The enemy platform can be divided into "solid enemy platform" and "hollow enemy platform" according to the structure. The solid enemy platform is not built flush with the wall, there is no arrow window, only the pedal on the top of the stage; The hollow enemy platform is a hollow balcony with windows on all sides and built across the city wall. Soldiers guarding the city can live in it, store weapons and ammunition and fight the invading enemy. The construction of the enemy platform greatly strengthened the defensive function of the city wall.
Basic introduction Chinese name: the source of the enemy station:? The nature of See Only editor: other explanations of military architecture: the origin and existence of hostile radio stations, the enemy platform of the Great Wall, the enemy platform of Xi 'an city wall, historical records, detailed description of the structure, and the towers used to defend the enemy on the city wall. In the Ming Dynasty, Yao Shizhen's "See Wei Bian" rolled down: "The difference is about three miles, and it is several times heavier around the water. Tear down the slate of the private house and build an enemy platform along the wall. " Wei Qing Yuan's "Guarding the City and Defending the City": "Outside the city, it is advisable to prepare a wall, a wall of cattle and horses, and a door." The existing enemy platform of the Great Wall is a pier built across the wall, which is higher than the wall. During the field investigation of the Ming Great Wall in Tangshan, there were two kinds of enemy platforms: solid enemy platforms and hollow enemy platforms. There are 662 enemy platforms in Qian 'an, Qian 'an xi, Zunhua and other places, only 3 are solid enemy platforms, and the rest are hollow enemy platforms. The solid enemy platform is not built flush with the wall, there is no arrow window, only the pedal on the top of the stage. In Tangshan, they are distributed in the Great Wall in the northern section of Dalingzhai, Qianxi County, with the numbers of 209, 2 12 and 2 13 respectively. They are all located inside the city wall and are basically square. The base is made of prefabricated stone, and the wall above the base is tiled to the top with rectangular blue bricks. The whole enemy platform is obviously separated from the base, and the wall looks trapezoidal from the outside. There are crib openings around the top of the wall, and there are observation holes in the crib. The bottom of platform 209 is 8.55 meters long, 8.7 meters wide, 7.7 meters high and the crib mouth is 0.7 meters high. The parapet under the crib is 0.7 meters high. The bottom of 2 12 platform is square, 9.4m square, and the platform is 5.4m high. The bottom of 2 13 platform is 8.7 meters square, and the platform is 6.7 meters high, in which the height of the stone foundation at the lower part of the wall is 1.5 meters ... These three solid enemy platforms are well preserved. There are 559 hollow enemy platforms in Tangshan, about 20% of which are well preserved. The hollow enemy platform is a hollow balcony with windows on all sides built across the Great Wall. Soldiers guarding the city can live in it, store weapons and ammunition and fight the invading enemy. The establishment of hollow enemy platform is an important symbol of the gradual strengthening of the defense system of the Great Wall in Ming Dynasty. The founder of the hollow enemy platform was Qi Jiguang, a famous Ming Dynasty. Xi 'an city wall enemy station Xi 'an city wall extends from the city gate to both sides. Every 120 meters, there are 98 enemy platforms with a width of 20 meters and a length of 12 meters, which are even with the top of the city. There are 20 east-west walls and 29 north-south walls. Three sides of the outer side of the enemy platform are provided with crib walls, and the crib walls are provided with crib openings. The crib mouth is one foot four inches (about 0.44 meters) wide, which is convenient for throwing bricks, stones, wood and shooting arrows to prevent the enemy from attacking the city. The distance between two enemy platforms is1.20m, and the intersection of firepower is 60m, which is the effective range and killing range of ancient long-range and throwing weapons such as bows and arrows, crossbows, flying hooks and throwing guns. Once the enemy attacks the city and climbs the city wall, a dense crossfire network can be formed from the high altitude between the front of the enemy station and the left and right sides outside the main wall, killing the enemy at the gate, making it difficult for the enemy to get close to the city wall, thus improving the defensive function of the city wall. At the beginning of the Ming Dynasty, 98 enemy platforms were built in Xi 'an. By the time of 1982, there were more than 89 enemy platforms, and 9 were damaged. Since 1983, Xi 'an Environmental Protection Construction Committee has repaired four enemy stations, and there are 93 enemy stations in the city. According to the historical book Biography of Qi Jiguang in Ming Dynasty, since Jiajing, the Great Wall has been repaired, but no pier has been built. Following the traffic jam in Guang Guang, he discussed the platform construction of the enemy. He said briefly, "The border wall of Yuji Town stretches for 2,000 miles, and every defect is flawed. It's useless to spend money than to repair it next year. Please cross the wall as a platform. The platform is five feet high and has three floors in the virtual space. Platform 100 people, armored battle available. Let the guards paint the land and work, and build 1,200 first. " In Qi Jiguang's training records, the process, construction method and use of building a hollow enemy platform are clearly stated. He first said that the former Great Wall was relatively low and thin, and it was easy to tear down. "There are small masonry platforms and walls in the middle, which don't help each other. The sergeant suddenly stood under the summer rain, frost and snow, and there was no place to live. Arms and equipment such as temporary departure are far from being delivered; If you put it on the wall, there is no hiding place; The enemy is outnumbered, so it is difficult to stand idly by. A broken wall straddles the river. When the general trend breaks through, it is irresistible. Today, the hollow enemy platform is built, and all the generals will hinder it. Its system, ranging from three to four feet high, is twelve feet wide around and seventeen or eighteen feet. Every rush place (that is, dangerous place) has dozens or a hundred steps; The slow place is still 140, 50 steps, or more than 200 steps as one. Save the left and right. " The way to build a platform: "The foundation is level with the city wall, with a height of more than ten feet and a height of four or five feet, and the middle layer is empty. There are arrow windows on all sides, the upper floor is built with stilts, surrounded by internal guards and soldiers, and artillery is fired to attack the enemy. The enemy can't reach the target, and the enemy can't ride close. Each station has a general manager who is responsible for dispatching attacks. There are two officers and deputies in Taiwan Province Trench, and there are thirty or fifty non-commissioned officers on both sides. A total of five units, a total of ten units, step by step. " With the supervision of Qi Jiguang and five years in Qin Long (157 1), the Great Wall enemy station project in Jizhou area was completed. According to Han Tai Ji (Volume 59) and Meng Qi Cemetery Records, only100000 yuan was used for all the funds, which was1100000 less than the original estimate of1200000. From then on, 10 17, the majestic enemy platform, stood on the line of defense stretching for 2,000 miles from Shanhaiguan in the east to Zhenbian in the west (now the west of Changping County). With the terrain, they are high and low, abrupt and staggered, and they are spectacular. These hollow enemy platforms are generally composed of upper, middle and lower parts. The lower part is the base, which is made of big stones and has the same height as the city wall. The middle part is a hollow part. Some of them are supported by brick walls and brick arches, which are connected with each other. Some are supported by wooden columns and wooden floors, and the outside is covered with thick brick walls, forming a large indoor space of one or two floors for soldiers to station and store food and weapons. The upper part is the top of the platform, and most enemy platforms have towers in the center for the soldiers guarding the city to shelter from the wind and rain. There are some platforms on the platform for burning smoke and raising flames to give an alarm, but there are no towers. There are holes between some floors on the upper and lower floors, rope ladders and wooden ladders are used, and some brick or stone stepping passages are left on the brick wall for only one person to pass through. The number of arrow windows and building doors in the central hollow part varies with the size of the enemy platform. Generally, there are three arrow windows in the front and back of each floor, two arrow windows in the left and right, and four or five arrow windows on both sides of the larger enemy platform. Villagers near the Great Wall often refer to enemy platforms as "three-eye buildings", "four-eye buildings" and "five-eye buildings" according to the number of arrow windows on both sides. Some enemy platforms of the Great Wall are not uniform, but independent of the wall, which we call piers. It has been found in Shitizi West in xifengkou, Huimin Village West in xifengkou, Xichengyu and other places, and the architectural structure of these piers is basically the same as that of the hollow enemy platform with the same wall. According to the function and internal structure of the hollow enemy platform, we can divide it into six types: single-tube arch without column, double-tube arch with double columns, three-tube arch with three columns, four-tube arch with four columns, and wooden column floor without tube arch. The following are introduced separately. Detailed structural drawing 1: plane section of single-tube arch pillar-free enemy platform (1: 200) 1. Single-tube arch column-free enemy platform 18 has been found in Tangshan, mainly distributed in the west of tiemenguan. The more representative is the 303 enemy platform, which is rectangular in plane, with a length of 13.8m and a width of 7m, and is well preserved (Figure 1). Grooves are dug around the bottom of the four walls of the base of this enemy platform, leveled with rectangular strips, and the upper part is paved with blue bricks. The height of the pedestal is even with the top of the city wall, and the pedestal is divided in proportion from bottom to top. The center of the pedestal is filled with pebbles and mountain skin soil. Three or four layers of blue bricks are tiled at the top of the base, and the top layer is staggered and leveled with square bricks. The whole pedestal rides on the Great Wall, with less internal protrusion and more external protrusion, which meets the use requirements. Above the base is a cylindrical arch coupon in the same direction as the Great Wall. The arched coupon is10.5m long, 4.2m wide and1.2m high. The wall at one end of the pipe arch is thickened and connected by a ladder. The ladder is made of wood, with a mouth width of 0.8m and steps of 15- 17, and each step is 0.3m high and 0.25m wide. At both ends of the cylindrical arch coupon, there are 1 doors on the wall of Shuncheng, and the doorframe is a stone arch coupon-shaped arch, with a total height of1.88m, a width of 0.66m and a thickness of 0.27m. The inner arch of the doorframe has a total height of 2.4m, a width of 1.2m and a total thickness of1. There is an arrow window on the outer side of the two doorways, and there are five arrow windows on the inner and outer walls of the barrel arch, with holes below. Each arrow window of the same enemy platform has the same size and basically the same structure. This kind of enemy platform has no column in the middle and a large space, with an area of not less than 40 square meters. If one person lives every two square meters, it can accommodate 20 foot soldiers, and it can accommodate about 100 people in wartime. According to 1: the perforation of the lower wall of the pier at the top of the abutment and the corner of the brick pier around the upper floor of the enemy platform are zigzag, and the pier is 0.6m high, 3m wide, 0.4m thick and 0.6m wide. There are perforated and drainage grooves on the wall at the lower part of the crib, and the distance between the grooves and the wall is generally 0.60-0.80m. There are two layers of zigzag lines around the outside of the bottom of the building wall (press 1), with two or three layers of blue bricks on the top and a rectangular floor of blue bricks in the middle. However, today, all the buildings have collapsed and the size cannot be measured. 2. Two-cylinder arch and two-column enemy platform Figure 2: Plane section of two-cylinder arch and two-column enemy platform (1: 200) Take the enemy platform at Xuliukou 1 1 in Gan 'an County as an example. The plane is rectangular, with a length of 1 1.3m and a width of 10.2m (Figure 2). Built across the city wall, the whole enemy platform protrudes inward 1.2m and outward 5m. Dig a groove around the bottom of the base and tamp it, level it with rectangular stone, then plaster it with rectangular blue bricks, level it with staggered joints according to the ratio of110, tamp it with crushed stones and mountain soil in the middle, and tamp it to the top of the base with the increase of surrounding walls. Generally, the height of the foundation part is equal to or close to the top of the city wall. The plane is paved with three or four layers of blue bricks, the top layer is square bricks, and the plane is staggered upwards. There is a fence on the upper part of the base, and two large tube arches, namely two long houses, are built in the middle, and a partition wall is formed at the left and right junction of the two tube arches. There are three coupon doors on the partition wall, each with a total height of 2.5m, a width of1.28m and a thickness of 0.86m.. A square brick column is formed between the two ticket doors, and the bottom of the column is1.8m long and1.3m wide. On both sides of the brick column and the coupon door are two tube coupons. The tube arch is 8.2 meters long, 3 meters wide and 4. 1 meter in total height. At both ends of the double-tube arch, there is a coupon door along the wall, with a total height of 2.2 meters and a width of 1.5 meters. There is an arrow window on the outside of the city wall, with a total height of 1 m and a width of 0.6 m. There are three arrow windows on the inner and outer walls of the two tubular arches, which are evenly and symmetrically located and have the same size. There is a passage on the inner wall to go upstairs. The entrance of the building is 0.78m wide, with 16 steps, each of which is 0.3m high and 0.25m wide. In this kind of enemy platform, there is also a patio on the roof, and ladders and other instruments are used to climb to the top of the platform. Some patios are open at the corner of the barrel arch, while others are open in the middle, which are generally square,1.2m square. The top surface of the enemy platform is10.5m long and 9.2m wide, and the surface is paved with square bricks. The walls of Yu Zhou on all sides have collapsed, with a residual height of 0.4-0.6m and a width of 0.4m.. The unique base address of the middle floor is 6.72m long and 4.45m wide, and the entrance of the floor is1.02m wide. Third, the double-tube arch and three-column enemy platform takes the enemy platform at No.44 Hekou, Gan 'an County as an example. The plane is rectangular, with a length of 13.7m and a width of 9m. The outside of the pedestal is 4.2m high and the inside is 3.8m high (Figure 3). Fig. 3: Plane sectional view of double-tube arch and three-column enemy platform (1: 200). Planing and tamping the bottom of the pedestal, then smearing white ash on the rectangular strip stone and leveling all around. Slabs are generally 0.8- 1m long and 0.3m thick. After leveling, build by laying bricks or stones with rectangular blue bricks and plaster them with white ash, and stagger them. The wall thickness is about 1 m, and the middle is filled with gravel and mountain skin soil to the top. The top surface is paved with three or four layers of blue bricks, and the top layer is made of square blue bricks, and the planes are staggered upwards. The brick thickness around the top surface of the pedestal is 1. 1 m, and there are four arrow windows on the inner and outer walls, all of which are arched with bluestone. The arch width in the arrow window is 1.05m, the arch foot is 1.6m, the arch height is 0.5m, the thickness (depth) is 0.6m, the arch width outside the window is 0.6m, the arch foot is 0.5m, the arch height is 0.32m and the thickness is 0.32m. There are window sills at the bottom and window shaft holes at both ends. There is a small perforation at the lower part of the arrow window, with a width of 0.3m and a height of 0.4m. A door is opened on the left and right side walls, and the two arrow windows are on the inner side and communicate with the city wall. The left and right doors are stone door frames, with a door frame thickness of 0.27 m, a door width of 0.66 m, an arch foot height of 1.52 m and an arch height of 0.35 m. The stone door frame is a brick arch piece with a width of 1.6m, an arch foot height of 1.73m, an arch height of 0.7m and a thickness of 0.74. There is a staircase on the wall near the door, with a building width of 0.8m and 15 steps, each of which is 0.3m high and 0.25m wide. There are two long tubular arches between the four walls. The arch foot is 3.3m high, the arch height1.2m and the total length10m. A partition wall is formed between the two pipe arches, with a wall thickness of1.53m. There are four connecting doors on the wall, and the partition wall is divided into three square brick columns with rectangular cross sections, with a length of 1.9m, 2m, 1.6m and a width of 1.5m respectively. The coupon door is 2m high, totaling1.5m.. Four. Three-tube arch and four-column enemy platform Figure 4: Plan section of three-tube arch and four-column enemy platform (1: 200) Take No.70 enemy platform near Lengkou, Gan 'an County as an example. The plane is rectangular, with a length of11.25m from north to south and a length of 9.35m from east to west (Figure 4). The base is 2.7 meters high inside and 4 meters high outside. At the bottom of the surrounding walls, the groove is planed first, then the wall is rammed, and then the rectangular stone is plastered with white mortar. After leveling, the upper part of the wall began to be built with evergreen bricks, coated with white mortar, staggered and leveled to the top surface of the pedestal. After the middle is filled with gravel and mountain skin soil, the surface is paved with three or four layers of blue bricks, and the top layer is made of square bricks, and the plane is staggered and flat. Around the upper part of the base, the four walls continue to be built with rectangular blue bricks. The structure of the south wall and the north wall is basically the same. The entrances are all inside the enemy platform, and two arrow windows are built outside. The gate crossing is arched with prefabricated stones to form a stone door frame. The thickness of stone is 0.27m, the width of door frame mouth is 0.66m, the arch foot 1.52m, the arch height is 0.35m, and the width of door frame is the same as that of stone. There is a horizontal cornerstone under the frame, and there is a circular door shaft at both ends of the cornerstone, with a diameter of 9 cm, a depth of 5 cm and a wheelbase of 6 1 cm. The cornerstone is 0.75m wide and 0.23m thick. The brick arch wall in the door frame is 0.74m thick, 1.73m high and 0.7m high. There are two arrow windows outside the door. The arch width of the arrow window is1.08m, the arch foot is1.07m, the arch height is 0.5m and the depth is 0.63m. The arrow window is 0.59m high from the base surface 1m, the width is 0.56m high and the arch height is 0.35m.. The window opening of the arrow window is widened to 0.7m, the window sill is 0.4m wide, the inside is thick and the outside is thin, and the inside is cut with a notch for placing a wooden frame, with a width of 7.5cm and a depth of 8.5cm. The arrow window sill has an arc perforation with a downward direction of 0.4m, a width of 0.46m and a total height of 0.52m. There are five arrow windows in the east wall and four arrow windows in the west wall, and each arrow window has a perforation, so the arrow window sill has five arrow windows. In addition, on the right side wall of the inner arch of the four-wall arrow window of the enemy platform, at the height of1.1-1.35m, an arrow-shaped groove with a total length of 0.45m and an arrow shaft length of 0.28m is chiseled (according to photo 2), with three arrow grooves in each group on the east wall, north, south and east. This phenomenon was only found in this enemy station during the investigation, and nothing else was found. Photo 2: Arrow-shaped grooves on the wall. There are three tube arches in the middle along the direction of the Great Wall (north and south). The width of the middle tube arch is 2.35 meters, and the width of the tube arches on both sides is 1.3- 1.32 meters. The height of the three pipe arches is the same, that is, the arch foot is 3.3 meters high and the arch height is 1.2 meters. Two partition walls are formed between the three pipe arches, and the thickness of the partition wall is 0.86 meters. Three connecting doors are respectively connected to the two partition walls to form four rectangular brick columns. The middle door is wide and the sides are narrow. The width of the middle ticket door is 2.45m, the arch foot height is1.25m, the arch height is1.3m, the width of the two sides ticket doors is1.24-1.26m, the arch foot height is1.8m, and the arch height is 0.7m.. A smoke crossing was found on the wall on one side of the partition arch, which went straight to the top of the enemy platform. The smoke crossing is 0.4m high, 0.2m wide and 0.2m high from the base surface. The top of the enemy platform is rectangular, with a length of10.8m from north to south and a width of 9.5m from east to west. The top is paved with blue bricks and there is a building in the middle. The building is 7.24 meters long from north to south and 4.4 meters wide from east to west. The other four walls range in height from 2m to 4m, with a wall thickness of 0.68m.. There is a door and window in the western wall, but they are all destroyed. The building is surrounded by walls and cribs, but they have collapsed, and several perforations and sinks can be seen in some areas. Nanshan wall of the building is apart from Nanyu wall 1.8m, west wall is apart from Xiyu wall 2.85m, north wall is apart from Beiyu wall 1.85m, and east wall is apart from Dongyu wall1.85m.. Outside the western wall, there are stairs for foot soldiers to go up and down, with a width of 0.8 meters. Fig. 5: Plane sectional view of four-column enemy platform with circular tube arch (1: 200) Fig. 3: Opening of enemy platform V. Four-column enemy platform with circular tube arch The most representative enemy platform is No.250 in Guanbei section of Yumuling, qianxi county. The plane is square, 10 meter square (Figure 5). The bottom around the base of the enemy platform shall be leveled and tamped, leveled with rectangular stones plastered with white gypsum, and then paved with blue bricks. The surface of the blue brick is plastered with white ash and tiled, and it is divided from bottom to top in proportion. From the side, it is trapezoidal, narrow at the top and wide at the bottom. The middle of the four walls is filled with gravel blocks and mountain skin soil to form the base surface. The plane of the base is three or four layers of blue bricks, the last layer is square bricks, and brick walls continue to be built around it to form a central space. The east and west walls (the east-west direction of the Great Wall) are respectively provided with a door and two arrow windows, and both doors are connected with the north side wall. The door frame is made of stone, the thickness of the frame stone is 0.23m, the width of the inner opening of the door frame is 0.7m, the arch foot 1.3m and the arch height is 0.3m (photo 3). The arch stone is made of three prefabricated arc stones with the same thickness as the frame. There is a door sill under the door frame, with a width of 0.48 m, an outer thickness of 0.2 m and an inner thickness of 0. 12 m ... There are door shaft round holes at both ends inside, and a threshold with a width of 0.2 m in the middle. The entrance is a brick arch coupon, with a width of 1. 17m, an arch foot height of 1.6m and an arch height of 0.6m. The south gate wall is 0.68m thick, and the north gate wall is widened to 1. 17m due to the top stairs. There are two arrow windows near the outside of the city wall, the size and shape of which are basically the same. The arch width in the window is 0.85m, the arch foot1.4m, and the arch height is 0.5m. The window is 0.72m deep, 0.95m from the top surface of the base, 0.5m wide, 0.48m high at the arch foot, 0.3m high at the wall, 0.28m thick ... The cornerstone of the transverse window at the bottom of the window is 0.4m wide and protrudes out of the wall. There are perforations under each arrow window, with a width of 0.3 m and a height of 0.35 m. There are 5 arrow windows on the south wall and 2 arrow windows on the north wall, with the same size as above. A circular tube arch is built inside the four walls, with a width of 1.25m, an arch foot height of 2.6m and an arch height of1.1m.. There are four gates in the middle, east, west, north and south, with a width of 1.2m, an arch foot height of 1.5m and an arch height of 0.35m The four brick columns are separated by four gates. There is a hidden hole at the bottom of each pillar. In addition to the north wall, there are two small niches on the other three walls. The niche is 0.45 meters wide, 0.3 meters high and 0.45 meters deep, with an average distance of 65438 0.5 meters from the base surface. There are stairs on the north wall, the entrance of the building is 0.7 meters wide, there are brick stairs, and there are 15 steps. The top is square, 9.5 meters long and 9.5 meters wide. Four battlements in Yu Zhou collapsed, with the highest remaining height of 0.3 meters. Some places have perforations and sinks. There are two layers of sawtooth bricks outside the four walls at the bottom of the perforation, and the outlet angle of a flat brick is 5 cm. The ruins of the central building are not clear, and only broken bricks can be seen on the surface. Fig. 6: Plane sectional view of bearing enemy platform with tubular arch wood column joint plate (1: 200) VI. There are more than 10 such enemy platforms found on the Great Wall of Tangshan. Take the enemy platform at No.34 Hehekou, Gan 'an County as an example. The plane is nearly square, with a length of 1 1.4m from north to south and a length of 1 1.5m from east to west (Figure 6). Like other enemy platforms, the building structure of the base of the enemy platform is planed and compacted from the bottom to all sides, leveled with rectangular stones with white mortar, and then staggered to the top with rectangular blue bricks with white mortar. Gravel blocks and mountain soil are filled in the middle of the four walls of the base, and three or four layers of blue bricks are paved on the surface, and the top layer is square brick. The planes are staggered and leveled upwards to form the base plane, and the walls are continuously built around the plane to the top. The top is supported by wooden columns and boards. The enemy platform of this building structure is not easy to preserve and the damage is very serious (photo 4). In our investigation, this enemy platform is well preserved, except for the existence of the east wall and the north wall, so it is not difficult to see that its overall orientation is not a cylindrical arch. Traces of circular wooden columns were found on the walls on both sides, with a diameter of about 0.3 meters. There are traces of wooden grooves on the top of the inner side of the north wall and the east wall. The width of the trough is 0.2-0.25m, and there are 4 wooden pillars on the east wall and 3 wooden pillars on the north wall. There are arrow windows and arrow doors on the wall between the wooden pillars, all of which are arch coupons. There are five arrow windows on the east wall, which are different from other enemy platforms on the wall. Two of the five arrow windows are at the bottom and three are at the top. The lower part is 0.9m away from the base surface, and the upper part is1.3m away from the base surface. The window size is basically the same, with the mouth width of 0.45m, the arch foot height of 0.7m and the arch height of 0.18m. There is a door inside the north wall, which can't be measured because of its collapse. There are four arrow windows on the outside, two up and two down, the same size as the east wall. The top has collapsed and the situation is unknown. Fig. 4: Load-bearing enemy platform of tubeless wooden column building. The enemy platform of the Great Wall is a part of the whole Great Wall defense system, which closely cooperates with the city wall platform, beacon tower and other buildings. In areas where there are no beacon towers, enemy stations are also places where beacon towers are spread. In the garrison of the border guards, the enemy station has also become a solid fortress. When the enemy invaded, he went on stage to fight. The platform is equipped with weapons and trench, and the garrison commands, so that the enemy can't get close to Taiwan Province. Even if the enemy breaks into the side wall, the enemy defenders can still stick to the platform and shoot at the enemy's flank and rear. Under the enemy's platform, there are other troops stationed on the chariot to cooperate with the defenders on the platform, so that the enemy can't break down the wall and invade. The construction of the enemy platform has greatly strengthened the defensive function of the Great Wall.