Chinese junks – variously sized trading and transportation ships used in Asia from the second century CE to the modern day – work by partnering a sturdy keelless hull with a versatile and mobile sail-plan, in order to generate a fast and highly stable sailing platform.
The sail-plan of a junk differs from that of traditional square-rigged ships, with the junk’s various sails capable of being moved inwards towards the ship’s lengthy central axis, allowing it to be easily modified in order to sail into the wind. The sails themselves also differ from the traditional variety, with long horizontal struts called battens providing a rigid shape – akin to that of Venetian blinds – and greater tear-resistance in high wind. Further increasing the power and speed of a junk is its tendency to spread its sails over multiple masts, with five or more common on larger vessels.
Junk hulls were traditionally constructed from softwoods such as cedar and sported a horseshoeshaped stern, elevated poop deck and flat base with no keel. Due to this, junk hulls are fitted with an overly large keel and series of lee and centreboards (lifting foils) to remain stable. Hulls were also strengthened greatly by multiple partitioning lengthways and sideways internally, creating a series of interior compartments. The addition of these matrix braces increased hull integrity – especially from sideways pressure – and also dramatically reduced flooding speed if breeched, with a series of limber holes (drainage holes) transferring water outside.
Chinese junks developed from smaller living or fishing boats such as sampans in the Han Dynasty of 206 BCE-220 AD, being used primarily to traverse inland waterways and coastal waters. However, by the 15th Century AD their size and role had evolved massively into trans-continent trading and military vessels, carrying hundreds of men and tons of products. Indeed, according to Chinese historical documentation, during the missions of renowned explorer and mariner Zheng He, junks had been transformed into 420-feet long, 180-feet wide treasure ships, boasting nine masts and crewed by over 130 men. During He’s 1405 tour of the Indian Ocean, the explorer commanded over 300 junks and 30,000 men.
Today, the role of junks has diminished from its military and trading height due to the rise of modern technology and transportation methods. However, they are still commonly used by civilians to fish, commute, trade and travel, as well as by tourists who board them on sightseeing tours.