The Song Dynasty's Water Transport Instrument Elephant Platform is a masterpiece of ancient mechanical manufacturing technology, demonstrating the highest level of traditional mechanical engineering technology. The chronometer combines astronomical measuring instruments and a striking device, and is driven and operated by a system of hydraulic gears. It took Su Song and Han Gonglian five years to complete its design and manufacture in the seventh year of Yuan You. Su Song also wrote the "New Ritual Elephant Law" during the reign of Shaosheng, describing in detail the structure and dimensions of the water transport instrument elephant platform, with illustrations to reveal its mysteries. The height of the water transport instrument is 36At 65 feet and 21 feet wide, it is a square wooden building. Its main powerplant was a pivot wheel, with a bucket and an iron pick on the edges. At the top there is a lever mechanism, which acts as the escapement of a clock, which controls the rotation of the pivot wheel at a fixed speed. It was one of the world's first escapements and is of great significance in the history of mechanical development.
The day and night wheel is a timekeeping device that automatically signals the time by means of wooden figures, bells and drums. The observatory is also equipped with an armillary and armillary sphere for observing celestial phenomena and showing the movement of celestial bodies. The armillary sphere is located in a wooden house with a roof panel that can be opened and closed, which serves the same purpose as a roof that can be opened in modern telescope observations. The water flow system is injected into the Tianhe (receiving tank) by the river cart through the cylinder car, and then the pivot wheel is driven by the copper kettle drip device (Tianchi, flat water kettle). The day and night wheels are driven by transmission gears, which include the day and night bell drum wheel, the day and night hour first wheel, the announcer wheel, the night leakage gold cymbal wheel, and the night leakage wheel. The elephant is equipped with a sky wheel, which is connected to the wheel axle of the day and night machine. The armillary sphere is equipped with a ring gear (Tianyun single ring) and a pinion called a Tianhub, which allows it to move with the water wheel. The whole gear system is geared from 6 gears to 600 teeth, and the operation is precise and stable.
According to the scale of the "New Ritual Imagery Law", Wang Zhenduo successfully restored the water transport instrument and elephant platform and displayed it in the Chinese History Museum. The gear system of the hydropower-driven astronomical instrument was also used in an instrument made by Wang Hao called Xuanji Yuheng. According to the "History of the Song Dynasty and the Chronicles of the Law", in the sixth year of Xuanhe (1124), the Xuanji Yuheng was produced, an instrument that activated the gears by injecting water. There are 43 wheels underneath it, and the hooks and keys are staggered and run in order, without human intervention. Most of them travel 2,928 teeth per day, and those who travel less than 1 tooth every five days. The difference in speed is significant, but it is able to operate synchronously, and the density is almost comparable to that of the Creator. In addition to the water transport instrument elephant platform, the Song Dynasty also had other outstanding achievements in mechanical manufacturing, such as the guide car and the Jili drum car.
The History of the Song Dynasty and the Yufu Zhi detailed the structure of the guide car, and it is recorded that Yansu began to manufacture the guide car in the fifth year of Renzong Tiansheng. The structure of the car is a unilogue with a reconstructed exterior covered with a wooden statue of an immortal above the trunk with a finger pointing south. The wheels are divided into large and small wheels, with a total of nine large and small wheels, and the total number of gears is one hundred and twenty. Among them, the diameter of the large wheel is six feet, the circumference is one zhang eight feet, and there is a vertical wheel with a diameter of two feet and four inches on each side, each wheel has 24 teeth, and the distance between the teeth is three inches;There are also two small flat wheels with a diameter of three inches under the crossbar at the end of the wheel, and there is a small flat wheel with a diameter of one foot and two inches on the left and right sides, and the diameter of the big flat wheel in the middle is four feet eight inches, and the circumference is one foot four feet four inches, with forty-eight teeth, and the distance between the teeth is three inches. The vehicle** also has a mandrel with a diameter of three inches and a height of eight feet. The car is also carved with a wooden statue of an immortal pointing south.
In the first year of Daguan, Wu Deren presented the production method of the guide car and the drum car in Jili. The Jili drum car also uses a gear drive, and the wooden figure beats the drum to indicate the distance traveled by the vehicle. Both vehicles were restored and rebuilt by Wang Zhenduo and are on display in the Museum of Chinese History.