Overhead cable—sliding bridge over high mountains and valleys
The Great Nujiang gorge and the Biluo Snowy Mountains and the Gaoligong Mountains on both sides of the gorge have range upon range of hills. Dangerous rocks tower aloft and cliffs are quite precipitous. Water in the valley flows rapidly and tempestuously. From ancient times on, the traffic there was very inconvenient, and it is said, “blue sheep has no way out and monkeys worry, too”. There are only several ferry crossings where the flow of water is a bit slow and wooden boats can cross the water. Except that, there is no place for erecting bridges and wading across. The Nu people on the two sides of the river could only cross the valley by the old means—overhead cable to keep contact and communication with each other.
Overhead cable is an indispensable important transportation facility for the Nus. The way of making it is: firstly twist bamboo strips into large rope as thick as the wrist. Then draw the rope across the river and fix it on big trees, wood stakes or cliffs. People use sliding board (clipper) as assisting tool to slide along the bamboo rope across the air. The sliding board is a hard wooden chute, which is 7-8 cuns (traditional Chinese weight unit) long and about 4 cuns wide with two symmetrical holes on the back for tying rope. When people use it, they put the groove of the board on the rope, cross flax rope or leather belt around the holes, fix the rope or belt on the waist, hold the sliding board with the posture of lying supinely and take advantage of the opportunity to slide down.
There are two kinds of overhead cable: flat cable and steep cable. Flat cable only has one rope, which is flat without degree of inclination and can be used when coming and going. But it’s hard to cross the river by this method. Because the middle part of the rope hangs down naturally, when people reach the middle, they have to make use of the strength of the four limbs to climb up the rope hand over hand to the opposite bank. Steep cable needs two ropes—one for coming and one for going. One end of the rope is high and the other end is low, and it has degree of inclination to some extent. This method is quick and saves effort, but it’s likely to get hurt and it needs particular carefulness.
It’s not only people that can be carried by the overhead cable, but also goods and domestic animals. It is said that the Nus’ invention of overhead cable was inspired by spider, which weave net among trees and climb back and forth. With the development of the society, several modern bridges have been built over the Nujiang River, but the overhead cable is still deeply favored by the Nus and still lies across the Nuiang River as a traditional transporting tool. However, the dangerous and breakable bamboo has been replaced by solid iron rope with pulley.