The Elgin, Joliet & Eastern (EJ&E) Railway Bridge Number 552,
now owned and maintained by CN, was originally built in 1888
with a movable vertical lift span dating from the 1930s. Located
on the Illinois River approximately 20 miles southwest of
Joliet, Ill., the bridge had the distinction of being the most
frequently hit bridge spanning a navigable waterway in the
United States. It was struck by navigation traffic 170 times
between 1992 and 2001. CN made the decision to replace the
existing span with a longer span to increase the horizontal
clearance under the bridge. Collins was approached by the
project's contractor, McHugh Construction and its erection sub-
contractor, Danny's Construction, to evaluate the feasibility of
designing a temporary erection and launching runway structure
that could be used to support the erection of a replacement
1,100-ton bridge span and allow it to be moved into place. The
original lift span was 150 feet long, providing only 120 feet of
clearance for river traffic. The new mov