e-mosty June 2018 American Bridges American Bridges | Page 12

Figure 16: Steel girders
Figure 17: The project´s first steel girder assembly is slowly
lowered to its final location atop a pair of concrete piers
More than 100,000 tons of steel girders went into the
project. With the distance between pier caps
extending as far as 400 feet, individual girders were
assembled into groups (typically of three) on land,
floated down river via barge and lifted into place.
Atop the girders deck panels were installed. They
form a base for the driving surface.
Figure 18: The I Lift NY super crane places the new
bridge´s first pier cap with exact precision
The girder assemblies include infrastructure to carry
communications, electrical power, water and
compressed air to support bridge operations.
Larger girders and deck segments are lifted with the
I Lift NY which is a floating crane with lifting capacity
of up to 1,900 tons (the largest girder weighs 1,100
tons, largest approach pile cap 600 tons) and with
328-foot lift arm.
Figure 20: Installation of concrete road deck panels
Building the bridge requires more than 300,000 cubic
yards of concrete. TZC decided – in order to avoid
using local roads – to utilize three floating concrete
batch plants on the Hudson River, Figures 21 and 22.
Each floating batch plant is about 60 feet wide and
200 feet long and produces an average of 125 cubic
yards of concrete per hour.
Crushed stone from a nearby quarry is delivered by
barge. The materials are mixed in precise proportions
by an on-board operator. The final concrete mixture is
then pumped with a specialized hose to the various
sections of the bridge.
← Figure 19: The I Lift NY super crane - moments before raising
a pair of precast pile caps, each weighing 550 tons
2/2018