Manhattan’s South Ferry subway station is back in service, fully recovered from severe flooding sustained in Superstorm Sandy nearly five years ago.
Located near Battery Park, the new station is the southern terminus for New York City Transit’s (NYCT) No. 1 train. Prior to its closure, the heavily used station — a key connection to the Staten Island Ferry terminal — served more than eight million passengers annually.
When Sandy reached the shores of New York City on Oct. 29, 2012, it caused widespread damage throughout the city and in many NYCT facilities, particularly those located in low-lying areas.
South Ferry terminal station, which dates to 1905 and had been extensively renovated in 2009, was among the hardest hit. During the storm, the station was submerged in 80 feet of water — an estimated 15 million gallons of water from track level to the concourse level. The station was forced to shut down immediately, and throughout the rehabilitation.
The salt water and sewer water intrusion caused a great deal of damage to both the station environment and the operational system equipment, including the escalators and elevators, fare control, electrical, mechanical and ventilation systems, communications systems, and track/signal systems.
“It was critical to bring South Ferry station back up for public service,” said Erdem Dogan, project manager for the construction-phase support. “Hence, New York City Transit implemented an expedited program for design and construction to achieve this objective.”
Assessing the Damage
WSP, along with its joint venture partner and sub-consultant firms, performed station rehabilitation and flood mitigation designs, including the associated construction-phase support. The firm was also responsible for leak remediation, addressing the leakage problems that the station and adjacent tunnels experienced since the original construction of the complex.
“A number of flood mitigation measures were designed and installed to protect the station complex,” Dogan said. “For example, the three station entrances are now provided with water-tight stainless-steel canopy structures equipped with inflatable marine-type flood doors to minimize floodwater infiltration.”
Other station improvements and customized design solutions included:
- Hardening of various rooms and ventilation structures to handle flood loads
- Use of marine-type flood doors and watertight hollow metal doors for several critical rooms
- Use of flood panels at elevator doors, stairs and service corridors
- Large capacity pumps at track level, powered by emergency generators
- Vent covers for street grates
- Check valves, backwater valves, and isolation valves to minimize or prevent water infiltration in critical rooms
The expedited design schedule presented the team with several challenges.
“An extensive condition survey was conducted at a very early stage of the design effort to determine the level and extent of damage that occurred to many systems components, including equipment, conduits, ducts, wiring, and to coordinate with NYCT for items to be replaced and reconditioned,” Dogan said. “Various flood protection measures needed to be closely coordinated with the client prior to implementation of the designs.”
During construction, WSP provided expedited shop drawing reviews and coordinated reviews with NYCT. Flood mitigation designs were also provided for temporary protection of the station complex until permanent mitigation measures could be installed.
The old South Ferry station outer loop platforms, which served the area from 1905 until its closure in 2009, was brought back into service in 2013 for commuters and remained in use through the completion of the rehabilitation project.
“Other than the watertight glass and stainless steel entrance canopies with marine-type flood doors, the architectural scope of this project was to restore South Ferry station as it looked when it opened in 2009,” Dogan said.
As part of the scope of work, the joint venture has prepared design documents for a number of construction contracts. Prior to main construction works of the station complex, two early phase construction documents were prepared for implementing near term flood mitigation measures to temporarily protect the station complex until final mitigation measures could be installed. Similarly, an early removal of damaged items from the station complex was prepared to expedite the construction works until final rehabilitation documents could be prepared. The joint venture also prepared two additional contract documents for works to be performed by small business contractors.
Back in Service
The South Ferry terminal station officially re-opened for service on June 27, and with the exception of some minor work remaining in back-of-house spaces and in the old loop station area, the project is essentially completed.
Although the budgeted construction cost was about $344 million, Dogan said the project team expects that the station rehabilitation project will be completed under budget.
“The client was very pleased with the effort by all involved with the project, and for the successful and timely completion of the station works,” he said.
Dogan, who also served as the project manager for the extension of the No. 7 subway line extension to Hudson Yards and the new 34th Street Hudson Yards subway station completed in 2015, was glad he could play a role in bringing this important station back into service for New York City commuters.
“For me personally and for our team, it is very gratifying when we get the chance to be part of a major project like this, and participate through successful completion of the project,” he said.
Richard Reitz is the editor, U.S. Communications, for WSP USA.
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