I did the same thing you did as a kid. I walked across the B&O railroad, now CSX, bridge in my town of Defiance, Ohio. It is a high level Warren deck truss that sees double the train traffic now than in the 1980's. Boy, I remember my Grandmother Sweinhagen getting extremely mad at me. God rest her soul. I took plenty a risk being curious about that big railroad bridge.
I played on this bridge as a kid even though my dad told me not too.
I believe that you have totally misidentified this bridge.
The bridge is not an ex ITC or BN structure. It is the former C&A/Alton RR/GM&ORR then ICG Old Main bridge from Wann to downtown Alton.
At one time the track extended all the to Godfrey to reconnect with the Alton Cutoff between Wann Tower and Godfrey Tower that goes via the College Ave. Amtrak Station.
The rail line over this bridge is now owned by the Union Pacific after they acquired if from the SP/SSW back in 1996.
It is used several nights a week for the UP Wann Switcher to service both the north side of what is left of the steel mill and the Flour mill in Alton.
At one time in the late 1960's early 1970's as many as 5 switch jobs a day used the bridge at least twice during each shift to take outbound frt. cars to Wann Yard and then deliver inbound cars to the many rail served industries then in the area.
Alton in the 1960's was the 3rd largest Industrial Area in the State of Illinois following behind only Chicago and Rockford in manufacturing output.
The former ITC bridge over Woodriver Creek is located about a mile south of the bridge pictured and west of the brass mill.
It is still used by the Norfolk Southern daily to access their Federal Yard located at the foot of Cut Street near the site of the former Alton Box Board Plant.
The Burlington (CB&Q) and later BN used the ITC bridge to get to the former M&IB&B Alton Bridge over the Mississippi River to run to connect with their own trackage at West Alton, MO.
The M&IB&B Alton Bridge was dismantled when made redundant by the BN merger and the new Alton Lock and Dam in 1990.
An excellent book on the history of the Alton Bridge is available from Mr. Ronald Schmitt, a former Altonian and current resident of Urbana, IL
It is titled: SPANNING THE MISSISSIPPI: The Alton Bridge and Its Railroad, ISBN 978-0-9826603-0-0
The CB&Q line from Beardstown to East Alton did have a bridge at one time over Woodriver Creek that was located just west of the Western Winchester Cartridge (Olin) powder mill plant in East Alton, and east of the GM&O (UP) Cutoff bridge over the same creek. The CB&Q Beardstown Line connected with the Big 4 (NYC) trackage at that point to run to Wann Tower and then on the Joint GM&O/NYC tracks to E. St. Louis.
It was abandoned by the CB&Q in 1980 in favor of trackage rights on Conrail (later MP/UP) from Toland, IL to Lenox Tower in Mitchell, IL to reach the East St. Louis terminal.
I am the co-founder of the GM&O Historical Society, grew up in Alton, worked for the GM&O/ICG and retired from the UP as a Train Dispatcher in 2006. My HO Scale model railroad is based on the ITC and GM&O in the Alton Area between about 1949 and 1965 and I have a considerable amount of research, maps, photos, aerial photos, railroad track profiles and timetables to back up my modeling efforts.
Please feel free to consult me on any historical matters concerning the railroad history of the Alton Area.
Robert F. Schramm