Manayunk Bridge
Encyclopedia
The Manayunk Bridge is a historic bridge in Pennsylvania
across the Schuylkill River
and adjacent Schuylkill Canal
between Bala Cynwyd
, Montgomery County
and the Manayunk
neighborhood of Philadelphia.
, it is notable as a large concrete
open spandrel arch bridge
built on a reverse curve
, earning both the current bridge and its 1883 wrought-iron-truss predecessor the nickname of "S-Bridge." The bridge's challenging geometry was executed by T. L. Eyre, a Philadelphia contractor. Another notable feature is the saw-toothed construction joints along a 65-degree skew
.
In 1976, SEPTA purchased the bridge for its Cynwyd Line
. Weather-related expansion and contraction of the bridge, coupled with the shedding of pieces of concrete due to spall
ing, led to its closure by SEPTA on October 25, 1986. Fearing demolition, a rehabilitation campaign commenced in 1996 and completed in 1999. During the rehab, it was revealed that SEPTA had been overzealous in their closure of the bridge, as the internal steel reinforcement was not compromised as SEPTA had suggested. Further investigation by Urban Engineers determined that the bridge was safe and only needed surface work to stop the spalling. In 1999, construction finished on a project to stabilize and refurbish the viaduct, but train service did not return to Ivy Ridge as expected.
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...
across the Schuylkill River
Schuylkill River
The Schuylkill River is a river in Pennsylvania. It is a designated Pennsylvania Scenic River.The river is about long. Its watershed of about lies entirely within the state of Pennsylvania. The source of its eastern branch is in the Appalachian Mountains at Tuscarora Springs, near Tamaqua in...
and adjacent Schuylkill Canal
Schuylkill Canal
Schuylkill Canal is the common, but technically inaccurate, name for the Schuylkill Navigation, a 19th-century commercial waterway in and along the Schuylkill River in the U.S. state of Pennsylvania. The "canal" was actually a system of interconnected man-made canals and slack-water pools in the...
between Bala Cynwyd
Bala Cynwyd, Pennsylvania
Bala Cynwyd is a community in Lower Merion Township which is located on the Main Line in southeastern Pennsylvania, bordering the western edge of Philadelphia at US Route 1 . It was originally two separate towns, Bala and Cynwyd, but is commonly treated as a single community...
, Montgomery County
Montgomery County, Pennsylvania
Montgomery County is a county located in the U.S. state of Pennsylvania, in the United States. As of 2010, the population was 799,874, making it the third most populous county in Pennsylvania . The county seat is Norristown.The county was created on September 10, 1784, out of land originally part...
and the Manayunk
Manayunk, Philadelphia, Pennsylvania
Manayunk is a neighborhood in the northwestern section of the city of Philadelphia, Pennsylvania in the United States. Located on the banks of the Schuylkill River, it contains the first canal begun in the United States . The area's name comes from the language of the Lenape Indians...
neighborhood of Philadelphia.
History
Built by the former Schuylkill Valley Division of the Pennsylvania RailroadPennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....
, it is notable as a large concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
open spandrel arch bridge
Arch bridge
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...
built on a reverse curve
Reverse curve
In civil engineering, a reverse curve is a section of the horizontal alignment of a highway or railroad route in which a curve to the left or right is followed immediately by a curve in the opposite direction....
, earning both the current bridge and its 1883 wrought-iron-truss predecessor the nickname of "S-Bridge." The bridge's challenging geometry was executed by T. L. Eyre, a Philadelphia contractor. Another notable feature is the saw-toothed construction joints along a 65-degree skew
Skew arch
A skew arch is a method of construction that enables an arch bridge to span an obstacle at some angle other than a right angle. This results in the faces of the arch not being perpendicular to its abutments and its plan view being a parallelogram, rather than the rectangle that is the plan view of...
.
In 1976, SEPTA purchased the bridge for its Cynwyd Line
Cynwyd Line
The Cynwyd Line is a SEPTA Regional Rail line running from Center City Philadelphia to Cynwyd in Montgomery County.Originally known as the Ivy Ridge Branch, service was truncated on October 25, 1986 from Ivy Ridge to its current terminus at Cynwyd....
. Weather-related expansion and contraction of the bridge, coupled with the shedding of pieces of concrete due to spall
Spall
Spall are flakes of a material that are broken off a larger solid body and can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure...
ing, led to its closure by SEPTA on October 25, 1986. Fearing demolition, a rehabilitation campaign commenced in 1996 and completed in 1999. During the rehab, it was revealed that SEPTA had been overzealous in their closure of the bridge, as the internal steel reinforcement was not compromised as SEPTA had suggested. Further investigation by Urban Engineers determined that the bridge was safe and only needed surface work to stop the spalling. In 1999, construction finished on a project to stabilize and refurbish the viaduct, but train service did not return to Ivy Ridge as expected.
Manayunk Bridge Rail Trail
SEPTA had little interest in restoring passenger train service after rehabilitation was completed. Indeed, many attempts were made in 1996 to terminate Cynwyd service altogether due to its lower ridership (the 1986 cutback closed three of the line's six stations). A small but strong (and politically connected) rider protest resulted in SEPTA not only retaining service, but adding additional trains to Cynwyd by 1997. However, train service was not re-extended over the bridge as expected. Though there have been repeated calls to restore the discontinued service between Cynwyd and Ivy Ridge, SEPTA permanently dropped plans for restoration in 2008 when all 2.5 miles of trackage north of Cynwyd was removed between 2008 and June 2010 for the Cynwyd Heritage Rail Trail and Ivy Ridge Rail Trail. The Manayunk Bridge is slated to also be converted into a rail trail connecting the two aforementioned rail trails.Further reading
- Harry Garforth, Jr., Rails Through Manayunk, Silver Brook Junction Publishing Company, Telford, PA. 1999.
- Michael Bezilla, Electric Traction on the Pennsylvania Railroad 1895-1968, Penn State University, 1988.