Page 54 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

the utilities that were already buried below. They could then
Find out how about the feat of engineering that

necessary, and reconstruct the road surface. replace the pipes above the subway, modifying their design if For deeper tunnels, engineers used powerful explosives that were more efficient than digging by hand, but did result in a number of casualties. A variety of techniques were used to overcome some of the installation problems, such as passing the tunnel through a river. To build some of the underwater subway areas, engineers cleverly constructed the tunnel sections

s pumping the water out.

ork’ took place over 100 years ago

that could quickly and efficiently move people in, out and

How was New Y

subway built?
The construction of the first subway line began in 1900. Engineers of the time had to take into account various challenges such as uneven topography, hard bedrock and the sheer number of water, sewage and gas pipes that already lay underground. The project was no mean feat – around 8,000 labourers were employed to excavate the subways, thousands of which sustained injuries and more For shallower tunnels, the engineers often preferred to dig down from the road surface, a

around Manhattan. than 40 lost their lives. Cable network Underground telephone lines are integrated re with police and fi alarm systems in cable ducts. Separate ducts are used for high voltage electrical cables.

nderneath the city’s pop-up-book skyline lies a sprawling subway system. Transporting nearly two Ubillion passengers annually, it operates 365 days a year, 24/7, on over 1,287 kilometres (800 miles) of track, connecting the boroughs of New York, except Staten Island. During the late 19th century, New York experienced a population boom due to the huge numbers of immigrants that arrived from Europe, meaning that almost 3.5 million people were living there by 1900. This placed a

54 How It Works Avenue’s subway, which began in 2007