How Long Do Submarines Stay Submerged? Curious Answers Revealed

Devangana Rathore
Jan 20, 2023 By Devangana Rathore
Originally Published on Dec 07, 2021
Fact-checked by Sakshi Raturi
How Long Do Submarines Stay Submerged? Curious Answers Revealed
?
Age: 3-18
Read time: 8.3 Min

Submarines are incredible nautical vessels that can travel underwater and remain there for extended periods of time.

For this reason, they were initially deployed by the German Navy during the world wars to wreak havoc against allied ships. Submarines are classified as diesel-electric or nuclear submarines, depending on the type of engine they use.

Diesel-engine submarines, often just diesel submarines, are submarines powered by diesel-electric engines. Nuclear-powered submarines, or commonly nuclear subs, utilize energy produced by a nuclear reactor on board. Submarines are mostly made of high-strength alloyed steel, with a depth limit of 820–1,148 ft (250–350 m).

Are you able to experience the waves in a submarine while it is immersed? Usually, a sunk sub does not rock in response to surface wave action.

However, if the sub goes too deep, the force outside the pressure hull exceeds the metal hull's compression strength, causing a catastrophic hull collapse and sinking. Because submarines are virtually always submerged, there is no need for a window, and there's nothing much to see.

For the crew of a crippled underwater sub, there are two choices: escape or rescue. A crew escapes a submarine and rises to the surface without help, whereas recovery is carried out by outside forces, which remove the stranded crew from the submarine.

To learn more fun things about the world, check out our articles on how long clones liveandhow many animals died on the Titanic.

Submarine Definition

Submarines have long piqued the interest of Navy aficionados, and many have wondered what it would be like living on board a Navy submarine. The way they are used for national security is a closely guarded secret for members of the Navy.

Nuclear submarines were a crucial part of the nuclear triad during World War II and strategically and tactically in the war against terrorism, with highly improved weapon systems.

There were experiments in the 30s and 40s and during the Cold War, but not just experimental submarines were built; the Swedish Gotland-class submarine, debuted in 1996, was the first functional AIP submarine using Sterling engines that ran on diesel with liquid oxygen.

Artful is the third submarine in the Astute class submarine to be launched, with four more on the way.

Earlier designs had a 'conning tower', which was a separate pressure tank above the main structure of the boat that enabled for shorter periscopes. The structure is on top and reinforced to allow it to the surface beneath ice caps.

A British crew once emerged beside the North Pole to play football. Someone had to be on the lookout with an SA80 rifle in case a polar bear came by.

Reasons Why Submarines Stay In Water

Rising to the surface is one way for a submarine to emerge. To do so, seawater is replaced with high-pressure air that is pushed into the ballast tanks.

The weight of the seawater keeps the sub below the surface; therefore, disturbing it causes it to rise to the surface. Driving to the surface is another option.

Planes run the length of a submarine's bow, stem, and superstructure. The sub can raise as it cruises by orienting them. Low-pressure air may push seawater out from the ballast tanks once it reaches the surface, allowing it to float above the ocean.

The planesman and helmsman use controls to modify the rudder and diving planes to drive right, left, up and down. The commander of the guard sits near the Ballast Control Panel (BCP) and operates it.

The teardrop shell design enables a submarine to slice neatly through the ocean if there is water across all sides. Even more advanced devices allow us to use electricity to collect oxygen from saltwater and purify carbon dioxide before it is released into the ocean.

Submarines typically carry a 90-day food supply, allowing them to stay submerged for three months.

How long can a diesel-electric submarine stay submerged compared to a nuclear submarine?

Diesel-electric submarines may remain immersed for up to 48 hours without recharging their batteries, but they should surface to operate a generator. Nuclear-powered submarines in the army may remain submerged for extended periods of time.

They don't have an issue with air because they produce their oxygen and maintain the atmosphere on board. Food and supplies are the only things that limit how long they can stay underwater.

Submarines powered by diesel have a maximum underwater time of several days. They can't use air-breathing engines when fully submerged, so they depend on battery capacity and electric motors. They'd have to come to the surface and then use a snorkel mast collecting air to charge batteries and swap clean air for diesel engines.

The diesel engine in a conventional submarine provides electricity that can be used to operate the propeller and other equipment. The issue is that such a combustion engine is fundamentally loud and requires air, which is scarce aboard an underwater vehicle. Submarines powered by diesel must therefore surface regularly to replenish their batteries.

Nuclear submarines have always had a significant advantage over inexpensive diesel submarines in endurance, sound, and speed. On the other hand, the New Air Independent Propulsion (AIP) innovation has greatly improved efficiency for a new generation of submarines that pay a fraction of the expense of a nuclear-powered vessel.

The ability to extract oxygen from saltwater is a feature of nuclear subs. Nuclear submarines can stay underwater for months at a time. It is a nuclear submarine that produces its own oxygen by electrolyzing water.

What is the longest a submarine has stayed submerged?

The HMS Warspite's longest, submerged trip, from November 1982 through to March 1983, was publicly disclosed. They were immersed for 111 days!

As the name implies, a diesel submarine is powered by a diesel engine and must therefore emerge (or get to at least periscope depth). Submarine periscopes can be up to 60 ft (18.2 m) long.

When a sub is submerged to a depth equivalent to the periscope's height, it is considered at periscope depth. The periscope is the long, thin tube placed in front of the sub.

The 'eye of the submarine' is a fitting moniker. It allows the crew of the sub to see the surrounding horizon while remaining below.

A periscope can see for 11-12 mi (17.7-19.3 km) out at sea. A submerged submarine returns to the top every few days not just to replenish its supply of air oxygen above the ocean's surface but also to get rid of waste gases produced aboard.

Two escape trunks, similar to airlocks, are available on Navy submarines and can be used as evacuation routes. Crew enter the escape trunk while wearing life preservers with a hood that has a bubble of air to inhale. Then, the lower gate is closed, the trunk fills with water, and the submarine comes up to sea pressure.

Nuclear-powered submarines have become extremely quiet, at least more than a diesel submarine running its engine. Nuclear-powered submarines will be unable to identify each other with passive sonar.

The hydraulics of a nuclear reactor make noise as they circulate coolant liquid, whereas the engines in an AIP sub are almost silent. Diesel-powered submarines may achieve this level of silence when operating on battery power, but only for a few hours.

Nuclear submarines can operate underwater for three to four months at a time and easily span seas. While few conventional submarines can travel the distance, none have the same depth of endurance below. As a result, surfaced submarines are pretty easy to identify and attack. A nuclear-powered submarine can descend to roughly 984 ft (300 m).

Nuclear submarines have an undeniable advantage in terms of speed. Attack submarines from the United States may be capable of immersed speeds of more than 35 mph (56.3 kph). The most excellent immersed rate of the German Type 214 is the standard of AIP submarines, at 23 mph (37 kph).

When traveling sustainably with AIP, relative to diesel or nuclear subs, an AIP submarine is likely to shift at modest speeds.

For instance, if a Gotland class submarine wants to stay below the surface for as long as possible, it must slow down to just six mph (9.6 kph), which is far too sluggish for long-distance transits or cruising alongside surface ships.

In addition, because current AIP tech does not generate enough power for more incredible speeds, many AIP submarines are equipped with loud diesel engines for backup.

Since the submarine HMS Conqueror destroyed the Gen Belgrano during the Falklands War, the Royal Navy hasn't used a torpedo in action. However, during the conflicts in Kosovo, Iraq, Afghanistan, and Libya, British submarines launched scores of Tomahawk missiles.

Although AIP vessels may not be able to accomplish all that a nuclear submarine can, having an enormous fleet of submarines to chase down rival ships and submarines for dominance of the seas can be highly beneficial. Giant AIP-powered submarines are not difficult to operate; China has already accomplished this.

France is selling a cheaper AIP-powered variant of the Barracuda-class nuclear attack submarine. Operating AIP submarines from forwarding ports would be a very stealthy and cost-effective way for the Navy to extend its sea-control mission.

Because of the blockade at Port Arthur, the Russians dispatched all submarines to Vladivostok, where they assembled seven boats and the world's first 'functioning submarine fleet' on January 1, 1905. Military submarines first influenced World War I when the German submarine SM U-9 sunk three British ships in less than an hour in 1914.

The only thing that prevents them from staying submerged is a lack of food.

Shipping was critical in supplying food to the British people, raw materials to industries, and fuel and weaponry to the armed forces. Occasionally, a member of a crew is injured or becomes ill, necessitating medical care.

Submarines in the Navy lack ports or portholes through which the crew can observe life below the surface. If the atmosphere fails, the crew can connect masks to oxygen ports on the ceilings.

Here at Kidadl, we have carefully created lots of interesting family-friendly factsfor everyone to enjoy! If you liked learning how long submarines stay submerged,then why not take a look at our articles on Vikings and Anglo Saxons facts or astounding Arctic Ocean Islands facts?

We Want Your Photos!
We Want Your Photos!

We Want Your Photos!

Do you have a photo you are happy to share that would improve this article?
Email your photos

More for You

See All

Written by Devangana Rathore

Bachelor of Arts specializing in English Language, Master of Philosophy

Devangana Rathore picture

Devangana RathoreBachelor of Arts specializing in English Language, Master of Philosophy

Devangana is a highly accomplished content writer and a deep thinker with a Master's degree in Philosophy from Trinity College, Dublin. With a wealth of experience in copywriting, she has worked with The Career Coach in Dublin and is constantly looking to enhance her skills through online courses from some of the world's leading universities. Devangana has a strong background in computer science and is also an accomplished editor and social media manager. Her leadership skills were honed during her time as the literacy society president and student president at the University of Delhi.

Read full bio >
Fact-checked by Sakshi Raturi

Postgraduate Diploma in Management

Sakshi Raturi picture

Sakshi RaturiPostgraduate Diploma in Management

Sakshi has experience in marketing strategy, social media planning, and recruiting industry experts for capstone projects, she has displayed a commitment to enhancing their skills and knowledge. She has won multiple awards, including a Certificate of Appreciation for Creative Writing and a Certificate of Merit for Immaculate Turut, and is always seeking new opportunities to grow and develop.

Read full bio >