[00:00.29]Lesson 17
[00:02.83]The longest suspension bridge in the world
[00:12.30]How is the bridge supported?
[00:16.67]Verrazano, an Italian about whom little is known, sailed into New York Harbour in 1524 and named it Angouleme.
[00:28.43]He described it as 'a very agreeable situation located within two small hills in the midst of which flowed a great river.'
[00:39.43]Though Verrazano is by no means considered to be a great explorer, his name will probably remain immortal,
[00:48.07]for on November 21st, 1964, the longest suspension bridge in the world was named after him.
[00:59.32]The Verrazano Bridge, which was designed by Othmar Ammann, joins Brooklyn to Staten Island.
[01:07.72]It has a span of 4, 260 feet.
[01:12.52]The bridge is so long that the shape of the earth had to be taken into account by its designer.
[01:19.92]Two great towers support four huge cables.
[01:25.53]The towers are built on immense underwater platforms made of steel and concrete.
[01:32.28]The platforms extend to a depth of over 100 feet under the sea.
[01:37.65]These alone took sixteen months to build.
[01:41.48]Above the surface of the water, the towers rise to a height of nearly 700 feet.
[01:48.25]They support the cables from which the bridge has been suspended.
[01:52.62]Each of the four cables contains 26, 108 lengths of wire.
[01:59.62]It has been estimated that if the bridge were packed with cars, it would still only be carrying a third of its total capacity.
[02:09.73]However, size and strength are not the only important things about this bridge.
[02:15.93]Despite its immensity, it is both simple and elegant,
[02:21.49]fulfilling its designer's dream to creat 'an enormous object drawn as faintly as possible'.
1524年，一位鲜为人知的意大利人维拉萨诺驾船驶进纽约港，并将该港名为安古拉姆。他对该港作了这样的描述：“地理位置十分适宜，位于两座小山的中间，一条大河从中间流过”。虽然维拉萨诺绝对算不上一个伟大的探险家，但他的名字将流芳百世，因为1964年11月21日建成的一座世界上最长的吊桥是以他的名字命名。
维拉萨诺大桥由奥斯马.阿曼设计，连结着布鲁克林与斯塔顿岛，桥长4,260英尺。由于桥身太长，设计者不得不考虑了地表的形状。两座巨塔支撑着4根粗大的钢缆。塔身建在巨大的水下钢盘混凝土平台上。平台深入海底100英尺。仅这两座塔就花了16个月才建成。塔身高出水面将近700英尺。高塔支撑着钢缆，而钢缆又悬吊着大桥，4根钢缆中的每根由26，108股钢绳组成。据估计，若桥上摆满了汽车，也只不过是桥的总承载力的1/3。然而，这座桥重要特点不仅是它的规模与强度。尽管此桥很大，但它的结构简单，造型优美，实现了设计者企图创造一个“尽量用细线条勾画出一个庞然大物”的梦想。