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Submarines
Submarines are naval craft that can operate for an extended period of time underwater. They are used primarily as warships, as well as for business, scientific and other purposes. Submarines are different from submersibles, which only have limited underwater capability.
2,056 Questions
What does zero bubble on a sub mean?
Zero-bubble is the submarine term for maintaining a Zero trim angle as it travels through ocean. The "bubble" itself is from a ship's Clinometer (inclination/declination meter), that shows the ship's trim angle. Though modern vessels primarily use electronics to measure trim angle, traditional Clinometers (essentially just an air bubble in a curved tube) are still used as backups for modern devices.
The trim angle on a submarine is the up angle (inclination), down angle (declination), or zero angle (no angle at all) that a boat maintains as it travels at a specific depth, or travels to and from different depths. Zero bubble means the boat is traveling through the water with no angle up or down, or completely level.
This does not mean it can't change depth without any angle - most boats frequently do change depth while maintaining a zero bubble by using their dive planes, while the trim planes maintain a steady trim.
One analogy that most people experience in flying is an aircraft's final approach to an airport; the aircraft descends from altitude while maintaining a seemingly level flight all the way down.
Why are submarines torpedo shaped and not cubes or spheres?
A couple of reasons.
A submarine isn't shaped like a cube because water flowing around a cube would make noise that could be heard on sonar. Submarine forces work very hard to make their submarines less audible.
It also isn't shaped like a cube because depending on the way the cube is oriented in the water, it would take more power to push the submarine through the water.
A combat submarine isn't shaped like a sphere because a sphere won't hold as much load as they would the shape they are made. They have made spherical-shaped submersibles for extremely deep-water exploration because a sphere is the most pressure-resistant shape.
Where do you get stationed in the navy for submarines?
The primary U.S. Submarine Bases are:
Groton, Connecticut (New London)
Norfolk, Virginia
King's Bay, Georgia
Mare Island, California (San Francisco)
San Diego, California
Bangor, Washington
Pearl Harbor, Hawaii
Groton, King's Bay and Bangor are Submarine bases only; King's Bay and Bangor are the Trident Submarine refit facilities. Groton is the traditional home of all Submariners, being just a stone's throw from General Dynamics' Electric Boat Division, where modern U.S. submarines began over a century ago.
The other bases are combined Naval Bases, meaning they have ships, submarines, and aircraft bases, as well as Command and Support facilities.
Best spots? Pearl, San Diego, or Groton. I was stationed out of Charleston, S.C., for 6 years, but NS Charleston is gone now. If I had a choice today, I'd probably pick either San Diego or Pearl - Groton sucks in the winter.
What distinguishes MHD submarines from ordinary ones?
MagnetoHydroDynamic propulsion (MHD) uses electromagnetism without moving parts to move water and propel the submarine forward. Though believed to be silent and stealthy (in large part due to the Clancy novel "Hunt for Red October", which featured an MHD Type drive) in reality the gases and electromagnetic signature would be detectable by a range of ASW sensors commonly in use. In other words, sounds great, but in practical application for blue water ops, it's not realistic. It could be good for coastal defense though.
Its primary disadvantage is speed - it's slow compared to boats of Diesel Electric or Nuclear propulsion with conventional screws. In any combat situation, speed is critical, especially when you've got a 55 knot torpedo aimed up your stern. Speed is one of the primary reasons that the U.S. and other major countries moved to Nuclear Power for their submarine fleets. Speed equals overall tactical advantage in any engagement, or when time is a factor in getting to a global hot spot. Only nations without real blue water navies, save for Russia, still operate DE boats. Most who use them are for coastal defense only, though modern technology gives them comparable speed to older nuclear submarines. However, top speed is still limited by battery consumption, and at some point they still need to recharge their batteries. Running a diesel is an instant target acquisition for any nuclear submarine Sonar gang on the ball.
What are the different types of submarines?
Modern submarines (true submarines, not Deep Submergence Vehicles, which rely on a support tender and run on batteries charged by the tender) are generally of two types, Nuclear and Diesel-Electric.
Nuclear Power is the preferred method of propulsion for most modern submarines, since their speed, range, and diving capability outweigh the advantages of a DE boat, which is quieter when running on battery with its electric motor. However, all DE's must eventually recharge their batteries with their diesel engines (even modern boats who can go weeks without a battery charge), and that key tactical limitation is what gives Nuclear boats the overall advantage.
When the debate concerning the conversion to Nuclear Power or staying with DE technology (the cost for NP is far greater, but so is the capability), a test was devised where one nuclear submarine was pitted against several DE submarines. The rest is history - each DE submarine was detected and "sunk" via simulated attack when it had to come to periscope depth and snorkel to recharge its batteries. Since that time, the U.S Navy now exclusively builds nuclear submarines, the last DE boat being retired almost 20 years ago.
SUBMARINE CLASSES
There are several classes that U.S. submarines fall into;
SSN - SSN's are Fast-Attack submarines, and are the hunter-killer descendants of the old WWI/WWII Fleet boats. Far more lethal, they can carry a range of weapons, from cruise missiles, torpedoes, mines, and special weapons. The only real threat to an SSN is another SSN.
SSBN - SSBN's are Ballistic Missile Submarines, and their primary mission is Nuclear Deterrence. Armed with several (U.S. boats can carry up to 24) ballistic missiles, each with several MIRV's, they provide a covert and mobile deterrent that still cannot be adequately prepared for.
SSGN - SSGN's are Guided, or Cruise Missile Submarines. Many SSBN's were converted to SSGN's after the Cold War and as a result of treaty requirements. They usually carry different configurations of Tomahawk Cruise Missiles.
What was the naval tactic used to reduce the sinking of ships by German submarines?
The primary tactic employed by the Allies in WWII to try and initially stem shipping losses to U-boats was the Convoy System. Ships in convoys were easier to screen and protect from attacks, and the chances of more material making it to its destination improved even if there were some losses.
Over the course of the war, the escorted convoy system, decoy ships (armed vessels disguised as merchants), recoverable ASW aircraft, and eventually long range bombers spelled the end of the successes the Germans enjoyed early in the war.
The capture of U-110 by the HMS Bulldog, resulting in one of the biggest Intel coups for the Allies when her Enigma code machine and books were recovered intact, also significantly aided the allied convoy system. Early in the war, the Allies could not break the Enigma code and it was a big factor in heavy shipping losses. Afterward, they were able to
read enough code to help convoys avoid known U-boat patrol locations. At the end of the war, combined efforts led to U-boat losses that were huge - a 75% casualty rate.
The trick is to use Alka-Selter tablets and something to weight it down enough to ensure that the bottle will sink. It's an old trick used by submarine models I had when I was a kid, long before I served onboard real submarines.
Try this:
Use a length of copper tubing and duct-tape it to one side of the bottle as a ballast weight. Punch holes (nail size should be good enough) in the side where the ballast weight is. You'll need to leave the cap off or the water won't flow through the holes in the bottom.
To get it to rise again, you'll need several Alka-Selter tablets along with a surgical or cleaning glove, or alternatively, a long balloon. You'll have to break the tablets (don't crush them) to make them small enough to get through the neck of the bottle.
A balloon is a better choice. Put the tablets into the empty balloon, and then use a plastic tube (or something else) to ensure that the mouth of the balloon stays wide open. Put the balloon with the tablets into the bottle so that the mouth goes in first.
If you do it right, when you put the bottle in the water, the ballast weight should allow the water to come through the holes in bottom and the bottle neck. Eventually as it sinks, the water will enter the mouth of the balloon, and hit the Alka-Seltzer tablets. The gas from the tablets will fill the balloon and it should force it against the bottle neck and keep water from coming in. The gas should also force the water out of the holes in the bottom and float it to the surface again.
You can also try keeping the cap on and putting a hole in the opposite side of the bottle from the weight to let the air out as it sinks, but remember that when the balloon inflates it needs to close the whichever hole you use.
You might have to experiment with the right amount of weight and tablets, but you get the idea.
Who invented the first submarine used in war?
Though David Bushnell's Turtle is the first submarine credited with use in combat during the Revolutionary War, it never made much of an impact as none of its attacks were successful.
The Confederate States' Army confiscated the privately built submarine H.L. Hunley (now being preserved in Charleston, S.C. after her discovery a few years ago) for use as a warship during the Civil War. The Hunley was privately designed and built by marine engineer Horace L. Hunley, James McClintock, and Baxter Wilson. Contrary to popular belief, the Hunley was never a commissioned vessel in the Confederate Navy; it was operated by the Confederate Army, and crewed by 8 Confederate Army soldiers and 1 Confederate Navy sailor.
Though the U.S. Navy also had a commissioned submarine in the Civil War (USS Alligator, 1862), the Hunley is considered to be the first submarine to be successfully used in war, and is also credited with the first sinking of a ship by a submarine during wartime. The Hunley successfully attacked and sunk the USS Housatonic, then anchored in Charleston Harbor. The Hunley sank on her return trip back to base following the attack.
Though it's long been believed she sank as a result of flooding as a result of the shockwave from her attack, her position when found, plus forensic examination of the wreck and crew remains has indicated that they in fact suffocated rather than drowned, as was widely believed at the time. This has led to the belief that she sank after her crew became unconscious and unable to power the boat. Regardless, her impact on naval warfare is undeniable, and would likely have changed naval tactics far sooner had she survived.
Submarines are used both for military and rersearch purposes.
When water fills a submarines flotation tanks the overall density of the submarine does what?
the overall density goes up.
How do submarines locate where they are?
Modern submarine use several methods of navigation; a common misconception is that they use Sonar to navigate, but that's limited and not practical, except in a very few circumstances.
All submarines use charts (corroborated with dead reckoning plotter and fathometer soundings), satellite (GPS), electronic gyro, visual references, radar (close to shore), for primary navigation in most oceans. On rare occasions, uncharted mountains or navigational screwups have led to submarine accidents. My own boat hit an underwater mountain in the Mediterranean in 1977; the USS San Francisco hit an uncharted mountain a few years ago.
The main periscope can also be fixed with a sextant if necessary to get a star fix or to take a sun line. Of course the Navigator can also do it the old fashioned way and take a sextant to the bridge while on the surface as well. There are always multiple backups for all submarine systems.
GPS is the primary method of navigation; sensors are located within the main periscope, (along with lots of other cool stuff). Navigational fixes are taken at periscope depth when a boat is doing routine housekeeping operations (e.g., trash disposal, receiving radio traffic, blowing sanitary tanks, etc.). However, no one fix, even GPS, is taken at face-value; fixes are taken from each navigational system, and then checked against each other for accuracy by the Quartermasters. The results are then reported to the Navigator.
The reason for cross-checking is because electronic systems are not infallible. It was this error that led to my boat's accident in '77.
At that time, there were several systems in place as there are today; the boat was in the Mediterranean Sea, and was carrying a replacement Quartermaster. Rather than follow proper procedure (as it turned out during the post-accident investigations and courts-martial) he trusted only one system for a fix, which was hyper accurate on his own boat. However, at the time, that system on my boat was malfunctioning. He also failed to report his findings to the Navigator. When the analysis was done later, it showed that the boat was almost 2 miles off course. The QM's dereliction was the only reason that the CO, XO, and the Navigator weren't relieved of their positions, as is customary in such cases, particularly with nuclear vessels. Typically it is a career-ender for all officers involved.
Has a submarine ever gone under the north pole?
Absolutely; the first boat to do so was the USS Nautilus (SSN-571) on her historic trip under the Pole in August 1958. In the past 35 years, regular visits by submarines (known as ICEX's, or Ice Expeditions) to the North Pole happen every year, usually supported by the Applied Physics Laboratory Ice Station (APLIS).
Having been there myself, the Arctic is a completely different world, both on the ice surface and underneath. Sonar-wise, it's extremely noisy, due to the ice floes constantly shifting and cracking with the water movement and storm activity on the surface. This makes for a perfect hiding area for Ballistic Missile submarines, and is a large reason why Arctic submarine activity has increased significantly during and since the Cold War.
Have a look at my Supervisor Bio page for some pics I took during LANTSUBICEX '86.
What was the fate of the us submarine swordfish?
There have been 2 submarines in the U.S. Navy named for the Swordfish:
1. USS Swordfish (SS-193) was a WW2 Sargo-class submarine. She was reported as presumed lost on January 15, 1945, after failing to report by radio, or in case of radio failure, report to ports in either Saipan or Midway.
The USS Kete (369), also operating in the area around Okinawa, detected a submarine on radar believed to be Swordfish. Several hours later, Ketedetected heavy depth charging in the same area, and this is believed to be the cause of Swordfish's loss.
2. USS Swordfish (SSN-579) was a highly decorated submarine in the Pacific fleet. She was stricken from the Naval Register and entered the Submarine Recycling Program in 1989, and finally scrapped in 1995.
How many bombs can a submarine have?
A typical US ballistic missile submarine has either:
- 24 Trident II missiles, each carrying 1 to 12 warheads
- 4 torpedo tubes with an unknown number of nuclear torpedos
24 to 288 missile warheads plus nuclear torpedos
- 154 Tomahawk cruise missiles
- 4 torpedo tubes with an unknown number of nuclear torpedos
154 missile warheads plus nuclear torpedos
Actual numbers for various types of submarine will vary.
Why did john holland build submarines?
John Holland built submarines to provide a new and effective means of naval warfare and to address the limitations of surface ships. His designs focused on stealth and the element of surprise, allowing submarines to operate undetected and strike from beneath the water. Holland's innovations laid the foundation for modern submarine technology, as he aimed to enhance naval capabilities and protect maritime interests. His work ultimately led to the development of the first successful military submarines.
What is the best shape for a plastecine submarine?
A fish or a cigar. Just the way they're designed now.
How is air recycled in submarines?
In modern submarines, the electrolyser separates oxygen from hydrogen in seawater to produce breathable oxygen. There is also a scrubber that removes excess CO2 from the air.
How does a steel submarine float on top of the water while it is in the harbor?
When a subs surfaced, it's a regular ship. It displaces water (it's filled with air NOT WATER).
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.
How does a submarine control its rate of ascent and descent?
It is the control planes on the submarine that are the primary method of normally controlling the rate of ascent or descent of the craft. Note that submarines have a few different configurations as regards planes. The stern planes are used alone, or in conjunction with the bow planes, if the boat is equiped with the latter ones, to change what is called "the bubble" or the angle of attack. On some boats, there are planes on what is called the fairwater or sail ("conning tower"), and these, the so-called fairwater planes, can be used to change depth slowly while maneuvering. It is these planes that are instrumental in maintaining depth on a properly trimmed boat as they are centrally mounted, and act to push the "whole boat" down or up without changing the bubble. Ballast tanks are flooded completely to dive and to conduct subsurface operations. The bouyancy of the boat (along with the trim) is controlled by the partially flooding the trim tanks.
