The Great Wall of China: Construction of the World’s Largest Project Ever Undertaken

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The Great Wall of China is an approximately 21,196 km long series of several walls constructed across northern China with an objective to protect the region from its enemy forces. These walls were built on difficult terrains such as mountain ridges and passes, rivers, and deserts to thwart the intrusion attempts into the mainland China.

Along with the walls, Chinese rulers constructed a number of tall towers at suitable places. The towers were guarded to keep an eye towards the northern plain and were used to send alerts by lightning a fire in case of attacks. The smoke would be seen by soldiers posted farther along the wall and would alert them to be prepared for the impending attack.

Most of the walls were constructed and destroyed for 2000 years. Chinese rulers used to construct and destroy walls at different places for several reasons. Therefore, the earlier walls have collapsed but a stone wall constructed by the last dynasty of China (Ming dynasty) still exists.

Chinese builders and rulers used to call these walls as Changcheng (meaning "long wall"). Some of the rulers even used to call them as border walls or frontier walls. However, the American and European visitors started calling them the great wall.

1. History of the Great Wall of China

The following points describe the history of the Great Wall of China:

1. In ancient times, the Chinese used to build walls around their houses, villages, and towns for protection.
2. Back then, China was divided into different factions. These regions used to be in conflict with each other and the ruler of each region used to build walls to protect their area.
3. Early walls were made of packed gravels. Rulers used to build such walls for temporary protection.
4. However, in 221 BCE, Qin Shihuang united all the regions and became the first emperor of united China. He wanted to protect China from northern enemies (known as Nomadic people). Therefore, he ordered to construct the first-ever long wall of China. This wall was made by connecting the existing gravel walls, by repairing them and building new walls where required. The first great wall, Qin Wall, took around ten years for construction.
5. A number of rulers reigned and died while fighting against the nomadic people, but the construction of the walls continued for years.
6. Later on, during the rule of Ming dynasty, the construction of the wall reached its peak. Significant sections of stones and bricks were used to construct the walls during the Ming regime.
7. At present, most of the visible portion of China's great wall was constructed during the rule of the Ming dynasty.

2. Location of the Great Wall of China

The location for construction of the wall was not predetermined. When northern enemies attacked one area, the Chinese rulers used to build the wall at that place. Later, the northern enemies would find a different location to attack from, which made the Chinese build more walls.

Sections built across deserts and plains are tall and wide, while the wall is narrow and shorter in the mountains. Across flatlands, the wall is straight and for other stretches, it is twisted and turned to follow the hills.

3. Materials Used in Construction

The following points describe the materials used during the construction of the Great Wall of China:

1. Before the Qin walls, the rulers of different regions used locally available materials and local building methods to construct the wall.
2. During the construction of Qin walls, indigenous people were forced to work as labor and were coerced to dig the ground by hands. This excavated earth was then mixed with the gravel, twigs, and tree plants.
3. Clay, wood, and stones were used as facing material for the wall construction.
4. The supply of materials was provided by hand, on the backs of animals, and via carts pulled by animals.
5. During the construction of Ming walls, bricks were first used as a building material for the walls.
6. Bricks were formed by mixing the earth and water. The mixture was baked in a small kiln constructed near to the walls.
7. For the construction of the Ming wall, they used a different mortar, which was made up of sticky rice flour. This mortar was so strong that the wall has stood firm even after 600 years.
8. Over steep and dangerous mountain passes, they used to form human chains and passed bricks from one to another. In winters, they splashed water on the ground to facilitate the movement of stone blocks along the icy roads.

4. Construction Methodology of the Great Wall of China

The construction of the walls is divided into two parts. The first one is the walls constructed during the Qin dynasty, and second, the walls constructed during the Ming dynasty.

4.1 Construction of Walls During Qin dynasty

Hangtu method was used for the construction of the wall during the Qin dynasty. Hangtu means the tamping (hang) of earth (tu) layer by layer until the wall becomes solid. Hangtu walls were easy to construct in a plain area. Though, in the mountainous area, stones were used in place of earth to give more rigidity to walls. In these areas, labors used to cut the stones from the mountains in the vicinity and used it for the construction of walls.

4.1.1 Construction Methodology

The following points describe the Hangtu method used during the construction of Qin Walls:

1. Firstly, workers made the framework for the construction of the walls using wood.
2. After that, the workers poured the layer of earth inside the framework.
3. Then the layer of earth was tamped using wooden poles with stone filling at the end. Process of pouring and tamping continued till the wall reached the desired height.
4. Following this, they removed the wooden frameworks and used them for the next section of the wall. This process was continued till the desired end of the wall was reached.

4.2 Construction of Walls During Ming dynasty

In the initial years of the rule of the Ming dynasty, the workers continued to construct the walls using the Hangtu method.

After 1500 CE, northern enemies (Mongol nomads) started to settle along the borders of China. With time, their numbers grew around the borders, making them wanting to trade for food and other goods. However, Ming dynasty rulers didn’t want to establish any relationship with the Mongols, due to which the Mongols launched an attack on the Chinese.

The Mongolian army was much powerful than the Chinese army. Hence, this war went on for decades. Finally, the Chinese decided to build another long wall to protect the entire border. This time, they wanted to construct stronger walls than before.

4.2.1 Construction Methodology

The following points describe the construction method used during the Ming dynasty:

1. The basic plan of construction was the same as the Hangtu method. However, the workers used stone and bricks instead of wooden frames and earth.
2. For the construction of high walls, a solid foundation was needed. Therefore, to provide a solid foundation, workers dug two parallel trenches of around 2 feet deep. They then filled the trenches with the stones.
3. After that, they used the bricks to construct the wall on top of the two trenches. The gap between the two walls was filled with rubble and earth.
4. The top of the wall was covered by a brick layer so that a road could be created over it.
5. Builders also provided the drainage system such that the system funneled the rainwater away from the wall.
6. The Ming wall base was wider and the wall tapered as it was reaching the top. Most of the walls had a bottom base of around 6 feet and top base of around 5 feet.
7. The road along the top of the wall was wide enough to allow soldiers and horses to travel.
8. Crenellated battlements of 7 feet height were constructed on top of the wall. Battlements were the crucial features in structures designed for defense.
9. The height of Ming walls was kept around 23 to 26 feet on open ground, whereas in the mountainous regions, the wall height was limited to a few feet. Some stretches in the mountains are so steep that the wall looks like a stairway to the sky.

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