This bridge has a single rail line. The HPL in New Orleans has dual rail lines. The mention of 1989 may be from when the roadways were widened.
A real workhorse of a bridge! Two train tracks PLUS two vehicular lanes along both sides (4 total lanes for cars) Narrow lanes are less than 9' wide! Very scary with big trucks and cars and trains. I suggest adult diapers for the driver and passengers just keep eyes closed during crossing! See YouTube for videos.
Truss span lengths are 490', 848', 650', 848', and 490'. Engineering News Record had a detailed article on its design and construction.
This bridge was built in 1940. Great site!
This bridge was completed and open to traffic approximately in 1940 not 1989. My father helped construct the substructure of the bridge which is why I was born in Baton Rouge in 1938.