SCIENTIFIC CONCEPTS

What is a submarine?

U.S. Navy photo 80-G-709366, Public domain, via Wikimedia Commons

A submarine is a craft that can transport people under the surface of the sea. It relies on several processes to make it work. The main concept of the submarine has to do with water displacement and maintaining neutral buoyancy when submerged. They're neither floating or sinking. In order to do this, a submarine has blisters on the hull called ballast tanks. Filled with air in the ballast tanks, the submarine floats. Filled with water in the same tanks, the submarine submerges.

This concept holds water for all submarines designed to this day. While submerged, ballast tanks are adjusted to maintain trim of the submarine so the crew can move about safely and accomplish their tasks in military service or scientific study. The submarine has undergone many changes since its inception. The submarines also had to serve in a variety of roles. Many new roles are being created today, like launching drones, deploying US Navy Seals and fighting the war on terror, war on drugs and lastly, continuing to launch ballistic missiles in the event of war.

For science based missions, submersibles are valuable in understanding oceanography. They can go anywhere in the world and are usually stowed aboard research vessels. The Russian Akademik Keldysh is one example. These craft are capable of doing work with robotic arms to gather samples, go into areas that would present a danger to the crew with an ROV (Remotely Operated Vechicle) attached to a tether. Some feature ports with glass several inches thick. Submersibles are also used in rescue situations of trapped crew on a submarine. These are called DSRVs or a Deep Submergence Rescue Vehicle.

All submarines and submersibles face a common threat. They must handle the pressure exerted on the hulls. Surface pressure is 14.5 PSI. For every 33 feet of depth, water pressure increases 14.5 pounds/ square inch. (PSI) (Oceanservice.NOAA) Hull breaches can be deadly killing the crew instantly from a violent implosion. All submarines and submersibles are built to withstand a certain depth and nothing more. Two US Navy submarines, USS Thresher and USS Scorpion were lost as a result of an implosion and sadly with all crew killed in both submarines.

Links to Scientific Concepts

Types of submarines:

Diesel- Electric- This craft was used in the early to late 20^th century by the Chinese and Soviet navies. The principle is simple. A diesel engine will charge a battery to run electric motors. Early submarines ran on the surface to ventilate the diesel exhaust and prevent the crew from being poisoned. The batteries were big and bulky and often located toward the bottom of the hull. The diesel electric had a limited time submerged. It was often 13 hours before recharging batteries. Later adaptations invented by the German Navy in WWII created a snorkel so that a diesel engine could run submerged. (Schwab, 250)

Electric- Batteries connected to an electric motor drive or a tether to a ship without a diesel to recharge them. They are meant to be underwater for a short specified amount of time. These are usually in manned submersibles. The drive tends to be direct and they use devices called THRUSTERS capable of pivoting to provide both steering and propulsion at the same time. Thrusters are similar in appearance to a box fan. An example of one is shown on the picture of Alvin posted below. (Wikipedia)

Nuclear- Nuclear submarines are the largest of their type. On board is a nuclear reactor to provide propulsion and electrical power to run the ship or as some old salts refer to it, "The Boat.” Water is converted to steam from nuclear fission. Atoms of Uranium 238 are split and the heat makes the steam. Steam is channeled to a turbine, almost like a surface ship. The greatest advantage of nuclear energy is that the submarine can remain below for months. An example shown at the bottom of the page, is the LOS ANGELES CLASS attack submarine. The concepts are also nearly identical to the larger OHIO CLASS ballistic missile submarines. Unlike a Diesel Electric submarine, Nuclear Submarines are capable of remaining submerged for months at a time in order to fulfill their missions. The only thing limiting patrol is food. (Schwab, 251)

Designs and Devices

Cross section of the HL Hunley.

Unknown author, Public domain, via Wikimedia Commons

Links

THE TURTLE

THE HL HUNLEY

DIVING PLANES

Early examples of the submarine were hand cranked. One of the earliest designs was The Turtle used in The Revolutionary War by the Continental Navy. They were small and there was limited space .

Another example, The Confederate Hunley was famous for sinking the USS Housatonic before becoming lost herself during the Civil War. The submarine was found, raised and is currently undergoing preservation as well as restoration. The remains of the sailors entombed received a proper burial.

William Oliver Stevens, Public domain, via Wikimedia Commons

Above: Bushnell's Turtle

The German Type VIIc U Boat

Below: A section drawing of a typical German Type VIIc U Boat in World War II. This is an example of a diesel- electric submarine. If you look at the bottom of the hull, you will see the batteries that run the electric motor. Going aft you can see one of the diesel engines used for both propulsion and charging the batteries.

David W. Taylor Model Basin, U.S. Navy, Public domain, via Wikimedia Commons

Darkone, CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons

The U995, a Type VIIc preserved as a museum in Kiel, Germany

The captured U 3008 used by the US Navy to test the snorkeling device.

USN, Public domain, via Wikimedia Commons

Links

JUERGEN PROCHNOW U BOAT TOUR

THE SUBMARINE SNORKEL

ALFRED VON TIRPITZ

U BOAT IN WWI

The reality of the U Boat was its mission. Unlike our modern submarines to do strategic deterrence, these were designed to hunt allied shipping and sink it with torpedoes. Essentially, the mission did not change that much since WWI. The aim was part of the Nazi Plan to starve out Britain. As such they were intended to be offensive weapons.

40,000 German sailors were in the U Boat Service. 30,000 never returned. What you are looking at is a 75% loss. U Boat sailors averaged 1 patrol.

The snorkel device as shown in this picture (left and below) enabled the German U boats in WWII to run diesel engines underwater. We're on the starboard side looking aft.

It had an air intake and an exhaust that were next to each other. Another function of the snorkel was to provide fresh air to the crew below the surface. The system was not without its flaws. One of them was heat from the diesels making life uncomfortable for the crew. The other was excessive vibration caused by the diesel engines. Another drawback was that the U boats were noisy and easily detected by the Allied destroyers.

Although they could run faster submerged, they were unable to use the periscopes. Hydrophones, like passive sonar, became useless from the noise of the diesel engines. Another issue that arose was immediately shutting down the diesels if the snorkel lost air supply. Monitoring the air supply was extremely important when the snorkel was in use. If the engines consumed the air inside the U boat, the crew would have been poisoned. (Preston, 46)

The head of a submarine snorkel.

Daderot, CC0, via Wikimedia Commons

Typical WWII US Navy Submarines

The video below shows the workings of a Diesel Electric submarine from 1955. The submarine shown is actually a modernized World War II submarine.

Below: An example of a WWII Balao Class US Navy Submarine, USS Ling SS-297 shown near the end of WWII,

USN, Public domain, via Wikimedia Commons

Submersibles- Exploring the Depths

This is the Alvin used by WHOI (Woods Hole Oceanographic Institute) The first Alvin was made famous for exploring the ocean and later took Dr. Robert Ballard to the site of Titanic’s remains. A new Alvin joined Wood Hole in 2012. Alvin is a submersible. It carries a crew of 3 inside a sphere designed to withstand the pressure of the depths below. (Schwab, 252) The submarines shown all have propeller shafts. A submersible navigates through the use of thrusters which do the job of both diving plane and screw type propellers. The rack shown is for a tether connected ROV. (Remote Operated Vehicle) This is able to go inside areas where a submersible cannot. This is far from comfortable. It lacks a toilet and most of the time the crew are in there for compression and decompression. A submersible is capable of diving deeper than a submarine by its design.

The original uploader was Jholman at English Wikipedia.Later versions were uploaded by Aarchiba at en.wikipedia., Public domain, via Wikimedia Commons

Kirt L. Onthank, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

Systems

Breathable air:

Water Electrolysis involves the running of electrical current through a water source. What happens is that water is broken down into 2 parts of hydrogen to 1 part of oxygen. The crew breathe the oxygen and vent the hydrogen overboard. Oxygen is collected into a tank and released into the atmosphere when oxygen levels are low.

Scrubbers- Scrubbers are filters that remove carbon dioxide from the air or atmosphere much in the way the Space Shuttle, International Space Station and Apollo missions do. In addition to surface to recharge batteries, Diesel Electric submarines needed to ventilate and recharge the air in the submarine. Scrubbers let you remain submerged. Scrubbers use a substance called soda lime to absorb carbon dioxide through a scrubber machine. This is a mix of NaOH (Sodium Hydroxide) and CaOH (Calcium Hydroxide) (Scienceabc.com)

Drinkable water can come from three means:

Reverse Osmosis- This means water is forced through a semi permeable membrane through suction. The salts are removed and the result is drinkable water for the crew and water to cool the reactor. (Wikipedia)

The Nuclear Reactor

A Nuclear Reactor is used to generate power by splitting an atom. In this case, the fuel is Uranium 238. As the result of splitting the atom, heat is generated. When you cool the reactor with water, the heat from the fission reaction transfers to the water and generates steam. This steam is used to turn a turbine and in turn generates electricity by a generator. This provides power for the submarine as well as the electric motors responsible for turning the screws. (propellers)

Nuclear reactors generate more energy than a conventionally powered ship. This means that the ship can run for years without refueling. There does come a point where the reactor does need to be refueled. The main problem is in what to do with the waste. Since it's radioactive and poses a threat, the waste is buried for thousands of years.

Links

NUCLEAR REACTOR

A cutaway of a Nuclear Reactor

Emoscopes, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons

NetMarine; cropped by Beyond My Ken (talk) 05:23, 7 May 2010 (UTC)derivative work: Beyond My Ken, CC BY-SA 3.0 <http://creativecommons.org/licenses/by-sa/3.0/>, via Wikimedia Commons

Silent Running

Silence was important in WWII, but it became even more so in the days of The Cold War.

Here we see an example of anechoic tile applied to the Royal Navy's HMS Triumph. All these are rubber tiles applied to the hull skin. Their purpose is to absorb and dampen sound in order to make a submarine more silent. Sound travels faster in water than in air. As a result, silence is a part of submarine life. There are several systems applied both around and in to make sure a noise does not give a position away. Operating under these conditions is called silent running.

The most important systems for silent running begin with the sailors. Slamming doors, toilet seats and talking loudly all betray a position. How and where items are stored make all the difference. The other part of the silence is making sure the machinery itself is quiet inside. While it can never be 100% quiet, it comes as close as possible.

Avoiding detection was extremely important in the cold war and is is still a part of submarine operations today.

Ballistic and Nuclear Attack Submarines

OS2 JOHN BOUVIA, USN, Public domain, via Wikimedia Commons

Here is a LOS ANGELES Class Attack Submarine. Most of its inner workings are similar to a ballistic submarine except that Tomahawk missiles are stored forward and torpedoes are launched. Submarines have two hulls. There is an outer hull and a pressure hull. Inside the pressure hull is where everything happens. A majority of the space is machinery needed to operate the submarine for its task. The space left over, albeit very little is where the crew lives their day to day existence. Nuclear submarines can do what other submarines cannot. They can remain submerged for months. The only reason would be to resupply their food or the end of their patrol. Out of all of the submarines, these are the most comfortable. They are air conditioned, and there is a constant source of fresh air provided by water electrolysis.

Mike1979 Russia.Mike1979 Russia at ru.wikipedia, Public domain, via Wikimedia Commons

Fred Maroon, Public domain, via Wikimedia Commons

By comparison, a Nuclear Ballistic Submarine of the OHIO Class. You can see as evident, the similarities of the Attack Submarine. It is however, a larger submarine designed for a mission of the crew rehearse constantly by drills- launching nuclear missiles with multiple warheads. Like Attack Submarines, these remain stealthy too. To avoid detection, a ballistic submarine is engineered to be quiet with a rubberized skin on the outer hull. An example of these tiles is shown above.

Left: A dive station on a Los Angeles Class Attack Submarine.

Voytek S, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons

Line drawing of the Ohio class in its original SSBN configuration.

(1) Sonar dome, (2) Main ballast tanks, (3) Computer room, (4) Integrated radio room, (5) Sonar room, (6) Command and control center, (7) Navigation center, (8) Missile control center, (9) Engine room, (10) Reactor compartment, (11) Auxiliary machinery room no. 2, (12) Crew's berthing (13) Auxiliary machinery room no. 1, (14) Torpedo room, (15) Wardroom, (16) Chief petty officer quarters, (17) Missile compartment

Rescue Equipment

A typical DSRV (Deep Submergence Rescue Vehicle)

U.S. Navy, Journalist 3rd Class Wes Eplen, Public domain, via Wikimedia Commons

The DSRV as shown is aboard a submarine. At the base is a docking skirt designed to seal over a hatch or a submarine to rescue trapped crew and bring them safely to the surface. This was designed following the loss of the USS Thresher and USS Scorpion. It can dive to a depth of 6,000 feet and capable of rescuing 24 sailors and bringing them safely to the surface. (Wikipedia)

The reason for the DSRV was a submarine called the USS Squalus which sank in an accident in 1939. A challenge was in bringing the surviving sailors to the surface. This became an ordeal for the crew which helped to shape the future of the rescue of submariners.

The sinking of the Squalas was not the end of her story. She was raised, salvaged and rebuilt. Her new name would be USS Sailfish. She would serve the remainder of the war and would be scrapped. Her conning tower is on display in Portsmouth, NH

Videos

These videos are meant to show an idea of what it takes to operate a submarine. Some show ordinary aspects of life going on within the pressure hull. One of the most important things to notice is that is a time to be serious. At their stations each is expected to perform their duties and through intensive study, submariners are pinned with the coveted "Dolphins" which show that their training as a submariner is complete. You will also notice in the videos that the little space available is not wasted.

This is a good video showing life aboard submarines in the world serving various navies.

As you can see in this video, the comparison to the USS Ohio shows a similar life aboard the USS Wyoming. The US Navy trains to a very high standard its submarine crews to the levels instilled by Admiral Hyman G. Rickover.

This video covers a tour of the US Ballistic Missile Submarine USS Ohio. It takes you on a tour as part of a news feature in San Diego, CA where there is a US Navy Base. This video as well helps to understand what happens within a submarine at sea.

This is a more modern tour of a nuclear attack submarine in comparison to the "Submarines: Sharks of Steel" video. Note the masks worn by the crew of the USS New Mexico.

A video of a US nuclear submarine diving.

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