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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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โˆ™ 2013-11-01 12:51:48
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Q: How do submarines float and dive?
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Related questions

How can submarines float and sink?

Submarines change their depth by use of ballast tanks. To dive, they open their tanks so that they become filled with water. They also angle their dive planes. To surface, they pump the water out of their tanks and fill them with pressurised air.

Do people float in submarines?


Does submarines float?

Yes, they does.

How far can submarines dive?

U.S. Submarines can dive 800-plus feet. (Official depth; however, can dive deeper. The US Navy itself acknowledges that most of it's attack submarines can operate down to at least 985 feet, and many to over 1400 feet.

How far can submarines dive underwater?

Straight to the bottom of the ocean.

How does a submarine dive under water from the surface?

Submarines dive by opening vent valves that allow sea water to push air out of their ballast tanks.

How many feet can a submarine dive?

A few submarines have gone to the bottom of the Pacific Ocean, 6 miles down, but, most can only dive to a few hundred feet. Any deeper and the pressure would crush their hulls. Diving to a few hundred feet is good enough for most military and civilian submarines. Also, how deep certain military submarines can dive is top secret information and is known only to a few people in the navy.

What weapons did Japan bring to Pearl Harbor?

Kate Torpedo Airplanes, Val Dive Bombers, Zero Fighter Planes, Mini-Submarines launched from Mother Submarines.

Why do submarines float to the surface when the air is let out?

They rise to the surface when air is pumped IN. They sink when air is let out

Ships float submarines sink?

Submarines can go downward because they flood their buoyancy tanks with water. This reduces the buoyancy of the sub, allowing it to go down. To rise again, the water is pumped out of these tanks.

What did Japan attack Pearl Harbor with?

Five Mini-Subs (launched from Mother Submarines), and over 300 dive bombers, torpedo bombers, and fighter planes.

How deep can submarine dive in to the water?

it depends if the water is really deep or not and how good in shape the submarine isAns 2 - The operational depth of submarines is secret -(or 'classified' as navies say it) However it's generally accepted that most modern submarines can dive to around 1,500 feet and possibly even more in the case of the very latest. Submarines evolve and improve continually as no country wants anothers warships to be better.

Did the Confederacy have the advantage in submarines over the Union?

The Confederacy led in the experimentation with submarines. The most successful was the HL Hunley. The inventor was killed in a test dive with his new and imaginative war vessel. The Confederate submarine sank the Federal warshipthe USS Housatonic in the Charleston harbor. The submarine, however, was dragged down by the sinking Housatonic. The Confederacy decided to end experimentation with submarines after that. The Union had no submarines.

What bird can swim under water?

Penguins can swim. Some other birds can dive or swim/float.

How much submarine dive into deep water?

All military submarines dive into deep water. The deeper they can cruise,the harder they are to find. I call 'deep' any more than 120 feet down, but most modern military submarines can operate as deep as 900 feet, many even to 1500 and possibly more. There are now many civilian submarines (shallow divers) which show tourists the undersea reefs and fish life. These generally operate between 30 and 90 feet down and I doubt that any could safely dive deeper than 200 feet at most.

Can all ducks dive?

Duck in Old English literally means "to duck, bend down low as if to get under something, or dive." Therefore I would assume that ducks can indeed "dive." A little sarcasm added here, I don't believe that DEAD ducks can dive. Maybe sink of float. ;)

How do submarines navigate and find ravines valleys mountains flatland canyons under water?

Naval submarines do not dive deep enough to go near underwater mountains. This is contrary to what you may have seen in the movies. They use sounding charts to determine the depth of the water in which they are navigating. They avoid such underwater objects. Research submarines use cameras and sonar, as well as charts, to guide them.

How do submarines float sink and stay in the middle of the sea or ocean?

They use ballast tanks to contain sea water or air to control their depth

What do crocodiles swallow so they can dive deeper?

They swallow stones that aid digestion and help them swim, since they naturally float.

To what depth can submarines go?

WWII US Gato class subs could exceed 400 feet. ANS 2 - Some modern submarines can dive to at least 1,500 feet, some possibly even 2,000. -The Navies involved will never admit it

How do submarines and whales sink and float in water as needed?

Submarines and whales have ways to adjust their buoyancy. That's how they sink and float as needed. Each has a different method of adjusting buoyancy.The submarine controls buoyancy by adjusting ballast. Submarines have ballast tanks that can be filled with air or flooded down with water. When full of air, the ballast tanks provide enough buoyancy to keep the submarine afloat (provided the pressure hull is not full of water). The ballast tanks are open on the bottom, and have valves (called main vents) on the top. When we open the main vents, air is forced out by sea water that is coming in at the bottom. Once the ballast tanks are flooded, the boat will submerge. The crew then "fine tunes" the buoyancy by adding water to or pumping water out of tanks inside the pressure hull. These tanks are also used to trim the ship so it is neither heavy in the bow or the stern.Whales can fill their lungs with air to float or swim on or near the surface. When they dive, they take a breath and swim down against the upward force of buoyancy. As they move deeper, pressure forces their ribs (which are not rigidly attached to their vertebrae) inward and their lungs are compressed. This reduces buoyancy and makes it easier to go deeper. As far as actual "control" of their buoyancy, investigators are still not clear about many aspects of the workings of whale physiology, and debate and speculation continue.

Why do ships float while submarines sink?

Submarines are designed with enough ballast and control systems to allow them to submerge and surface as needed.Surface ships are designed only with enough ballast and control systems to keep them on the surface. While they can sink just as well as submarines can, their ability to re-surface without a salvage operation is non-existent.

What are synonyms of swim?

bathe, breast-stroke, crawl, dive, dog paddle, float, freestyle, glide,, go wading, high-dive, move, paddle, race, stroke, submerge, wade I got these from I hope these help!

What are some verbs for birds?

fly / squawk / eat / hop / sing / peck / lay / float / lay / migrate / dive / glide / hoot / wade

How do you respond if a victim submerges before being reached by a rescuer?

you want to bring a folat and dive down and put the float in there hand and swim them to shore

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