The plane shape is square. The construction of the enemy platform usually protrudes inside and outside the city wall, and the size of the protrusion depends on the terrain, which is conducive to the development of firepower and the implementation of side shooting. It protrudes about 4 ~ 5 meters to the outside and about 1 ~ 2 meters to the inside, so the enemy platform is also called the enemy platform. But there are also a few that just protrude outward. The structure of the enemy platform is divided into upper and lower floors, which is actually a building that integrates the fighting and living equipment of the foot soldiers guarding the platform. The enemy platform built by Qi Jiguang in Yuji Town is about 9.6 meters high and 38.4 meters in circumference. The lower floor of the enemy platform is arched with bricks, forming several small rooms that can accommodate 10 ~ 30 people. There is a gun window for gun shooting on the wall of the room. There are battlements, gaps and shooting holes on the upper floor of the enemy platform, and some auxiliary facilities for fireworks and alarm are equipped. For example, the first, second and fourth enemy platforms in the south and the first, second, third and fourth enemy platforms in the north of the west gate of Badaling. The construction of enemy platforms and wall platforms on the Great Wall Line has greatly improved the robustness of the Great Wall defense. First of all, it can save troops. As long as we stubbornly hold the enemy platform and the city wall platform, we can effectively control the city wall section between the two platforms, thus reducing the distribution of troops between the two platforms. Secondly, the city wall platform and the enemy platform can give full play to the power of firearms, and use the gun windows or holes on the platform to cross and shoot sideways intensively, which can fully control the top, wall and foot of the city wall between the two platforms, making it difficult for the invading enemy to stand at the gate. All kinds of firearms on the two planes, such as guns, shotgun, rockets, crossbows and even rolling stones, can be used to strike siege fighters in a layered, concentrated and intensive manner. Even if a small number of enemies climb the city wall, because the enemy platform is higher than the top of the wall, they can still annihilate the enemy at the top of the wall and prevent its expansion. In bad weather conditions, such as fog, rain, snow, wind and poor visibility at night, it will be difficult for the enemy to attack the city wall. The enemy station is a peripheral defense and can fight independently. Even if the enemy breaks through the wall, he can shoot the enemy from behind or from the side. Its troops, firearms, and storage are sufficient, and it can be held for a long time. With the mobile troops transferred from the depth and side, it can destroy the enemy who broke into the city wall and repair the broken wall. The specifications and structure of the enemy platform are all based on the terrain conditions, and the size of the enemy platform built on various terrains is quite difficult to be consistent. Take Badaling enemy station as an example. Generally, the platform is 7.2m high, and the platform height is1.5m.. The bottom layer of the enemy platform is about12m long and 8.2m wide, while the upper layer is about11.7m long and 8m wide. There is a cannon window on the lower floor of the enemy platform, and you can shoot sideways outside the wall. There are steps in the enemy platform for going up and down, and the gun windows and holes of the enemy platform are shaped like outlines, which not only take care of the opening of the visual and shooting boundaries, but also take care of the protection and camouflage of the garrison personnel according to the situation. The distance between two cars on the city wall line depends on the terrain, the direction of the city wall, the cross control distance of firearms and other conditions. Usually, an enemy platform (or wall platform) is maintained every 300 ~ 500 meters, but it depends on the importance of the garrison area and whether the terrain is easy to control. For example, in Badaling's "North Gate Key", the distance between the first, second and third stations is less than 200 meters, but the distance between the third and fourth stations is more than 400 meters. Another example is Jinshanling, where 158 enemy platforms are built on the Great Wall Line, which is only 25 kilometers long, and the average interval between each enemy platform is only 100 meters, which shows the importance of the lot. These enemy platforms are magnificent and the architectural art is wonderful. The plane of the pier is square, flat, round and angular, and the top has eaves, ceilings, four corners and octagonal tops, all of which are masonry structures. The ticket gate of the enemy station is made of white marble stone, engraved with floral relief, which is exquisite and unique. This shows the great creativity of millions of working people.
Enemy platforms (protruding from the wall) each have 60 officers and men, 1 the commander is in charge, and 5 commanders 1, 10 commander 1. Each machine is equipped with French machine guns, magic machine guns, other weapons, signal equipment and food and drinking water for one month.