A model of the Nest Car. (PHOTO: Museum Tongji University)

By ZONG Shihan

In ancient times, the military deployed a vehicle equipped with a cabin for observing enemy movements from a high altitude, known as the Nest Car because the cabin was suspended high up on a pole, just like a bird's nest.

The Nest Car was made portable via a set of wheels at its base, allowing it to be pushed about by the military. Attached to the vehicle were two vertical wooden poles, connected by a small horizontal wooden pole at the top. The cabin was suspended on the small horizontal wooden pole with ropes and connected to a pulley, which could be lifted and lowered as desired.

The cabin was wrapped in cowhide to repel arrow attacks and accommodated two soldiers, who could keep a 360 degree lookout for the enemy through 12 observation portals.

The history of the Nest Car can be traced back to 575 BC. According to Chinese history first detailed in the narrative chronicles of the Zuo Zhuan, written in the late Spring and Autumn Annals (770-476 BC), in the Battle of Yanling, the king of Chu and the prime minister jointly boarded the Nest Car to observe the movements of the Jin army from a high altitude. The text clearly records the scene of the king of Chu observing the Jin army gathering and divining in their camp.

The technological innovation of the Nest Car is mainly reflected in two aspects. The first point is that a pulley is used as a lifting device on the Nest Car. The pulley shaft on the vehicle could change the direction, allowing soldiers to lift the cabin to the top of the support poles by rotating the pulley on the ground.

The second point is that the Nest Car served as a mobile watchtower. In ancient times, there were watchtowers located on important buildings and campsites. However, the invention of the Nest Car made the watchtower portable, allowing soldiers to conduct reconnaissance missions at any time and place, providing reliable intelligence for military strategy formulation.