| [00:01.080] |
--- lesson 17 The longest suspension bridge in the world |
| [00:07.320] |
--- Listen to the tape then answer the question below. |
| [00:12.920] |
--- How is the bridge supported? |
| [00:17.520] |
Verrazano, an Italian about whom little is known, sailed into New York Harbour in 1524 and named it Angouleme. |
| [00:28.640] |
He described it as 'a very agreeable situation located within two small hills in the midst of which flowed a great river.' |
| [00:37.560] |
Though Verrazano is by no means considered to be a great explorer, his name will probably remain immortal, |
| [00:45.680] |
for on November 21st, 1964, the longest suspension bridge in the world was named after him. |
| [00:54.280] |
The Verrazano Bridge, which was designed by Othmar Ammann, joins Brooklyn to Staten Island. |
| [01:02.400] |
It has a span of 4,260 feet. |
| [01:06.880] |
The bridge is so long that the shape of the earth had to be taken into account by its designer. |
| [01:13.880] |
Two great towers support four huge cables. |
| [01:18.320] |
The towers are built on immense underwater platforms made of steel and concrete. |
| [01:24.520] |
The platforms extend to a depth of over 100 feet under the sea. |
| [01:29.720] |
These alone took sixteen months to build. |
| [01:33.520] |
Above the surface of the water, the towers rise to a height of nearly 700 feet. |
| [01:40.000] |
They support the cables from which the bridge has been suspended. |
| [01:44.720] |
Each of the four cables contains 26,108 lengths of wire. |
| [01:51.760] |
It has been estimated that if the bridge were packed with cars, it would still only be carrying a third of its total capacity. |
| [02:00.120] |
However, size and strength are not the only important things about this bridge. |
| [02:06.520] |
Despite its immensity, it is both simple and elegant, |
| [02:10.840] |
fulfilling its designer's dream to create 'an enormous object drawn as faintly as possible'. |
