Submarines

Until the advent of Nuclear Power for submarines, which gave them much greater speed capability underwater than on the surface, submarines were essentially designed as low-profile surface vessels with limited submergence capability. As such, their overall design made them noiser underwater and faster on the surface rather than quieter and faster underwater, the hallmark of modern submarine designs.

The most hydrodynamically efficient model of submarine is the elongated teardrop shape that is characteristic of most large modern military u-boats. These boats have a rounded nose, a hull diameter that is appropriate to the design objectives of that particular boat, and then the hull tapers down in diameter back past midships to just a few feet around at the aft end where the screw is attached to the shaft. It makes for really good hydrodynamic performance and good efficiency. It's a quiet shape, too, and it's all about the noise, isn't it? Sharp points on the bow make for extreme difficulties in design and add little to nothing to the performance of the hydrofoil. (It's more about cross-sectional area after considerations regarding the shape of the nose, or bow.)

Also, as mentioned, a nuclear submarine is operationally efficient because it can operate at sea for extended periods without the need for fuel, and, more importantly, can operate UNDER the water for a long time because the propulsion system doesn't require air - oxygen - as part of its power generating cycle. Lastly, think about this: an old diesel electric submarine, when it is operating underwater using its battery banks to drive an electric motor to turn the screw, is REALLY quiet. A nuclear boat constantly runs pumps and steam turbines while underwater, and these actually make more noise than the electric systems that drive the old boats when they are submerged. Of course, when the old boats surface to run engines to charge batteries, they can be heard for many miles and identified for what they are.

The "V" stands for "vehicular"

Water enters the starfish through the madreporite or the tube feet, but mainly the madreporite.

Control room, submarines

Atlantic Ocean.

The primary reason for the shift to Submarines rather than Battleships and other surface combatants is that in previous wars, most naval engagements were between surface warships, or warships against merchant vessels. With the advent of better submarine technology in WWI, and the early successes of the Kriegsmarine U-Boats in the Battle of the Atlantic, it became apparent that submarines as a weapons delivery platform had become a viable threat.

Advances in Air Power had shown also that Battleships were vulnerable to airplane attacks; until that time, airplanes were not believed to be capable of sinking or seriously damaging a Battleship. However, a static controlled test (the results of which were initially "skewed" by the Navy) conclusively proved that airplanes as a mobile artillery delivery system (bombers and torpedo planes) were a serious threat to the Battleship. The sinking of the Bismarck by WWI vintage torpedo planes from the British carrier Ark Royal, along with the Japanese attack at Pearl Harbor, were the final nails in the coffin of the Battleship as the premier weapons platform of the fleet. After that, carriers and submarines were the preferred weapons of choice, and remain so today because of their ability to be rapidly positioned in hot spots around the world. Carriers are more obvious since they cannot be easily hidden - they are an overt statement of a country's projection of power around the globe. However, no carrier battle group is ever without a submarine escort.

While the carrier can project air power to any part of the planet, and has today become a symbol of the host country's overall power, the submarine's inherent ability to control the shipping lanes and stop supplies are what led to Japan's ultimate defeat in WWII. Though they had carriers early in the war, they failed to replace them. As their supply lines grew longer and longer across the Pacific, it became easier for American submarines to interdict and destroy enemy shipping and cutoff vital supplies. Even today, most heavy supplies are moved by ship, as well as strategic minerals and raw materials necessary for National Security. It is this reason why the Navy exists to begin with - to control the seas and shipping lanes and ensure that vital supplies necessary to the country get here.

There are many raw materials that the US needs to survive that are not found within the borders of the US; they must be shipped in via merchant vessels. Oil is but one strategic import; Titanium is widely used in aerospace applications, but is not found here. The list of strategic materials is longer than most people realize, but it is oil that is usually singled out.

Submarines in World War II were not true submersibles as we know them today; they were surface vessels with a limited ability to remain submerged for extended periods. It wasn't until the advent of Nuclear Power in the '50's when Admiral Rickover led the effort to design, build and install the first reactor in a submarine that the true submarine was born. Today, only crew limitations require submarines to enter port and resupply.

The Japanese military did not cooperate with the axis navies. Their enemies were in the Pacific Ocean, so they would not have sent ships to the Atlantic. The allies controlled the locks at Panama, so if Japanese ships wanted access to the Atlantic, they would have had to have sailed south between South America and Antarctica.

So, no, the Japanese subs and ships did not play an important role in the "battle of the Atlantic", whatever that would have been.

The top 5 are as follows. The United States has 73. Followed by China with 63, Russia with 56, and N and S Korea each has 26. Remember, these numbers are always changing.

There is no sub that goes to the Titanic. The Titanic is so deep in the cold waters that it takes a special diving bell that can go down that far and deep. Films have been made of the 2-3 trips that it has made and you can most likely find them online.

You can make one with a baby carrot, four toothpicks, and baking powder (not baking soda). You will also need a dull knife with a fairly narrow tip. Cut the carrot in half the long way. Eat the other half. Hollow out a small area in the middle of the flat side. Stick the two of the toothpicks in the round side in the front at an angle. Stick the other two toothpicks in the round side in the back at an angle. Pack as much baking powder into the hollowed out area as you can. Place in water. To see it done, go to: http://www.metacafe.com/watch/805804/baking_powder_submarine/

They have male nurses on board. They are called corpman.

It depends on the water in the area of operation, but absolutely, especially from aircraft.

If close enough to a surface vessel and the water is clear enough, it can be seen as well, but not as easily.

Aircraft spotting of submarines underwater was a major concern for both Allied and Axis submarines during WWII, and the limited depth capability of those boats meant they were more susceptible to aerial attack even after they dove. T they're a lot harder to detect today (submarine sonar can pick up aircraft noise and thus either go deep or stay deep), though being detected in shallow water or clear ocean is still a very real threat. It's one reason that submarines have been painted black for decades - they're harder to spot.

Depending on the clarity of the water, submarines have been spotted from the air as deep as 400', but they're usually spotted at Periscope Depth, which is around 65' keel depth depending on the boat.

It's easier for aircraft to spot them in the clearer waters of the Pacific or the Caribbean rather than the Atlantic, but the operating depth of most boats is deeper than most aircraft can spot them anyway. You have to literally be over them and looking as well - again, black isn't easy to spot from the air against the darker background of deep ocean. Generally, the attempt is made by ASW aircraft to locate a boat by sonar (sonobuoys or dipping sonar from a helo), and then visual scanning is attempted. However, as an old submarine Sonarman, I can tell you that once an aircraft is picked up (a helo has to be low enough on the water to use dipping sonar that it can be heard, and sonobuoys make unmistakable splashes when they hit the water), a boat captain won't give an aircraft the opportunity to get a look.

As an example of the concern of being spotted from the air, during the Cold War when I was submariner, the onboard emergency buoy, which could be released in the event the boat sank in shallower water, was normally painted orange so it could be more easily spotted if released and on the surface (it had about 400' of cable). The buoy was painted black and welded to the deck if going on special ops in hostile waters so that it couldn't be spotted from the air.

All shiny metal surfaces are also painted black, so that sunlight can't reflect off of them and potentially alert an aircraft to a boat's presence.

Charleston Harbor

There are 2 primary reasons:

1. Pressure in the boat helps to seal hull valves and other mechanical equipment that rely on seals to keep water out of the boat.

2. Monitoring the air pressure in the boat is a primary way to discover leaks or flooding; if there is a drop in pressure for no apparent reason, it's a good bet that water is coming in from somewhere.

The key to the range and duration of the modern nuclear submarine is the nuclear reactor. The reactor generates heat through nuclear fission, and this does not use air (or the oxygen in it). The heat is used to make steam, and the steam drives conventional steam turbines. With a large power source and no requirement to be on the surface, the boats can stay down for an extended period limited only by the amount of provisions they can stow aboard prior to deployment.

Believe it or not, yes - Shark attacks against submarines and submarine Towed Sonar Arrays are actually quite common, and also cause a lot of damage when they bite a Towed Array. I've seen myself shark bite damage to my old boat's Towed Array cable, and some arrays are often found with shark's teeth still in them.

Of course attacking the boat itself won't do any damage, other than chip some paint. But they see submarines as a threat in their space and act accordingly.

The conventions for naming U.S. Navy vessels has a long and varied history, dating back to the earliest days of the Republic. Today, it's pretty standard, but it depends on the type of vessel, and in special cases, the naming convention for a vessel can be changed by the Secretary of the Navy.

The most recent example of ship naming are the USS Michael Murphy (DDG-112), and Arleigh Burke-class guided missile destroyer, and the USS Michael Monsoor (DDG-1001) one of the new Zumwalt-class guided missile destroyers. Both were named for Navy SEAL's who were killed in action in Iraq and Afghanistan (Murphy in Afghanistan in 2005, Monsoor in Iraq in 2006), and were both posthumously awarded the Medal of Honor.

The Federation of American Scientists maintains a good reference list of Navy vessel types and their naming conventions. The link is below.

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.

When ever they were presented with targets of opportunity.

IJN subs were deployed for "fleet warfare", not merchant raiding. The costly job of sinking allied warships fell to the IJN sub fleet. It's estimated that IJN submarines sank less than 50 merchant ships during the war.