Caissons and Towers
In 1870, construction began on the caissons
to build the massive 300-foot tall towers
to support
the suspension cables.
The towers were the tallest structures in New York City
for over thirty years.
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The caisson
BrooklynBridgeCaisson.jpg; In: Mid-Manhattan Picture Collection New York City -- bridge construction; Published Date: 1883
Library Division: Mid-Manhattan Library / Picture Collection; Description: 1 folder (4 pictures); Specific Material Type: Prints;Item Physical Description: 1 print : b&w ; 9 x 12 cm. (3 1/4 x 4 3/4 in.)
Notes: Written on border: "May 1883." "Building Brooklyn Bridge."; Collection Guide: The Picture Collection of the New York Public Library; Digital Image ID: 800508; Digital Record ID: 708880; NYPL Call Number: PC NEW YC-Bri
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New York Harbor, as seen from the Brooklyn tower of the suspension-bridge.
NYHarborBrooklyntower1873.jpg; Creator(s): Bonwill, Charles E. H. , b. ca. 1836 -- Artist; In: Mid-Manhattan Picture Collection New York City -- harbor; Published Date: 1873
Library Division: Mid-Manhattan Library / Picture Collection; Specific Material Type: Prints; Item Physical Description: 1 print : b&w ; 25 x 36 cm. (9 3/4 x 14 1/4 in.)
Notes: Printed on border: "From a sketch by C.E.H. Bonwill. -- [See page 966.]"; Digital Image ID: 805042; Digital Record ID: 692326; NYPL Call Number: PC NEW YC-Harb
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From Harper's Magazine (1871):
A Harper's Magazine journalist wrote of a visit to the caissons, describing the air lock as "an iron can or jar of large size, sufficient for a dozen
men to stand in erect...like meats for preservation." When compressed air was let into the lock, "the compression of the common air...in the chamber
develops an oppressive heat, like that of an oven, while the increasing density of the air begins to be painfully felt in pressure upon the organs
of respiration, and particularly in the ears."
One visitor "was so much overcome by the heat...that he insisted on being let out before the lock was filled." The relatively cooler air of the
caisson came as a relief.
Inside the caisson, pulses speeded up, then slowed to as few as 15 beats per minute. It was difficult to speak and impossible to whistle because
the muscles of respiration were unequal to the task. The tongue felt slow and cumbersome, the skin itched, noses bled easily. Deep voices became
shrill trebles, a powder blast - used to pulverize boulders - had the sharp crack of a pistol shot.
But all of that was merely discomfort. A far more dangerous foe lurked in the gloomy recesses of the caissons: Under pressure, the bloodstream
dissolved enormous quantities of gases. When a worker returned to normal pressure through the airlock, this overload of gases came out of solution
and formed bubbles in the bloodstream, causing excruciating pain and damage to the joints.
It was called caisson disease or "the bends," but it wasn't understood. It was supposed that pressure merely drove the blood deeper inside the body,
leading to congestion in the spinal cord and brain. Medical opinion of the day could only suggest that workers should eat and rest well.
Frank Harris arrived in New York City from his native Ireland in 1871. The fifteen-year-old moved into a Brooklyn boarding house where a fellow
resident - Mike - told him of jobs paying five dollars a day for working in the Brooklyn Bridge caissons. We join Frank's story as he and Mike go
to the construction site:
"Next morning Mike took me to Brooklyn Bridge soon after five o'clock to see the contractor; he wanted to engage Mike at once but shook his head over
me. 'Give me a trial,' I pleaded; 'you'll see I'll make good.' After a pause, 'O.K.,' he said; 'four shifts have gone down already underhanded: you may try.'
In the bare shed where we got ready, the men told me no one could do the work for long without getting the 'bends'; the 'bends' were a sort of convulsive
fit that twisted one's body like a knot and often made you an invalid for life. They soon explained the whole procedure to me. We worked, it appeared, in
a huge bell-shaped caisson of iron that went to the bottom of the river and was pumped full of compressed air to keep the water from entering it from
below: the top of the caisson is a room called the 'material chamber,' into which the stuff dug out of the river passes up and is carted away. On the
side of the caisson is another room, called the 'air-lock,' into which we were to go to be 'compressed.' As the compressed air is admitted, the blood
keeps absorbing the gasses of the air till the tension of the gasses in the blood becomes equal to that in the air: When this equilibrium has been
reached, men can work in the caisson for hours without serious discomfort, if sufficient pure air is constantly pumped in. It was the foul air that
did the harm, it appeared. 'If they'd pump in good air, it would be O.K; but that would cost a little time and trouble, and men's lives are cheaper.'
When we went into the 'air-lock' and they turned on one air-lock after another of compressed air, the men put their hands to their ears and I soon
imitated them, for the pain was very acute. When the air was fully compressed, the door of the air-lock opened at a touch and we all went down to work
with pick and shovel on the gravelly bottom.
My headache soon became acute. The six of us were working naked to the waist in a small iron chamber with a temperature of about 80 degrees Fahrenheit:
in five minutes the sweat was pouring from us, and all the while we were standing in icy water that was only kept from rising by the terrific air pressure.
No wonder the headaches were blinding. The men didn't work for more than ten minutes at a time, but I plugged on steadily, resolved to prove myself and
get constant employment; only one man, a Swede named Anderson, worked at all as hard.
The amount done each week was estimated, he told me, by an inspector. Anderson was known to the contractor and received half a wage extra as head of our gang. He assured me I could stay as long as I liked, but he advised me to leave at the end of a month: it was too unhealthy.
...One day, just as the 'decompression' of an hour and a half was ending, an Italian named Manfredi fell down and writhed about, knocking his face on the
floor till the blood spurted from his nose and mouth. When we got him into the shed, his legs were twisted like plaited hair. The surgeon had him taken to
the hospital. I made up my mind that a month would be enough for me." |
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