Paragraph on “How can trains run underground and climb mountains?” complete paragraph for Class 9, Class 10, Class 11 and Class 12
How can trains run underground and climb mountains?
In big cities there is often no room for railway tracks. Trains go either under or over the roads. The ‘tube’ trains in London run as much as 67 m (220 ft) deep. Whole stations are hollowed out under the surface. In New York the subway sometimes runs under-ground and sometimes on stilts over the road.
When main railway lines have to cross mountains they often run through tunnels. The Simplon tunnel under the Alps is over 19 km (12 miles) long and 2,135 m (7,000 ft deep. Some railways go up into the mountains. The Antofagasta-Bolivia railway in Chile goes up to a height of 4,800 m (15,800 ft) in the Andes Mountains. For very steep climbs special railways have big cogs under the engines. These fit into holes in the track to stop the train slipping. This arrangement is called a ‘rack’ railway. Wherever this does not work, cable railways are used, with cars hanging from wires.