July 4, 2004 Ramps, west platform extension, counterweights and pier
construction
This morning's sun was warm and inviting and as I bicycled under the approaches
I was a symmetry that just asked for a photo. Here are the under bellies of
the west approach - first, from the west and then to the east.
The west approach
Extending to anchor 6 on the west platform: waiting for cross members
Eastward side of the west platform: ready to add the 6th anchor
and cross beams which
are waiting on a nearby barge.
Note the stack of concrete blocks adjacent to the
4th anchor (counting from the pylon out) in the left photo. The total weight
is 125 tons and this stack of blocks rides on a carriage that can be moved
in response to changing load conditions.
There appear to actually be 2 stacks of concrete blocks (counterweights) one
located near the pylon (right photo) and one between the 3rd and 4th
anchors (see below). These were not obvious in the
June 6 photos.
A delicate balancing act:
When biking back across the bridge I
notices a stack of what appear to be concrete blocks on the east platform
resting on the west pylon. I got to thinking - hmmm - because the
east platform is 5 cable stays long and the west platform is 6 cable stays
long, then probably this is one of several counterweights necessary
to keep the bridge platform balanced?
Note the stack of concrete blocks adjacent to the 4th
left cable anchor and the hint of a symmetric stack of blocks adjacent
to the 4th right cable anchor (marked by another green porta-potty).
Compare the location with their
location on July 11 (below).
The Post and Courier (July 18) explains the counterweight management as
follows:
"Counterweight system: Huge diesel engines drive 3 carts loaded with concrete
slabs. Each car weights 125 tons and is located on top of the two pulley
systems per tower. Workers will position the series of cards during construction
to keep the bridge balanced as the roadway extends out across the river. The
carts also will be used to stabilize the road deck during a hurricane."
The east pylon - 5 anchors and growing (but more slowly than the west pylon).
