the genius of a suspension bridge is that you can hang the bridge from above
that you can hang the bridge from above
that you can hang the bridge from above but then of course that raises a whole
but then of course that raises a whole
but then of course that raises a whole new set of challenges how do you hang a
new set of challenges how do you hang a
new set of challenges how do you hang a bridge from above well you have to begin
bridge from above well you have to begin
bridge from above well you have to begin with towers Engineers use huge towers on
with towers Engineers use huge towers on
with towers Engineers use huge towers on either end of the bridge to suspend a
either end of the bridge to suspend a
either end of the bridge to suspend a flat roadway from
flat roadway from
flat roadway from arcing cables which are encased in 60000
arcing cables which are encased in 60000
arcing cables which are encased in 60000 ton stone blocks called a garages on
ton stone blocks called a garages on
ton stone blocks called a garages on either Shore smaller cables called
either Shore smaller cables called
either Shore smaller cables called suspenders hang down from the main
suspenders hang down from the main
suspenders hang down from the main cables and hold up the roadway the heavy
cables and hold up the roadway the heavy
cables and hold up the roadway the heavy weight of the road pulls down on the
weight of the road pulls down on the
weight of the road pulls down on the cables but the Anchorage’s keep the
cables but the Anchorage’s keep the
cables but the Anchorage’s keep the cables pulled taut holding the road up
cables pulled taut holding the road up
cables pulled taut holding the road up the combined forces push down on the
the combined forces push down on the
the combined forces push down on the towers compressing them into a solid
towers compressing them into a solid
towers compressing them into a solid rigid mass
since the towers cables and Anchorage’s
since the towers cables and Anchorage’s do all the work of holding up the
do all the work of holding up the
do all the work of holding up the roadway additional pillars underneath
roadway additional pillars underneath
roadway additional pillars underneath aren’t needed keeping the river clear
aren’t needed keeping the river clear
aren’t needed keeping the river clear it’s an ingenious way to make a bridge
it’s an ingenious way to make a bridge
it’s an ingenious way to make a bridge and it also sort of seems to defy nature
and it also sort of seems to defy nature
and it also sort of seems to defy nature because there doesn’t seem to be any way
because there doesn’t seem to be any way
because there doesn’t seem to be any way that it’s being held up before now no
that it’s being held up before now no
that it’s being held up before now no one has dared used these engineering
one has dared used these engineering
one has dared used these engineering Marvel’s to cross a river this wide the
Marvel’s to cross a river this wide the
Marvel’s to cross a river this wide the Brooklyn bridges center span will need
Brooklyn bridges center span will need
Brooklyn bridges center span will need to be over 1500 feet 50 percent longer
to be over 1500 feet 50 percent longer
to be over 1500 feet 50 percent longer than any suspension bridge ever built
than any suspension bridge ever built
than any suspension bridge ever built connecting City Hall in Manhattan with
connecting City Hall in Manhattan with
connecting City Hall in Manhattan with downtown Brooklyn it seems like an
downtown Brooklyn it seems like an
downtown Brooklyn it seems like an impossible job but one man in America is
impossible job but one man in America is
impossible job but one man in America is up to the challenge a civil engineer
up to the challenge a civil engineer
up to the challenge a civil engineer named John Augustus Roebling even at one
named John Augustus Roebling even at one
named John Augustus Roebling even at one of the river’s narrowest points the
of the river’s narrowest points the
of the river’s narrowest points the bridge will require a center span that
bridge will require a center span that
bridge will require a center span that will stretch a staggering fifteen
will stretch a staggering fifteen
will stretch a staggering fifteen hundred ninety five and a half feet
hundred ninety five and a half feet
hundred ninety five and a half feet he will need 14,000 miles of wire to
he will need 14,000 miles of wire to
he will need 14,000 miles of wire to make the four main cables it hangs from
make the four main cables it hangs from
make the four main cables it hangs from to hold all that up he designs towers of
to hold all that up he designs towers of
to hold all that up he designs towers of stone taller than almost every building
stone taller than almost every building
stone taller than almost every building in the city but then tragedy strikes in
in the city but then tragedy strikes in
in the city but then tragedy strikes in 1869 while making final sightings for
1869 while making final sightings for
1869 while making final sightings for the bridge roebling’s foot is crushed by
the bridge roebling’s foot is crushed by
the bridge roebling’s foot is crushed by a ferry slamming into its slip his toes
a ferry slamming into its slip his toes
a ferry slamming into its slip his toes are amputated and he dies soon after of
are amputated and he dies soon after of
are amputated and he dies soon after of an infection
an infection
an infection one of the largest engineering projects
one of the largest engineering projects
one of the largest engineering projects ever attempted is internally
ever attempted is internally
ever attempted is internally but salvation is found close to home his
but salvation is found close to home his
but salvation is found close to home his son Washington Roebling must take his
son Washington Roebling must take his
son Washington Roebling must take his father’s place as chief engineer finally
father’s place as chief engineer finally
father’s place as chief engineer finally the massive effort is ready to begin on
the massive effort is ready to begin on
the massive effort is ready to begin on January 3rd 1870 the first of a
January 3rd 1870 the first of a
January 3rd 1870 the first of a workforce that would reach nearly 1,000
workforce that would reach nearly 1,000
workforce that would reach nearly 1,000 men report to duty their first challenge
men report to duty their first challenge
men report to duty their first challenge is to erect the massive gothic arches
is to erect the massive gothic arches
is to erect the massive gothic arches that will one day become one of the
that will one day become one of the
that will one day become one of the bridges most iconic features but their
bridges most iconic features but their
bridges most iconic features but their foundations must rest on solid ground at
foundations must rest on solid ground at
foundations must rest on solid ground at river bottom to be sturdy
river bottom to be sturdy
river bottom to be sturdy that means Robley must somehow send men
that means Robley must somehow send men
that means Robley must somehow send men up to 80 feet underwater to dig away the
up to 80 feet underwater to dig away the
up to 80 feet underwater to dig away the riverbed down to bedrock Roebling turns
riverbed down to bedrock Roebling turns
riverbed down to bedrock Roebling turns to a risky new device an open bottom
to a risky new device an open bottom
to a risky new device an open bottom blocks of wood and iron called a caisson
blocks of wood and iron called a caisson
blocks of wood and iron called a caisson pneumatic caissons are basically large
pneumatic caissons are basically large
pneumatic caissons are basically large boxes that are placed upside down so
boxes that are placed upside down so
boxes that are placed upside down so that what would normally be the bottom
that what would normally be the bottom
that what would normally be the bottom of the boxes up at the top and the open
of the boxes up at the top and the open
of the boxes up at the top and the open bottom is facing down into the water
bottom is facing down into the water
bottom is facing down into the water sunk to the bottom of the river highly
sunk to the bottom of the river highly
sunk to the bottom of the river highly pressurized air is pumped into the open
pressurized air is pumped into the open
pressurized air is pumped into the open area forcing the water out men climb
area forcing the water out men climb
area forcing the water out men climb inside through airlocks to work in the
inside through airlocks to work in the
inside through airlocks to work in the craft pressurized space some compare it
craft pressurized space some compare it
craft pressurized space some compare it to hell unbearably hot and humid
to hell unbearably hot and humid
to hell unbearably hot and humid in danger from both fire and drought men
in danger from both fire and drought men
in danger from both fire and drought men spend a year toiling in these case odds
spend a year toiling in these case odds
spend a year toiling in these case odds digging away at a rate of more than a
digging away at a rate of more than a
digging away at a rate of more than a foot per day at the riverbed beneath
foot per day at the riverbed beneath
foot per day at the riverbed beneath them it was a challenge like no one had
them it was a challenge like no one had
them it was a challenge like no one had ever taken on before every day they
ever taken on before every day they
ever taken on before every day they would go down there through airlocks and
would go down there through airlocks and
would go down there through airlocks and gave with picks and shovels and slowly
gave with picks and shovels and slowly
gave with picks and shovels and slowly but surely go down through the riverbed
but surely go down through the riverbed
but surely go down through the riverbed down to bedrock
but the pressurized air that keeps the
but the pressurized air that keeps the water out also leads to a mysterious
water out also leads to a mysterious
water out also leads to a mysterious sickness
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