On Sat, 8 Jan 2011 15:47:13 -0800 (PST), Joe Cool
wrote:

Technically that new bridge is NOT a suspension bridge, but a cable-
stayed bridge.

Not quite. It is a sort of a hybrid between the classic suspension
bridge and the cable stayed bridge. If you look closely at the
pictures, you can see that all cables except the outer ones attach to
the outer cable. Here is a picture of another such bridge, where the
cable are clearly visible:

http://www.newsworld.co.kr/cont/0207/50.html

To carry on: This type of bridge can and has been built without the
"support bridge" to hold it up. I seem to recall that a similar
bridge was built some years ago across the Mississippi River without
support steel; but I could be mistaken.

The tallest bridge in the world, the Millau Viaduct, is a cable stayed
bridge. It was built using support towers between the actual towers,
but no support bridge.

To do so the towers are built first (as usual) and the road bed
sections cantilevered out from each side of the tower while supported
in position by a crane. At this point the cable stay for that section
is installed on each side of the tower to keep things in balance. The
crane is then moved to hoist the next section into position. Rinse and
repeat as required.

In the case of the Millau Viaduct, the road sections were slid in
place using a hydraulically operated wedge system, sliding on Teflon
bearings. This is probably why the intermediate support towers were
necessary.
--
RoRo