The South Ferry Subway Station is at the southern tip of Manhattan, alongside Battery Park, which looks out over New York Harbor and its famous resident, the Statue of Liberty. It’s not surprising that it is the subway system’s second-busiest station, with about 6 million riders passing through it annually. The station was built in 1905, when there were about half as many people living in the city as there are now. Even so, it was busy from the start. Boats brought new immigrants from Ellis Island to Manhattan. The subway station there was the portal through which they entered the city. Also in 1905, five ferries were commissioned for service between Staten Island and Manhattan, so the island’s residents could easily commute to work. Although the flow of immigration through Ellis Island declined after 1924, the number of ferry commuters has grown considerably, and there has always been a steady stream of tourists who come to see the statue and historic buildings nearby.
In 1905, trains typically were five cars long, which the South Ferry platform to accommodated. Today, trains have about 10 cars. This means anyone taking the No. 1 southbound IRT local to South Ferry will have to board the first five cars. Since it is the end of the line, there is a single track that does a 180-degree turn around the station. Turnarounds are noisy, slow and produce extra wear on wheels and tracks. Also, access to the station from the street is only by a single stairway.
The No. 1 train ran directly under the World Trade Center, so rebuilding the tracks was part of the immediate repair work needed to restore lower Manhattan’s infrastructure after the Sept. 11, 2001, attacks. It was then that the Metropolitan Transportation Authority (MTA) decided to replace the existing station and build a new one underneath it.
The new 700-foot station will have two tracks (pockets) to create a terminal with an island platform. Trains will terminate and start in both pockets from this station with a diamond crossover switch to move the trains to the proper track, effectively doubling passenger capacity. It will have three entrances from the street, elevator access and underground pedestrian access from the ferry terminal, the Whitehall Street subway station and eventually several other terminals, which will form part of a new World Trade Center downtown transit hub.
The MTA did the design and oversees the project. The general contractor is Judlau Contracting, College Point, N.Y., and the contractor in charge of all electrical work is Five Star Electric Corp., Ozone Park, N.Y.
Michael Gelb, project executive for Five Star Electric, said the project could not have been undertaken without the electrical workers of IBEW Local 3.
Local 3 President John E. Marchell and business representative Michael O’Neill said working on the New York subways requires a unique set of skills and knowledge that can be gained only by years of experience working on the system. Marchell, for example, worked on the subways for approximately 25 of his 44 years in the local. Local 3 typically has anywhere from 500 to 2,000 members working on the subway.
Gelb said that when he was recruited for the project, he was told it was just like working on a tall building lying down on its side. He has since learned that it is nothing like that. As Marchell said, it’s more “like a city within a city.”
There are two absolute requirements: Keep the trains moving on schedule (headway), and keep the passengers safe. The intersection between these two mandates is the signal system, which is “the heart of the [subway] system,” Marchell said. The heart of the signal system, in turn, is knowing the exact location of every train at any given moment. This is done in a way that is clever, simple, rugged and reliable: insulated joints. According to Bob Sceles of Five Star Electric, each of the three rails has a special function. There’s the 660V DC power (third) rail, the “negative rail” and the 4–8V AC “signal rail.”
The third and the negative (common) rails are, for the most part, continuous, but the signal rail is broken up into segments with insulated joints between each section. The length of each segment varies according to the need for control at a particular location. There are more short segments near busy stations and around curves. Low-voltage AC is supplied from relay rooms located near the major stations. When the metal train wheels arrive at a section of the signal rail, they complete a circuit by shorting the signal rail to the negative rail, and with an evolved relay system transmit back to the relay room to indicate its location and light an indicator on a “mimic board.”
The main board is located at the New York City Transit Rail Control Center, which is something like an airport control tower, but many times larger. More than 50 people work there, monitoring the entire system. They can track the location of every single train, and the condition of every signal light, track switch and stop-arm. This is replicated for much smaller areas by means of a network of local control towers and dispatcher rooms, dispersed throughout the system.
There actually are many different mimic boards. Several have only indications (indication panels), while other panels can control the switches (control panels). Panels range in size from 3-by-5 feet to 15-by-7 feet (on other projects, they range up to 8-by-30 feet).
“This is the most vital part of how the ‘railroad’ works. If this doesn’t work, nothing works,” said Sceles, who has been working on the system since 1992.
The project involves a new stretch of tunnel at the north end of the station with tracks and signals that tie into the existing ones. About 170,000 feet of new wire connects the various functions. Inside the tunnel, there is a signal light system for the motorman. When a signal turns red, a trip arm connected to it rises. If the train, for whatever reason, should move past it, that arm will activate the train’s air brakes and bring the train to a stop.
Then there is the “blue light” system. At points along the tunnel, there are blue lights that highlight the location of a switch that can be used to remove third rail power. There is a telephone at each of these positions. Whoever has disconnected the power must immediately report to the dispatcher the reason for their action.
There is a wireless radio system that allows the motorman to talk to the dispatcher. The signal from the motorman’s cab is picked up by a Radiax slotted coaxial cable, which serves as a continuous antenna running all through the tunnels.
A recurring theme with these safety and signaling systems is they all must be fail-safe and redundant. If any component of any system fails, that function must automatically switch over to a fallback system or stop the train.
And all of these systems must function reliably in an atmosphere that always contains steel dust from the abrasion between the wheels and the track.
The new station
A new relay room processes all of the inputs from the train and tracks, applies them to relay ladder logic and outputs the signals that control the stops, track switches and signal lights. There will be two new electrical distribution rooms, normal and reserve (backup), which feed power to the relay room. The relay room has an automatic transfer switch that kicks in the reserve power if the normal power fails.
There will be a new pump room to deal with the problem of the water that collects in the tunnels.
A simple list of the systems that Five Star is installing in the station will give an idea of the project’s complexity:
> Two independent communications systems, one for talking to the motormen plus a customer information system for making schedule announcements by voice and message boards and for making evacuation announcements in the event of an emergency
> Fire alarm and suppression systems—two heat-detecting cables, one on each side of the station. In the event of a fire, a section of cable will melt, and the alarm system will be able to indicate where in the station the fire is located. Given the eight air conditioning systems, the station will also have standard duct detectors. There is an Inergen suppression system for rooms with critical equipment, and hydrogen detectors for those rooms.
> Although Lockheed Martin has the main security system contract, Five Star is responsible for a significant portion. The company has started installing CCTV cameras that will have facial recognition software upon completion.
Other electrical systems in the station include lighting, two elevators and seven escalators, card swipe turnstiles, Metrocard vending machines, telephones for offices and for public access.
Actually doing the work is dangerous and difficult. The conduit, in order to stand up to the damp environment, is galvanized steel, which is very heavy. And electricians new to the job are advised to kick the empty conduit before pulling it off the stack to make sure no rats are in it.
Sometimes a general order is issued to stop train traffic in the area during slower times at night or on weekends. If there’s only a limited amount of work to be done, a flag person, or “flaggy,” is brought in at night to warn off approaching trains. The flaggy brings along a portable trip arm that works just like the ones at the signal lights.
“It never gets boring. There’s a different problem every day,” Sceles said. One small example occurred, during my visit to the Five Star office. Specially manufactured equipment racks were being installed, but some of the cables provided by the manufacturer were too short. Problem: how to get the proper cables with a minimum of hassle and paperwork. An impromptu three-man conference came up with a satisfactory solution.
“For roughing in conduit and pulling cable, we use electricians, and then when it comes to the systems installation, we have people who are more familiar with each system,” Gelb said. Five Star Electric has plenty of people “already in the shop” who have the needed experience. If none are available at the right moment, the company turns to Local 3. Five Star Electric doesn’t have special departments. Gelb relies on his foremen to select people with the needed skills.
Testing is scheduled to begin this month and go until the end of 2008. The plan is to decommission the old station and connect to the existing system over the first months of 2009.
“And then we’ll be out of there,” Gelb said.
There will be 100-hour tests on the pumps, 40-hour tests on the elevators and escalators. The track switches and trip arms will be operated repeatedly until everyone is satisfied. Most important will be to make sure that all of the fail-safe and redundant systems operate as they should.
As Mike O’Neill said, “The people walking by have no idea of what’s going on under their feet.”
BROWN is an electrical engineer, technical writer and editor. He serves as managing editor for SECURITY + LIFE SAFETY SYSTEMS magazine. For many years, he designed high-power electronics systems for industry, research laboratories and government. Reach him at firstname.lastname@example.org.