In 208 AD, Cao Cao and Liu Bei conquered Sun Quan after the Battle of Chibi, and were finally forced by Sun Quan's army to Maicheng in Southern Xu. Cao Cao was besieged by Sun Quan's army in Maicheng, the city walls were breached, and Cao Cao was in a desperate situation.
At this critical juncture, Cao Cao found a technician named Liangyi, and together they designed and built a diving vehicle. The dive vehicle can move underwater, and its compartment is equipped with an air ** device that allows people to breathe in the water. Cao Cao planned to use the submersible vehicle to take refuge in the water and avoid the pursuit of enemy forces.
When Sun Quan's army invaded the city, Cao Cao took a diving vehicle and dived into the river outside the city. Seeing that the city was empty, Sun Quan's army thought that Cao Cao had fled, so the pursuing soldiers shot arrows into the river, but the arrows were not fixed and could not hit Cao Cao, who had dived underwater. In the dense shooting of the rain of arrows, Cao Cao successfully evaded Sun Quan's pursuit with a diving vehicle.
This story shows Cao Cao's cleverness and ability to cope in critical moments. Not only was he able to flexibly use existing resources, but he was also able to create new devices at critical moments to deal with the enemy's encirclement and interception, and finally successfully escaped the enemy's pursuit. This story has also become one of the classic allusions in Chinese history and has been widely praised by later generations. Cao Cao of the Three Kingdoms