SUBMARINES INSTRUCTION MODULE 8

SUBMARINES INSTRUCTION MODULE 8 1 Description of Module This module covers history of submarines, types, parts, working of submarine and dangers on submarine. This module also demonstrates the underlying principles in the design and operation of submarines like Buoyancy, Boyle s Law, Effect of water pressure on the submarine with the help of hands on activities, class exercises and check on learning. 2 Targeted SOL S Physics Standards (PH 7) Math hstandards d (A1) Math Standards (A 11) Earth Sciences (ES 1) 3 1

Topics Covered S.No Topic 1. Origin of Submarines 2. Types of Submarines 3. External Parts of Submarine 4. Internal Parts of Submarine 5. Force acting on a Hydroplane 6. How Submarines Work? 7. Boyle s Law 8. Pressure on Submarine 9. Use of Sonar in Submarines 10. Safety on Submarines 4 Origin of Submarines Man has always wanted to explore the ocean depths. Invented primarily to destroy enemy ships in war. 5 What is a Submarine? A vessel that can be submerged and navigated under water. A submarine has even been used to descend into the Mariana Trench, the deepest known part of the world s oceans, seven miles below the surface. 6 2

Hands-on Activity 1 Cup Submarine 7 Has Anyone Read 20,000 Leagues Under The Sea? Author Jules Verne wrote about the adventures of Captain Nemo and his incredible electric powered submarine called the Nautilus (1869). 8 Journey of Submarines (18 th 20 th Century) World s First Battle Submarine- Turtle. By David Bushnell (American) in 1776 World s Largest Submarine- Typhoon. By Russians in 1994 9 3

History of Few Famous Submarines Fulton s Submarine (1801) The first Practical Submarine The Hunley (1864) Used in American Civil War The Resurgam (1879) The world's second mechanically propelled submarine 10 Submarine Timeline 11 The First ACTUAL Submarine First actual submarine was made in 1620 by a Dutch inventor. It was named The Drebbel. Made of wood and covered with greased-leather. It was very leaky and not very safe. 12 4

Submarine Built in 1776 (Turtle) David Bushnell built a strange submarine made of oak. It had two hand-cranks to provide power. However, the operator was knee-deep in water! 13 Another Attempt in 1864 During the Civil War, submarine H.L. Hunley made the first successful underwater attack. Was the first submarine to sink an enemy warship. The torpedo hit its target, the USS Housatonic, but the explosion was so great it sank both ships! 14 U-boats in 1941 U-boats were larger and specifically designed for long-range patrols. Large battery allowed it to cruise submerged for long periods and high speed. Managed to sink 192 boats and killing more than 5,400 people during the war. 15 5

First Nuclear Submarine - 1954 USS Nautilus was the world's first operational nuclear-powered submarine. First vessel to complete a submerged transit across the North Pole. It can remain submerged for weeks, even months. 16 Identify the Following Submarines DREBBEL USS NAUTILUS TURTLE H.L. HUNLEY 17 CLASS EXERCISE - 1 Crossword Puzzle 18 6

Solve the Crossword Puzzle - Answers S U B M A R I N E A A R H U N L E Y I T U B O A T I N L A U T U R T L E S R D R E B B E L N C T Y P H O O N 19 Types of Submarines Pleasure Submarine Scientific Submarine Military Submarine 20 Pleasure Submarines Pleasure Submarines are usually quite small and expensive, used to admire undersea life. Gemini The Pleasure Submarine Phoenix 1000 Seattle 1000 21 7

Scientific Submarines Used to investigate the floor of oceans or lakes and bring back biological samples or artifacts. One of the most famous scientific submarines is Alvin (1964), a 16-ton research submersible. Discovered the resting place of the ocean liner Titanic which sank in 1912. ALVIN 22 Military Submarines Used as weapons during time of war and to hold nuclear missiles. These submarines can go anywhere on Earth where the Ocean stretches, including the water beneath the floating ice of the North Pole. 23 CLASS EXERCISE - 2 Types of Submarines 24 8

Answers 1. These submarines are used to bring back biological artifacts from the ocean floor SCIENTIFIC SUBMARINES 2. These submarines are used for naval wars and to hold nuclear missiles MILITARY SUBMARINES 3. These submarines are usually quite small in size and expensive PLEASURE SUBMARINES 4. This submarine discovered the resting place of the ocean liner Titanic SCIENTIFIC SUBMARINE 25 External Parts of Submarine 26 Periscope The periscope is usually extended through the Sail (conning tower). At shallow depths, it allows to search for targets and threats in the surrounding sea and air. Made with mirrors and lenses that reflect and bend images down a long tube to the eye of a sailor. 27 9

Rudder and Propeller A propeller is a type of fan which transmits power by converting rotational motion into thrust. Rudder controls side-to-side turning. Propeller Rudder 28 Diving Planes Diving plane, also known as Hydroplane, control the submarine s rise and descent. There are two sets of diving planes, the sail planes, which are located on the sail, and the stern planes,, which are located at the stern with the rudder and propeller. 29 Match the Given Parts of Submarine 1. Sail 2. Sail Planes 3. Periscope 4. Propeller 5. Rudder 6. Stern Planes 7. Radio Antenna 30 10

Answers Periscope Radio Antenna Sail Rudder Propeller Sail Planes Stern Planes 31 Hands-on Activity 2 Periscope Construction 32 Internal Parts of Submarine Hull and Ballast Tanks Engine Planes Batteries Navigation Systems Life-support systems Ballast Tank Section 33 11

Pressure Hull The pressure of water pushing inwards is the biggest problem. Most submarines have two hulls. The outer hull is waterproof, while the inner one (Pressure Hull) is much stronger and resistant to immense water pressure. 34 Ballast Tanks Spaces in between the two hulls that can be filled with either air or water are called the ballast tanks. When they are filled with air, the submarine rises to the surface. With water inside the tanks, the sub submerges towards the seabed. 35 Engine Most submarines have dieselelectric engines. Once the diesel engine has fully charged the batteries, the submarine can switch off its engine and go underwater. Military submarines are now nuclear powered. 36 12

Just as sharks have fins to help them swim and dive, submarines have fins called hydroplanes. As the submarine ss propellers push it forward, water rushes over the planes, creating an upward or downward force that helps the sub gradually rise or fall. The fins can be tilted to change the angle. Planes Angle of the dive planes, left low speed, right high speed 37 F = C A sin(θ) 0.5 ρ v 2 Force Acting on a Hydroplane Where, F : Force on Hydroplane (N) C : Friction coefficient (C = 0.1) A : Area of Hydroplane (m 2 ) v : Velocity of submarine (m/s) ρ : density of water (ρ = 1000 kg/m 3 ) θ : angle of Hydroplane (deg) 38 Navigation Systems Submarines navigate using GPS, SONAR, a system similar to radar, Inertial Guidance. 39 13

Submarine Navigation Global Positioning System (GPS) accurately determines latitude and longitude. Sonar uses sound propagation to navigate. Inertial Guidance Systems keep track of how far the submarine has travelled, and in which direction by using gyroscopes. Submarines can raise various antenna masts, radar masts and periscopes to facilitate communications and navigation 40 Life-Support Systems The nuclear engine of the sub, provides warmth and generates electricity. It makes oxygen for people p to breathe by chemically separating molecules of water. It can even make their own drinking water from seawater using electricity. Inside View of a Submarine 41 CLASS EXERCISE 3 Force on a Hydroplane 42 14

Force Acting on a Hydroplane 1. A model submarine with square Hydroplanes of dimension 5 x 5 cm, with velocity 2.78 m/s and angle of Hydroplane is 30 degrees. Calculate the Force on Hydroplane. Answer: F = C A sin (θ) 0.5 ρ v 2 = 0.1 * (5*5*10-4 ) * sin (30) * 0.5 * 1000 * (2.78) 2 = 0.48 N 43 Archimedes Principle It is told that, while talking a bath Archimedes, the great philosopher and mathematician, discovered a method for figuring out whether his King s crown had been made of pure gold. We now call his discovery Archimedes' Principle, which states that an object placed in a fluid is buoyed upward by a force equal in weight to the fluid displaced (pushed out of the way) by the object. 44 Archimedes Principle The weight of the displaced fluid is directly proportional to the volume of the displaced fluid. Weight (W) Volume (V) 45 15

Hands-on Activity 3 Archimedes Principle 46 How Submarines Work? - Buoyancy When Submarine is placed in the water, it experiences an upward force called as the buoyant force. This force acts opposite to the force of gravity. Example: An empty can will push enough water molecules out of the way to create an upward force greater than its weight. Whereas a rock of same weight will sink. SUBMARINE Buoyant Force 47 How Submarines Work? Sink & Swim To dive underwater and then resurface, the submarine must be able to control its density. An empty pybottle will float on the surface. A partially filled bottle will float underwater. A full bottle will sink to the bottom. This is accomplished by pumping water in and out of the submarine. Empty Bottle Partially Filled Bottle Full Filled Bottle 48 16

Working of Submarine Sink & Swim When the submarine is on the surface, the ballast tanks are filled with air. To dive, the operator opens up valves at the top and lets air out. Seawater rushes in to fill the space that was taken up by air. Hence the submarine submerges. 49 Boyle s Law Boyle s law states that at constant temperature, the absolute pressure and the volume of a gas are inversely proportional. In short, as one increases the other decreases. If pressure doubles, volume shrinks to half. 50 Effect of Boyle s Law on Submarine Going into water, the pressure on the submarine is initially equal to one atmospheric pressure. Boyle s law governs the relationship between volume and pressure. Submarines need to be extremely strong to withstand the extremely high pressure of water pushing down on them. Where: P1 = internal pressure V1 = internal volume P2 = external pressure V2 = external volume 51 17

CLASS EXERCISE 4 Boyle s Law 52 Application of Boyle s Law A small research submarine with inside volume of air 12 x 10 4 Liters has an internal pressure of 1.0 atm. If the submarine descends to a depth where the pressure is 150 atm, what will the volume of the air inside be if the hull of the submarine breaks? Solution: P1*V1 = P2*V2 12 x 10 4 x 1.0 = 150 x V2 12,000 / 15 = V2 V2 = 400 Liters Hence the volume of the gas is 400 Liters 53 Hands-on Activity 4 Boyle s Law 54 18

Pressure on Submarine Engineers found that cylindrical shapes can withstand large amount of pressure. That is why pressurized tanks and submarines are built with cylindrical i l cross sections. Low Pressure The deeper you go underwater, the higher the water pressure. When you re down underwater, there s more water pushing down on you from above than if you re right at the top. Water Column High Pressure 55 Effect of Water Pressure Pressure is all around us. Although submarines are designed and tested to be safe underwater, the problems of increasing water pressure affect them as they submerge. Pressure increases rapidly underwater. 56 As a diver or submarine gets deeper, for every 33 feet of depth, pressure increases 14.7 pounds per square inch, or one "atmosphere." Effect of Water Pressure The weight of the air at the surface (14.7 psi) must also be added when figuring underwater pressure. 57 19

CLASS EXERCISE 5 Math Under Pressure 58 59 Math Under Pressure Use the attached graph, and what you know about air and water pressure to answer these questions. 1. John has dropped a quarter into a swimming pool. To get it back, he must dive to the bottom of the 11' section of the pool. How many pounds per square inch of pressure will he be under before he dives into the water? 14.7 psi. How will that number change as he swims to the bottom of the pool? WHY? Pressure will increase as the deeper he dives, the greater the pressure on him. 60 20

Math Under Pressure 2. A cliff diver in Acapulco dives from a 200-feet cliff into the ocean. He is moving so fast that his body plunges to a depth where the pressure on his body is just over 44 pounds per square inch. How far underwater is he? 66 feet. How many atmospheres are pressing on him? 3 atm. 61 Math Under Pressure 3. A submarine is planning to make a test dive to a depth of 2,425 feet. How many atmospheres is that? 74.48 including 1 atmosphere of surface air pressure. What do you think will happen to the sub if its construction can't take the pressure? It will implode or be crushed. 62 Math Under Pressure 4. During a U.S. Navy exercise at sea, two submarines are playing hide-and-seek to test their invisibility. At first, the subs dive as deep as they can go, but then each hides in the ocean. Sub #1 stops at a depth where it is affected by 88.3 lbs/sq.in. of pressure. Sub #2 is floating at a depth of 165 feet. Which is deeper? They are at the same depth. 63 21

Use of SONAR in Submarines Sonar is an acronym for Sound Navigation and Ranging. Sonar mapping uses sound waves to map out the contours or the shape of the ocean bottom. To locate a target, a submarine uses Active and Passive Sonar. 64 Active Sonar Active Sonar (echolocation) emits pulses of sound waves that travel through the water, reflect off the target and return to the ship. Sound transmitter and a receiver are used. To measure the distance to an object, the time from transmission of a pulse to reception is measured and converted into a range by knowing the speed of sound. 65 Passive Sonar involves listening to sounds generated by the target (such as a submarine or torpedo). Passive sonar listens without transmitting. Passive sonar systems may have large sonic databases, but the sonar operator usually finally classifies the signals manually. Passive Sonar Sonar trace of the Wreck fish scarp 66 22

67 Hands-on Activity 5 SONAR Mapping 68 Nuclear Submarines A Nuclear Submarine is a submarine powered by nuclear reactor. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long durations. Current generations of nuclear submarines never need dto be refueled throughout their 25-year lifespan. 69 23

Life on a Nuclear Submarine Essentially unlimited power allows a nuclear-powered submarine to maintain a far more comfortable environment that was ever possible in conventional submarines. These submarines have a wide range of equipment to combat threats like fire and flooding and conduct regular drills. 70 Safety on Submarines The greatest threats to a submerged submarine are Fire and Flooding. Damage Control Equipment should be readily available. Fire Rescue attempts from the surface must occur very quickly. Flooding 71 Damage Control Equipment OBA (Oxygen Breathing Apparatus) Damage Control Tool Roll, Bolt Cutter, and Spill Kit Roll Steam Suit 72 24

Rescue Attempts Attempts will typically involve trying to get some type of rescue vehicle down to remove the crew. Rescue vehicles include Deep- Submergence Rescue Vehicles (DSRV) and diving bells. DSRV secured to the deck of a submarine 73 Hands-on Activity 6 Build a Submarine Model 74 Overview In this module we have learnt about: Origin of Submarines Types and Parts of Submarines How Submarines Work Archimedes Principle Boyle s Law Effect of Buoyancy and Water Pressure on Submarines Use of Sonar in Submarines Safety on Submarines 75 25

THANK YOU THANK YOU Contact Information: Alok K. Verma Ray Ferrari Professor http://www.themarinetech.org Director Project Director Lean Institute Old Dominion University Phone (757) 683-3766 E-mail averma@odu.edu 76 26