Inclined Plane Bridge
Encyclopedia
The Inclined Plane Bridge is a 237 feet (72.2 m), Pennsylvania through truss bridge that spans Stonycreek River in Johnstown
, Cambria County
, in the U.S. state
of Pennsylvania
. It connects the city to the lower station of the Johnstown Inclined Plane
. The bridge was listed on the National Register of Historic Places
in 1988 and was documented by the Historic American Engineering Record
(HAER) in 1997.
on the Little Conemaugh River
, upstream of Johnstown, collapsed. The resulting deluge
devastated the city, killing over 2,000 people. As the city rebuilt, the Cambria Iron Company
started work on a residential development atop Yoder Hill, overlooking the city. To provide easy transportation across the steep slope for the residents of the new community of Westmont
, as well as to function as an escape route for future floods, the company opted to construct the Johnstown Inclined Plane
, a funicular. A bridge had to be built to connect Johnstown to the lower station of the incline, on the opposite side of Stonycreek River as the city.
Work started on the bridge on June 11, 1890, with excavation of the bridge's abutment
s finished a week later. By March 20, 1891, only the approach to the bridge remained to be completed. The bridge, officially, was opened on June 1, 1891, at the same time as the incline. On March 17, 1936, nearly 4,000 people crowded on the approach, the bridge, and numerous boats to escape to higher ground via the incline as Stoneycreek and Conemaugh
Rivers overflowed their banks. The floodwaters continued downstream and eventually reached Pittsburgh.
The Works Progress Administration
appropriated $17,812 in October 1936 to repair the bridge's approach and replace stringers, handrails and the road deck. The Pennsylvania Department of Highways, the predecessor to the Pennsylvania Department of Transportation
(PennDOT), acquired the bridge in 1964. It was listed on the National Register of Historic Places
on June 22, 1988. On September 1, 2000, PennDOT undertook a $2.3 million renovation of the bridge and the access road leading to it. Work was suspended from April to September 2001, to allow operation of the incline. The renovations were completed on December 14, 2001, after PennDOT finished repairs to the bridge deck.
and steel riveted together to form a Pennsylvania truss
. The Pennsylvania, or Petit, truss is "essentially a Pratt truss" with the outermost horizontal girders being "polygonal" and having "subdivided panels" to "stiffen the truss under heavy loads." At 237 feet (72.2 m) long, the Inclined Plane Bridge is relatively short for a Pennsylvania truss; bridges of this sort are generally 250 to 600 ft (76.2 to 182.9 ) long.
Johnstown, Pennsylvania
Johnstown is a city in Cambria County, Pennsylvania, United States, west-southwest of Altoona, Pennsylvania and east of Pittsburgh. The population was 20,978 at the 2010 census. It is the principal city of the Johnstown, Pennsylvania, Metropolitan Statistical Area, which includes Cambria County...
, Cambria County
Cambria County, Pennsylvania
Cambria County is a county located in the U.S. state of Pennsylvania. It comprises the Johnstown, Pennsylvania, Metropolitan Statistical Area. As of 2010, the population was 143,679....
, in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
. It connects the city to the lower station of the Johnstown Inclined Plane
Johnstown Inclined Plane
The Johnstown Inclined Plane is a funicular in Johnstown, Cambria County in the U.S. state of Pennsylvania. The incline and its two stations connect the city of Johnstown, situated in a valley at the confluence of the Stonycreek and the Little Conemaugh Rivers, to the borough of Westmont on Yoder...
. The bridge was listed on the National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
in 1988 and was documented by the Historic American Engineering Record
Historic American Buildings Survey
The Historic American Buildings Survey , Historic American Engineering Record , and Historic American Landscapes Survey are programs of the National Park Service established for the purpose of documenting historic places. Records consists of measured drawings, archival photographs, and written...
(HAER) in 1997.
History
On May 31, 1889, the South Fork DamSouth Fork Dam
The South Fork Dam was located on Lake Conemaugh, an artificial body of water located near South Fork, Pennsylvania, United States. On May 31, 1889, the South Fork Dam failed catastrophically and 20 million tons of water from Lake Conemaugh burst through and raced 14 miles downstream, causing the...
on the Little Conemaugh River
Little Conemaugh River
The Little Conemaugh River is a tributary of the Conemaugh River, approximately 30 mi long, in western Pennsylvania in the United States....
, upstream of Johnstown, collapsed. The resulting deluge
Johnstown Flood
The Johnstown Flood occurred on May 31, 1889. It was the result of the catastrophic failure of the South Fork Dam situated upstream of the town of Johnstown, Pennsylvania, USA, made worse by several days of extremely heavy rainfall...
devastated the city, killing over 2,000 people. As the city rebuilt, the Cambria Iron Company
Cambria Iron Company
Cambria Iron Company is a National Historic Landmark located in Johnstown, Pennsylvania. The company was founded in 1852 and made many important contributions to the iron and steel industry...
started work on a residential development atop Yoder Hill, overlooking the city. To provide easy transportation across the steep slope for the residents of the new community of Westmont
Westmont, Pennsylvania
Westmont is a borough in Cambria County, Pennsylvania, United States. It is part of the Johnstown, Pennsylvania Metropolitan Statistical Area. The population was 5,523 at the 2000 census.-Geography:...
, as well as to function as an escape route for future floods, the company opted to construct the Johnstown Inclined Plane
Johnstown Inclined Plane
The Johnstown Inclined Plane is a funicular in Johnstown, Cambria County in the U.S. state of Pennsylvania. The incline and its two stations connect the city of Johnstown, situated in a valley at the confluence of the Stonycreek and the Little Conemaugh Rivers, to the borough of Westmont on Yoder...
, a funicular. A bridge had to be built to connect Johnstown to the lower station of the incline, on the opposite side of Stonycreek River as the city.
Work started on the bridge on June 11, 1890, with excavation of the bridge's abutment
Abutment
An abutment is, generally, the point where two structures or objects meet. This word comes from the verb abut, which means adjoin or having common boundary. An abutment is an engineering term that describes a structure located at the ends of a bridge, where the bridge slab adjoins the approaching...
s finished a week later. By March 20, 1891, only the approach to the bridge remained to be completed. The bridge, officially, was opened on June 1, 1891, at the same time as the incline. On March 17, 1936, nearly 4,000 people crowded on the approach, the bridge, and numerous boats to escape to higher ground via the incline as Stoneycreek and Conemaugh
Conemaugh River
The Conemaugh River is a long tributary of the Kiskiminetas River in Westmoreland, Indiana, and Cambria counties in the U.S. state of Pennsylvania.- Course :...
Rivers overflowed their banks. The floodwaters continued downstream and eventually reached Pittsburgh.
The Works Progress Administration
Works Progress Administration
The Works Progress Administration was the largest and most ambitious New Deal agency, employing millions of unskilled workers to carry out public works projects, including the construction of public buildings and roads, and operated large arts, drama, media, and literacy projects...
appropriated $17,812 in October 1936 to repair the bridge's approach and replace stringers, handrails and the road deck. The Pennsylvania Department of Highways, the predecessor to the Pennsylvania Department of Transportation
Pennsylvania Department of Transportation
The Pennsylvania Department of Transportation oversees transportation issues in the Commonwealth of Pennsylvania. The administrator of PennDOT is the Pennsylvania Secretary of Transportation, currently Barry Schoch Presently, PennDOT supports over of state roads and highways, about 25,000...
(PennDOT), acquired the bridge in 1964. It was listed on the National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
on June 22, 1988. On September 1, 2000, PennDOT undertook a $2.3 million renovation of the bridge and the access road leading to it. Work was suspended from April to September 2001, to allow operation of the incline. The renovations were completed on December 14, 2001, after PennDOT finished repairs to the bridge deck.
Design
The Inclined Plane Bridge was made from of wrought ironWrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
and steel riveted together to form a Pennsylvania truss
Truss
In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...
. The Pennsylvania, or Petit, truss is "essentially a Pratt truss" with the outermost horizontal girders being "polygonal" and having "subdivided panels" to "stiffen the truss under heavy loads." At 237 feet (72.2 m) long, the Inclined Plane Bridge is relatively short for a Pennsylvania truss; bridges of this sort are generally 250 to 600 ft (76.2 to 182.9 ) long.
See also
- List of bridges on the National Register of Historic Places in Pennsylvania
- National Register of Historic Places listings in Cambria County, PennsylvaniaNational Register of Historic Places listings in Cambria County, PennsylvaniaThis is a list of the National Register of Historic Places listings in Cambria County, Pennsylvania.This is intended to be a complete list of the properties and districts on National Register of Historic Places in the Cambria County, Pennsylvania...