart of the USS Thresher's loss.

In those days, during any casualty, the procedure was to perform a Reactor Scram (inserting all Control Rods to slow reaction to minimum), or to shut down the reactor. This left her without vital propulsion power after a major hull valve ruptured and left her with a major flooding casualty to fight. Pressure at deeper depths compresses air, and any air dumped into the MBT's during an emergency blow will take time to expand as the boat heads for shallower water. However, without functional propulsion, if the boat is sinking already, it's fighting a losing battle. Without the aid of her main engines to push her to the surface, Thresher's sinking was inevitable.

The loss of the Thresher led to many changes in the Nuclear Submarine program in the U.S. (SUBSAFE QA program), and for other Allied Nations with similar capability. Since the institution of the SUBSAFE program, there has not been a similar accident in the U.S. submarine fleet.
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Inventions
Submarines

# Who invented the submarine?

Submarines were envisioned long ago as an undersea weapon to be used against surface ships, but technology could not deliver one for practical naval warfare for hundreds of years following their ideation.

Though modern historians credit the submarine's invention to one individual, it's not quite that cut and dry. As it is probable that the earliest sailors wondered what it might be like to sail beneath the sea, it might be best to say that the submarine appeared as the result of a journey of many technological and scientific steps over hundreds of years. The creation of a pressure hull of sorts had to be coupled with solutions to problems associated with buoyancy as well as water pressure. All this had to be merged with weapons, crew facilities, and the critical issue of suitable propulsion, air, ballast control, etc. Imagine trying to build a fully functioning submarine with the tools of a blacksmith.

While there were many who contributed to submarine development over the centuries, there are several key individuals who are responsible for advancing submarine design, development, and engineering over the course of several hundred years, ultimately leading to the technologically advanced submarines we have today:

Leonardo da Vinci

Cornelius Jacobszoon Drebbel

William Bourne

David Bushnell

Robert Fulton

Horace Hunley

John P. Holland

Hyman G. Rickover

Leonardo da Vinci

Leonardo da Vinci conceptualized the submarine, and it is possible (probable) that others could have thought of the idea of an undersea vehicle, but the technology to put a working model in the water and safely and effectively operate it didn't come along for over a century following Leonardo.

William Bourne /Cornelius Jacobszoon Drebbel

Historians credit the invention of the submarine to William Bourne, a British mathematician and ex-Royal Navy gunner who published a design in 1578. The first navigable submarine for which reliable construction data exists was built from Bourne's design in 1620 by Cornelius Jacobszoon Drebbel, a Dutch inventor in the employ of King James I of England.

David Bushnell's Turtle

David Bushnell's submarine Turtle, designed by Bushnell and built in Old Saybrook, Connecticut in 1775, was so named because it looked like a turtle due to its shape. It was manually powered, constructed of wood, heavily covered in pitch and reinforced with metal bands. Though it is considered the first submarine used in combat (Revolutionary War) its attacks on British warships were never successful. This was due in large part because it didn't have a way to penetrate the copper cladding around the lower part of British warship hulls. It was sunk by the British while attached to its tender.

Robert Fulton's Nautilus

Robert Fulton's submarine Nautilus, designed between 1793-97, was the first practical working submarine design of record. It had a working ballast system, successfully dove to 25 feet and returned to the surface without any deaths, and successfully attacked stationary targets.

Living in France at the time, Fulton petitioned the French Government twice to fund his project, but was rejected. He later approached the French Minister of Marine to subsidize the construction, and was finally given permission in 1800. Though it had initially impressed the French during trials, the Nautilus suffered from leaks, which is the primary reason Fulton gave up. When Napoleon wanted to see it, he found that Fulton had already dismantled the Nautilus and destroyed many of its key components. Napoleon thought that Fulton was a charlatan, and the French Navy had no use for what they believed then to be a suicidal machine.

Even though Fulton's project didn't continue, the British, wanting to keep control over what appeared to them to be a potentially lethal device, brought Fulton to Britain to continue his submarine work. However, with Nelson's victory over the French fleet at the Battle of Trafalgar, the French threat was eliminated, and Fulton was ignored until he finally left to return to America. His papers were left at the U.S. Consul in London, and went undiscovered until 1920. He never again worked on submarine designs, though his contributions to submarine development are still remembered and honored today.

Horace L. Hunley & the H.L. HunleySubmarine

While its place in submarine evolution is small, her place in changing Naval Warfare history forever is significant. The first submarine to successfully sink an enemy combatant, the H.L. Hunley, was commandeered by the Confederate States' Army from its inventor, Confederate Marine Engineer Horace Lawson Hunley, and his business partners.

Built specifically as a submarine by Hunley, it incorporated a hand-cranked screw (7 crewmen) for propulsion, 2 watertight hatches, 2 conning towers (fore and aft), and a working ballast system. Her spar torpedo (essentially a long pole with a remote-detonated explosive charge on the end) was designed to pierce wooden ships with the charge, then back away and detonate it from a safe distance using an attached wire.

It was successfully used to attack and sink the Union sloop-of-war USSHousatonic on February 17, 1864, then anchored in Charleston Harbor, during the the Civil War Union blockade of Charleston, S.C. Often incorrectly referred to as the CSS Hunley, it in fact was never a commissioned warship in the Confederate States of America. It was commandeered by the Confederate Army, crewed by 1 Confederate sailor and 8 Confederate Army soldiers.

Though the Hunley was thought to have been sunk by the explosion of the attack, investigation of historical records showed that she had signaled her base on Sullivan's Island with a blue carbide lamp that her attack was successful, and that she was returning to base. New forensic evidence uncovered after the recovery of the Hunley several years ago revealed that her crew likely died of asphyxiation due to lack of oxygen, while returning to Sullivan's Island. One key factor is that the crew remains were found at their posts, rather than grouped near an exit, which would be the natural response to sinking.

Had they successfully returned from her mission, it is likely that submarine engineering and evolution would've advanced a lot faster than it did.

John Phillip Holland & the Diesel-Electric Submarine

The "better" submarine design, over 30 years after the Hunley's sinking, incorporated internal combustion engines, electric motors, generators, and battery technology. John Phillip Holland's USS Holland(SS-1), the U.S. Navy's first commissioned submarine (launched in May 1897, commissioned in 1900), was the first real effective submarine design. Incorporating rechargeable battery technology and combustion engines for surface transit/battery charging, the Holland is considered the forerunner of all modern submarines.

Holland was also the first to apply for and receive patents on key submarine technology, much of which is essentially the same today, though more advanced in some areas. The company founded to build submarines to his designs, Electric Boat, still survives as one of the United States' premier submarine builders, General Dynamics' Electric Boat Division, in Groton, CT.

Hyman G. Rickover, Nuclear Power, and the Nautilus

Not until the advent of Nuclear Power and the vision of Naval Engineer Hyman G. Rickover (Admiral Rickover, "Father of the Nuclear Navy"), did submarines become true submersibles.

Until that time, submarines were essentially designed as surface vessels that had a limited submerged operational capability, and were designed to run faster on the surface than underwater. Captured U-boats after WWII showed how far the Germans had advanced the art of submarine hull design and technology; while many of these innovations found their way into modern submarines, it was Rickover who realized that harnessing a nuclear reactor in a small design used to power submarines (and later ships) would give submarine warfare a significant technological boost. Unlike diesel-electric technology, nuclear power offers the advantage of huge power generation, which means better equipment (sensors, weapons, navigation, huge fresh water / air generating capacity, etc.), underwater speed (a major departure from previous designs) and virtually unlimited cruising range.

With Rickover's successful pressurized-water reactor design (still in use today) installed on the United States' (and the world's) first nuclear powered submarine, USS Nautilus (SSN-571), nuclear power changed submarine technology and warfare from the limited role that it had in previous conflicts to the multiple mission threat it is today.

The application of Nuclear Power "sealed the deal" and allowed for the development of the highly capable and extremely complex modern submarine. Modern boats are only limited by her crew requirements, can dive deeper and move much faster underwater than on the surface, and have many different tactical capabilities. They are true submarines by every definition.

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Submarines

# How do you get submarine disqualified?

There are quite a few different ways, but the screening process is pretty rigorous, so it doesn't happen that often. However, the most common is a medical DQ. Submarines aren't exactly the most healthiest of places to work (I was medically DQ'd for asthma after 5 years aboard my boat), and medical DQ's happen more than is commonly known. If problems don't get you while you're on active duty, something usually crops up after you leave the Navy.

Other ways are losing your security clearance (you need a minimum Secret clearance to be a crewmember), psychological problems (doesn't happen that often since they can't tell the wackos from the normal submariners, at least not easily), accidents, suicide, or major disciplinary infractions (drugs, etc.).

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Submarines

# What is keel of submarine?

The keel of a submarine (or any ship for that matter) is the backbone of the ship, and its primary structural element. Keels are always laid first during shipbuilding, and structural supports are added over time to it. Laying a keel is typically done with a ceremony.

A keel is similar to a human spine, though it's on the bottom of the ship. Like a spine, it is the key support structure of the vessel; if a keel is broken, the ship usually will lose structural integrity altogether and sink. This is often what happens when ships run aground.

Breaking a ship's keel is also the primary method of how modern torpedoes work. Rather than just impact them, they swim under the ship and explode, creating an air pocket beneath the keel. The bow and stern of the ship cannot support the full weight of the ship in the middle, and the keel breaks, snapping the ship in half.

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Technology
Submarines

# What are negative impacts of submarines have on life?

Contrary to activist groups claims, Navy ships and submarines rarely use active sonar. Active sonar produces sound, and lots of it, that gives away a vessel's position to other enemy ships and submarines.

The biggest impact that subs have on marine life, is that they pump waste overboard. Sewage is very popular with schools of fish, because the think it tastes great. Oil being pumped overboard is bad. The crews make every effort not to pump oily waste overboard. There are collection tanks just for oily water and such.

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WW2 Naval Warfare
WW1 Naval Warfare
Submarines

# What does Unrestricted Submarine Warfare refer to?

Unrestricted Submarine Warfare (URSW) is a Naval doctrine in which a submarine will attack any vessel carrying a flag of its enemies, its enemies' allies, or others suspected of giving aid to an enemy, without warning or provocation. The doctrine applies to any vessel, whether it is civilian or military in nature, large or small.

HISTORY

Prior to WWI, belligerents observed "Prize" or "Cruiser" rules, which stated that the ship couldn't sink a passenger ship, only a merchant vessel of an enemy nation, and that the crew/passengers aboard any vessel must be clear and safe before it was sunk. These rules were from the days of sailing vessels, and with WWI and the advent of submarine warfare and modern weapons, it didn't take long to determine that those rules were obsolete. This was essentially the basis for Germany's initial submarine warfare policy.

Though Germany initially tried to comply with Prize Rules, as WWI submarine warfare progressed, it became apparent that those rules were outdated and even dangerous. With its practice of warning ships and allowing passengers and crew to leave prior to sinking, it meant that the attacking submarine would be a sitting duck to any enemy vessels or aircraft. The ship's crew only needed to summon military assistance by radio, and the passengers and crew could take their time to evacuate the ship, giving time for aid to arrive.

URSW & THE SINKING OF THE BRITISH PASSENGER LINER RMS LUSITANIA

On May 1, 1915, the British passenger liner RMS Lusitania departed New York for Britain. Just a few days earlier, Germany had released this notice via its embassy in Washington, D.C.:

Notice!Travelers intending to embark on the Atlantic voyage are reminded that a state of war exists between Germany and her allies and Great Britain and her allies; that the zone of war includes the waters adjacent to the British Isles; that, in accordance with formal notice given by the Imperial German Government, vessels flying the flag of Great Britain, or any of her allies, are liable to destruction in those waters and that travelers sailing in the war zone on the ships of Great Britain or her allies do so at their own risk.

Imperial German Embassy

Washington, D.C. 22nd April 1915

On May 6, 1915, the British passenger liner RMS Lusitania was torpedoed by the German U-boat U-20, just 11.5 miles off the coast of Ireland, sinking in 18 minutes. Of the 1198 passengers who died, almost 100 were children, and she also carried 139 Americans, 128 of which died in the sinking. Among the passengers were many American and British dignitaries and luminaries of the day.

The resulting world public backlash pressured the German leadership to revert to a policy of Restricted Submarine Warfare. They reverted back to URSW in 1917 to counter the British blockade of Germany, hoping to break the back of British shipping and to delay the U.S. entry into the war, but by then it was too late. Had they held fast and continued their policy of URSW after the Lusitania, WWI may have turned out much differently, as URSW and advancements in submarine warfare in general were relatively new during WWI. As a result, Anti-Submarine Warfare (ASW) techniques had not yet significantly progressed enough to deter a significant submarine threat if Germany had continued.

Their reversion back to a URSW policy was also one of the key elements leading to the entry of the United States into WWI.

UNRESTRICTED SUBMARINE WARFARE DURING WWII

Until the advent of the escorted convoy system and improved Anti-Submarine Warfare (ASW) techniques, German U-boats during WWII conducting URSW in the Battle of the Atlantic caused devastating losses for Allied shipping. However, contrary to Hollywood fiction and wartime propaganda, it is well known that many U-Boat commanders would give aid (including food, water, and blankets) to survivors and point them toward the nearest land, despite official Nazi policy.

Following the Japanese attack on Pearl Harbor and its declaration of war on America, one of the first commands to deployed Pacific-fleet U.S. submarine commanders was to "Execute Unrestricted Submarine Warfare" against Japan. It was this policy that bought the U.S. enough time to repair the fleet at Pearl Harbor, and help reinforce the Carrier Groups that had survived to counter the Japanese expansion into the Pacific. Japan's failure to deal with the U.S. submarine threat helped speed her defeat in the Pacific Theatre.

LEGACY

Even today, the mere threat of URSW can tie up a fleet's resources. During the Falklands War in 1982, the sinking of the Argentine Navy Cruiser ARA General Belgrano by the British nuclear submarine HMS Conqueror, had a chilling effect on Argentine Naval operations. After the sinking, the entire Argentine Navy fleet retired back to port for the remainder of the war, save for their one remaining conventional DE submarine, the ARA San Luis.

The British, having captured and scuttled the only other Argentine submarine, remained on the defensive as a result of the San Luis' presence. Though the San Luis failed to successfully attack 2 British ships (some torpedoes missed, others were dealt with by torpedo countermeasures), the threat from the San Luis tied up one carrier, eleven destroyers, five nuclear-powered submarines, one diesel submarine, and over 25 helicopters.
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Submarines
Nuclear Weapons

# How fast can a nuclear submarine submerge?

It depends on the size of the boat and the type of water it's in (saltwater is more buoyant than fresh), but in most cases the average time is less than a minute from popping the corks on the Main Ballast Tanks to the time the Sail clears the waterline. The pictures you see of today's modern submarines only show about the top 1/5 of the boat; the rest is underwater. Once the Main Ballast Tanks start flooding and all that water comes in, it doesn't take much time to get underwater.

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Submarines
US Navy

# What does BB mean for a navy ship?

Prior to 1920, the USN used the designations B for battleship and then a hull number, such as B-1, B-2, etc. Same for destroyers, etc. D-1, D-2, etc. After WW1 (1918) a wider variety of naval vessels began to enter the USN inventory...blimps (airships/balloons), submarine tenders, salvage vessels, aircraft carriers (heavier than air vs airships), etc. Those vessels REQUIRED more than one letter, such as the aircraft carrier; the carrier (CV) was "C" for carrier and "V" for heavier than air (airplanes, not balloons). So, for paper work purposes, two letters were needed to maintain consistency and uniformity. Without such an organization, confusion would result. In 1920, the new designation for battleships and destroyers became BB & DD; "B" for battleship and "D" for destroyer, the second letters "B" and "D" meant nothing, other than making battleships and destroyers easier to document during administrative functions.

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Submarines

# What steel is used in US submarines?

HY80 steel and variants, a flexible steel alloy, has for decades been used on modern U.S. and Allied submarines. Its flexible properties are what makes it an asset - it contracts and expands as sea pressure increases/decreases with submerged operations. Internal submarine decks are not actually attached to the hull - they're actually hanging from from suspended cables and the decks are several inches from the sides of the hull to allow for the contraction as the boat goes deep.

About 25 years ago, there was a lot of controversy about the Russian ALFA class Fast-Attack and her known Titanium hull, able to reach depths near 3000'. Many in Congress wanted to know why the U.S. didn't have something similar. Fortunately, idiots remain in Congress and Engineers design Nuclear Submarines.

Titanium is extremely strong, but it is not flexible - sure, the ALFA can dive deep, but each time it puts stress on the hull when it deep-dives it becomes more brittle over time. It's like putting increased pressure on an eggshell - eventually it'll crack. This doesn't happen with HY80. It remains flexible over decades and hundreds of dives and surfaces.

Also, you don't need a submarine that can go to 3000'. All you need is a weapon that'll go to 3000'. At that depth, even minimal damage to the pressure hull would result in a major casualty and likely loss of the boat.

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Military Equipment
Submarines

# How are torpedoes fired from submarines?

Torpedoes are shot from submarines, not "fired". "Fire" is a Hollywood term when referring to a torpedo launch; in real life, the word "fire" means only one thing on a submarine, so that there is a clear distinction between the two terms.

Torpedoes are shot from submarines using one of two methods: water impulse ejection, or swim out. Both methods have been used for decades, since the beginning of modern submarine designs.

Swim outs are rarely, if ever, used in modern submarines, unless there's an emergency or the impulse system is down. If it's necessary, the torpedo tube is flooded, and the outer tube doors are opened, the torpedo engine is activated, and the weapon "swims out" of the tube toward the target.

Before 1969, torpedo electrical checks were performed with the weapon on the rack in the torpedo room. Since the loss of the USS Scorpion, widely believed to have been sunk by a hot-running torpedo during electrical checks that detonated before deactivation, all torpedoes are now electrically checked while the weapon is in the torpedo tube. This is a precaution in case the weapon engines activate during checks; if it does, it can swim out or be ejected.

Water impulse ejection is the most common method. Each horizontal torpedo tube, when flooded, is connected via another vertical tube to a third tube which has a piston ram in it. One side of the piston has water, which is the same as the water which floods the tube. The other side is connected to a high pressure air flask, capable of dumping about 3000psi instantly into the air side of the piston ram.

During target tracking, when a target shooting solution is calculated (both by hand, plot, and computer) the information is fed electronically into the torpedo's guidance system. The Commanding Officer will order "Firing Point Procedures" in the Control Room, which is the final step before launching the weapon. At the proper angle, and when the weapon is ready, the CO will order "Shoot", and the crew will send a command to the air flask, which immediately dumps air into the piston ram. The air pressure, which is higher than the outer sea pressure, forces the water out of the tube, along with the the torpedo itself. Once the torpedo has traveled a certain distance from the boat, the engine will start, and it will begin its journey toward the target. As a safety precaution, the torpedo needs to be a certain range away from the boat before the warhead arms to prevent it locking onto the boat it was launched from. If you're sleeping next to the tube in one of the crew spaces, or in the torpedo room itself (portable racks), the noise will wake you up if you're not used to it.

Though most torpedo solutions are derived over time by tracking a target, there are procedures to deal with an immediate threat as well. If Sonar detects a hostile torpedo in the water being launched, the hostile torpedo bearing can quickly be input into the torpedo guidance system, and "Snap Shot" toward the hostile torpedo's bearing. All modern torpedoes are both wire-guided and have active-passive homing sonar. If they lock onto a target, they are nearly impossible to evade, despite what Hollywood would have people believe.

Ejecting water in an empty tube during tube testing is called shooting "water slugs". It's not powerful enough to affect a boat underway, but its' strong enough to move a mooring bumper in port while moored next to a pier.

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Submarines
Missiles

# Why are ballistic missile submarines called boomers?

The term comes from the "B" and "M" letters in the acronym, "FBM", which stands for Fleet Ballistic Missile (Fleet Ballistic Missile Submarine). The combined "BM" was translated into a Navy nickname, Boomer. It's similar to a BMW automobile being called a Beemer.

The fact that ballistic missiles go "boom" when they explode also played a role in the slang term. Otherwise, they could have been called "beemers" also.

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Germany in WW2
Submarines

# How did German submarine warfare pushed the US toward war?

By using submarines, the German war machine was able to come close to America's shoreline and this surely pushed the u.s. To act

It did - one U-boat even sunk a ship in the St-Laurence Seaway, and many U-boat crews were startled by the ease with which they could torpedo ships close to the US shore until the ships' crews realised the value of black-out conditions.

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Submarines

# What is the hydrophone used for?

A hydrophone is an underwater microphone designed to listen to below-water sounds. It can record and listen to sounds in other mediums (air, underground), but it won't be as accurate and sensitive, since it has been based of a sound impedance match exclusively to water.

Hydrophones are also capable as acting like a speaker and producing sounds. This is how submarines go "active" and ping the water. Some submarines sonar is so powerful that it can boil the water around the hydrophones after a couple of full power pulses. It is also the primary means of defeating unauthorized divers around a sub when it is surfaced and/or in port. The sound will disorient and confuse the diver like a flash-bank grenade would in a room.

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Inventions
World War 1
War and Military History
Submarines

# Why were submarines not used before World War I?

The H L Hunley was used during the Civil War, and was credited with the first sinking by a submarine. Look it up on the web for more details. Here is one site: http://soundwaves.usgs.gov/2000/09/ I believe that submarines became more practical when the internal combustion engine was refined. This corresponds with WW1 in many respects. There are probably metallurgy issues with hull design, but I don't know enough to comment on that issue. The biggest issue for submarines is the lack of air. Not only is it vital for the crew of the submarine, all of the early means of mobility required air. The Hunley was 'man powered' and the crew had to breath. Steam and gas engines depend upon burning of fuel, which requires air. Most of the early submarines were diesel powered when they where on the surface, but required battery technology to run when underwater. The electric motors and batteries powerful enough to run them for any length of time were not available prior to the turn of the century. When the above problems were solved and reliable self-powered torpedoes were introduced, the submarine was added to the arsenal of the World's navies, but they were still held out of wartime participation because these navies were controlled by admirals who saw the sub as a dangerous and dirty way to fight, which it was, and a far cry from lines of battleships dueling each other gloriously as they had done in previous centuries. Only World War 1 broke this cycle. In the Russo-Japanese War of 1905-06, both sides operated submarines obtained from the USA, but they never saw any important action. The Spanish Navy had a few subs in 1898, whereas the US Navy had none at the time, but these were not properly used either.

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Submarines

# How many nuclear submarines have ever sank?

A total of 8 known nuclear submarines have sunk (all but one due to accidents) in the almost 55 years since they were created.

U.S. NAVY

USS Thresher (SSN-593) - Thresher-class (lead boat) Fast-Attack. April 10, 1963, during sea trials off Cape Cod. Major hull valve failure, leading to the SUBSAFE program.

USS Scorpion (SSN-589) - Skipjack-class Fast-Attack. May 22, 1968, returning home from Med deployment. Suspected torpedo hot-run incident and subsequent detonation before disarming.

SOVIET NAVY

K-27 - Experimental Soviet Fast-Attack, (2 lead-bismuth reactors in a modified November-class hull). Scuttled after a reactor control rod failure in the Kara Sea, September 6, 1982, in violation of International Regulations.

K-8 - November-class Fast-Attack, sank April 11, 1970 while being towed in rough seas following a major onboard fire.

K-219 - Yankee I class Ballistic Missile submarine. Sank East of Bermuda on October 3, 1986 while being towed after suffering major casualties and damage following an onboard missile explosion.

K-218 (Komsomolets) - Mike-class Fast-Attack, sank April 7, 1989 following a major onboard fire.

RUSSIAN NAVY (Post USSR)

K-214 (Kursk) - Oscar II class Fast-Attack. Sank August 12, 2000 in the Barents Sea following multiple onboard torpedo explosions (one triggered 2 others). The Kursk is the only nuclear submarine to sink after suffering major damage and later be salvaged. The History Channel and Discovery Channel often show documentaries on the raising of the Kursk.

K-159 - Decommissioned November-class Fast Attack. Sank August 28, 2003 after she broke from her mooring pontoons.

All boats are periodically checked for radation leakage of any type (reactors or weapons) and for any evidence of wreck tampering / attempted salvage. Most of the wrecks are in waters deep enough to preclude any salvage or tampering though.

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World War 2
Australia in WW2
Submarines

# What impact did the Japanese submarine attack on Sydney have on Australians?

Australia had been attacked by air in the north at Darwin. Its pans to defend a line around Brisbane were upset by the daring attack in Sydney Harbour. This attack increased public fears of an amphibious attack on the south, but of course this could not have happened as the Japanese had run out of resources to do any out any substantial invasion. The best they had left for the invasion of New Guinea was a marine regiment in the failed attempt at Milne Bay and a scratch half-division at Kokoda.

Australia's forces were five infantry and three armoured divisions in Australia and three infantry divisions returning from the Middle East. Still, that didn't stop[ a panic over the Sydney event. Our government was not very adept at responding to psychological warfare to put it mildly.

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Submarines
US Navy

# What is the qualification requirement for serving on board nuclear submarines as officer?

The basic requirements for serving aboard a Nuclear Submarine, be it as an enlisted sailor or commissioned officer, are pretty straightforward:

1. Citizenship - Must be a U.S. Citizen (No Foreign Nationals).
2. Volunteer for Hazardous Duty - Must be a Volunteer for Submarine Duty (serving aboard a submarine is considered Hazardous Duty for pay / promotion purposes).
3. Security Clearance - Must pass a Background Investigation and be granted a minimumSecret security clearance (Top Secret for Officers and key Enlisted personnel).
4. Advanced Health Screening - Must pass Health (including pressure testing) and Psychological Evaluations, which are well beyond Navy entrance screening standards.
5. Nuclear PRP - Must be granted acceptance to, and maintain status in, the Nuclear Personnel Reliability Program (Officers, Corpsmen, & Key Weapons Handling Personnel).
6. Submarine Warfare Qualification - Like all Submariners, must Qualify in Submarines. There are no exceptions; if you don't qualify, you're history.

Though submarine duty has an almost romantic attraction, and those of us who've served aboard them (most of us anyway) wouldn't trade the experience for anything, duty aboard a nuclear submarine takes its toll in some way on just about everyone, either in health, family, or career. It's easy to be attracted to, and want something when you don't know all the facts, and of course they won't tell you all the facts before you volunteer, primarily due to the fact that it's classified, and if they did, they'd have a lot fewer applicants.

That's the easy part.

Here are a few unclassified facts:

1. Submarine duty is rewarding, but it's also a high-stress, high-pressure, no mistake job, particularly for Officers. I have personally seen Officer careers ended by making a single clerical mistake regarding the nuclear propulsion systems. There is absolutely no room for error onboard any nuclear vessel, and the Navy has a strict zero-tolerance policy for anyone who screws up in the propulsion spaces.

Unrestricted Line officers who volunteer for submarine duty typically do so for the added challenge, prestige, and engineering experience. Those that make it far enough in their careers to actually command a boat usually haven't made any mistakes (though I'm sad to say these days there are more than a few idiots who shouldn't be allowed to command an RC submarine in a backyard wading pool).

2. Divorce rates are typically higher, around 70-75%, since unlike ships, submarines do not transmit any communication while at sea unless it's a severe emergency or they are specifically ordered to. Coupled with the fact that you can't talk about anything you work on because it's classified, any mission you go on, where you're going, where you've been, etc., makes it extremely difficult for the average family to deal with.

Wives literally have to take care of everything while you're at sea - bills, banking, car/home repairs, kids, pets, emergencies (e.g., fire, flooding, accidents, medical, etc.) and all without the support of a husband they can talk to every night or help them with. Extended family usually helps, but most women who marry submariners don't fully understand what's involved, and not everyone will be stationed in a port near their families. There is of course a Navy support system in place to help dependents, and it's gotten better over the years, but it's no substitute for a spouse. Even then, remember the increased stress the sailor is already under to begin with.

To give you an idea of how much separation time I'm referring to, during my first year aboard, I calculated that we were either at sea or away from home port a total of 293 days. That was about average the rest of my time onboard as well. For the first 5 years I was married, I estimate I only spent a total of 1 or 2 years of time with my wife, probably less.

During the time you're actually in port at home, you're still on a 4 day watch schedule, meaning that every 4 days you get to spend 24 hrs on the boat while the other 2/3 of the crew gets to go home. Your only function in port if not training is to ready the boat to get underway again.

For those that think the "steady schedule" of Ballistic Missile submarines is more conducive to family life than serving on a Fast-Attack, think again; the divorce rates are actually higher for Boomer sailors. That's because wives know that their husbands are going to be at sea for a specified period of time, and can get away with cheating on them without much fear of being discovered. The sailor's term for them is "Boomer Widow".

We've been married now for over 32 years, but we're the exception; of everyone I served with, we are the only ones who are still together, and that's largely due to the fact that she was a sailor too when we married, so it was much easier for her to deal with. Everyone else is on at least their 2nd or 3rd spouse, or just gave up dealing with long-term relationships.

In the end though, I chose to leave after 8 years (5 years of that was Sea Duty), as it got real tough coming home from sea and having my daughter run to the other side of the living room because she didn't know who I was.

Forget anniversaries, holidays, birthdays, and anything else you're used to in life - even 25 years later, they come and go and I've never really regained any appreciation for them. Like they are at sea, they're just another day on the calendar.

3. Health - Even though submarine air is purified mechanically and chemically, submarine environments are hardly clean. Aside from the host of carcinogenic agents used onboard, there's diesel fumes (my first year I slept directly above the Diesel-Generator room), and a host of other lovely things that can hurt or kill you. That's why it's all-volunteer, and it's considered hazardous duty. Radiation is typically the least of your worries.

To give you an idea of how bad the air can be, the ship's brass plaque is typically mounted outside the Commanding Officer's stateroom. After polishing to a bright luster with Brasso, it only takes about 2 weeks for it to re-tarnish itself due to the atmosphere.

Altered sleep patterns are common among most submariners, myself included, even so many years later. The constant changing of time schedules affects the body in ways you can't appreciate until you've experienced it. For example, we used to leave port on Romeo time (Eastern Standard or Daylight time), then switch to Zulu Time (GMT) after clearing the harbor. After the Maneuvering Watch (watch stations for entering/exiting port) is secured, the boat goes into an 18 hour watch rotation, meaning you're on watch for 6 hours, then off for 12. That's of course unless you're short-handed, and are in a 12 hr on/12 hr off watch rotation (Port/Starboard watch rotation). It doesn't take long at sea to lose track of time, and the only real way you know what time of day it is, is by the meal they're serving.

After all that for a few weeks or months, you come home, and switch back to Romeo time again.

Forget sunlight also, unless you see it in a DVD, video, or the Periscope.

I lost 2 friends to suicide and more than one to accidents or illness that resulted in their disqualification from submarine duty or medical discharge. I myself developed asthma at the height of my career, disqualifying me from submarine duty and effectively ending my Navy career. Most of my back problems are also directly related to my boat time (lots of heavy lifting), and 3 spinal operations later, it's a constant reminder of what it cost me.

It wasn't as big a deal for me - I always knew I could make it in the civilian job market, and I did pretty good after I was discharged. But Officers typically plan for a long career, and the slightest problem can end those plans. The Navy doesn't publish such statistics, but the rate of deaths or disqualifications is higher than they admit. Still, Officers who have successful tours aboard a nuclear submarine typically do pretty well after they leave the service. Those that are screw-ups are a different story.

Aside from the regular aspects of submarine duty that affect crew, it's particularly tougher for submarine Officers, since virtually all Officers (except the Navigator and Supply Officer), if they want a submarine command of their own, must qualify as an Engineer before that's even a possibility. Submarine Officers are typically pushed toward Engineering anyway, as that's just the nature of serving aboard a nuclear boat.

Add to that the normal Officer qualification and evaluation requirements that are just part of being a Naval Officer, and it makes the job that much more stressful.

Having said all that, I still wouldn't trade my experiences for anything in the world. I did and saw things in several years that people can only dream about. Is it hazardous and dangerous? You're damned right it is, and don't think for one minute the risks aren't that big. But it's also one of the most rewarding and fulfilling jobs in the Navy. Submariners are picked from the top of the Navy's sailors, and if you want to work with the best, there is no better place to go. The Submarine Force constitutes only about 2% of the Navy, and volunteers go through a rigorous screening process.

My point is that if you do decide to volunteer, do so with the full knowledge of what it could cost you later in life in terms of health and/or family. I had no illusions about submarine duty before volunteering, either with health or family; my wife and I almost didn't get married because of our differing opinions about what my career path should've been (obviously we worked it out).

Even with the problems I have now, I have no regrets. But it's not for everyone; I've found that to really motivate me and perform well, I need a high-stress, high pressure environment to work in, and submarine duty gave me that. After leaving the Navy, the only thing I found comparable was working in the Space Program, on both manned flight & unmanned satellite programs.

Most submariners are the same way, thriving in such environments. However, not everyone is cut out to exist in tight quarters for long periods, working extremely long hours (caffeine will become a necessity of life), and be under constant pressure to get everything you do right. If you're such a person, or want to discover whether or not you are that kind of person, then it's worth the risk. But don't volunteer with romantic illusions of the type of submarine duty seen in movies, as real submarine life is a far cry from fictional portrayals. The work is hard, the hours are long, and the sacrifices are many. In the end, each individual will need to determine whether or not the rewards were worth the sacrifices.

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Submarines

# Are submarines soundproof?

No, the opposite is true. Sound travels through water much better than air,and the steel hull is very good at transferring sound from water to air, or vice versa.The sound of submarines is detected by AWAKS aircraft many miles away, and even from satellites.

Although that isn't completely incorrect, all submarines employ ways to reduce sound output (called transients). Some common ones are sound dampeners, floating sound mounts, and vibration reducers. All of these devices have the same objective: prevent vibrations and sounds from escaping the hull.

Submarines have always relied on stealth to complete their missions so we wouldn't be very useful if we could be detected by every awacs or fishing trawler passing by. True, some submarines are quieter than others, and any submarine can be given away by a poorly timed transient, but all in all they attempt to minimize sounds passing through the hull.

More:

Submarines are not sound proof at all. All measures are made to minimize sound transients. Similar to the way your car has motor mounts that are made of rubber to prevent loud sound and vibration from entering the cab a submarine has sound mounts on every piece of equipment that has moving parts. Pipes have small pieces of metal to stop vibrations as fluid passes through it. Motors have mounts. Solid pipes have rubber isolation hoses to separate them from pumps that move back and forth while running. Electronic equipment has sound mounts to prevent hum from entering the deck. Even the deck has its own isolators from the hull. The crew wear soft soled shoes even to reduce the amount of noise they make walking. The outer hull is even cover in rubber tiles to prevent active sonar pings from reverberating off the hull. Something as simple as paint on a sound mount can transmit sound through the hull.

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Inventions
Physics
Large Ships
Submarines

# Explain why controlling the buoyancy is a critical feature of a submarine?

Controlling the buoyancy of the boat allows her crew to ascend, descend or maintain depth.

How it works: Let's say we are at sea on a sub that has a volume of 100 cubic meters. Our water density gauge says the boat is in water that weighs 1025 kg per cubic meter. If we adjust the weight of our boat to 102,500 kg (the weight of an equal volume of water to the volume of our vessel), it will maintain the depth we want to be at. We can also use fairwater planes to climb and dive. The problem is, if we want to surface the boat and have part of it above the surface we've got to reduce the weight, so we pump some water out and the boat will float to the surface. If we want to efficiently dive the boat it needs to weigh more than the water, so we pump in some water and it goes down.

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WW2 Naval Warfare
WW1 Naval Warfare
Submarines

# What did the policy of unrestricted submarine warfare do?

In WW1, the German policy of unrestricted submarine warfare irritated neutral nations such as the United States and eventually helped public opinion to support the US entry into the war.

In WW2 the German policy of unrestricted submarine warfare in the Atlantic irritated nominally neutral nations such as the United States and provided a rationale for increasing US support of Britain and its allies.

In WW2 the American policy of unrestricted submarine warfare in the Pacific probably contributed to the degradation of Japanese economic capabilities as the war progressed.

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Submarines

# What is the reason for submarines?

Submarines were invented primarily to destroy enemy ships in war, but initially they were considered underhanded by most naval officers because they were meant to attack without warning. The evolution of the submarine in wartime due to less restricted naval thinking by others helped changed that viewpoint forever.

While Submarine roles are continuously being redefined over the course of their nearly 400 year old use, as technology has evolved, their primary roles over the past 100 years have included:

Anti-ship warfare

Anti-Submarine Warfare

Land Attack (Nuclear and Conventional )

Strategic Deterrence

Covert Intelligence

Covert Operator Insertion & Recovery

Covert Rescue

Search & Rescue

Mine Laying

Convoy Escort

Quick-Response to World Conflicts (submarines can get into position faster than surface vessels and undetected)

Naval & Scientific Research

Detection, Documentation, and Salvage Assistance of Naval Artifacts/Wreckage

Sailors have always dreamed of traveling under the ocean surface - Leonardo Da Vinci, an inventor of many war machines of his time, drew some of the first submarine concept designs, but they weren't put to practical use until many years later. They were eventually conceived as a craft that could sneak up on its target and sink it by means of an explosive charge. Originally, that was meant to be attached somehow, then detonated by means of a timed device. David Bushnell, inventor of the submarine Turtle, the first submarine used in combat during the Revolutionary War (but not successfully) proved that gunpowder could be detonated underwater. Unfortunately, the Turtle wasn't sufficient enough in power and design to overcome the problems with his concept of attack, boring a hole into the side of a ship and planting a charge.

The success of the submarine as a weapon finally came to pass with the Confederate submarine H.L. Hunley, which successfully planted its spar torpedo (an explosive charge on the end of a long pole attached to the submarine) into the Union sloop-of-war USS Housatonic in Charleston Harbor (South Carolina). The Hunley crew then detonated it by remote line (150' rope) as it backed away. Recent evidence found after analyzing the salvaged wreck shows that it did not sink from flooding damage caused by the explosion as previously thought; after signaling Confederate forces at her base on Sullivan's Island that the mission was successful, her crew apparently died from lack of oxygen as she was attempting to return to base after sinking the Housatonic in Charleston Harbor.

Submarine warfare evolved early in the 20th century as an anti-shipping weapon, meant to deny an enemy the means of resupplying itself. Up until the advent of airplanes, shipping was, and still is today, the primary means of moving large amounts of materials and supplies around the globe. The ability to control strategic areas of ocean by means of a weapon that is silent and can strike with little or no warning has as much impact and meaning on global events today as it did then.

Submarines are not considered vessels per se - the are considered a weapon in and of itself, and the submarine is fought as a weapon during battles.

During WWI, the submarine was used primarily as a regional weapon with restrictions on their use. Its development and significance as a major threat during the war cemented the submarine firmly in the minds of Naval strategists as a major weapon, and submarine technology and experimentation continued to evolve after the war ended.

In WWII, both Germany and the United States showed the world the value of the submarine as a weapon that can change the course of global events. For Germany, its initial successes with U-boats in the Battle of the Atlantic nearly isolated and destroyed Britain by cutting off vital supplies and war material. It wasn't until effective Anti-Submarine Warfare (ASW) measures were developed by the Allies that the U-boat threat was nullified.

In the Pacific, though the Japanese scored a major blow at Pearl Harbor, they failed to destroy either the American submarine or carrier fleets. Executing Unrestricted Submarine Warfare against Japanese targets, American submarines were able to eventually choke the supply lines to Japan the way Germany had done to Britain early in the war, but in the Pacific example, the Japanese weren't able to counter the submarine threat. Their successful attacks on Japanese targets allowed the fleet to rebuild after Pearl Harbor within months.

Submarines in WWII were also used to rescue downed fliers, insert covert operatives into hostile areas, and rescue prisoners and VIP's from enemy areas. These operations continue today.

It should be noted that until the advent of Nuclear Power and significant increases in battery technology, submarines up to that point weren't true submersibles. They were built primarily as surface ships with limited submerged operational capability. Nuclear Power changed that forever. With unlimited power, a modern submarine is only restricted by the needs of her crew. With more power comes more speed and the ability to add more weapons and operational capability. The submarine during the Cold War evolved into 2 distinct types - Fast-Attack, for ASW operations, and Ballistic Missile, for Strategic Deterrence.

After the START II Treaty removed Ballistic missiles from older type FBM submarines, they were refitted as SEAL delivery vehicles or Cruise missle platforms (SSGN). Fast-Attack submarines are already equipped with both torpedo tube launched and in some cases vertical tube launched (VLS) cruise missiles as well as guided torpedoes.

An FBM's mission is to continually remain undetected - they are the most effective nuclear deterrent that the U.S. has. Fast-Attack submarine missions are multi-faceted, serving as cruise missile platforms, advance scouts for Carrier Battle Groups, hunter-killer missions, SEAL delivery, research missions, and even salvage/DSRV (Deep Submergence Rescue Vehicle) transport and delivery to target.

Today's modern submarines are true submersibles in every sense of the word. The ability to travel undetected in the vast oceans of the world is not only a major advantage, but a distinct physical and psychological threat to any enemy. A single submarine can tie up enemy ASW forces at length, or force them to alter battle plans. The best example is the Falklands War, in which 2 Argentinian Diesel-Electric boats tied up British ASW forces, while their own Fast-Attack, HMS Conqueror, scored the only modern day submarine torpedo kill against the light cruiser General Belgrano. After the war, it was found that the Argentinian submarines never left port.

The last successful wartime sinking of a large Naval vessel was in 1982 by the British Royal Navy attack submarine HMS Conqueror during the Falklands War. The Conqueror attacked and sank the Argentine Cruiser ARA General Belgrano, an old WWII U.S. Navy Light Cruiser sold to Argentina. Although it carried modern homing torpedoes, their reliability was in question, so the Captain of the Conquerorused 1925 era Mk 8 torpedoes instead. The Belgrano sunk within minutes of being struck by 3 torpedo hits, with the loss of over 300 crew.

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Submarines

# How do you properly board a US Submarine?

Just like you do any Navy vessel:

1. Walk down the brow (without tripping or falling overboard into the water).

2. Turn toward the U.S. Flag at the stern of the boat, render a hand salute.

3. Turn toward the Topside Watch (who is typically right at the end of the brow), render a salute, and request permission to come aboard.

3. You present your ID card, and the watch will check your clearance status in the topside watch records. If an escort is needed, he'll call down below for one.

In cases of Flag Officers, the procedure is essentially the same, except the watch will ring the topside bell 4 times (2 bells, pause, 2 bells) and then announce the Officer's arrival. For example, if the Squadron Commander for Submarine Squadron 4 was coming aboard, the watch would announce over the 1mc (general announcing circuit) 4 bells, then "Subron 4 arriving".

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US Civil War
War and Military History
Submarines

# When did the HL Hunley sink?

The Confederate Submarine H.L. Hunley actually sank 3 times:

August 29, 1863 - Sank during test dive preparations when dive planes were prematurely engaged.

October 15, 1863 - Failed to surface after a mock attack.

February 17, 1864 - Sank while returning to her base at Sullivan's Island, S.C., after her historic and successful attack on the Union sloop-of-war USS Housatonic in Charleston Harbor.

She was salvaged after the first 2 sinkings and returned to service; however, until she was raised in 2000, her fate remained a mystery for 136 years. Long believed to have sunk as a result of the explosion from her Spar Torpedo, that is now known to be incorrect. She is now known to have survived the attack, and signaled Confederate forces at her base on Sullivan's Island that she was returning after her successful attack on the USS Housatonic. There is strong evidence which has been found during the restoration and preservation efforts (as well as forensic examination of crew remains) that her crew did not drown as believed, but that they died from a lack of oxygen.

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Submarines

# What is the average age of submarine commander?

It depends on the country and type of submarine (Fast-Attack or Boomer) but for U.S. Nuclear Submarines the typical age is between 38 and 42, and they must be a Navy Commander. Boomer C.O.'s are typically either senior Commanders or Captains, depending on the class of boat, and they must have served previously as Engineer Officer aboard a previous nuclear submarine, and served as an Executive Officer on another boat as well. The typical average command time for U.S. boats is about 3 years. The system is similar for the Russian Fleet. Submarine commanders are a truly elite group, given the exacting standards they must meet, and the career hurdles/approvals they must overcome.

Other countries with smaller submarine fleets will use Lieutenants or Lieutenant Commanders, commanding Diesel-Electric boats, and their command times are much shorter, given the lower ratio of boats to prospective commanding officers. DE boat commanders also do not have the rigorous training requirements for nuclear engineering.

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Boats and Watercraft
Large Ships
Submarines