Turtle ship

thumb|Model of a turtle ship in the [[War Memorial of Korea]]

A turtle ship (; ) was a type of warship that was used by the Korean Joseon Navy from the early 15th century up until the 19th century. They were used alongside the panokseon warships in the fight against invading Japanese fleets. The ship's name derives from its covering that was said to resemble a turtle shell. Some historians have described it as a very early type of ironclad though the historical evidence for this is uncertain.

History

The first references to older, first-generation turtle ships, known as gwiseon (, ), come from 1413 and 1415 records in the Annals of the Joseon Dynasty, which mention a mock battle between a gwiseon and a Japanese warship. However, these early turtle ships soon fell out of use as Korea's naval preparedness decreased during a long period of relative peace.

Turtle ships participated in the war against Japanese naval forces supporting Toyotomi Hideyoshi's attempts to conquer Korea from 1592 to 1598. Korean Admiral Yi Sun-sin, who won all battles against the Japanese Navy, is credited with designing the improved turtle ship. From their first appearance in the Battle of Sacheon, his turtle ships contributed to winning 16 battles against the Japanese fleet under the command of various Daimyos primarily from Western Japan, though under the command of Wŏn Kyun the Joseon Navy suffered a devastating defeat in the Battle of Chilcheollyang. It is unknown precisely how many of Yi's Turtle Ships were constructed. The cost of one of these armored warships would have been high, especially if the deck was lined with hexagonal iron plates as some sources suggest.

Design and construction

thumb|Depiction of 1795 ship considered to resemble Yi's 1592 version.

Later turtle ships show some structural changes from earlier versions. For example, later iterations of the turtle ship had a higher bulwark height. This alteration in the design was made so that more bulwark slots could be added. In turn, these slots could be used for additional weaponry or ventilation for the vessel's occupants. Early illustrations also show initial versions of the ship consisting of overlapping planks on the deck structure, while later depictions show the deck of the vessel covered with flush, hexagonal plates made of wood or iron. Nonetheless, in both earlier and later versions, the turtle ship was designed to be surprisingly fast, as it was both oar and sail-powered.

Roofing

thumb|Estimation of the early 15th century turtle ship according to an illustration from 1795There are non-contemporary sources that state that the turtle ship was covered with metal plates,. While it is clear from the available sources that the roof of the ship was covered with iron spikes to prevent boarding, there is split opinion among historians on whether the turtle ship was ironclad.

There are no contemporary Korean sources from Yi Sun-sin's time that refer to the turtle ship as ironclad. When the French Navy threatened Korea, the government ordered an ironclad ship be built "like the turtle ship." However, despite all efforts the design failed to float. Turnbull believes that the 19th-century experience should not rule out a "limited amount of armor plating in 1592".

Spikes

Metal spikes were used to cover the top of the turtle ship to deter boarding tactics used by the Japanese. According to historical records, the spikes were covered with empty rice sacks or rice mats to lure the Japanese into trying to board, since the boarding would appear safe. However, modern authors have found this to be unlikely since such an arrangement would have invited enemy fire arrows.

Armament

thumb|Three large [[Chongtong at the Jinju Fortress museum. The closest is a cheonja-chongtong, the second is a jija-chongtong, and the third is a hyeonja-chongtong.]]The turtle ship was equipped with cheonja "heaven", jija "earth", hyeonja "black", and hwangja "yellow" type chongtong (Joseon cannons). There was also an arquebus known as seungja (victory). The seungja ranged while the hwangja was the lightest but with a range of . According to Hae-Ill Bak, one Japanese record of the Battle of Angolpo records the experience of two Japanese commanders on July 9, 1592, in their battle against turtle ships: "their (turtle ships') attack continued until about 6 o'clock in the afternoon by firing large fire-arrows through repeated alternate approaches, even as close as 18–30 feet. As a result, almost every part of our ships—the turret, the passages and the side shielding—were totally destroyed..." a private commercial company. They have done extensive research on the original design of the turtle ship, and made several real-size reconstructions of them for commercial use. These were deployed in a Korean drama, The Immortal Admiral Yi Sun-sin.

thumb|Reconstructed Korean turtle ship at [[Yeosu harbor.]]

Several museums host turtle ships on display, and people can visit and go inside a 1:1 scale turtle ship that is anchored at Yeosu. North Korean delegations to the south seem to be more reserved about the significance of its historical role.thumb|Turtle ship, as featured on the 5 Won coin.

Notes

Sources

Korean Spirit and Culture Promotion Project: "Admiral Yi Sun-sin. A Brief Overview of his Life and Achievements" KSCPP, Korean Spirit and Culture I,