Patterson Viaduct

Template:Use mdy dates Template:Use American English Template:Infobox Bridge The Patterson Viaduct was built by the Baltimore and Ohio Railroad (B&O) as part of its Old Main Line during May to December 1829. The viaduct spanned the Patapsco River at Ilchester, Maryland. It was heavily damaged by a flood in 1868 and subsequently replaced with other structures. In 2006, it was restored to limited service when a footbridge was built atop the surviving arch and abutments.

History and design

Original bridge

The Patterson Viaduct was one of three (along with the Carrollton Viaduct and Oliver Viaduct) constructed for the first phase of the railroad, which ran Template:Convert between Baltimore and Ellicott's Mills (today's Ellicott City). Similar in construction to the Carrollton Viaduct, the Patterson Viaduct was named for B&O director and well known civic leader and merchant William Patterson, who also donated land for Patterson Park in east Baltimore. It was designed by Caspar Wever and built under the supervision of John McCartney, one of Wever's assistants. McCartney's good work on the Patterson Viaduct was later rewarded with the contract to build the longer curving Thomas Viaduct downstream over the Patapsco at Relay in 1833–1835.

Constructed of granite blocks, the viaduct was about Template:Convert long, rising about Template:Convert above its foundations. It had four graduated arches: two of Template:Convert chord length each and two of Template:Convert chord length each. The two smaller side arches allowed the passage of two county roadways, one on each side of the river. The exterior surfaces of the granite blocks were rusticated.

Patterson ceremonially opened the viaduct on December 4, 1829, a year and a half after construction began on the line, the first in America. In 1830, the viaduct was part of the route used by the B&O's first horse-drawn carriage train to Ellicott's Mills inaugurating railway traffic.

Second bridge

The viaduct was almost totally destroyed in 1868 by a massive flood that devastated and wiped out numerous stone mills and industrial structures along the river. In 1869, it was replaced by a single-span Bollman truss of cast and wrought iron by Wendel Bollman, reusing the original roadway arch and upstream wing wall of the west abutment.

In 1903, the Bollman truss was supplanted when the track was moved to a new bridge and alignment about Template:Convert upstream with the opening of the Ilchester Tunnel.

Third bridge

File:Patterson Viaduct Footbridge 2020a.jpg

The new footbridge

File:Grist Mill Walking Bridge 02.JPG

The 2006 footbridge built on the original abutments

Today, all that remains of the original 1829 viaduct is the single arch that spanned the roadway on the west bank and the abutment on the east bank. The ruins were listed on the National Register of Historic Places on June 3, 1976. In 2006, a cable-stayed footbridge carrying the Grist Mill Trail, with a design that echoes the historic architecture and engineering of a Bollman Bridge, was added atop the abutments.

See also

• List of Howard County properties in the Maryland Historical Trust
• List of bridges documented by the Historic American Engineering Record in Maryland
• List of tunnels documented by the Historic American Engineering Record in Maryland
• List of bridges on the National Register of Historic Places in Maryland

External links

• Maryland Historical Trust, Crownsville, MD. Template:MHT url Accessed 2016-01-22.
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