Wittpenn Bridge Replacement Offers Faster, More Efficient Operation
New York City in the 1920's was bustling with business and activity, and existing primitive roads and bridges were an ongoing challenge. By the end of the decade, six major bridge projects were planned to improve highway connections in and around Newark and Jersey City, New Jersey. One of those was the New Jersey Route 7 Bridge, crossing the Hackensack River. Dedicated in a heavy downpour on November 5, 1930, in attendance was former Jersey City Mayor Henry Otto Wittpenn, then a member of the New Jersey State Highway Department. When Wittpenn died the following year, the new bridge was named in his honor.
Completed in less than two years at a cost of just $3 million, the original New Jersey Route 7 started in Jersey City and crossed over the Hackensack to Kearny. Another notable bridge included in this same long-range plan was a proposed high-level viaduct spanning both the Hackensack and Passaic Rivers. Later dubbed the Pulaski Skyway, this bridge soared 135 feet above the river and was considered an engineering marvel upon its completion in 1933.
The 86-year-old Wittpenn is a vertical lift bridge at 2,169 feet long with 14 deck-girder spans and three through-truss approach spans, two tower spans and a 209-foot vertical lift main span. It currently provides four 10-foot travel lanes (two eastbound and westbound) with no shoulders and no physical separation between opposing traffic lanes on the bridge.
Modernizing the Crossing
Original preliminary designs for the new project were completed in November 2005. Soon after this process, the project underwent a value engineering rightsizing review, which resulted in a revised design in August 2007. The new vertical lift bridge currently under construction will carry two 12-foot through lanes, a 12-foot auxiliary lane, an 8 to 10-foot right shoulder in each direction and a 6-foot sidewalk along the eastbound roadway. An 8-foot median consisting of variable width inside shoulders and a median barrier will separate opposing traffic flows. The new Wittpenn also will accommodate pedestrian and bicycle traffic and will provide for a minimum vertical clearance of 70 feet above Mean High Water (MHW) EL 2.19 in the closed position, as compared to only 35 feet for the existing bridge.
The most interesting part of this story is the bridge's deck. With the help of researchers at Lehigh University, New Jersey Department of Transportation (NJDOT) looked at a prototype for the deck, examining different connection options. Eventually the orthotropic deck was selected because of its overall successful performance for critical stresses and load distribution. "From our perspective, the steel orthotropic deck on the new bridge will likely provide 100 years of life. While you pay more up front, it has great benefits on the back end," said Laine Rankin, NJDOT Executive Regional Manager.
The orthotropic design isn't a new technology and can be found on other U.S. bridges such as New York's Verranzano Narrows and Bronx Whitestone Bridges, and on some portions of the San Francisco Bay Bridge. "The decks for those bridges are replacement decks, whereas, the Wittpenn is one of a few new orthotropic bridges in North America," she notes. Utilized successfully for years in thousands of bridges worldwide in Europe, Asia, and South America, there are also a number of movable bridges in Alaska constructed with orthotropic decks.
Why an Orthotropic Deck?
Developed in Germany in the 1930's, orthotropic decks are similar to U.S. battleship decks, with a thin steel plate featuring a series of longitudinal "ribs" and floor beams, with a wearing surface of 100 percent steel superstructure. These same design principles can be seen within the layers of some types of cardboard.
The main advantage of the orthotropic deck is offsite prefabrication, which results in faster construction and higher quality control. It's also lightweight, which is a critical characteristic for a movable bridge. The lighter weight allows the bridge to be more efficient and allows for faster operation. Since the bridge is more efficient, it requires less maintenance, which reduces lifecycle costs. As a highly redundant system, minor cracking is often just a nuisance rather than a serious structural threat. Orthotropic decks also allow for longer span lengths, which provide a better riding surface than others with more connections. Orthotropic decks offer good cold weather constructability, since there is no temperature requirement for concrete to cure. Finally, corrosion resistance has historically been very good, partially from the wearing surface and closed ribs.
While the biggest disadvantage for this type deck is higher initial fabrication costs, these are offset in the long run due to lower maintenance costs. According to Rankin, "From the beginning when we let the project, we have continued to do it cost effectively. For example, we were able to save money during the right-of-way phase of construction by working with area businesses to resolve their situations without further cost to either party." NJDOT worked closely with CSX regarding the rights-of-way said Communications Director Steve Schapiro, "This is a great example of how we work with the public and business owners to mitigate issues and save money by not relocating businesses."
Cost and Scheduling
The project is on schedule at a cost of $480 million. Funded by federal dollars, some was allocated from the American Recovery and Renewal Act (ARRA) and the remainder from the Port Authority of New York and New Jersey's Lincoln Tunnel Access Program (LTAP). All construction costs were from LTAP; most of the design costs were covered by federal funds. The entire bridge construction project has a long, 11-year completion cycle because it sits in a congested area, with many right-of-way activities. As certain sections of the right-of-way are completed, contractors move on to the next phase. "Phasing the project in this manner enabled us to start sooner and allowed us to focus contracts on specific kinds of work," said Project Manager Mahesh Patel.
With a total of five contracts, targeted completion is set for 2022. The project began in 2011 with the first contract, which involved water-only activities. It included the construction of three concrete fender systems for the new bridge foundation. Contract 2 covered the pier foundations and superstructure deck cover. Contract 3 is currently under construction, with the fabrication of the vertical lift bridge. "Contract 3 is mostly steel structural work, as well as mechanical/ electrical items. VIGOR is fabricating the main deck at their Oregon headquarters," Patel noted. Roughly 50 percent of the deck is complete and will be shipped down the west coast and through the Panama Canal and back up the east coast for delivery. When installed, the complete deck will be the size of a football field. Contract 4 is scheduled for summer 2017 and includes the connections to the bridge and removal of old bridge.
Another exciting part of the Wittpenn Bridge story is its connection to the East Coast Greenway bicycle route. The East Coast Greenway is a 3,000-mile trail system linking 25 major cities from Maine to Florida. A pathway to health and adventure for non-motorized travelers including walkers, cyclists, skiers, skaters, equestrians, and wheelchair users, it links together publicly owned, firm-surface trails. "The Wittpenn will be the missing piece of the East Coast Greenway in the city," says Rankin. The 8-10-foot pedestrian right-of-way offers the bridge's connection to the Greenway.
It's also important to note that any Federal project of this type must undergo a strict environmental assessment. While much of the area adjacent to the bridge has contaminated soil and industrial waste, according to Rankin, no significant issues have resulted from the assessment. "Based on soil samples, we will follow the required criteria to dispose of that soil."
Oregon Iron Works-VIGOR was selected to create the Wittpenn bridge deck offsite at their facility in Portland, Oregon. "Since the work on the bridge needed to meet our Buy American standards, we are happy to work with an American company who offers this expertise," Rankin said. Expected to be complete in 2017, the bridge deck portion of the project will be shipped in five separate sections. "The U.S. Coast Guard tells us the Hackensack River Channel can be closed for a maximum of 21 straight days. We expect the deck section placement to take 14 days," she noted.
"Despite the challenges in terms of design and fabrication for some very complex welds, working with VIGOR assures us a good product with their years of experience building bridges throughout the world," Rankin shared. VIGOR Vice President of Sales and Marketing for Complex Fabrication Thomas J. Hickman concurred and said what makes the orthotropic deck desirable is its strength to weight ratio. "This deck will have a 3/8-inch asphalt emulsion vs. a standard plate-style bridge, which would have 8 to 10 inches of concrete. While orthotropic decks are more expensive, they have huge advantages in terms of weight." Very few of these have been built in the U.S. largely because of the cost of labor. The funding to replace the old bridge came from Federal Highway dollars, which meant that a U.S. company would need to be involved. "VIGOR had the expertise and the technology right here in the U.S., narrowing the field to the movable span (vertical lift) bridge," Hickman shared.
"Using state-of-the-art technology to replace aging infrastructure, this is one of the largest lift span bridges in the U.S., making it such a large and costly endeavor," commented Schapiro. "My grandkids will be the beneficiaries of what this new bridge will provide."