The Thomas Viaduct spans the

Patapsco River The Patapsco River mainstem is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 river in central Maryland that flows into the Chesapeake Bay. The river's tidal port ...

and Patapsco Valley between Relay, Maryland and

Elkridge, Maryland Elkridge is an unincorporated community and census-designated place (CDP) in Howard County, Maryland, United States. The population was 15,593 at the 2010 census. Founded early in the 18th century, Elkridge is adjacent to two other counties, A ...

, USA. It was commissioned by the

Baltimore and Ohio Railroad The Baltimore and Ohio Railroad was the first common carrier railroad and the oldest railroad in the United States, with its first section opening in 1830. Merchants from Baltimore, which had benefited to some extent from the construction of ...

(B&O); built between July 4, 1833, and July 4, 1835; and named for Philip E. Thomas, the company's first president. It remains the world's oldest multiple arched stone railroad bridge. At its completion, the Thomas Viaduct was the largest railroad bridge in the United States and the country's first multi-span

masonry Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

bridge A bridge is a structure built to span a physical obstacle (such as a body of water, valley, road, or rail) without blocking the way underneath. It is constructed for the purpose of providing passage over the obstacle, which is usually somethi ...

to be built on a curve. In 1964, it was designated as a

National Historic Landmark A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...

. In 2010, the bridge was designated as a National Historic Civil Engineering Landmark by the

American Society of Civil Engineers American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

. The

viaduct A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide va ...

is now owned and operated by

CSX Transportation CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. The railroad operates approximately 21,000 route miles () of track. ...

and still in use today, making it one of the oldest railroad bridges still in service.

Design

This Roman-arch stone bridge is divided into eight spans. It was designed by

Benjamin Henry Latrobe, II Benjamin Henry Latrobe II (December 19, 1806 – October 19, 1878) was an American civil engineer, best known for his railway bridges, and a railway executive. Personal life Born in Philadelphia, Pennsylvania on December 19, 1806, he was th ...

, then B&O's assistant engineer and later its chief engineer. The main design problem to overcome was that of constructing such a large bridge on a curve. The design called for several variations in span and

pier Seaside pleasure pier in England.html" ;"title="Brighton, England">Brighton, England. The first seaside piers were built in England in the early 19th century. A pier is a raised structure that rises above a body of water and usually juts out ...

widths between the opposite sides of the structure. This problem was solved by having the lateral pier faces laid out on radial lines, making the piers essentially wedge-shaped and fitted to the 4-degree curve. The viaduct was built by John McCartney of

Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...

, who received the contract after completing the Patterson Viaduct. Caspar Wever, the railroad's chief of construction, supervised the work. The span of the viaduct is long; the individual arches are roughly in span, with a height of from the water level to the base of the rail. The width at the top of the spandrel wall

copings Coping refers to conscious strategies used to reduce unpleasant emotions. Coping strategies can be cognitions or behaviours and can be individual or social. Theories of coping Hundreds of coping strategies have been proposed in an attempt to ...

is . The bridge is constructed using a rough-dressed

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; ...

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...

ashlar Ashlar () is finely dressed (cut, worked) stone, either an individual stone that has been worked until squared, or a structure built from such stones. Ashlar is the finest stone masonry unit, generally rectangular cuboid, mentioned by Vitr ...

from Patapsco River

quarries A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environ ...

, known as Woodstock granite. A wooden-floored walkway built for pedestrian and railway employee use is wide and supported by

cast iron Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impu ...

brackets and edged with ornamental cast iron railings. The viaduct contains of masonry and cost $142,236.51, equal to $ today.

History

The Baltimore and Ohio Railroad was one of the oldest railroads in the United States. Construction began on July 4, 1828, with the original route following the upper branch of the

which led west to

Ellicott's Mills Ellicott City is an unincorporated community and census-designated place in, and the county seat of, Howard County, Maryland, United States. Part of the Baltimore metropolitan area, its population was 65,834 at the 2010 census, making it the mo ...

(later renamed Ellicott City) from the lower Patapsco which is the "Basin" (now

Inner Harbor The Inner Harbor is a historic seaport, tourist attraction, and landmark of the city of Baltimore, Maryland. It was described by the Urban Land Institute in 2009 as "the model for post-industrial waterfront redevelopment around the world". The ...

) at downtown Baltimore and the Baltimore Harbor and Port of the lower river estuary leading southeast 15 miles to flow into the

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the ...

. (''See Baltimore Terminal Subdivision and

Old Main Line Subdivision The Old Main Line Subdivision is a railroad line owned and operated by CSX Transportation in the U.S. state of Maryland. The line runs from Relay (outside Baltimore) west to Point of Rocks, and was once the main line of the Baltimore and Ohio Ra ...

.'') In 1835 the

Washington Branch Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

was constructed, including the Thomas Viaduct. This new line branched at

Relay A relay Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off A relay is an electrically operated swit ...

, the site of a former

post road A post road is a road designated for the transportation of postal mail. In past centuries, only major towns had a post house and the roads used by post riders or mail coaches to carry mail among them were particularly important ones or, due ...

hotel and changing point for stage horses. The 1830s Relay House served as a hotel until it was replaced by the $50,078.41 (equal to $ today) Viaduct Hotel in 1872. The Gothic combination railroad station and hotel operated until 1938 and was torn down in 1950. When the Thomas Viaduct was completed, a

obelisk An obelisk (; from grc, ὀβελίσκος ; diminutive of ''obelos'', " spit, nail, pointed pillar") is a tall, four-sided, narrow tapering monument which ends in a pyramid-like shape or pyramidion at the top. Originally constructed by An ...

with the names of the builder, directors of the railroad, the

architect An architect is a person who plans, designs and oversees the construction of buildings. To practice architecture means to provide services in connection with the design of buildings and the space within the site surrounding the buildings that h ...

(engineer) and others associated with the viaduct was erected at the east end in Relay, by builder John McCartney. On one side the monument reads: ''The Thomas Viaduct, Commenced July 4, 1833 Finished, July 4, 1835''. He also celebrated the completed work by having his men kneel on the deck of the viaduct while mock " baptizing" them with a pint of

whiskey Whisky or whiskey is a type of distilled alcoholic beverage made from fermented grain mash. Various grains (which may be malted) are used for different varieties, including barley, corn, rye, and wheat. Whisky is typically aged in wooden c ...

. Until after the

American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by state ...

, the B&O was the only railroad into Washington, D.C., thus the Thomas Viaduct was essential for supply trains to reach the capital of the Union during that conflict. To prevent sabotage, the bridge was heavily guarded by Union troops stationed along its length. In 1929, extensive mortar work on the masonry was carried out, and again in 1937. To counteract deterioration of the masonry, the Thomas Viaduct underwent more cosmetic upgrades in 1938 performed by the B&O Maintenance of Way Department. The work consisted primarily to improve facilities for drainage, relocation of loose arch ring stones and the application of a

grout Grout is a dense fluid which hardens to fill gaps or used as reinforcement in existing structures. Grout is generally a mixture of water, cement and sand, and is employed in pressure grouting, embedding rebar in masonry walls, connecting sec ...

mixture to the stone spandrels filling. Nevertheless, the bridge is still indicative of the way in which the B&O track and major structures were put down in the most permanent manner possible. At an unknown date, railing blocks were removed from the north side of the deck and a bracketed walkway added giving more lateral clearance. Little work had been done on the viaduct until the repairs of 1937–1938 which, according to a 1949 report by the Chief Engineer of the B&O, would keep future maintenance to a minimum. From the 1880s to the 1950s, Thomas Viaduct carried B&O's famed ''

Royal Blue Line The ''Royal Blue'' was the Baltimore and Ohio Railroad (B&O)'s flagship passenger train between New York City and Washington, D.C., in the United States, beginning in 1890. The Baltimore-based B&O also used the name between 1890 and 1917 fo ...

'' passenger trains between New York and Washington. Until the late 1960s, the bridge also carried B&O passenger trains traveling to points west of Washington, such as the '' Capital Limited'' to

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = List of sovereign states, Count ...

and the '' National Limited'' to St. Louis. With the advent of

Amtrak The National Railroad Passenger Corporation, doing business as Amtrak () , is the national passenger railroad company of the United States. It operates inter-city rail service in 46 of the 48 contiguous U.S. States and nine cities in Canada ...

on May 1, 1971, B&O ended its passenger train service, except for local Baltimore–Washington commuter trains. In 1986, CSX acquired the B&O and all of its trackage, including the Thomas Viaduct. Today, MARC's "Camden Line" train service runs daily trains over the Viaduct. ''See'' Capital Subdivision. During design and construction, the Thomas Viaduct was nicknamed "Latrobe's Folly" after the designer Benjamin Latrobe II, because at the time many doubted that it could even support its own weight. Contrary to these predictions, the Thomas Viaduct survived the great flood of 1868 as well as

Hurricane Agnes Hurricane Agnes in 1972 was the costliest hurricane to hit the United States at the time, causing an estimated $2.1 billion in damage. The hurricane's death toll was 128. The effects of Agnes were widespread, from the Caribbean to Canada, ...

in 1972, two floods that wiped out the Patapsco Valley and destroyed nearly everything in their path; and to this day it continues to carry 300- ton (270

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

)

diesel locomotive A diesel locomotive is a type of railway locomotive in which the prime mover is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving whe ...

s passengers and heavy freight

traffic Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation. Traffic laws govern and regulate traffic, while rules of the road include traffi ...

. The bridge was designated a

on January 28, 1964, and and administratively listed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artist ...

on October 15, 1966. In 2010, the bridge designated as a National Historic Civil Engineering Landmark by the

. In 2014 and 2015, the non-profit historic preservation organization Preservation Howard County placed the Viaduct on its list of the top 10 endangered historic places in Howard County. The Patapsco Heritage Greenway group announced plans to add handrails to the bridge in 2015.

References and footnotes

External links

National Historic Landmark informationThe Thomas Viaduct At Relay Maryland
at archive.org * * - includes 1978 photo
Rasmussen, Frederick N. "Thomas Viaduct celebrates its 175th anniversary in July," ''The Baltimore Sun'', Saturday, June 19, 2010.American Society of Civil Engineers landmark information
*
Many historic and contemporary photos and images of the Thomas Viaduct
{{Authority control Baltimore and Ohio Railroad bridges Bridges completed in 1835 Crossings of the Patapsco River Railroad bridges on the National Register of Historic Places in Maryland CSX Transportation bridges Historic Civil Engineering Landmarks National Historic Landmarks in Maryland Railroad bridges in Maryland Viaducts in the United States Bridges in Baltimore County, Maryland Bridges in Howard County, Maryland Historic American Engineering Record in Maryland Elkridge, Maryland History of rail transportation in the United States Railroad-related National Historic Landmarks National Register of Historic Places in Baltimore County, Maryland Stone arch bridges in the United States 1835 establishments in Maryland

Design

History

See also

References and footnotes

External links