In the mid-19th century, suspension bridges were collapsing all across Europe.
十九世纪中期,欧洲不断发生悬索桥坍塌事故。
Their industrial cables frayed during turbulent weather and snapped under the weight of their decks.
用于悬索桥的工业钢缆因善变的天气而受损,支撑不住桥的重量而断裂。
So when a German-American engineer named John Roebling
当一位名叫约翰·罗布林的德裔美国工程师
proposed building the largest and most expensive suspension bridge ever conceived over New York's East River, city officials were understandably skeptical.
提出横跨纽约东河建造一座最大且最贵的吊桥,纽约的市政官员们纷纷对此表示了怀疑。
But Manhattan was increasingly overcrowded, and commuters from Brooklyn clogged the river.
但是当时的曼哈顿人口过于密集,而且来自布鲁克林的通勤者都需要经过这条河。
In February of 1867, the government approved Roebling's proposal.
于是在1867年2月,政府批准了罗布林的建议。
To avoid the failures of European bridges, Roebling designed a hybrid bridge model.
为了避免类似欧洲悬索桥坍塌的事故再次发生,罗布林设计了一个混合桥梁模型。
From suspension bridges, he incorporated large cables supported by central pillars and anchored at each bank.
他将悬索桥上由中心桥塔支撑的大型钢缆固定在每个河岸上。
This design was ideal for supporting long decks, which hung from smaller vertical cables.
这样的设计将大桥悬挂在一排较短的垂直钢缆上,有助于支撑桥面。
But Roebling's model also drew from cable-stayed bridges.
罗布林的灵感还来自斜拉桥。
These shorter structures held up their decks with diagonal cables that ran directly to support towers.
这些较短的构造有助于直接与桥塔相连的斜拉索固定桥面。
By adding these additional cables, Roebling improved the bridge's stability, while also reducing the weight on its anchor cables.
通过添加这些钢缆,罗布林增强了桥的稳定性,同时减少了施加于锚缆的重量。
Similar designs had been used for some other bridges but the scope of Roebling's plan here dwarfed them all.
虽然相似的设计已经被采用过,但是罗布林这次的计划使其他设计都相形见绌。
His new bridge's deck spanned over 480 meters -- 1.5 times longer than any previously built suspension bridge.
他设计的桥面长达480米--比之前的任何一座悬索桥都要长1.5倍。
Since standard hemp rope would tear under the deck's 14,680 tons, his proposal called for over 5,600 kilometers of metal wire to create the bridge's cables.
因为普通麻绳会在近1.5万吨的桥面重量下断裂,罗布林建议使用5.6公里长的钢丝制作悬索桥的钢缆。
To support all this weight, the towers would need to stand over 90 meters above sea level -- making them the tallest structures in the Western Hemisphere.
为了承受这个重量,这些支撑桥塔必须高出海平面90米以上--使得这座桥成为了西半球最高的建筑。
Roebling was confident his design would work, but while surveying the site in 1869, an incoming boat crushed his foot against the dock.
罗布林对自己的设计很有信心,但是当他在1869年进行实地勘察时,一艘渡船冲向码头,他的脚严重受伤。
Within a month, tetanus had claimed his life. Fortunately, John Roebling's son, Washington, was also a trained engineer and took over his father's role.
不到一个月,他就因破伤风离世。幸运的是,罗布林的儿子华盛顿也是一位训练有素的工程师,因此他接替了父亲的工作。
The following year, construction on the tower foundations finally began.
在接下来的一年,桥基的建设工作终于开始了。
This first step in construction was also the most challenging.
建桥的第一步是最具挑战性的。
Building on the rocky river bed involved the use of a largely untested technology: pneumatic caissons.
为了在布满石块的河床上建造桥基,华盛顿采用了未经测试的技术:气压沉箱。
Workers lowered these airtight wooden boxes into the river, where a system of pipes pumped pressurized air in and water out.
工人们把很多密封的木箱放进河里,用一套管道注入压缩空气,将水排出。
Once established, air locks allowed workers to enter the chamber and excavate the river bottom.
这一项工作完成后,工人才能进入沉箱里挖掘河底。
They placed layers of stone on top of the caisson as they dug.
他们挖掘河底的同时,把一层层石头堆积在箱体顶部。
When it finally hit the bedrock, they filled it with concrete, becoming the tower's permanent foundation.
当沉箱最终到达基岩时,工人用混凝土把沉箱填满,塔基也随之建成。
Working conditions in these caissons were dismal and dangerous.
但是沉箱里的工作条件是非常危险的。
Lit only by candles and gas lamps, the chambers caught fire several times, forcing them to be evacuated and flooded.
由于只能用蜡烛和煤气灯照明,在沉箱里发生过几次火灾,导致工人被迫撤离,或是因海水涌入而丧命。
Even more dangerous was a mysterious ailment called "the bends."
更危险的是一种叫做“the bends”的神秘疾病。
Today, we understand this as decompression sickness, but at the time, it appeared to be an unexplainable pain or dizziness that killed several workmen.
今天,我们将其理解为减压病,但是在当时,这种未知的疾病带来了无法解释的疼痛或头晕,许多工人因此丧命。
In 1872, it nearly claimed the life of the chief engineer.
1872年,减压病也差点要了总工程师的命。
Washington survived, but was left paralyzed and bedridden. Yet once again, the Roeblings proved indomitable.
虽然华盛顿活下来了,但是从此瘫痪,卧床不起。然而,事实再一次证明,罗布林家族是不屈不挠的。
Washington's wife Emily not only carried communications between her husband and the engineers, but soon took over day-to-day project management.
华盛顿的妻子艾米丽不仅负责起了丈夫和工程师之间的沟通,还接管了日常的管理工作。
Unfortunately, the bridge's troubles were far from over. By 1877, construction was over budget and behind schedule.
不幸的是,这座桥的麻烦还远未结束。到1877年,桥塔的建造超出了预算,进度落后。
Worse still, it turned out the bridge's cable contractor had been selling them faulty wires.
更糟糕的是,这座桥的钢缆供应商其实一直在向他们供应不合格的钢丝。
This would have been a fatal flaw if not for the abundant failsafes in John Roebling's design.
多亏了罗布林设计中包含的多重安全保障,才没有酿成大祸。
After reinforcing the cables with additional wires, they suspended the deck piece by piece.
使用额外的钢丝加固了钢缆之后,工人们把桥面一个一个悬吊起来。
It took 14 years, the modern equivalent of over 400 million dollars, and the life's work of three different Roeblings,
这项工程历时十四年,造价相当于现在的4亿美元,汇聚了罗夫林家族三代人的心血,
but when the Brooklyn Bridge finally opened on May 24, 1883, its splendor was undeniable.
但当布鲁克林大桥终于在1883年5月24日竣工时,它的辉煌壮丽是不可否认的。
Today, the Brooklyn Bridge still stands atop its antique caissons, supporting the gothic towers and intersecting cables that frame a gateway to New York City.
今天的布鲁克林大桥依然矗立在古老沉箱上,支撑着哥特式桥塔和交叉的钢缆,肩负着连通纽约市的使命。