Knowing Submarines

[MZUBAIR]

I was going through "How deep submarine can go?", n I found an intresting interview from US mariner. Here u go n enjoy


1.What is unusual about serving on a submarine?
A submarine is among the most technologically advanced machines ever built. The combination of computer technology, precision navigation, atmosphere regeneration, sensitive sonar equipment, sound quieting, nuclear power, and precision weapons make for a most unusual environment. Imagine working and living in a 300-foot long, 30-foot wide, three-story building with no windows and surrounded by technology. Then lock the doors, submerge beneath the surface of the ocean and travel silently underwater for months. This requires a tremendous amount of skill, knowledge, personal discipline, and teamwork. Over one hundred crewmembers work and live together for months at a time to defend their country and protect U.S. interests around the world.

2.How big is a submarine?
The U.S. Navy has two principal classes of submarines: attack submarines and fleet ballistic missile submarines. Attack submarines, which seek out and attack enemy ships and submarines, are smaller and faster than missile submarines. Most U.S. fast attack submarines are of the USS Los Angeles class. They are 362 feet long-just longer than the length of a football field-and 33 feet wide. They displace almost 6,900 tons on the surface and 7,200 tons when they are submerged. U.S. fleet ballistic missile submarines of the USS Ohio class (a.k.a., Trident submarines, referring to the type of missile which they carry) are 560 feet long (almost the length of two football fields, a few feet longer than the Washington Monument). They have a beam of 42 feet and displace almost 17,000 tons on the surface and 18,750 tons when submerged.

3.What is the difference between attack (SSN) and fleet ballistic missile (SSBN) submarines?
Attack submarines (designated SSN and commonly called fast attacks) are designed to pursue and attack enemy submarines and surface ships using torpedoes. They also carry cruise missiles with conventional high-explosive warheads to attack enemy shore facilities. Fast attack submarines launched cruise missiles against targets in Iraq during Operation Desert Storm and targets in Serbia during the conflict in Kosovo. They also conduct intelligence, surveillance and reconnaissance missions, mine laying and support special operations.

Fleet ballistic missile submarines (designated as "SSBNs") carry long-range nuclear warhead missiles. They roam the ocean avoiding contact with other submarines and surface ships. The ability of the fleet ballistic missile submarine to survive a nuclear attack against the United States made them the most credible nuclear deterrent during the Cold War. Fortunately, the threat of nuclear retaliation that U.S. missile submarines have represented continues to be an effective deterrent in preventing nuclear missile attacks on the U.S. 4. How many missiles and warheads are on a fleet ballistic missile submarine? A U.S. Navy fleet ballistic missile submarine carries 24 Trident ballistic missiles. Each missile carries several nuclear Multiple Independently-targetable Re-entry Vehicles (MIRVs).

4.What types of missions can a submarine perform? Depending upon whether it is an attack submarine or a fleet ballistic missile submarine, a submarine is capable of performing many kinds of important missions:

•Sea Control (denying the ocean to hostile naval forces through anti-submarine and anti-surface warfare)
•Anti-Submarine Warfare (detecting and destroying hostile submarines)
•Anti-Surface Warfare (detecting and destroying hostile surface ships)
•Strategic Deterrence (the capability to rapidly launch retaliatory strikes against any nation attacking the United States with nuclear weapons)
•Landing Special Operations Forces (performing covert infiltration of hostile regions by commando forces)
•Search and Rescue (rescuing aviators shot down over the ocean or special operations forces stranded near the ocean)
•Intelligence, Surveillance, and Reconnaissance (listening for hostile actions, electronic communications and information)
•Battle Group Support (providing intelligence and undersea protection for aircraft carriers and their escort ships)
•Mine Warfare (laying minefields to deny ocean areas to hostile forces)
•Cruise Missile Strike Capability (striking ground-based inland targets with conventional-warhead cruise missiles)
•Transportation of personnel and cargo (covertly moving critical forces and supplies)

5.How are submarines named?
Previously, attack submarines were named after fish and ballistic missile submarines for famous figures in American history. Today, attack submarines have principally been given names of cities, and ballistic missile submarines have usually received the names of states. The newest classes of fast attack submarines are named for states, famous Americans, and earlier classes of submarines.

6.How many people are on a submarine?
Crew size varies depending upon the type and class of submarines, but a typical U.S. Navy submarine crew consists of 14 Officers, 18 Chief Petty Officers (senior enlisted men), and 109 other enlisted men. A submarine will sometimes go to sea for short periods with fewer personnel than this because there are crew members on scheduled leave or in a Navy school.

7.How are people on a submarine organized?
The crew is divided into different groups depending upon their job. For example, the Executive department works for the XO (the second officer in command) and performs various administrative tasks. The Engineering department, under the supervision of the Chief Engineer, is responsible for the safe operation of the nuclear reactor. The Weapons department is managed by the Weapons Officer and it maintains the ship's torpedoes, cruise missiles, ballistic missiles and sonar suite. The Operations department which works for the Navigator charts the ship's position and operates the communication equipment. Lastly, the Supply department under the Supply Officer manages the ship's stores, machinery spare parts, and cooks the meals.

8.How old is the commanding officer of a submarine?
The average age of a Commanding Officer is 38-42.

9.What special training is required to be on a submarine?
Submariners are some of the most highly trained and skilled people in the Navy. The training is highly technical and each crew has to be able to operate, maintain, and repair every system or piece of equipment on board. The jobs needed to safely operate a submarine include, but not limited to, electricians, chemists, reactor equipment technicians, sonar operators and repair technicians, electronic system maintenance and operations technicians, torpedo and weapons technicians, propulsion and machinery operators, navigators, clerks, cooks, and supply specialists. Basic shore-based training teaches submariners fundamental skills before they are assigned to the submarine, but each crewmember continues to learn and gain more expertise after they are assigned aboard the submarine. As sailors gain operational experience, they receive advanced training in equipment maintenance, troubleshooting, and advanced operational techniques. Training continues throughout a Submariner's career to keep pace with technological developments. Regardless of their specialty, everyone also has to learn how everything on the ship works and how to respond in emergencies to become "qualified in submarines" and earn the right to wear the coveted gold or silver dolphins on their uniform.

10.Can women go on submarines?
Women are not currently assigned to submarine crews because of the very limited habitability and privacy onboard a submarine. However, women have been on submarines for short durations as civilian technicians for specialized equipment testing, family members for one-day dependent cruises, and female midshipmen conducting two-day orientation cruises.

11.How do I get to serve on a submarine?
Join the Navy and volunteer for submarine service. Everyone in the submarine force is a volunteer. There are several tests that you have to take to assess your suitability as a Submariner. The Navy then sends you to the schools that you need to get your specialized training. Before you know it, you'll be walking aboard a submarine as a Submariner.

12.Why are submarines painted black?
Submarines are painted black to help them hide. It is essential for submarines to hide while doing their job. The black color has proven to best help the submarine hide in the ocean.

13.How fast can a submarine go?
U.S. nuclear-powered submarines can go faster than 20 knots (nautical miles per hour) underwater, which is approximately 23 miles per hour or 37 kilometers per hour. Nuclear power enables submarines to maintain these speeds for as long as needed, giving our submarines the capability to go anywhere in the world relatively quickly.

14.Why can a submarine go faster underwater than on the surface?
A submarine's "tear drop" hull design allows it to slice cleanly through the ocean when there is water on all sides. When a "tear drop" hull submarine is on the surface, a great deal of energy is used to generate the bow wave and wake. That energy is then unavailable for propulsion. The hulls of older submarines, like the World War II vessels and the first nuclear-powered submarine, USS Nautilus, were designed with narrow bows to move faster on the surface than they did underwater.

15.How does a submarine submerge?
Submarines stay on the surface by keeping their ballast tanks filled with air. To submerge, the submarine opens special valves at the top of the ballast tanks. When the valves open, air escapes out the top of the tanks as seawater enters the tank from the bottom. Since the seawater entering the tank is heavier than the air it replaces, the submarine becomes heavier and submerges.

16.How deep can you go in a submarine?
U.S. Navy submarines can submerge deeper than 800 feet. The actual depth is classified, but it is less than the deep-diving U.S. Navy-supported civilian research submarines that explore the bottom of the oceans.

17.How long can submarines stay underwater?
Nuclear-powered submarines can stay submerged for long periods of time. They are designed and manned to stay underwater long enough to support a wide variety of missions, which can last for several months. Submarines have equipment to make oxygen and keep the air safe. Food and supplies are the only limitations on submergence time for a nuclear submarine. Normally, submarines carry a 90-day supply of food.

Historically, diesel-powered submarines operated internal-combustion, air-breathing engines on the surface or just below the surface by using a snorkel mast (snorkeling). When completely submerged, a diesel-powered submarine uses its battery power and electric motors for propulsion. Depending on speed and other battery use, the submarine could stay underwater for up to several days before recharging batteries and exchanging stale air for fresh air.

18.How does a submarine surface?
There are several ways to get to the surface, including blowing to the surface and driving to the surface. Blowing to the surface can be done at any depth by blowing high-pressure air into the ballast tanks. As the air replaces the seawater in the ballast tanks, the submarine becomes lighter, causing it to rise to the surface. To drive to the surface, the submarine simply positions its planes (i.e., stubby "wings" at the stern and on the superstructure or bow of the submarine) to rise and the submarine ascends to the surface. The submarine then uses low-pressure air to force seawater out of its very large ballast tanks to remain on the surface.

19.What does it feel like to be on a submarine underwater?
Although it is difficult for most people to imagine living on a submarine, challenging submarine living conditions actually build strong fellowship among the crew. The crews are highly motivated, and quickly adapt to changing conditions. It is a busy life of specialized work, watches, and drills. There are four meals a day: breakfast, lunch, dinner, and midrats. There is always plenty of food. Crew members usually get about six hours of sleep per day; most people fall to sleep very quickly because they are tired after a long workday. The days pass without sunrises and sunsets, because on a submarine operating at sea, the only view of the sky is through the periscope! Compared to life on a surface ship, submarines are quieter and the ride is smoother because the submarine is rarely affected by the surface waves. The air is cleaner than the air outside, and many submariners notice the strong smell of the ocean when the hatch is opened after a long time.

20.Do you get claustrophobic?
No. All prospective Submariners are evaluated for claustrophobic tendencies. People who tend to get claustrophobic are not allowed to become Submariners.

 

[MZUBAIR]

21.Can you feel the waves on a submarine when it's under the water?
It depends on how big the waves are at the surface and how deep is the submarine. During normal weather conditions, a submerged submarine will not rock with the motion of the waves on the surface. In fact, during even moderate storms the submarine stays perfectly level at its submerged depth while the waves crash above. In extremely violent storms like hurricanes and cyclones, wave motion can reach 400 feet or more below the surface. Though not as violent as on the surface, these large waves can cause a submarine to take 5 to 10 degree rolls.

22.What does the crew do during its free time?
At sea, the typical submarine day is 18 hours long, not 24 hours. Submarine crews are divided into three watch sections. Each section is on duty (on watch) for 6 hours, and then spends 12 hours off watch. When on watch, the crew members are actively operating their assigned equipment. Examples of watch stations that are manned continuously at sea are: Radioman of the Watch (operates radio equipment), Quartermaster of the Watch (determines the submarine's position in the ocean), Engine Room Lower Level Watch (operates all equipment located in the lower level of the engine room), Throttleman (operates the throttles which control the main engines, which, in turn, control the speed of the ship's propeller) and Planesman (operates the submarine's diving or steering controls). Under normal conditions, there are approximately 25 crew members "on watch" at the same time. Under special conditions, such as battle stations and when entering or leaving port, everyone has a watch station.

During the 12 hours out of each 18-hour day that submarine crewmen are not actually on watch, they engage in a wide variety of activities. Crew members who are off watch eat, attend training sessions and study, both for advancement examinations, and in order to become qualified to stand other watchstations. Others may perform routine preventive maintenance on the equipment that they are responsible for (e.g., a radioman periodically changes emergency batteries on some of his radio gear, an electrician periodically inspects the ship's wiring for problems, etc.). A wide variety of activities are available during free time. The ships carry about 400 movies, which are exchanged for newer ones in each port. Card games and various board games, such as a Backgammon or Cribbage, are also popular. There are also some athletic equipment on board, such as an exercise bike, versa climber, rowing machines, and free weights. U.S. fleet ballistic missile submarines have more athletic equipment than SSNs because they have more space. SSBNs are so large that some people even run marathons by running around the perimeter of the missile compartment many thousands of times!

23.What do you eat?
Being a cook on a submarine is a very important and demanding job. The quality of food served has a great impact on crew morale. Imagine shopping for 120 men for six months and planning every meal! Submariners eat the same food as you would find at almost any table in an American home. They have ongoing contests to determine which ship cooks the best meals. The fresh fruit, vegetables, eggs, and milk usually don't last for more than a few weeks, but the creative cooks on submarines work wonders with canned and frozen foods to supplement the meals they create. Submariners have four meals per day - breakfast, lunch, dinner and midnight rations, commonly known as "midrats." Menus include eggs, hotcakes, and cereal for breakfast; deli sandwiches, hamburgers, and pizza for lunch; pasta, steak, chicken, and pork dishes for dinner; and leftovers for midrats.

24.Where do you keep all the food stored?
Submarines have several storerooms, refrigerated rooms, and freezers. On long deployments, however, the amount of food required exceeds available storage space. Cans of food are stored on the floors in the passageways throughout the ship and people simply walk on the top of the cans.

25.Where do Submariners sleep?
On U.S. Navy submarines, living quarters are called "berthing areas" that provide no more than 15 square feet of space per man for sleep and personal belongings. On most submarines, each crewman's bed (called a bunk, berth or rack) has a reading light, a ventilation duct, an earphone jack for the ship's audio entertainment system, and a curtain to provide a small (but welcome) measure of privacy. The crewmen store their clothing and personal belongings in a sturdy pan-like locker beneath their mattress. When a U.S. Navy submarine is at sea, lights in the berthing areas are normally dimmed. About one third of the crew is asleep at a time because submarines operate 24 hours a day. The crew works in shifts, normally six hours on, 12 hours off. Only the captain and executive officer of the submarine have private rooms, called staterooms, in which to work and sleep. Sometimes, there are more people onboard than there are regular bunks. When this happens, a few of the crewmen have to sleep in makeshift bunks in the torpedo room. These temporary bunks are fitted on storage racks where torpedoes and missiles are normally kept. Space is always very limited on submarines, and there are very few large or open spaces where people can make a bed.

26.What clothes do you wear?
When in port, crew members wear regular Navy uniforms. At sea, members wear one-piece blue coveralls called "poopy suits." They are very comfortable to wear and reduces the number of clothes the sailor has to bring to sea. Submarine crews usually wear sneakers or other soft bottomed shoes when at sea, as sound quieting and stealth are always foremost in a submariner's mind.

27.Who does the laundry?
On U.S. Navy submarines, there is an area designated for laundry, typically with one washer and one dryer. Laundry is done weekly by division on a rotational basis. Each division appoints someone weekly to perform this task.

28.How does the submarine crew get medical attention?
All submarines have a highly trained, experienced medical specialist on board called a hospital corpsman. These individuals receive training similar to that given to a physician's assistant in the civilian world. In emergencies, these individuals are even trained to perform basic surgeries. Preferably, however, emergency cases are either rapidly delivered to a shore facility by returning to port or by helicopter emergency medical evacuation from the submarine. It may also be possible to transfer the sick person to a better-equipped surface ship either by small boat or helicopter.

29.Can you see outside when you are underwater?
Submarines do not have any windows to allow the crew to see outside underwater. The Navy has one special purpose research submarine, NR1, that has a viewing window and special underwater cameras and lights, but most submarines have only periscopes for outside vision. To use a periscope, submarines need to be close to the surface. This is called periscope depth or PD. At PD, submariners use the periscope to look outside to make sure any nearby ships are at a safe distance and to avoid detection from hostile ships or aircraft. Periscopes on submarines rotate horizontally so that the user can see around the horizon for a full 360 degrees. If a hostile ship or plane is seen in the area, the submarine will go deeper. The periscope can also be used to obtain information about a potential target before an attack. Most of the time, submarines are submerged at deeper depths and use their sonar systems to obtain fire control solutions on enemy targets.

30.What does it look like through the periscope?
Like the typical World War II movies, there are dashed lines on the eyepiece for the viewer to determine a potential target's distance from the submarine. What may not be known is that modern periscopes have a lot more capability. These include night vision, a still camera, a video camera, many internal antennas, and it can magnify what is being observed.

31.How do you know where you are going underwater?
Submarine Navigators and Quartermasters use ocean navigational charts just like other ships, but probably pay closer attention to the depth of water. Submarines have a computer that knows how fast the ship is going and in what direction. This computer can also sense when the submarine turns; the Quartermaster sets a position where the ship starts from and the computer keeps track of where the ship is at any time after that. Submarines also have an antenna that can receive signals from Global Positioning System (GPS) satellites when near enough to the surface to receive a signal. When on the surface, the quartermasters may use a sextant to obtain navigation fixes as a backup to our modern day systems.

32.How do you get air on a submarine?
Outside air is brought on board the submarine through access hatches while in port and through a snorkel mast while submerged at periscope depth. Once the submarine submerges below periscope depth, there are machines that continuously clear the air of contaminants. There is also oxygen-generating equipment on board the submarine to further replenish the air that Submariners breathe. The air on a submarine is continuously monitored and maintained for habitability.

33.How do you communicate?
Submarines use specialized equipment to communicate with shore bases and ships, either directly or through a satellite. Submarines can send and receive both voice and non-voice information.

34.How do you get letters on submarines?
Letters and packages mailed to submarines while they are at sea are forwarded to the next port that they are scheduled to visit. The crew is always very excited when there is mail call during a deployment. (You can't receive home-made cookies via email.)

35.Can you get e-mail on submarines?
With today's technology, submarines can send and receive e-mail while in port and under limited conditions while at sea. The Navy is working to expand e-mail connectivity without compromising submarine stealth and security. On longer deployments, crew members receive limited communications known as "family grams" via the submarine's normal message traffic.

36.How far away can you hear other ships?
Submarines use large underwater listening devices called "sonar" to navigate and detect other objects underwater. Submarine sonar is affected by weather, water temperature, biologics, and other natural conditions. A submarine can often hear a ship miles away.

37.How does sonar work?
Sonar (SOund NAvigation and Ranging) gives our submarines virtual "eyes" underwater. Sonar is used primarily to detect ships and submarines. There are two types of sonar: active and passive. When using active sonar, a submarine transmits a pulse of sound into the water and listens for how long it takes to bounce off another object such as a ship or submarine and return. This gives information about that ship or submarine's direction and distance away. Unfortunately, if a submarine uses active sonar, all the other sonar-capable ships and submarines in the area would know that the submarine is there. Since the primary advantage that submarines enjoy is stealth (other ships don't know where they are), most submarines rarely use active sonar. Passive sonar listens for the sounds coming from other ships and submarines. When a submarine uses passive sonar, it is able to obtain information about other ships and submarines without revealing its own position. Like detectives examining a crime scene, skilled sonar operators can determine such things as ship speed, number of propellers and even the exact kind of ship just by listening to the sounds.

38.What does sonar sound like?
Active sonar makes sounds much like the "pings" you've probably heard on TV shows and in movies. Submarines usually don't use active sonar because after the first ping, the submarine is no longer covert. Instead, they use passive sonar. Passive sonar listens only and puts no noise in the water.

39.Does active or passive sonar affect the marine environment?
Navy sonar has little or no effect on marine life. Active sonar is like the echo locator used by some deep diving whales to hunt for prey. Passive sonar has no effect on marine life.

40.Can you hear whales, porpoises, and other sea animals?
Yes. Advanced sonar systems are designed to listen for man-made noises from other ships and submarines, but they can also hear the many natural sounds of the ocean including whales, porpoises, and shrimp. It is really very noisy underwater if you have the right equipment to listen carefully. Our sonar technicians are proficient at identifying the many different sounds underwater including sea life or biologics.

41.What weapons are on a submarine?
Submarines can carry torpedoes, cruise missiles, and mines. Fleet ballistic missile submarines carry long-range ballistic missiles. Torpedoes can be used against an enemy ship or submarine. Ballistic missiles are used to destroy land targets thousands of miles away from the ocean and are maintained as a deterrent system (to keep other countries from using ballistic missiles against the U.S.). Cruise missiles provide a precision strike capability and can be used against land or ship targets several hundred miles from the submarine. Mines can be laid without the submarine being seen. These mines remain hidden in the water inside an enemy harbor or shipping channel and can sink an enemy ship.

42.How do you get rid of trash or waste on a submarine?
Submarines store their non-biodegradable waste until their operations allow them to unload it when in port. Waste is then transferred to a shore facility. While at sea, a submarine follows procedures set forth in international law. Today, the U.S. submarine force is taking steps (such as the use of improved packaging) to dramatically reduce the amount of waste discharged at sea. In addition, submarines are installing systems to turn food waste into biodegradable pulp that can safely be disposed of overboard. Plastic material is compressed and stored onboard until the ship returns to port where the material is recycled or disposed of properly.

43.How does the nuclear reactor work?
The reactor uses fuel containing uranium, which is a radioactive metal. The reactor generates heat by a process called fission. Fission occurs when the uranium atom splits. Special equipment captures the heat produced. The heat that is generated by the reactor is then used to heat water and make steam, which turns the submarine's main engines and electrical generators, just like most surface ships' engines have been doing for decades using oil-fired boilers.

44.How long does the nuclear fuel last?
The submarines that we have built during the past several years have fuel that will last for the life of the ship, which is approximately 33 years. By not having to refuel, the submarine can stay operational and on the front lines defending the country for far longer periods of time.

45.Are you worried about nuclear radiation?
Safety is always paramount on a nuclear submarine. The submarine is designed and operated to ensure the crew, the public, and the environment are protected from the risks of radiation. The reactor is designed with "shielding" around it to reduce radiation levels. On board, radiation levels are very low. In fact, a submariner gets less radiation at sea than a person gets on a beach from the sun and other natural background radiation sources. Each crewman wears a dosimeter, a device that measures levels of exposure to radiation, at all times. Each man's dosimeter is checked periodically; the Navy monitors exactly how much radiation each man has been exposed to, and has strict controls in place to minimize everyone's exposure.

46.Where are submarines based or homeported?
Submarines are based or homeported at U.S. Navy submarine bases at Groton, CT; Norfolk, VA; Kings Bay, GA; Bangor, WA; San Diego, CA; and Pearl Harbor, HI. Large support ships, called submarine tenders, are stationed in La Maddalena, Italy in the Mediterranean Sea and Guam in the Pacific Ocean, where they can support submarines that are "forward deployed" away from their homeports in the U.S.

47.What seaports do submarines visit?
Submarines visit a wide variety of ports both in the United States and abroad. Submarines have visited such ports as Toulon, France; Halifax, Nova Scotia; Portsmouth, England; Haifa, Israel; Perth, Australia; Yokosuka and Sasebo, Japan; Singapore; and Chinhae, Korea.

48.What do submarines in other countries do?
Submarines from other countries support their own country's national defense in much the same way U.S. submarines protect ours.

49.Why don't we have diesel-powered submarines like other countries?
The United States uses a forward presence defense, deploying its forces overseas. Diesel submarines travel too slowly and have too limited a range to cover the wide areas of ocean and respond rapidly to crises around the world.

50.How do submarines help in modern conflicts like Kosovo or Iraq?
Submarines are always deployed in the oceans around the world, and with their nuclear reactors and great speed are often the first ships on station when a crisis develops. Fast attack submarines also travel with U.S. aircraft carriers and their escorts to protect them from enemy submarines or ships. Submarines can also be a silent detection post, listening for enemy communications, allowing us to learn much about enemy plans and capabilities. They can launch Tomahawk cruise missiles very accurately into enemy territory or quietly deliver a small reconnaissance team to a shore close by.

51.What was Admiral Rickover's impact on the modern submarine force?
Admiral Hyman G. Rickover was a very strong and effective manager and engineer. He had the "radicalquot; idea to bring nuclear power to submarines. This Captain Nemo-like idea turned out to be a revolutionary point in U.S. submarine history. Nuclear power enables submarines to operate underwater continually. Older submarines operated underwater using a large battery and electric motors to turn the submarine's propeller. The battery usually had to be recharged at least once a day. This meant that the submarine needed to come to periscope depth and run a very loud diesel engine. If the submarine is making a lot of noise, it is difficult for the SONAR system to detect anything. This makes the submarine vulnerable to attack. It is very hard to sneak up on a quiet nuclear-powered submarine. Admiral Rickover's idea turned into reality, improving forever the endurance, stealth, and power of the U.S. submarine force.

52.How do you escape from a sinking submarine?
Most U.S. Navy submarines have two escape routes-called "escape trunks"-that can be used to escape if ever needed. They work like an "air lock" that you may have seen in a movie. The men climb into the escape trunk wearing a special life preserver that has a hood on it to provide a bubble of air to breathe. When the lower hatch is shut, the trunk is filled with water and pressurized to sea pressure. The trunk's outside hatch opens, and the men float to the surface.

53.How are people rescued from a sunken submarine?
There are systems built into the submarine to assist the crew to escape safely, if required. The Navy has also developed two rescue submarines called Deep Submersible Rescue Vehicles (DSRV). You may have seen them in the movies, Hunt for Red October, or Gray Lady Down. They drive up to the damaged submarine, mate to the escape hatch and take the crew to safety. New technologies are planned for incorporation into the next generation rescue system called the "Submarine Rescue Diving and Recompression System."

54.Have any U.S. nuclear submarines sank?
Yes, two: the USS Thresher (SSN 593) was lost on 10 April 1963 while on sea trials and the USS Scorpion (SSN 589) was lost on 27 May 1968 while transiting from a Mediterranean Sea deployment.

55.What caused the USS Thresher and USS Scorpion to sink?
The exact reasons are unknown. However since the losses occurred, the Navy has implemented many changes to submarine safety systems, improved training of its sailors, and created many "redundant" submarine systems to provide primary and backup safety measures. The primary change has been the introduction of the SUBSAFE system. SUBSAFE requires using certified materials, trained personnel and inspectors to conduct work on key submarine systems (e.g., hatches and seawater piping). No other U.S. submarines have been lost at sea in over thirty years following these extensive improvements.

56.Do submarines help find old shipwrecks?
Yes, advanced sonar systems can locate objects on the ocean floor. The Navy research submarine, NR-1, has been used to explore Roman shipwrecks in the Mediterranean Sea. Other smaller submersibles have been used for locating ships and other items such as the Titanic, which sank in 1912, and the Challenger Space Shuttle, which exploded in 1986. These smaller research submarines are equipped with "outside" cameras. They can also be remotely controlled from a nearby surface ship.

57.Where are U.S. Navy submarines built?
In the U.S., submarines are presently built in two places: Newport News, VA, by the Newport News Shipbuilding and Drydock Company and Groton, CT, by the General Dynamics Corporation's Electric Boat Division.

58.What happens to old submarines?
The Navy is very environmentally conscious. A lot of care is taken in disposing of decommissioned submarines responsibly. The nuclear fuel is removed from the reactor and sent to Idaho for processing. The nuclear reactor compartments are cut out, carefully sealed and taken to an approved disposal site in Washington State. After the submarine's hazardous materials are properly removed and disposed of, the submarines are then stored at Puget Sound Naval Shipyard in Bremerton, Washington where they are eventually cut up and the various metals recycled.

59.How did the submarine contribute to winning WWII?
After the attack on Pearl Harbor, many of the U.S. Navy's front-line Pacific Fleet surface ships were destroyed or severely damaged. The submarines carried the war to the enemy and were asked to independently hunt and destroy enemy ships and submarines. They did it very effectively and without the assistance of other supporting ships. The submarine force was the most effective anti-ship and anti-submarine weapon in the entire American arsenal during the war. Our submarines, though only about 2 percent of the U.S. Navy, destroyed over 30 percent of the Japanese Navy, including 8 aircraft carriers, 1 battleship and 11 cruisers. Our submarines also destroyed over 60 percent of the Japanese merchant fleet, crippling Japan's ability to supply its military forces and industrial war effort.

60.What is the difference between a WWII submarine and a modern submarine?
World War II submarines were powered by diesel engines on the surface and batteries when submerged. They could not go faster than 10 knots underwater for more than one hour, and they could not normally stay underwater for more than one day at a time. They carried diesel fuel for less than 90 days. They were not designed to dive deeper than about 300 feet. Today's nuclear submarines can go faster than 25 knots, dive deeper than 800 feet and stay underwater for more than 90 days (limited by the amount of food stored on board).

 

[MZUBAIR]

Any learning info abt submarine, ur share will be appreciated

 

[TOPGUN]

Good stuf learned alot in ashort span of time thx.