Many months! The biggest limitation is the amount of food they can carry for the crew. The actual limits are classified.
Submarines can produce their own air and water and with nuclear power they could stay submerged indefinitely. The limiting factor is the amount of storage space (there is not much) on a sub for food and the the size of the crew onboard that consumes it. The larger SSGN's can stay submerged longer than the SSN's because they have more storage space.
Torpedoes are the main armament. older Diesel submarines had deck guns for surface defense and anti-aircraft, but the modern ones do not have fixed deck armament. Of course FBM submarines carry Guided Missiles. More: Most WW2 Submarines carried several torpedoes, and had 4-6 forward firing tubes and 1-2 rear firing tubes. Older subs were not intended to run submerged full time the way modern subs do. There was no snorkel mast (technology taken from captured German subs at end of WW2) on most subs and they had to run on the surface to recharge their batteries for submerged operations. They also were faster on the surface than submerged. So they had surface weapons in addition to torpedo tubes. Usually a main gun, about 5 inches or so; and an anti-air gun similar to a .50 cal. The measurements would vary depending on the country as the US uses standard measurement and most other countries use metric.
In the EPL...3 Subs Universally in the main its also 3 subs
Subs (Submarines).
Everytime one of their nuclear subs sank we had to help them recover lives, etc.; though they often politely declined our offer thru fear that we might see some of their military secrets...which was a fairly valid point.
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Nuclear Submarines can stay almost indefently for them it is a question of Stores (food). Diesel Submarines are really not designed for under ice operations. AIP Subs can stay submerged for prolonged periods depending on the amount of Liquid Oxygen it has.
Nuclear submarines derive their power from a nuclear reactor that generates steam to drive turbines, which in turn propel the submarine. The nuclear reactor uses enriched uranium fuel to sustain a controlled nuclear reaction, providing continuous power without the need for refueling for extended periods underwater.
A German type VII U-boat could stay submerged for about 24 hours before it had to resurface to replenish its air supply. This air supply could be extended somewhat by limiting activities of the crew while submerged. The type IX could stay submerged for 11 days. The snorkel in 1943 allowed German subs to stay submerged and refresh air. All other US/UK/Jap etc subs could stay down 2 days before having to vent for fresh air and recharge batteries.
For modern nuclear subs, they could theoretically stay under indefinitely. Of course, there's a crew which has to eat and bathe, and food and toiletries do eventually run out.
Chernobly, it was completely uncontained. Collision of nuclear subs is also unlikely to result in any nuclear accident, just mechanical damage to body of the subs.
Until they implode, same as the old subs.
new subs are nuclear powered
Modern Marvels - 1994 Nuclear Subs 7-24 was released on: USA: 28 August 2001
http://americanhistory.si.edu/subs/history/timeline/cost/index.html
nuclear power makes hot water which turns into steam. instead of turbine how about a generator..
At Pearl Harbor, the Japanese used the HA-19 (type A) which had a complement of two crewmen; was 78 feet long, 6 feet wide, and a draft of 6 feet. It was armed with two torpedo tubes, which fired a 45cm type 97 torpedo. It was powered by a one shaft electrical motor which could move it at 23 knots at the surface, and 19 knots submerged. While submerged at 2mph, it had a range of approximately 100 miles. Mini subs (Midget Subs) had to be carried by mother submarines. I Boats, such as I-24, carried some of the attacking Mini-Submarines to their pre-attack areas for the Pearl Harbor assault on 07 December 1941.
Subs got longer as time progressed, for example, Germany's first U-boat (U1) was derived from a batch of subs bound for Russia during the Russo-Japanese War in 1904; those were about 139 feet in length. WWII US Navy Gato class subs were about 311 feet in length. By the time of the cold war, atomic subs were as long as WWII battleships...600 feet long!