One of the most epic engineering feats in history - Alex Gendler

譯者: Lilian Chiu 審譯者: Helen Chang

In the mid-19th century,

在十九世紀中期，

suspension bridges were collapsing all across Europe.

歐洲各地都有吊橋垮掉。

Their industrial cables frayed during turbulent weather

在猛烈的天氣下， 它們的工業纜繩會被磨損，

and snapped under the weight of their decks.

橋面的重量會讓它們斷裂。

So when a German-American engineer named John Roebling

當德裔美國工程師約翰·羅布林

proposed building the largest and most expensive suspension bridge

提出要建造跨越紐約東河

ever conceived over New York’s East River,

最大、最貴的吊橋時，

city officials were understandably skeptical.

不難理解市府官員都抱持懷疑。

But Manhattan was increasingly overcrowded,

但曼哈頓越來越過度擁擠，

and commuters from Brooklyn clogged the river.

來自布魯克林的通勤者 堵塞過河的交通。

In February of 1867, the government approved Roebling’s proposal.

1867 年 2 月，

政府核准了羅布林的提案。

To avoid the failures of European bridges,

為了重蹈歐洲橋樑的覆轍，

Roebling designed a hybrid bridge model.

羅布林設計了一種 混合式的橋樑模型。

From suspension bridges,

以吊橋為基礎， 他再整合了大纜繩，

he incorporated large cables supported by central pillars and anchored at each bank.

由中央樑柱支撐， 並固定在每邊的河岸。

This design was ideal for supporting long decks,

這種設計非常適合支撐長的橋面。

which hung from smaller vertical cables.

橋面用較小的垂直纜繩懸吊。

But Roebling’s model also drew from cable-stayed bridges.

但羅布林的模型也參考了斜張橋。

These shorter structures held up their decks with diagonal cables

這類比較短的橋樑結構是用 對角線纜繩來撐住橋面，

that ran directly to support towers.

對角纜繩直接連結在支撐塔上。

By adding these additional cables, Roebling improved the bridge’s stability,

羅布林加上這些額外的纜繩 來改善橋樑的穩定度，

while also reducing the weight on its anchor cables.

同時也能減少其錨索的重量。

Similar designs had been used for some other bridges

也有些其他橋樑用到類似的設計，

but the scope of Roebling’s plan here dwarfed them all.

但羅布林的計畫規模大到 讓它們都相形失色。

His new bridge’s deck spanned over 480 meters—

他的新橋面長度 超過四百八十公尺——

1.5 times longer than any previously built suspension bridge.

比過去建造過的任何吊橋 都要長一倍半以上。

Since standard hemp rope would tear under the deck’s 14,680 tons,

14680 公噸的橋面 就足以扯斷標準的麻繩，

his proposal called for over 5,600 kilometers of metal wire

他的提案會需要超過 5600 公里的金屬纜線

to create the bridge’s cables.

來製成該橋樑的纜繩。

To support all this weight,

要支撐這座橋的全部重量，

the towers would need to stand over 90 meters above sea level—

塔的高度必須要 超過水平面 90 公尺——

making them the tallest structures in the Western Hemisphere.

讓這些塔成為西半球最高的建築。

Roebling was confident his design would work,

羅布林很有自信， 相信他的設計行得通，

but while surveying the site in 1869,

但 1869 年，他去實地調查時，

an incoming boat crushed his foot against the dock.

一艘迎面而來的船 讓他的腳撞上了碼頭。

Within a month, tetanus had claimed his life.

一個月內，破傷風 就帶走了他的性命。

Fortunately, John Roebling's son, Washington, was also a trained engineer

幸運的是，約翰羅布林的兒子 華盛頓也是受過訓練的工程師，

and took over his father’s role.

接下了他父親的角色。

The following year, construction on the tower foundations finally began.

隔年終於開始建造塔的地基。

This first step in construction was also the most challenging.

建造的第一步 也是最有挑戰性的一步。

Building on the rocky river bed involved the use of a largely untested technology:

要在多岩的河床上施工會需要 用到一項幾乎沒有測試過的技術：

pneumatic caissons.

氣壓沉箱。

Workers lowered these airtight wooden boxes into the river,

工人會把這些密閉的 木盒子降到河裡，

where a system of pipes pumped pressurized air in and water out.

導管系統會將壓縮空氣 打入，把水抽出。

Once established, air locks allowed workers to enter the chamber

完成之後，空氣閉鎖 讓工人可以進入箱室內，

and excavate the river bottom.

可以開始開鑿河底。

They placed layers of stone on top of the caisson as they dug.

當他們挖掘時，他們會在 沉箱上面舖上數層石頭。

When it finally hit the bedrock, they filled it with concrete,

當沉箱終於碰到床岩時， 他們會把沉箱灌滿混凝土，

becoming the tower’s permanent foundation.

成為塔的永久地基。

Working conditions in these caissons were dismal and dangerous.

在這些沉箱中的工作條件 既危險又會讓人抑鬱。

Lit only by candles and gas lamps, the chambers caught fire several times,

只有來自蠟燭和瓦斯燈的光線，

有好幾次箱室都發生火災，

forcing them to be evacuated and flooded.

不得不將箱室撤離並灌水。

Even more dangerous was a mysterious ailment called "the bends."

更危險的是一種叫做 「減壓病」的神秘疾病。

Today, we understand this as decompression sickness,

現今，我們了解 這種病是壓力減少造成，

but at the time, it appeared to be an unexplainable pain or dizziness

但在當時，它就是種 無法解釋的痛楚或暈眩，

that killed several workmen.

造成數名工人死亡。

In 1872, it nearly claimed the life of the chief engineer.

1872 年，連總工程師 都差點因此喪命。

Washington survived, but was left paralyzed and bedridden.

華盛頓活下來了， 但卻從此癱瘓臥床。

Yet once again, the Roeblings proved indomitable.

但，羅布林家族再次 證明他們的不屈不撓。

Washington’s wife Emily not only carried communications

華盛頓的妻子艾蜜莉不僅負責起

between her husband and the engineers,

她丈夫和工程師之間的溝通，

but soon took over day-to-day project management.

很快的，她還接手了 每日的專案計畫管理。

Unfortunately, the bridge’s troubles were far from over.

不幸的是，這座橋的 麻煩還不只如此。

By 1877, construction was over budget and behind schedule.

1877 年，工程超支且進度落後。

Worse still, it turned out the bridge’s cable contractor

更糟糕的是，結果發現 該橋的纜繩包商

had been selling them faulty wires.

一直在賣有問題的纜線給他們。

This would have been a fatal flaw if not for the abundant failsafes

若不是約翰·羅布林的設計中 有足夠的故障保護機制，

in John Roebling’s design.

這就會是個致命的瑕疵。

After reinforcing the cables with additional wires,

在用額外的纜線來強化纜繩之後，

they suspended the deck piece by piece.

他們將橋面一片一片懸吊起來。

It took 14 years, the modern equivalent of over 400 million dollars,

花了十四年的時間，換成 現在的幣值要價超過四億美金，

and the life’s work of three different Roeblings,

這也是三位羅布林人生的傑作，

but when the Brooklyn Bridge finally opened on May 24, 1883,

但，當布魯克林大橋終於 在 1883 年 5 月 24 日開放時，

its splendor was undeniable.

它的光輝是無可否認的。

Today, the Brooklyn Bridge still stands atop its antique caissons,

現今，布魯克林大橋仍然 屹立在它的古老沉箱上，

supporting the gothic towers and intersecting cables

它們支撐著這些哥德式 高塔和交錯的纜繩，

that frame a gateway to New York City.

成為進入紐約市的大門。