山区路线在布线时,常因受地形限制,如小山包和困难地段展线,常以回头弯曲线或采用虚交点来进行定线。近来,有些单位采用双折点来布设回头弯,在计算上虽已大为简化,但仍需10～15分钟。现在,我们采用图解法之后,只花1～3分钟就可以解决了。其方法步 Mountain routes in the wiring, often due to terrain constraints, such as the hill package and the difficult sections of the line, often back to the curve or the use of virtual cross point to be set. Recently, some units use the double breakpoint to lay the turnback. Although the calculation has been greatly simplified, it still takes 10 to 15 minutes. Now, after we adopt the graphic method, it takes only 1 to 3 minutes to solve it. The method steps