() was a class of Korean oar- and sail-propelled ship that was the main class of warship used by Joseon during the late 16th century. The first ship of this class was constructed in 1555. These ships were built from sturdy pine wood and, as the primary warship of the Korean Navy, they were instrumental in victories under the command of Admiral Yi Sun-shin against numerically larger Japanese fleets during the 1592-1598 Japanese invasions of Korea.
A key feature of a was its multiple decks. The first deck had non-combatant personnel, such as the rowers, who were positioned between the lower deck and the upper deck, away from enemy fire. The combatant personnel were stationed on the upper deck, which allowed them to attack the enemy from a higher vantage point. The also had a raised roofed observation platform where the commander stood.
The served as the base for the Korean warship type called the geobukseon, which was used to great effect during the 1592-1598 Japanese invasions of Korea.
Characteristics
In line with the traditional structure of Korean ships, the had a U-shaped hull and a flat keel. This feature was due to the nature of the southern and western Korean coastal waters, which have a large tidal range and flat, expansive tidal plains. A flat keel enables a ship to sit comfortably on the tideland when the tide is out, after coming ashore or inside a wharf at high water. It also ensures greater mobility, a shallow draft, and in particular allows a ship to make sharp changes of direction at short notice. The 's features were among the main reasons why Admiral Yi was able to employ the Crane Wing formation at the Battle of Hansan Island with great success.
were propelled by both sails and oars. Of the two basic types of sail - square and lateen - the square sail has strong performance downwind but struggles windward, whereas the fore-and-aft lateen sail excels against the wind, at the cost of an increased crew requirement for handling. In the civilizations of Europe and around the Mediterranean Sea, square sails were used in the galleys of Ancient Greece and the Viking longships, and the fore-and-aft variety as early as the Mediterranean dromons of the Middle Ages. When the Age of Discovery began in the fifteenth century, multiple-masted ships equipped with both types of sails eventually appeared. In Korea fore-and-aft sail-equipped (i.e. double-masted) ships had been in use since the eighth century. The therefore had two masts by default, and possessed sufficient crew such that their position and angle could easily be managed so that the sails could be used in all winds, whether adverse or favorable.
had two to three levels stacked up on top of each other. By having multiple levels the rowers at the bottom were relatively safe, and marines at the top would have a height advantage over the enemy, firing down upon them and avoiding boarding of the ship. The upper deck had a tower in the middle of the ship that would be used for command and observation. The deck of the was broad and flat, making it ideal for the installation of cannons.
came in different sizes; the largest vessels estimated to range between and in length. Other sources indicate that the variation in size was greater, from to . The ship usually had 8 to 10 oars on each side, 50 to 60 oarsmen and sailors and another 125 marines (i.e. fighting men).
Construction
Because of the rough waters around Korea's coast, as well as the sudden changes in tides and currents, Korean boats throughout history had to be strong. Korean ship building tradition created simple, but very structurally sound vessels. Throughout Korea's naval history, strength and power was emphasized rather than speed.
Two types of woods were used to construct : pine for the hull and oak for the pegs and masts. Oak is a strong but heavy wood, so its use on ships was limited to the frame. Pine was also strong, but much lighter. Pine was usually allowed to season incompletely so that it would bend flexibly and not become too stiff. Despite its advantages pine had many knots and had to be cut thickly, thus the were built using thicker timbers. Instead of iron nails were held together by means of oak pegs, matching indentations, and interlocking teeth. This meant that as its boards absorbed water and expanded the fasteners did not rust, thus accounting for greater integrity of the hull.
