Song Rentong called the crossbow car "bed crossbow" or "bed crossbow". At that time, a crossbow gun was often a combination of two bows or three bows, which used the combined force of multiple bows to launch arrows, which was stronger than the previous generation. According to the analysis and research of modern people, the structure of multi-bow bed crossbow is very clever, and the tension of bowstring may use pulley. There are many kinds of multi-bow bed crossbows in Wu Yao in the Northern Song Dynasty, among which the most powerful three-bow bed crossbow is also called "Ba Niu crossbow", which requires 100 people to twist the shaft and pull the string. The arrow "Tieling with wooden pole" is known as "one gun and three swords", which is roughly like a javelin and three iron ridges are like three swords. The crossbow can also shoot "step arrows" and nail them to the wall in rows. The siege soldiers climbed up by climbing. During the Kaibao period of the Northern Song Dynasty (968-975 AD), Wei Pi improved the bed crossbow and greatly increased its range. Wei Pi Biography: "The old bed crossbow stopped shooting 700 steps, which increased Pi by a thousand steps." In the Song Dynasty, one step was 1.536 m, and a thousand steps were 1.536 m, which was one of the highest records that ancient long-range weapons could reach.
According to Wu Yao, the crossbow is fired with a mallet, and a special person is responsible for aiming and firing. Soldiers who use bed crossbows are a special class in the Song army, called "bed crossbow soldiers". In the first year of Jingdezhen (1004), Song Jun installed a crossbow in Chengtou. Liao army attacked the city. The soldiers guarding the crossbow were surprised. In desperation, they hit their teeth and sent crossbows, and arrows thundered out. Unexpectedly, Xiao Thar, the main commander in the Liao army array, was killed. Liao people didn't want to fight because the Lord was killed, so they made peace with the Northern Song Dynasty.
During the Southern Song Dynasty, China's bed crossbow also spread to zhina. Today, in the famous Angkor Wat in Cambodia, we can also see the stone carving images left over from the time when the Champo people fought with bed crossbows. One of the creations of Zhanpo people is to put a multi-bow bed crossbow on the elephant's back.
The Mongolian army, which perished in the Song Dynasty, vigorously recruited the crossbowmen in the Song Dynasty to serve it. When the Mongolian army marched westward, it used a large number of bed crossbows made by Han craftsmen and also manipulated by Han people. In his masterpiece History of World Conquerors, the Persian historian Zifinni described that when Xulie Uyghur Khan conquered the sturdy Muslim castle Maimendi in Mount Elbos on 1256, he once described it like this: "When there was nothing to do, a cow crossbow with a range of 2,500 steps made by Khitan craftsmen was aimed at those fools. Meteor-like projectiles burned many devilish pagan soldiers ... "The Arabs called the bed crossbow an ox crossbow, which should be derived from the name of" eight ox crossbows "inherent in the Han people. It is believed that the 2500 steps in Arabia are about one kilometer. At this time, the bed crossbow has obviously been used to launch flammable firearms. It may be some flammable balls, or it may be a rocket with an arson or gunpowder ball tied to the end of the arrow. In the Song Dynasty's military book "March Order", it is recorded: "Use crossbows to fire rockets and artillery to burn firewood." Artillery is the customary name for burning spherical shells in Song Dynasty.