瑞士是个较小的国家，全国面积只有41293平方公里，但其铁路网密度很大，结构复杂，在全国约3000公里铁路线上有7000座桥梁和246条隧道。由于瑞土地形复杂，山地和河流纵横，列车在阿尔卑斯等山地或隧道内发生火灾和其它重大事故时，普通消防车辆无法迅速到达现场灭火救灾。为? Switzerland is a smaller country with a land area of ​​only 12,493 square kilometers. However, its railway network is very dense and complex. There are 7,000 bridges and 246 tunnels on the railway line of about 3,000 km across the country. Due to the complex terrain of Ruitou, the vertical distribution of mountains and rivers, the fires and other serious accidents in the mountains and tunnels in the Alps, ordinary fire vehicles can not quickly reach the scene for fire fighting and disaster relief. for?