"The Thomas Viaduct was the first masonry arch bridge built on a curve and remains the largest of its type" [Bridge Hunter]
|Mark Hinsdale posted|
"The Orange Blossom Special"
In April, 1986, a pair of blue & gray GP40-2's belonging to Richmond, Fredericksburg & Potomac (RF&P) bring the southbound Orange Blossom Special (OBSS) across historic Thomas Viaduct at Relay MD, on the Baltimore & Ohio main line just outside Baltimore. By this time, the "Blossom," inaugurated in 1982 by Seaboard System, had expanded from its original Orlando to Wilmington DE market to operate from Tampa to the New York-New Jersey area, as a result of disasterous back to back freeze years in Florida, wiping out a sizable portion of the citrus traffic the specialty train carried. It was also during 1985 and '86 that RF&P power began to appear fairly often on the train, so that locomotive exchanges associated with the need to comply with RF&P's automatic train control (ATC) requirements on its line could be avoided. It was a relatively short period of time to catch these RF&P locomotives on the OBS, as steady installation of ATC equipment on newer, more powerful CSX locomotives would eventually render the practice obsolete. Photo by Mark Hinsdale
Francis Otterbein posted three photos with the comment:
The Thomas Viaduct is a stone masonry railroad bridge that spans the Patapsco River and the Patapsco Valley gorge between the towns of Relay and Elkridge, Maryland and is the first multispan masonry bridge constructed in the United States to be built on a curve. It is the world's second oldest railroad bridge still in use (the oldest is the Carrollton Viaduct located a few miles north) and is the world's largest multiple arched stone railroad bridge built on a curve. Check the website below for more photos and drawings of the viaduct