京张铁路“人”字形路线探析

A Study on Zigzag Route of Beijing-Zhangjiakou Railway

在京张铁路工程中,青龙桥附近的"人"字形路线作为该路重要标志多为后人称道。该处"人"字形路线设计最直接意图是缩短八达岭隧道开凿长度。"人"字形路线需要列车停顿、逆行,不仅限制运输还存在安全隐患,路线设计者詹天佑及之后工程师对此都有正确认识。京张铁路采用"人"字形路线是限于特殊地理环境、有限的资金与工期作出的无奈选择,从工程角度来讲不是最佳方案。后人对该路线有误解,未能认识到路线缺点。

The zigzag route near Qinglongqiao is seen as a symbol of BeijingZhangjiakou railway and is thought highly by descendants. The zigzag design was originally to shorten the length of the tunnel. The train would stop and retrograde on the zigzag line which not only limited the load but also raised the risk. In fact, the designer, Zhan Tianyou and following engineers were aware of these shortcomings. Because of the special geographical environment and limited budget and time, the design had no alternative but to choose zigzag. Based on the viewpoint of engineering, the zigzag route was not the best solution. Later generations misinterpreted the route and failed to recognize the shortcomings of the route.