In ancient China, some types of ladders have wheels under them, which can be pushed and driven, so they are also called "ladder cars", equipped with shields, winches, grappling hooks and other appliances, and some have lifting equipment with pulleys. The inventor of the ladder is generally believed to be the Spring and Autumn Period of the Lu State skilled craftsman Gongban (Luban), when King Chu Hui in order to achieve the purpose of dominance, ordered the public to make the first ladder in history. Huainanzi? Xu Shen noted that "the ladder can stand according to the clouds, so it looks at the enemy's city", indicating that another purpose of the ladder is to climb high and look far away to detect the enemy's situation.

The cloud ladder of the Warring States period, judging from the pattern shown in the bronze of the Warring States period of water and land attack patterns, is composed of three parts: the bottom is equipped with wheels, which can be moved; The ladder body can be lifted up and down, carried by manpower, and leaned on the city wall; The top of the ladder is equipped with a hook to hook the edge of the city and protect the head of the ladder from being pushed and destroyed by the defenders.

By the time of the Tang Dynasty, the ladder was a great improvement over the Warring States period: the ladder body (main ladder) was fixed on the chassis at an angle; In addition to the main ladder, there is also a movable ladder ladder (auxiliary ladder) to the city, the top of which is equipped with a pair of rollers, and can slide up and down along the city wall surface when climbing the city, which is called the flying cloud ladder; At the bottom of the ladder, "a large wooden bed with six wheels underneath". Because the main ladder adopts a fixed device, the ladder erection procedure is simplified, the ladder erection time is shortened, and the design of the movable upper city ladder greatly reduces the height of the ladder before engaging the enemy. When attacking the city, you only need to stop the main ladder under the city, and then set up the ladder on the main ladder to "sleep on the city", so as to reduce the danger and difficulty of setting up the ladder in front of the enemy, and at the same time ensure that the ladder is not too early to approach the edge of the city before ascending the city, so as to avoid being destroyed by the defenders.

The structure of the ladder in the Song Dynasty was greatly improved, adopting a folding structure connected by a rotating shaft in the middle, and adding protective facilities at the bottom of the ladder. In addition, there are many forms of ladders (auxiliary ladders) in the upper city, including flying ladders, bamboo flying ladders, tiptoe flying ladders, etc. These improvements made it easy and quick to enter the city and engage the enemy. After the Ming Dynasty, this kind of cumbersome and huge ladder was gradually abandoned because it could not resist the attack of firearms.

There were many ways to siege the city in ancient times, but most of them were based on the premise of quickly ascending the city, and the ladder must be bold, fast, and take advantage of the situation to enter the city. Therefore, there are all kinds of light and simple flying ladders that are commonly used. During the Han Dynasty, the Han army attacked Zhizhi City, which had a wooden city wall outside and an earthen city wall inside, and the defense was quite tight. The siege soldiers first shot back with bows and crossbows, repelled the defenders of the city, burned the wooden city with fire, held a crossbow and bow, and rushed into the wooden city with a long halberd, and then quickly approached the earth city, set up ladders on all sides, and climbed the city by the ladder, and quickly smashed the inner city. This siege method is to attack, try to shorten the confrontation time between the two sides, and quickly break through the city defense, so it is necessary to use a light ladder, the ladder structure is simple, light weight, and mostly wooden bamboo. In the Song Dynasty, the flying ladder was two or three zhang long, and the first end was equipped with two wheels, which was convenient for ants to attach to the city. In addition, there are "avoidance wooden flying ladders", "tiptoe flying ladders", and "bamboo flying ladders", which are slightly different in shape, but they are all light and practical.

The water cloud ladder in this article is just a kind of tiptoe ladder on the bow of the ship conceived by the author, as for whether it has appeared in ancient times, it remains to be examined.