The Turtle Ship, or Geobukseon (거북선 or “Kŏbuksŏn” in Korean), was a warship of the Joseon Dynasty (1392–1897). The Turtle Ship was based on the Panokseon (“board-roofed”) warship. After covering the whole deck of the panokseon with a metal board, you get the Turtle Ship. Given the cost problem and the issue with which iron rusts in salt water, the material for this cover was sometimes wooden rather than iron. In order to prevent the adversary from jumping over this ironclad lid, the lid was covered with iron spikes (awls). Artillery was fired from a dragon head naval ram and gate at the bow, while a turtle tail was built for the stern, and the additional cannons were fired from here.
Origin of the Turtle Ship
Efforts to perfect military vessels date back to the early Joseon Dynasty, and these efforts bore fruit in the form of the Turtle Ship in the 15th century. This historical warship was the world’s first armored battleship, or ironclad warship. It carried archers, gunners, and rowers.
The Turtle Ship was fully armored, and the vessel protected the crew while they fired a total of six pieces of artillery from the front, back, and sides of the hull. Some ships were mounted with the Hwacha, one of the first artillery guns in history. The earliest mention of the Turtle Ship comes from the Joseon Annals in 1415, the 15th year of King Taejong of Joseon.
All Turtle Ships had a limited field of vision, poor ventilation after firing artillery, and inadequate illumination inside.
The Joseon navy’s admiral, Yi Sun-sin, had a Turtle Ship constructed shortly before the Imjin War (1592–1598). The ship played a significant role in the Joseon navy’s victories against the Japanese Navy in all 16 battles before being defeated at the Battle of Chilcheollyang (1597), making its name synonymous with “horror” for the Japanese.
Purpose of the Turtle Ship
Skilled samurai soldiers spearheaded the Japanese invasion of Korea, and the Japanese possessed advantages, such as the arquebus, a decisive weapon.
The Turtle Ship was deployed to block the Japanese army’s access to the west and north of Korea by keeping them from crossing the West Sea. The Japanese invasion was a smashing triumph on land but a dismal failure at sea. Both the excellent tactics of Admiral Yi Sun-sin and the fearsome turtle ships contributed to the Japanese naval defeat.
The ships got their namesake due to their resemblance to turtles, which were completely covered with plates. The turtle ships’ primary objective was to assault the enemy command ship, damaging the enemy’s command center and morale.
The turtle ships would race straight toward the enemy command ship, ram it, and then fire cannonballs in every direction, destroying it and the other ships in the fleet. The Koreans were able to fire their weapons with more precision since the ship’s flat bottom minimized recoil.
A “Sea Monster”
In the 1592 naval engagements of Sacheon, Dangpo, and Hansan Island, which were won by the Joseon navy, the Turtle Ship charged in first, aimed specifically at the admiral ships, and sunk all the enemy ships before winning the war. Only 3 or 5 Turtle Ships were built during the whole Imjin War, showing the effectiveness of this ironclad ship.
The Chinese symbols for the Turtle Ship are read as “guiseon” (龜船) in the Veritable Records of the Joseon Dynasty (1392–1865). After their conquest of Korea in 1592, the Japanese gave this vessel the names Bokukaisen, Gikkaisen, or Kikaisen (亀甲船). These names are believed to resemble a sea monster in Japanese folklore called “Shachihoko.”
At the Battle of Chilcheollyang, the Japanese sank all of the Turtle Ships at dawn on the 16th day of the seventh lunar month in 1597. The ships were once again created after the Imjin War, also known as the “Japanese invasions of Korea”, with only minor adjustments made to their form and dimensions.
In order to hide it and protect it from enemy fire, the Turtle Ship used in battle had its spikes covered with a wet cloth. Yi Sun-sin is believed to be one of the greatest generals in history today. During his successive victories with the warship, no Japanese ships survived the battles.
Legacy
The Republic of Korea’s 500-won bill, which was introduced in September 1973, features Yi Sun-sin and the Turtle Ship on the front. After 1966, the Turtle Ship appeared on the 5 won coins. No, I was not there during the Okpo Battle.
The Turtle Ship’s Significance
The Korean navy lost all of its Turtle Ships at the Battle of Chilcheollyang (1597) after Admiral Yi was removed as commander. However, when Toyotomi Hideyoshi died in 1598, Japan no longer invaded Korea. The Turtle Ships did not completely halt the Japanese invasions, but they did provide the Koreans with naval superiority and slowed them down significantly.
A Tank on the Sea
Presumably in use since the Goryeo Dynasty (f. 918), Turtle Ships were sturdy vessels used as attack ships whose collisions with opposing vessels often resulted in a decisive victory in naval conflicts. Aside from the cannonballs, the ship had flame guns and sulfur bombs.
In order to prevent the adversary from climbing up from any direction and setting foot on the ship, Admiral Yi Sun-sin writes that “a plank was covered on top, and a narrow path was crossed over it, and the rest were stabbed with iron spikes, so that the enemy could crawl in all directions, but there was nowhere to go.“
There was no need for the fighters to worry about hand-to-hand combat when they were sailing on a Turtle Ship. The deck of the Turtle Ship was covered with metal plating to shield them from all hostile assaults. The ship was also deployed as an attack vessel, armed with artillery that could plow through targets from any angle.
To this day, the military ramifications of the Battle of the Imjin War, in which the Turtle Ship played a pivotal role in the defeat of Toyotomi Hideyoshi’s numerically superior invading troops, are still felt. After invading Korea, Hideyoshi’s ultimate plan was to conquer Ming China.
Sulfur from the Turtle’s Head
The Turtle Ship was shaped like a turtle from head to tail, with a cannon hole in her mouth. These features gave the vessel its name. In addition, Admiral Yi Sun-sin’s logbook reveals that he burned sulfur from the turtle’s head to conceal the ship and strike even greater fear into the hearts of the enemies.
The ship was quick and nimble, and the metal plating was almost impossible to breach. Located on the bow, the smoke ejection mechanism was fashioned like a dragon’s head and was an effective psychological weapon at the time.
When Yi Sun-sin reorganized the navy prior to the 1592 Imjin War, he significantly modified the Turtle Ship, which appears to have played a role as a formidable attack ship in naval battles. Today, the U.S. military media outlet USNI News named General Yi’s Turtle Ship as one of the seven most prestigious warships in the history of the world’s navy.
It was on March 27 of the lunar calendar in 1592 (the 25th year of King Seonjo) that the Turtle Ship was launched off the coast of Yeosu, and it was on April 12 of the lunar calendar, one day before the Japanese invasion, that the ship was completed for actual combat. Bonyeonggwiseon, Bangdapgwiseon, and Suncheongwiseon were the three Turtle Ships deployed during the Imjin War (1592–1598).
Impenetrable
Initially, there were only roughly 100–150 individuals on a Turtle Ship, together with 8 cannons and 40 troops. However, following the 1592 Imjin War, this warship tended to grow in size, with the second and third floors being added and the hull lengthened. The warship was utilized for charge and collision tactics and naval gun tactics since it was better in materiel and design versus Japanese ships.
The Japanese naval force’s expertise in approaching, boarding, and fighting in hand-to-hand combat failed to penetrate the ship’s top deck and defenses of blades and spears. Furthermore, a variety of strategies were available for a Turtle Ship, such as attacking directly at the Japanese army’s chief of staff with the aim of ending the battle quickly.
The ship was constructed once again during the 18th-century rebuilding of the Korean navy by King Sukjong of Joseon. Sukjong wanted to create an exact copy of the ship from the Imjin War of 1592. It was for naval training and parades.
How Many People Were on a Turtle Ship?
Each Turtle Ship held about 150 soldiers and 80–90 oarsmen.
- 1 captain
- 1 operation officer each on the left and right sides
- 5–6 senior officers (today’s lieutenant-level officers)
- 2 repairman chiefs
- 2 military band people
- 2 navigators
- 2 men for sails
- 2 men for anchors
- 14 cannon masters
- 8 firearms squad leaders
- 24 artillery gunners
- 90 oarsmen
- 150 soldiers in total
The Turtle Ship’s Design
Lid
The construction of the Turtle Ship consisted of a big iron or wooden lid that covered the top deck of the ship, a narrow, small intersection cut into this plate so that a small number of people could still walk, and iron spikes that prevented enemies from walking in any direction on this metal lid.
To facilitate an assault on the adversary, an embankment was placed on both the forward turtle head and the rear turtle tail. When facing the enemy ship, the ship’s deck could be immediately closed with the roof.
The iron spikes, which were controlled by a mechanism that could activate them all at once when encircled by the opposing ship, were reportedly disabled if soldiers wanted to walk on the roof deck to board an enemy ship.
Dimensions
The records in the Chungmugong Junseo specify the dimensions of the ship for the board, bow, belly, and tail. The Korean Naval Academy in Jinhae is home to a reconstructed Turtle Ship that, according to the Naval Historical Society of Australia, was built with the following dimensions: 113 feet long (35 m), 34 feet wide (10 m), and 21 feet high (6.5 m).
According to yet another source, most Turtle Ships measured between 100 and 120 feet (30 and 37 m) in length, making them far smaller than contemporary battleships.
Interior
On both sides of the hull, there were 22 gun ports and 12 entrances each. On the left side of the ship’s interior was the captain’s room, while the officers’ quarters were located on the right side.
Below the gun decks on both sides, there were 24 rooms used for various purposes, such as storage, the armory, and the soldiers’ rest area. The ship had 10 sails on each side, which contributed to its impressive speed.
The interior was structured on two levels. The upper level housed the cannons, while the lower level was for rowing the oars. Oarsmen would be stationed on the lower deck, while archers and gunners would man the top deck of these ships.
Additionally, there were water-filled compartments below, which are believed to have been used for storing water and utilizing water pumps. Some sources suggest the ship might have had a three-level structure, but this remains uncertain.
Attack
There were cannons on the top of the turtle’s head, as well as on the front, rear, left, and right sides of the ships. The ship’s bottom was outfitted with additional protrusions for use in charging maneuvers. With these design elements, the ship became the lead assault ship responsible for breaking opposing lines. Similar to tanks in today’s armies, the Turtle Ship played an important role in battle.
Defense
The Turtle Ship’s roof deck was fortified with timber armor fastened with iron spikes. Aside from deterring enemies from onboarding the ship, these spikes were additionally effective at deflecting projectiles in close combat. When compared to Japanese battleships, the construction and materials of the Korean Turtle Ships were sturdy enough to survive collisions.
Mobility
Oarsmen and gunners were stationed on the dock’s lower level, near the cannons. A typical crew of 82 was responsible for 10 oars on each side. So, there were at least four men on each oar.
The ship’s flat bottom made it easy to make sharp turns or abrupt course corrections, making it particularly well-suited to the tidal conditions found in the southern and western waters of the Korean Peninsula.
The turtle ships were great for coastal operations but not for ocean travel due to their design.
It was feasible to do a sharp U-turn in either direction while in motion. This made it possible for the unrestricted development of marine maneuvering techniques like hakikjin (“crane wing maneuver”), which Yi Sun-sin’s fleet used.
Turtle Ship After the Imjin War
The 1592 Japanese invasion of Korea (Imjin War) did not diminish the Turtle Ship’s or Geobukseon’s significance for naval warfare. According to the “Cradle of Maturity” (萬機要覽) written by Seo Young-bo (徐榮輔) in 1808, there were 16 Turtle Ships stationed throughout the country after the Imjin War (other sources state it as 13).
The dragon’s head eventually transformed into a turtle’s head, the ship’s size increased in general, the number of cannons and oars grew, and the ship’s stern section began to look much more like a turtle shell.
The success of the turtle ships in their battle against the Japanese fleet has been likened to the English victory against the Spanish Armada in 1588. Both cases demonstrate how formidable well-engineered naval boats may be when pitted against more massive but less nimble foes.
Reconstruction
On January 31, 1980, with the help of Admiral Yi Sun-sin’s manuscripts and associated data on medieval ship remains located near Namhae Bridge, a group of 16 academic specialists reconstructed the Turtle Ship. This 113-foot-long Turtle Ship is located at The Korean Naval Academy in Jinhae.
Unearthing the Turtle Ship
A Turtle Ship, said to have drowned in the seas of Chilcheondo 400 years ago, is the subject of ongoing excavation operations by the provincial government of Gyeongsangnam-do and the 21st Century Yi Sun-sin Research Society.
The exploration team has faced difficulties, including the high cost of the mission, a lack of adequate tools, and the inability to pinpoint the ship’s precise location.
The media picked up on a high schooler’s initiative to raise money for the Turtle Ship’s excavation expenditures, and many online citizens contributed to the cause.
Although the funding effort started off well, it hit a snag when the majority of individuals voiced doubts about digging the Turtle Ship. However, organizations advocating for the discovery of the ship continue their efforts in spite of this, with the Korean motto, “If there is even a 1% chance, we will never give up.”
Yearly Expenses of Operating the Turtle Ship
The record of the annual expenses for maintaining the Turtle Ship during the 42nd year of King Sukjong’s reign, on the 24th of October (the exact meanings of some terms are unknown):
Units of Soldiers
- Pil (필): 42 units (possibly squads)
- Ja (자): 34 units (possibly platoons)
- Chi (치): 6 units (possibly companies)
Expenses:
- 초둔, Chodun: 50 times (the amount of supply for operating the ship)
- 진석, Jinseok: 520 times (the amount of supply for food provisions)
- 생마, Saengma (Horse fodder): 50 units
- 생갈, Saenggal (Ox fodder): 50 units
- Yuo (Armor): 3 sets
- Yugangshik (Helmets): 3 sets
- Pyoja (Pieces): 7
A Timeline of the Turtle Ship’s History
- The Joseon Annals first mention the Turtle Ship in 1415, the 15th year of King Taejong of Joseon.
- In the 1592 naval engagements of Sacheon, Dangpo, and Hansan Island, which were won by the Joseon navy, the Turtle Ship charged in first, shot specifically at the admiral ships, and burned all the enemy ships before winning the war.
- The Border Defense Council of Joseon claimed in 1595 that the Turtle Ship was crucial to naval victories and that the enemy was most hesitant; thus, they advocated for the production of Turtle Ships to be sped up in order to protect Gyeongsang and Jeolla provinces. Only one Turtle Ship was stationed in each camp to act as the vanguard because of the ship’s smaller capacity compared to the panokseon, which could hold around 125 gunners. The Turtle Ship was designed more like a tank on the sea, spearheading the attacks.
- To make up for this, a changseon (船, “spear boat”), built by inserting many blades and spears into its body, was developed in 1606 (the 39th year of King Seonjo) by combining the benefits of the panokseon and the Turtle Ship.
- Prince Gwanghaegun reorganized the national fleet in 1622 and commissioned the construction of a Turtle Ship.
- Kim Su-hang of Yeonguijeong proposed turning the current 3/4 ships into Turtle Ships in 1687. For him, it was crucial that they look and function just like the ones from the Imjin War (1592–1598), including not making them too big.
- A military officer named Yun Pil-eun collaborated with Lee Sam to redesign the Turtle Ship in 1735. During this time, they modified the detachable shield installed on the top floor of the three-tiered structure and added a pointed beak to the front, making it more suitable for piercing through the wind. He is believed to display a model of the ship.
- When King Sunjo inquired about the Turtle Ship to a former governor, Yi Dang, in 1808, Dang said, “There are still Turtle Ships in the waterways of Tongyeong, and they can accommodate more than a thousand people, and when they float without oars, they look like turtles floating, and smoke comes out of their mouths and noses, and the Japanese are still surprised when they see them, thinking that they are man-catching machines.“
- The State Council of Joseon put out a plan to relocate Turtle Ships in 1867.
- The Seoul Government reconstructed the original 185-ton Turtle Ship in October 1990 and placed it at the Turtle Ship Ferry in Ichon-dong, Han River, with the goals of passing on a sense of national patriotism and educating young generations. Its dimensions are comparable to those of older Turtle Ships, but it features a window on the interior, a wooden frame for an external fake cannon, and an engine capable of speeds of 9–12 miles (15–20 km) per hour. Until November 2005, you could see it in Ichon-dong. It was given to Tongyeong by then-Mayor of Seoul Lee Myung-bak, made the journey from Seoul to Tongyeong through the Han River Estuary, and is now on display in Tongyeong after being transformed from freshwater to saltwater.
References
- Survey Results: What is The Greatest Warship of All Time? – USNI News
- Fighting Ships of the Far East – Google Books
- A Visual History of Ships and Navigation – Google Books
