※ This video is a re-edited version of part of <Documentary Prime - The Strongest Secret Weapon: Submarines> that aired on June 23, 2011, and may differ from the current situation. 1. Submarines, the secret weapon that is stealthy and deadly! After the appearance of the German submarine U-boat, the whole world came to realize the power of submarines! In 1914, when World War I broke out, all three British cruisers were attacked by German submarines and sank within an hour, the first naval defeat in world history. The British and French navies were helpless in the face of the German submarine attacks... Submarines, the secret weapon in the sea that approaches silently and launches deadly attacks! Today, countries around the world are competing to have better submarines! 2. The eyes of a submarine, sonar! How do submarines detect the location of enemies and attack in a place that becomes a world of darkness with almost no light even at a depth of just 100m? At these times, the sonar becomes the eyes of the submarine! The sonar installed on a submarine is used to determine the location through sound waves, which are vibrations of sound. Let's learn about the operating principle of using sonar to determine the location of the enemy! 3. Torpedoes, the submarine's deadly attack weapon! A submarine that detects an enemy through sonar attacks with torpedoes! The line-guided torpedo uses the submarine's detection ability to inform the enemy of the location, and after approaching the enemy ship, it cuts the line and attacks the enemy with the torpedo's detection ability! The submarine is equipped with 16 torpedoes and missiles, so it can sink surface ships even deep in the sea! Let's learn about the unmanned submersible developed to remove mines on the sea along with the way torpedoes attack the enemy! 4. Air-independent propulsion (AIP) for submarines where stealth is key! For a submarine that must approach the enemy stealthily, surfacing above the water is the most important thing to avoid. That's why AIP, the air-independent propulsion, was developed! Our country has adopted the fuel cell method, and has reversely utilized the electrolysis of water, and has used platinum and palladium as catalysts in the combination of hydrogen and oxygen to charge the battery, allowing it to operate underwater for two weeks without having to surface! 5. The submarine manufacturing process being revealed for the first time in Korea! The most important thing in manufacturing a submarine is to make an exact circle! The shape of the submarine must be an exact circle, that is, a true circle, in order to withstand the water pressure deep under the sea. The material is also important. It can withstand the high pressure underwater by using HY100 steel, which is called special steel. Our country dispatched technicians to Germany to build the submarine! The first ship was built in Germany and trained on-site. From the second ship onwards, our technicians built it directly at a domestic shipyard. No matter how powerful a shipbuilding country it is, was it possible to build a submarine that they learned after seeing it once? Let’s take a closer look at the submarine manufacturing process of our country, which stands tall in the world with its amazing technology! 6. South Korea, challenging the limits of submarines! Our country first operated a submarine in 1992! South Korea, which entered the market late, has now become one of the few countries in the world with submarine construction technology. In addition to manufacturing submarines, we are also focusing on periodic maintenance of submarines to operate them more safely. We have also opened the way for exports through maintenance, such as by maintaining Indonesian submarines! We look forward to the future of South Korea’s submarines armed with cutting-edge technology, as our country stands tall in the world through submarine maintenance and construction processes! ✔ ​​Program name: Documentary Prime - The Strongest Secret Weapon: Submarines ✔ Broadcast date: 2011.06.23 #TV로보보고라뻟도큐