Edward
January 19th, 2003, 05:20 PM
Text from nycroads.com:
http://www.nycroads.com/crossings/high
SUPPLYING AN EMERGING METROPOLIS WITH WATER: During the first decades of the nineteenth century, the rapid development of New York City required the construction of a far-reaching system to obtain clean water. Fires, pestilence and corruption ensued while the city's wells either ran dry or had become contaminated, providing impetus for the city's leaders to provide a long-term solution.
In 1833, the city established a Water Commission to plan a water supply system. Among the options for the water supply were the Bronx River, Morrisania Creek, Rye Pond and the Croton River. Major David B. Douglass, a hero from the War of 1812 and a West Point engineering professor, supported using the Croton River. Although this was the most expensive option, it could supply 40 million gallons of water a day to the city. The Croton Reservoir was also situated at a high level, so that it could supply the upper floors of city buildings.
On June 2, 1835, Douglass was appointed chief engineer of the Croton Aqueduct project. One of the centerpieces of the project was a high-level, multiple-arch bridge that was to "lend to New York some of the grandeur of imperial Rome." However, Douglas encountered early difficulties in Westchester County, the source of the Croton system. Local farmers demanded not only generous sums from the city, but also free water from the reservoirs. Nevertheless, the Water Commission suspected that the delays were due to corruption, and fired Douglas from his position.
In 1836, the Water Commission tapped John B. Jervis, an engineer with experience constructing the Delaware and Hudson Canal (where the town of Port Jervis was named after him) and the Erie Canal, was tapped to head the Croton Aqueduct project. Initially, Jervis was hesitant to undertake a project to construct a high-level arch bridge over the Harlem River. Jervis, who believed that municipal structures should be economical, instead argued for a low-level arched bridge with a 50-foot-draw.
However, local citizens argued that since the Croton Aqueduct was the greatest public work of its time, it deserved a monumental bridge - which was advanced earlier by Douglas - worthy of its nature. The "High Bridge" faction lobbied successfully for the New York State Legislature to pass a law requiring the aqueduct to either pass beneath the river by means of pipes, or to be placed on a high-level structure. Jervis reluctantly went along, and in 1837, the Water Commission accepted the High Bridge proposal. Construction of the bridge began two years later.
DESIGN AND CONSTRUCTION: Jervis tapped James Renwick, Jr., a young engineer, to assist in the construction of the High Bridge. Renwick later went out to oversee the construction of St. Patrick's Cathedral in Manhattan.
From end to end, the High Bridge measures 1,450 feet in length. The original design consisted of 15 circular masonry arches, eight of which were 80 feet long (over the Harlem River and the New York Central-Harlem Line), and seven of which were 50 feet long (all of them over land). The arches over the Harlem River had a clearance of 114 feet above mean high water. Two 33-inch-diameter pipes were laid within the arch walls to conduct the water. Gate chambers at either end of the bridge regulated the flow of water across the bridge. Finally, a pedestrian walkway was constructed 135 feet above the Harlem River valley.
While the High Bridge took its design cues from the Roman aqueducts, it included the most contemporary design conventions of its time. The loads from above the arch ring were made hollow, having only the material needed for strength. Passages were provided from the spandrel walls to the hollow space in the piers to allow water that might fall between the parapets to exit into an opening in the pier near the high water line of the river. This follow space between the sidewalls of the arch reduced the dead weight.
In 1848, the High Bridge went into the service for the first time. When it was completed, the masonry Croton Aqueduct wound its way for more than 40 miles through forests, villages and cities from a dam on the Croton River to two high-walled, rectangular reservoirs in Manhattan, the Receiving Reservoir at Yorkhill (the site of the Central Park Great Lawn) and the Distributing Reservoir at Murray Hill (the site of the New York Public Library).
DESIGN CHANGES ON THE HIGH BRIDGE: In 1860, a third, 90-inch-diameter pipe was added to the High Bridge, and the floor of the bridge was raised to accommodate it. In 1872, the High Bridge Watchtower was erected to equalize water pressure from the Croton Aqueduct.
While the third pipe supplied the burgeoning population of Greater New York, still more water was necessary. In the early years of the twentieth century, the Water Commission oversaw construction of the New Croton Aqueduct and Catskill Reservoir systems. The New Croton Aqueduct system was completed in 1906, and the Catskill Reservoir system was completed in 1926.
*
The original Croton Aqueduct inside the High Bridge closed not because of any structural defects, but because of security risks. On February 3, 1917, the same day that the German ambassador was sent back when the United States entered World War I, the Water Commission shut down the aqueduct. With tunnels supplying the city's water, and the threat of sabotaging the aqueducts removed, it was now easier to patrol the water supply.
It was also at this time that the Army Corps of Engineers expressed concern that the High Bridge's narrow 80-foot-wide arches obstructed the navigation of large craft on the Harlem River. The Corps served notice to New York City officials, demanding that the bridge arches over the navigable channel have a horizontal clearance of at least 100 feet. To provide this minimum clearance, the Corps proposed removing two of the alternate bridge piers. Vertical clearances were to remain at 114 feet above mean high water.
Responding to the Corps' requests, the New York City Commissioner of Plant and Structures advocated demolishing the High Bridge on the grounds that water no longer flowed through the structure, and that it was more expedient to demolish the bridge than to remodel it.
Many professional organizations, along with ordinary New Yorkers, derided both the Army Corps of Engineers and the New York City Board of Plant and Structures proposals. The American Institute of Consulting Engineers, the American Institute of Architects, the American Society of Civil Engineers and the American Institute of Fine Arts all favored preserving the bridge. In a 1923 editorial in Scientific American magazine, destruction of the High Bridge was regarded as "an act of vandalism without precedent in the history of our country."
The Army Corps of Engineers, the Board of Plant and Structures and citizen groups reached a compromise on the future of the high bridge. The plan involved removing five of the eight 80-foot-wide arches, replacing them with a single steel-plate girder arch that had a lateral clearance of 360 feet. The $1 million replacement project was completed in 1927.
The High Bridge Watchtower continued to function as a pumping station until it ceased operating in 1949.
PART OF "FORGOTTEN" NEW YORK? Although it was designated a landmark by a landmark by the New York Landmarks Preservation Commission in 1970, the High Bridge has fallen into neglect in recent decades. That same year, the walkway was closed when a pedestrian threw a rock onto a Circle Line boat below, killing a tourist on the boat.
However, the High Bridge may not be forgotten for much longer. In the late 1990's, Henry Stern, New York City parks commissioner, has announced it will pursue funding to reopen the unused High Bridge walkway. The Parks Department, which now has jurisdiction over the bridge, plans the following rehabilitation projects on the High Bridge:
The department plans to spend $30 million to repair the main span. The work, which would focus on peeling paint, corrosion, loose mortar and frozen expansion joints, would be funded by state and Federal transportation and preservation dollars.
In a separate project, the department plans to rehabilitate the existing stairways, build new bicycle ramps, and install soft floodlights on the span. This project is estimated to cost $6 million.
No construction dates have been set for these projects. Reopening the span would require a safety inspection, which would cost an additional $1 million. The last detailed inspection in 1986 showed that the bridge was safe for pedestrian travel.
The view of the High Bridge (http://www.wirednewyork.com/bridges/high_bridge/default.htm) from High Bridge Park.
http://www.wirednewyork.com/bridges/high_bridge/images/high_bridge_park_18jan03.jpg
The view of the High Bridge (http://www.wirednewyork.com/bridges/high_bridge/default.htm) from Harlem River Drive.
http://www.wirednewyork.com/bridges/high_bridge/images/high_bridge_harlem_river_jervis_31march02.jpg
The view of the High Bridge (http://www.wirednewyork.com/bridges/high_bridge/default.htm) from Harlem River Drive.
http://www.wirednewyork.com/bridges/high_bridge/images/high_bridge_harlem_river_drive_31march02.jpg
http://www.nycroads.com/crossings/high
SUPPLYING AN EMERGING METROPOLIS WITH WATER: During the first decades of the nineteenth century, the rapid development of New York City required the construction of a far-reaching system to obtain clean water. Fires, pestilence and corruption ensued while the city's wells either ran dry or had become contaminated, providing impetus for the city's leaders to provide a long-term solution.
In 1833, the city established a Water Commission to plan a water supply system. Among the options for the water supply were the Bronx River, Morrisania Creek, Rye Pond and the Croton River. Major David B. Douglass, a hero from the War of 1812 and a West Point engineering professor, supported using the Croton River. Although this was the most expensive option, it could supply 40 million gallons of water a day to the city. The Croton Reservoir was also situated at a high level, so that it could supply the upper floors of city buildings.
On June 2, 1835, Douglass was appointed chief engineer of the Croton Aqueduct project. One of the centerpieces of the project was a high-level, multiple-arch bridge that was to "lend to New York some of the grandeur of imperial Rome." However, Douglas encountered early difficulties in Westchester County, the source of the Croton system. Local farmers demanded not only generous sums from the city, but also free water from the reservoirs. Nevertheless, the Water Commission suspected that the delays were due to corruption, and fired Douglas from his position.
In 1836, the Water Commission tapped John B. Jervis, an engineer with experience constructing the Delaware and Hudson Canal (where the town of Port Jervis was named after him) and the Erie Canal, was tapped to head the Croton Aqueduct project. Initially, Jervis was hesitant to undertake a project to construct a high-level arch bridge over the Harlem River. Jervis, who believed that municipal structures should be economical, instead argued for a low-level arched bridge with a 50-foot-draw.
However, local citizens argued that since the Croton Aqueduct was the greatest public work of its time, it deserved a monumental bridge - which was advanced earlier by Douglas - worthy of its nature. The "High Bridge" faction lobbied successfully for the New York State Legislature to pass a law requiring the aqueduct to either pass beneath the river by means of pipes, or to be placed on a high-level structure. Jervis reluctantly went along, and in 1837, the Water Commission accepted the High Bridge proposal. Construction of the bridge began two years later.
DESIGN AND CONSTRUCTION: Jervis tapped James Renwick, Jr., a young engineer, to assist in the construction of the High Bridge. Renwick later went out to oversee the construction of St. Patrick's Cathedral in Manhattan.
From end to end, the High Bridge measures 1,450 feet in length. The original design consisted of 15 circular masonry arches, eight of which were 80 feet long (over the Harlem River and the New York Central-Harlem Line), and seven of which were 50 feet long (all of them over land). The arches over the Harlem River had a clearance of 114 feet above mean high water. Two 33-inch-diameter pipes were laid within the arch walls to conduct the water. Gate chambers at either end of the bridge regulated the flow of water across the bridge. Finally, a pedestrian walkway was constructed 135 feet above the Harlem River valley.
While the High Bridge took its design cues from the Roman aqueducts, it included the most contemporary design conventions of its time. The loads from above the arch ring were made hollow, having only the material needed for strength. Passages were provided from the spandrel walls to the hollow space in the piers to allow water that might fall between the parapets to exit into an opening in the pier near the high water line of the river. This follow space between the sidewalls of the arch reduced the dead weight.
In 1848, the High Bridge went into the service for the first time. When it was completed, the masonry Croton Aqueduct wound its way for more than 40 miles through forests, villages and cities from a dam on the Croton River to two high-walled, rectangular reservoirs in Manhattan, the Receiving Reservoir at Yorkhill (the site of the Central Park Great Lawn) and the Distributing Reservoir at Murray Hill (the site of the New York Public Library).
DESIGN CHANGES ON THE HIGH BRIDGE: In 1860, a third, 90-inch-diameter pipe was added to the High Bridge, and the floor of the bridge was raised to accommodate it. In 1872, the High Bridge Watchtower was erected to equalize water pressure from the Croton Aqueduct.
While the third pipe supplied the burgeoning population of Greater New York, still more water was necessary. In the early years of the twentieth century, the Water Commission oversaw construction of the New Croton Aqueduct and Catskill Reservoir systems. The New Croton Aqueduct system was completed in 1906, and the Catskill Reservoir system was completed in 1926.
*
The original Croton Aqueduct inside the High Bridge closed not because of any structural defects, but because of security risks. On February 3, 1917, the same day that the German ambassador was sent back when the United States entered World War I, the Water Commission shut down the aqueduct. With tunnels supplying the city's water, and the threat of sabotaging the aqueducts removed, it was now easier to patrol the water supply.
It was also at this time that the Army Corps of Engineers expressed concern that the High Bridge's narrow 80-foot-wide arches obstructed the navigation of large craft on the Harlem River. The Corps served notice to New York City officials, demanding that the bridge arches over the navigable channel have a horizontal clearance of at least 100 feet. To provide this minimum clearance, the Corps proposed removing two of the alternate bridge piers. Vertical clearances were to remain at 114 feet above mean high water.
Responding to the Corps' requests, the New York City Commissioner of Plant and Structures advocated demolishing the High Bridge on the grounds that water no longer flowed through the structure, and that it was more expedient to demolish the bridge than to remodel it.
Many professional organizations, along with ordinary New Yorkers, derided both the Army Corps of Engineers and the New York City Board of Plant and Structures proposals. The American Institute of Consulting Engineers, the American Institute of Architects, the American Society of Civil Engineers and the American Institute of Fine Arts all favored preserving the bridge. In a 1923 editorial in Scientific American magazine, destruction of the High Bridge was regarded as "an act of vandalism without precedent in the history of our country."
The Army Corps of Engineers, the Board of Plant and Structures and citizen groups reached a compromise on the future of the high bridge. The plan involved removing five of the eight 80-foot-wide arches, replacing them with a single steel-plate girder arch that had a lateral clearance of 360 feet. The $1 million replacement project was completed in 1927.
The High Bridge Watchtower continued to function as a pumping station until it ceased operating in 1949.
PART OF "FORGOTTEN" NEW YORK? Although it was designated a landmark by a landmark by the New York Landmarks Preservation Commission in 1970, the High Bridge has fallen into neglect in recent decades. That same year, the walkway was closed when a pedestrian threw a rock onto a Circle Line boat below, killing a tourist on the boat.
However, the High Bridge may not be forgotten for much longer. In the late 1990's, Henry Stern, New York City parks commissioner, has announced it will pursue funding to reopen the unused High Bridge walkway. The Parks Department, which now has jurisdiction over the bridge, plans the following rehabilitation projects on the High Bridge:
The department plans to spend $30 million to repair the main span. The work, which would focus on peeling paint, corrosion, loose mortar and frozen expansion joints, would be funded by state and Federal transportation and preservation dollars.
In a separate project, the department plans to rehabilitate the existing stairways, build new bicycle ramps, and install soft floodlights on the span. This project is estimated to cost $6 million.
No construction dates have been set for these projects. Reopening the span would require a safety inspection, which would cost an additional $1 million. The last detailed inspection in 1986 showed that the bridge was safe for pedestrian travel.
The view of the High Bridge (http://www.wirednewyork.com/bridges/high_bridge/default.htm) from High Bridge Park.
http://www.wirednewyork.com/bridges/high_bridge/images/high_bridge_park_18jan03.jpg
The view of the High Bridge (http://www.wirednewyork.com/bridges/high_bridge/default.htm) from Harlem River Drive.
http://www.wirednewyork.com/bridges/high_bridge/images/high_bridge_harlem_river_jervis_31march02.jpg
The view of the High Bridge (http://www.wirednewyork.com/bridges/high_bridge/default.htm) from Harlem River Drive.
http://www.wirednewyork.com/bridges/high_bridge/images/high_bridge_harlem_river_drive_31march02.jpg