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Federal Highway Administration Research and Technology
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This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: FHWA-HRT-05-005 Date: May/June 2005|
Publication Number: FHWA-HRT-05-005
Issue No: Vol. 68 No. 6
Date: May/June 2005
The city of New York is preserving its historic East River Bridges through a successful collaboration with Federal and State agencies.
New York City's East River bridges are more than mere components in the city's highway infrastructure. The Brooklyn, Manhattan, Queensboro, and Williamsburg Bridges are New York City's red carpets, ushering residents, commuters, and visitors alike in grand style to and from Manhattan, the nerve center of the city. The four bridges, built between 1883 and 1909, have faithfully served travelers for more than a century.
|The Brooklyn Bridge, shown here looking west toward Manhattan, is one of New York City’s oldest and most famous bridges. After years of neglect, the Brooklyn Bridge and the other East River bridges now are receiving the preventive maintenance they need to ensure a long service life.|
Despite the functional and symbolic importance of the bridges, however, New York City's transportation budget, like those of other municipalities around the country, was insufficient for maintaining the structures adequately over the years. "Bridge maintenance often took a back seat to other things," says Russell Holcomb, deputy chief engineer for bridge maintenance inspection and operations with the New York City Department of Transportation (NYCDOT). "When money was tight in the city in the 1970s, maintenance of the bridges fell behind."
According to the 1999 NYCDOT report Preventive Maintenance Management System for New York City Bridges, prepared by a consortium of civil engineering departments from NYC colleges and universities, the city deferred maintenance for years because of budget shortfalls.
At the same time, Federal legislation funded the full replacement of bridges, but not maintenance. Local governments found it more cost effective to let bridge conditions decline rather than spend money from strained operating budgets to maintain them properly. Therefore, only those bridges with a direct source of income, such as toll bridges, received any consistent long-term preventive maintenance. "Bridge maintenance has always been low-profile work," says Holcomb. "If something has to slip, it's easier to let a maintenance program slip than a large capital construction project, which is more visible."
Eventually this neglect caused serious problems for the East River bridges. In 1981, a corroded stay cable on the Brooklyn Bridge snapped and killed a pedestrian. The incident raised concerns about the hazards of poor maintenance. And in 1988 the city closed the Williamsburg Bridge, citing concerns about its condition. "It was a bold decision to close the bridge," Holcomb says. "It took a lot of work by several agencies to identify all the problems. The bridge was out of service for several months. And from this whole process came the realization that the time had come to take more proactive steps toward maintaining [and preserving] these bridges."
THE EAST RIVER BRIDGES
The four East River bridges in New York City typically carry about 493,000 vehicles and 340,000 subway riders daily, and are expected to carry many more vehicles and subway passengers when a $2.8 billion rehabilitation program is completed in 2012. The Brooklyn and Manhattan Bridges connect Brooklyn to Lower Manhattan, the Williamsburg Bridge connects Brooklyn to Downtown Manhattan, and the Queensboro Bridge connects Queens to Midtown Manhattan and the Upper East Side.
The Brooklyn Bridge was constructed between 1870 and 1883, and opened to traffic on May 24, 1883. It was the first suspension bridge built in New York City and the most celebrated of the East River bridges. The bridge stretches 1,834 meters (6,016 feet) in length and rises 41 meters (135 feet) above the river channel, with four cables supporting the bridge deck. Its main span of 486 meters (1,596 feet) between towers was the world's longest at the time. The towers, with their Gothic arches and massive granite masonry, continue to be a powerful presence in the social and physical life of New York City.
When it first opened, the Brooklyn Bridge supported two lanes for cable cars and four lanes for horse-drawn vehicles. In 1898 the bridge was modified to accommodate four lanes for mass transit and two for other vehicles. Growing automobile use after World War II led to the complete removal of all tracks and the redesign of the truss carrying the roadway. Today the bridge carries six vehicular lanes.
Opened to traffic in 1909, the Manhattan Bridge is a double-level cable suspension bridge with steel truss approach spans. This bridge spans the East River between Brooklyn and Manhattan. The bridge's main span extends 448 meters (1,470 feet), and the entire bridge spans 2,089 meters (6,855 feet). Four main cables support the suspended spans. These cables are supported by two steel towers and are anchored by concrete gravity structures at each end. The bridge carries a total of seven lanes of vehicular traffic and four subway tracks.
The Williamsburg Bridge connects Manhattan's Lower East Side with the Brooklyn community of Williamsburg. The bridge is a major East River crossing and carries traffic flow in and out of Lower Manhattan. The bridge was built over a period of 7 years and was officially opened to traffic on December 19, 1903. With a total length of 2,227 meters (7,308 feet), it was the world's longest suspension bridge and provided double the load-carrying capacity of the Brooklyn Bridge. The total deck's length, anchorage to anchorage, is 851 meters (2,793 feet). The central span extends 488 meters (1,600 feet) between the main towers and is suspended from the main cables. The side spans, each 182 meters (596 feet), are not suspended from the main cables but are supported by their own towers. The Williamsburg Bridge carries a total of eight traffic lanes and two subway tracks.
Built over a period of 8 years, the Queensboro Bridge was officially opened to traffic on June 18, 1909, connecting Manhattan in the vicinity of 59th Street and the borough of Queens at Queensboro Plaza. The total length of this cantilever truss bridge between anchorages is 1,135 meters (3,725 feet), and it extends across both channels of the East River and Roosevelt Island. With nine vehicle lanes and one lane devoted to pedestrian and bicycle traffic only, the Queensboro Bridge currently carries more traffic than any other East River bridge.
Emergency bridge repairs and full or partial closures prompted NYCDOT to sponsor a number of studies and investigations to evaluate the city's management practices and to find solutions to ensure the long-term well-being of the city's bridges. The studies found that inadequate regular maintenance led to the deterioration.
"Bridge maintenance is important to the traveling public," says David Hart, area engineer for the Federal Highway Administration (FHWA) assigned to the New York State Department of Transportation's (NYSDOT) Region 11. "We want our bridges to perform their function, carrying traffic over, in this case the East River, and at the same time we want them to last long. You have to maintain the bridge in order for it to last a long time."
New York City was not alone in recognizing the consequences of poor maintenance practices. Municipalities across the country began to pay more attention to their bridges, and the consensus was that it costs more to replace a bridge than to provide maintenance on a regular basis. Repairing "worst first" (or only addressing functional or structural needs after the needs have manifested themselves) is normally more expensive than proactively implementing a preventive plan or activity on a routine basis.
"One of the lessons learned, from a history of neglecting our facilities, is that if you neglect a bridge, it will cost more in the end," says Antonio Estevez, Federal liaison at NYSDOT. "It's really a very basic principle: Anything that you want to protect, whether it's a car or a house, if you neglect it, you'll likely pay a higher price later on."
In 1988, NYCDOT Commissioner Ross Sandler and Chief Engineer Samuel Schwartz prepared a comprehensive report to the mayor titled Spanning the 21st Century: Reconstructing A World Class Bridge Program. The report identified 31 structurally deficient city bridges that were either closed or partially closed, and offered recommendations to improve the condition of New York's bridges. The recommendations included conducting regular inspections, creating a comprehensive maintenance program, providing dedicated funding, and restructuring the organization. The report concluded that "No maintenance is no bargain."
That same year, the city awarded a contract to the Center for Infrastructure Studies at Columbia University, as the lead institution in a consortium of civil engineering departments from NYC colleges and universities, to develop a preventive maintenance management system (PMMS) for the city's bridges. The 1990 report Preventive Maintenance Management System for New York City Bridges indicated that the city's maintenance during the previous two decades was only 10 percent of that required for a full maintenance program. The report further noted that at the turn of the century, the Department of Bridges employed 209 maintenance workers on the Brooklyn Bridge alone. By the 1980s, this number had dwindled to 160 workers for 76 waterway bridges and 770 other bridges. The report recommended that the city repair and replace some bridges, as well as implement a full preventive maintenance program.
A decade later, NYCDOT contracted again with the Center for Infrastructure Studies to update the preventive maintenance management system. The center noted some improvements in the condition of bridges and urged the city to continue expansion of its preventive maintenance program.
Until 1996, the Federal Government paid for capital improvements to bridges, but not maintenance. Transportation legislation enacted that year allowed States and cities to use Federal money for certain maintenance activities.
"The Federal Government realized that it's pennywise and pound foolish to pay for reconstruction and not maintenance, because reconstruction inconveniences the community and is very expensive," says NYCDOT's Holcomb. "The [Federal Government] agreed that it's wiser to do the work before the need becomes critical. For example, painting is very important and can extend the life of a bridge. Today we're getting Federal money to maintain our structures because it's understood that a funded maintenance program is the least expensive way of extending the useful life of a structure."
1: Numbers from the Maintence Plan.
The table shows a detailed implementation plan for maintenance on the Brooklyn Bridge. The plan lists maintenance activities, indicates how frequently they are conducted, who performs each task, and contract item numbers if applicable. Source: NYCDOT.
Tapping into the newly available Federal funding, New York City developed a partnership with FHWA and NYSDOT, and in 1997 implemented a preventive maintenance program for the East River bridges. "FHWA has spent hundreds of millions of dollars to repair and reconstruct the East River bridges," says FHWA's Hart. "These facilities need to be maintained to keep the structures functioning the way they were rehabilitated to [perform]."
|Proper maintenance requires an adequate staff of trained personnel. Here, an NYCDOT maintenance crew performs the annual cleaning and lubrication of the solid rod suspenders spherical bearings on the Brooklyn Bridge.|
|Painting protects bridges from the harmful effects of corrosion and is an important preventive maintenance activity to extend the life of a bridge. A contractor working for NYCDOT is painting the salt splash zone on the Williamsburg Bridge.|
The State also is helping to ensure that the Federal investment is protected. "We act on behalf of FHWA to make sure that maintenance projects that are federally funded follow the standards and procedures that are approved by FHWA," says the NYSDOT Federal liaison Estevez. "This is just another way to confirm that things are done right."
The group formed a task force that meets regularly to discuss current and future plans for maintenance. The city committed to developing, implementing, and administering an adequate and efficient preventive maintenance program for the East River bridges. The program is a continuous process and is flexible enough to meet the individual needs and rehabilitation schedule of each bridge. For example, the Williamsburg and Manhattan Bridges are still undergoing major rehabilitation, and the city included most of the preventive maintenance activities as part of the rehabilitation contracts. On the Brooklyn and Queensboro Bridges, however, the major rehabilitations are complete, so these structures have stand-alone maintenance contracts.
PREVENTIVE MAINTENANCE ACTIVITIES
New York City's comprehensive bridge maintenance system includes the following activities:
Preventive maintenance requires regularly cleaning a bridge’s surfaces. Here a contractor washes the underside of a masonry pier on Manhattan Bridge approach.
Because NYCDOT has hands-on experience in the preventive maintenance requirements of the East River bridges, the city is uniquely qualified to manage maintenance on a day-to-day basis and to perform specialized maintenance activities. The East River Bridges Preventive Maintenance (ERB-PM) Program is guided by the following primary goals:
The program is divided into three categories: force account maintenance (which refers to work performed by NYCDOT that is eligible or qualified for reimbursement by FHWA), contract maintenance, and winter maintenance.
Force Account Maintenance. The force account is a means for NYCDOT to recoup 80 percent of the total costs for the preventive maintenance-related work it does. New York City's in-house personnel manage the overall program. The city prepares contracts and performs supervision and inspection of the maintenance activities.
Certain preventive maintenance work is considered special in nature. Through years of hands-on experience, the city's in-house maintenance personnel have gained considerable expertise in these tasks. Examples of specialized maintenance include the lubrication of the main cables and cable saddles at the Brooklyn and Williamsburg Bridges, and mechanical and electrical maintenance on the traveler systems (motorized movable platforms under the bridge roadway) on the Brooklyn, Manhattan, and Queensboro Bridges.
|A maintenance worker oils cables on the Williamsburg Bridge during an annual cleaning and lubrication cycle.|
|Travelers, or movable platforms below the bridge roadway, like the one shown here beneath the Brooklyn Bridge, help workers perform inspections and conduct maintenance on NYC’s long-span bridges.|
The city plans and prepares specific work orders for these specialized maintenance tasks and has prepared a comprehensive maintenance manual for traveler systems and cable lubrication. The in-house bridge maintenance group for the city also conducts quality assurance reviews to ensure that all maintenance activities are performed thoroughly and completely.
Contract Maintenance. Except for the specialized maintenance work described above, contractors perform most other preventive maintenance work on the bridges. These regular maintenance contracts are critical to the success of the program. "With many of these preventive maintenance contracts, a little bit of money is spent and a great benefit is received," says FHWA's Hart. The Brooklyn and Queensboro Bridges have been maintained through stand-alone preventive maintenance contracts since early 2000.
Winter Plan. Winter brings special challenges. Salt is typically used to melt snow and ice on the roadways, but it can be very damaging to the steel components in bridges. In recent years the city has been investigating environmentally acceptable and minimally corrosive anti-icing materials.
Currently, NYCDOT uses potassium acetate to control snow and ice on the four East River bridges. "Potassium acetate is much less corrosive than salt," says Holcomb. "But it works a little differently. It prevents the ice from binding to the roadway, so we spray it on, and then plow the slush off the roadway."
The city needs an adequate number of skilled in-house engineering and technical personnel to maintain the East River bridges and oversee the entire program. Currently, the ERB-PM program employs 12 engineers and 11 tradespeople. Current and anticipated staffing levels were developed based on discussions held with FHWA and NYSDOT during their reviews of the preventive maintenance program.
FHWA MEMORANDUM ON PREVENTIVE MAINTENANCE ELIGIBILITY
On October 8, 2004, FHWA Associate Administrator for Infrastructure King W. Gee issued a memorandum on preventive maintenance that was distributed to the field offices. The following paragraphs are adapted from the memorandum.
Timely preventive maintenance and preservation activities are necessary to ensure proper performance of the Nation's transportation infrastructure. Experience has shown that when properly applied, preventive maintenance is a cost effective way to extend the service life of highway facilities and therefore is eligible for Federal-aid funding. By using lower cost methods for system preservation, States can improve system conditions, minimize the impacts of road construction on the traveling public, and better manage their resources needed for long-term improvements, such as reconstruction or expansion. Preventive maintenance offers State DOTs a way to increase the return on their infrastructure investment.
During the 1990s, the U.S. Congress incrementally broadened, through legislation, the applicability of Federal-aid funding to preventive maintenance activities. Congress's acknowledgement of preventive maintenance activities as an eligible activity on Federal-aid highways is a logical step that reinforces the importance of implementing a continuing preventive maintenance program.
The FHWA division offices have an important role in promoting system preservation and are encouraged to work closely with their State DOT counterparts to establish a program that identifies eligible preventive maintenance measures for all roadway assets on Federal-aid highways. The American Association of State Highway and Transportation Officials defines preventive maintenance "as the planned strategy of cost effective treatments to an existing roadway system and its appurtenances that preserves the system, retards future deterioration, and maintains or improves the functional condition of the system without increasing structural capacity."
Projects that address deficiencies in the pavement structure or increase the capacity of the facility are not considered preventive maintenance and should be designed using appropriate resurfacing, restoration, and rehabilitation standards. Functionally, Federal-aid eligible preventive maintenance activities are those that address aging, oxidation, surface deterioration, and normal wear and tear from day-to-day performance and environmental conditions. Preventive maintenance activities extend the service life of the roadway asset or facility in a cost effective manner.
Division offices should work proactively with their State partners to establish a preservation component that is composed of various preventive maintenance activities and treatments. These include roadway activities such as joint repair, seal coats, pavement patching, thin overlays, shoulder repair, restoration of drainage systems, and bridge activities, such as crack sealing, joint repair, seismic retrofit, scour countermeasures, and painting. Many other activities that heretofore have been considered routine maintenance may be considered Federal-aid eligible on an areawide or systemwide basis as preventive maintenance (that is, extending the service life). These activities might include such work items as regionwide projects for periodic sign face cleaning, cleaning of drainage facilities, corrosion protection, and spray-applied sealant for bridge parapets and piers. These typical preventive maintenance work items are not intended to be all-inclusive but are rather a limited list of examples.
The final eligibility determination should be the result of collaboration between the division and the State DOT. This determination should be based on sound engineering judgment and economic evaluation, allowing flexibility in determining cost effective strategies for extending the service life of existing pavements, bridges, and essential highway appurtenances on Federal-aid highways.
All preventive maintenance projects should consider appropriate ways to maintain or enhance the current level of safety and accessibility. Isolated or obvious deficiencies should always be addressed. Safety enhancements such as the installation or upgrading of guardrail and end treatments, installation or replacement of traffic signs and pavement markings, removal or shielding of roadside obstacles, mitigation of edge dropoffs, the addition of paved shoulders or stabilization of unpaved shoulders, or installation of milled rumble strips should be encouraged and included in projects where they are determined to be a cost effective way to improve safety. To maintain flexibility in the preservation program, and in accordance with 23 U.S. Code 109(q), safety enhancements can be deferred and included within an operative safety management system or included in a future project in the Statewide Transportation Improvement Program. In no way shall preventive maintenance-type projects adversely impact the safety of the traveled way or its users.
As with any Federal-aid project, adequate warning devices for highway-rail grade crossings within the project limits or near the terminus shall be installed and functioning properly per the Code of Federal Regulations, Title 23, Part 646 (23 CFR 646) before opening the project to unrestricted use by traffic. For projects on the National Highway System, all traffic barriers shall comply with the FHWA September 29, 1994, memorandum Traffic Barrier Safety Policy and Guidance, signed by E. Dean Carlson. This work can be accomplished by force account or through other existing contracts prior to final acceptance.
FHWA supports the increased flexibility for using Federal-aid funding for cost effective preventive maintenance. The Maintenance Quality Action Team is developing technical guidance on preventive maintenance activities and transportation system preservation as a whole; that technical guidance is under development and will be issued in
|In-house maintenance personnel with NYCDOT conduct anti-icing operations on the Brooklyn Bridge. This truck is applying sand and liquid potassium acetate, an anti-icing chemical that is much less corrosive than salt.|
NYCDOT plans to implement several additional initiatives in the near future to enhance its preventive maintenance program, including purchasing new equipment to support the use of liquid potassium acetate as an anti-icing agent, putting into action a computerized preventive maintenance management system (PMMS), and implementing a new comprehensive maintenance program on NYCDOT's 25 movable bridges. The city expects to have a contract for the movable bridges in place by mid-2005.
The city currently uses retrofitted dump trucks to apply the potassium acetate for anti-icing, but NYCDOT's Division of Bridges expects the purchase of 18 new trucks to improve the anti-icing operations significantly. The new fleet will include 10 spray trucks, 5 units capable of spraying anti-icing liquids and spreading solids such as granulated de-icing materials, and 3 pickup trucks capable of both spraying and spreading.
In coordination with FHWA and NYSDOT, the city also will develop and implement a comprehensive computerized PMMS. "The city's new computerized preventive maintenance program will manage all the information and data, and it will give us a good idea as to how well things are working," Estevez says. The system will manage information for the East River bridges but will be expandable to include other bridges in the future. The computerized PMMS will include the following:
The ERB-PM program is the result of the combined efforts of FHWA, NYSDOT, and NYCDOT, and it represents the entire team's commitment to maintaining New York City's historic East River bridges. The program not only will help ensure many more years of safe and reliable use but also will maintain the bridges as symbols of New York City.
Mo Sharif, P.E., is a civil engineer at NYCDOT. He was in charge of implementing the ERB-PM program and has served as its director since 1997. He has more than 10 years of prior experience in the repair and maintenance of various New York City movable bridges and tunnels. He received his B.S. in engineering mechanics and materials from Southern Illinois University at Carbondale in 1984 and M.E. in structures from City College of New York in 1986.
For more information, visit www.nyc.gov/html/dot/html/motorist/eastriverbgs.html.