In fact, it’s like building blocks. The columns of the pendant tower are composed of sections, and the pendant tower was very low at the beginning. Whenever the height needs to be increased, a special device is used to pull apart one of the "joints" (the principle is: the lower end of the device is fixed on a standard section below, the upper end is fixed on the standard section above, and then the upper and lower ends can be opened by a hydraulic device) , and then put a standard section that forms the column into the opened space, then take away the device, lower the upper part and fix it. This is how the tall hanging tower grows section by section.