Turtle ships were the brainchild of Korean admiral Yi Sun Shin, who needed a ship capable of taking on the invading Japanese navy in the Seven Years' War (1592-1598). (See painting right) The Japanese used ship-to-ship boarding combat as their preferred tactic, in addition to cannon and other artillery. The Geobukseon were clad in iron plates and the topmost decks featured a roof covered in iron and metal spikes- making boarding a difficult task. A variety of cannon also aided to their air of invulnerability. They continued to be in commission into the 18th century before finally petering off in the early 19th.
Your typical Geobukseon was built from red pine or spruce and composed of three decks, two masts, and a LOT of rowers (considering how much weight was on this vessel, between armor, ammo, artillery, and manpower). The rowers (all 80 of them!) were covered by a roof of metal and spikes, giving the ship a broad, slightly domed shape (hence the moniker 'turtle'). For the foe foolhardy (or misinformed) enough to attempt to board the ship, the Koreans often set a surprise and covered the spike-laden canopies of their top decks with straw or thatch!
Needless to say, the turtle ships weren't precisely the fastest boats in the ocean, but with dedicated oarsmen they were capable of quick sprints in the event of a charge or retreat. Besides, much like their namesake reptile, slow and packing wins the race... or at least I think that's how the proverb goes.
See: THE PIRATE KING
Following the transmission of gunpowder technology from Ming dynasty China in 1373 the Koreans rapidly developed a highly advanced range of naval artillery. This marked a turning point where the Koreans began to favour an approach similar to that of the Chinese. This emphasised the bombardment of enemy vessels rather than attacking by ramming or boarding them.
These weapons included deck mounted mortars which fired the Korean version of Chinese 'thunder-crash' bombs - a hard-cased fragmentation projectile. They also used four classes of commonly used cannon, as distinguished by their size, which were typically mounted on mobile wooden carriages (as shown right).
This record painting of a fierce battle-scene during Imjinwaeran (the Japanese invasion of Korea in 1592) were drawn by Byeon Bak, an official artist of Dongnae-bu (district).
This picture depicts the scene of the battle, which lasted 2 days, April 13-14, at Busanjin, in the 25th year of King Seonjo's rule (1952). Busanjinseong citadel is the first barrier in Gyeongsang-do, as well as a strategic point, where the Japanese army would go through in order to land in Joseon. This fortress was surrounded with 8700 soldiers of Japanese invaders and their 700 war vessels on April 13, 1592. Jeong Bal, the cheomsa (head officer of the barrack) of Busanjin, had fiercely fought with 1000 Busanjin inhabitants and soldiers, to die for loyalty, and then the fortress collapsed. [from: Korea Fine Art]
The average turtle had about 18 cannon ports, though 16th century sources allude to 115 foot (35m), 72-gun behemoths (I'm a little doubtful, but I'm not going to argue with that many guns...). In addition to cannon-power, turtles also packed heat in their prows, which were shaped like dragon or turtle heads. These figureheads were rigged to do a variety of dazzling acts, including firing rounds, emitting noxious fumes or smoke, and even as flamethrowers. Let me repeat this again: FLAMETHROWERS. There was even iron ornamentation on the keel that could act as an impromptu battering ram in the case of very close combat.
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By 1410 it was common for their ships to be armed with a variety of cannon with records showing that at this time they possessed 160 ships of war with artillery on board.
these cannon would fire stone or iron balls, the preferred
projectile weapon used by the Koreans at this time was a giant arrow
iron tip and iron or leather fins (shown right). While these may look
rockets they were not self-propelled but rather fired from a cannon.
largest of these measured up to nine feet (around three metres) long.
projectiles possessed both a longer range and greater accuracy than
but had equivalent destructive power. They also had the advantages that
impact they would both damage the ship and also often shatter, spraying
splinters of wood among the crew of the ship they hit. As well as this,
could be easily converted into fire arrows. Turtle ships would
armed with a full range of normal cannon, firing both ball and arrow
projectiles, as well as being crewed by a number of archers.
A Geobukseon shaped like a turtle is the first ironclad warship in the world. Admiral Yi Sun-Sin(1545~1598) made this ship and drove many Japanese warships away with Geobukseon.
Geobukseon - Turtle ship Builders : Yi Sun-sin, Lt. Na Dae
Yong Operators : Joseon Dynasty Built : circa 1590
Korean admiral Yi Sun-sin is credited with designing the ship. His turtle ships were equipped with at least five different types of cannon. Their most distinguishable feature was a dragon-shaped head at the bow (front) that could launch cannon fire or flames from the mouth. Each was also equipped with a fully covered deck that was shielded to deflect cannon fire, and with iron spikes to discourage enemy men from attempting to board the ship.
On the bow of the vessel was mounted a dragon head which emitted sulfur smoke to effectively hide its movement from the enemy in short distance combat. The dragon head, which is considered the most distinguishing feature of the vessel, was large enough for a cannon to fit inside. The dragon head served as a form of psychological warfare, with the aim of striking fear into the hearts of Japanese sailors. Early versions of the turtle ship would burn poisonous materials in the dragon's head to release a poisonous smoke.
In the front of the ship was a large anchor. Below the anchor was a wooden crest that was shaped like a face, and these were used to ram into enemy ships.
Many different versions of the turtle ships served during the war, but in general they were about 100 to 120 feet long (30 to 37 metres long), and strongly resembled the Panokseon's bottom structure. The turtle ship was technically a hull that was placed on top of a Panokseon, with a large anchor held in the front of the ship, and other minor modifications. Item 317 at DESIGNER PARTY