Since ancient times, China's shipbuilding technology has been in a leading position, especially the three inventions of the groove, rudder and phi water plate, so that the Western shipbuilding and sailing world for a long time. The two Song dynasty shipbuilding and navigation technology continued to develop.

Its major achievements are four.

First, improved maneuvering gear, which is the rudder. The rudder first appeared in the Eastern Han Dynasty, to the Song Dynasty, in order to make the rudder can be used in deep and shallow water, there is a lifting rudder, can be adjusted through the pulley system to the rudder height. In order to reduce the rudder steering underwater resistance, and designed to move back and forth rudder shaft, composed of balanced rudder. Northern Song Zhang Zeduan “Qingming Shanghe Tu” painted fried river boats have been equipped with a balanced rudder can be raised and lowered. 1978 tianjin jinghai county unearthed on the song boat also found a balanced rudder in kind. At the same time, the Song Dynasty shipwrights and rudder blade on some small holes, so that the rudder torque greatly reduced, but the rudder effect has little effect, this is the open rudder. According to the estimate of comrade Xin Yuan O, the emergence of open rudder not later than the time of Song and Yuan.

Second, through the improvement of propulsion equipment and create the world's second early Ming ship, which is the “car ship”. On both sides of the boat symmetrically mounted on several pairs of wheels equipped with water-exciting blades to wheel instead of oars. People in the boat with their feet to pedal the wheel axis, driven outboard impeller rotation. The original oars and oars of the front and rear intermittent propulsion was improved for the impeller rotary continuous propulsion, greatly improving the propulsive efficiency, history said “its speed, such as flying, far better than the sails”. This Ming powder ship in the Tang Dezong Zhenyuan years (785-805 years) Li Gao has been able to manufacture, but did not see the promotion. The early Southern Song dynasty began to use the Ming wheel equipment warships. 1132 years (Shaoxing 2 years) know the Wuhui army Wang Yan made flying tiger warships, “the side of the four wheels, each wheel of eight hand, four people swirling good offices, the day line thousands of miles.” Of course, this is extremely fast. But it can be believed that, even if the daily traveling hundreds of miles, but also at that time the world any kind of ship can not expect the speed. A little later, the Southern Song general Li Gang, Yu Yunwen and so on also made the car boat, the largest kind of upper and lower three-storey, 7.5 zhang high, the length of 36 zhang, the two sides are equipped with 3040 wheels, fast, strong attack. 12 century 30 s active in the dongting lake area of the Zhongxiang, Yangmao insurgent army had used the car boat defeated the Song dynasty official army. Later, passenger boats and yachts were also 'but traveled on wheels and feet'. Meng Liang Records” Volume 12 ‘West Lake’ article said: ”more Jia Qiushu House car boat, no one on the shed to support the driver, but with the wheels on foot, its speed as fast as flying.

Third, the invention of watertight cabin and the use of dry dock. Watertight cabin technology for shipbuilding, increased anti-submergence, improve the safety factor, this point has been mentioned in the previous chapter. Here to introduce the invention of dry dock. According to Shen Kuo “Mengxi Bianan supplement” volume below, the early years of the Northern Song Dynasty, Zhejiang offered dragon boat, up to more than 20 feet long. Zhao Song royal family after a century of use, “years of decay, want to repair and the water can not be constructed.” Xining years eunuch Huang Huaijing offer plans to build dry dock, in the Jinming Pond north of the excavation 'big Ao' (pit), Ao neutralized beams and pillars, flooded, the boat led to the beams and pillars on top of the car empty Ao in the water, so that the boat can be repaired. Repair is completed, and then draw water in the Ao, the ship will float. This kind of thousand ship dock technology, open the first modern ship platform, is the Song Dynasty shipbuilding experience in another valuable heritage.

The fourth is the invention of the guiding instrument, the dirty sea compass. Vast ocean, looking around without end. Shipmasters can only rely on the long-term accumulation of experience to identify the direction of the ship, “daytime is to observe the sun, the night is to observe the stars”, both inconvenient, and error. Northern Song navigators began to modify the compass into a water compass, used for ocean voyages. This is a major technological breakthrough of epoch-making significance in the history of navigation. Shen Kuo “Meng Ao Pen Tan” contains “water floating method”, “bowl lip spinning fixed method”, “fingernail Shi fixed method” and “silk hanging method “and other four devices, including the water floating method is a magnetized steel needle across the wick, so that it floats in the water, mounted on the compass engraved with 24 directions, which is the earliest water compass, then called” floating needle ”.

The Northern Song Dynasty Zhu or “Pingzhou can talk” said: “Boat masters know the geography ......, cloudy and obscure, then look at the compass ...... will know where to go.” Xu Jing, “Xuanhe Fengzheng Goryeo Chart” said: “It is the night, the ocean can not live in the Wei, depending on the stars and dices forward. If obscure, then use the floating needle guide, to write north and south.” These are the two earliest records in the world about the navigation with “floating needle” guide. The emergence of the “floating needle” has determined the structure principle of the modern magnetic variation instrument, magnetic force instrument and aviation, navigation compass. The use of the water compass really solved the problem of finding the direction of the sea under the bad weather, mankind has only since then got rid of the constraints of the ocean and galloped in the vast and boundless oceans.