When we last left off with Regional Rail New York – Scenario B, we had discussed how hourly fringe frequencies would combine into frequent service in the core, under a takt regime. We also decided that service would double during the rush hour, thereby allowing takt to be kept. And finally, we realized that required infrastructure is a function of throughput, which is regulated by the signaling system.
Signalling and Throughput
Let us consider Grand Central’s approach. During the 8 AM – 9 AM peak hour, we know that, at Grand Central:
- The Hudson Line has 15 inbound and 2 outbound trains
- The Harlem Line has 16 inbound and 4 outbound trains
- The New Haven Line has 20 inbound and 5 outbound trains
From this, we can see that the Grand Central approach must be able to handle 51 inbound trains and 11 outbound trains. If we assume that, under current conditions, three tracks are inbound during peak, and one outbound, then this implies that the current signaling system handles, at minimum, a throughput of 17 tph.
Another case to consider is the East River tubes. Every LIRR train to and from Penn Station must traverse these tubes, and every NJT train deadheads through them (as the storage yard is at Sunnyside). From the schedules, we can see that:
- The LIRR has 14 inbound and 5 outbound trains
- NJT has 12 inbound and 10 outbound trains
- Amtrak has 2 southbound and 4 northbound trains
(where the North River Tubes are used as a proxy for the East River ones since Keystone trains must deadhead through them as well). From this information, we can calculate both the North and East river tubes’ maximum throughput:
- The East River Tubes handles 28 inbound and 19 outbound trains on four tracks
- The North River Tubes handles 14 inbound and 14 outbound trains on two tracks
This clearly gives per-track throughput of 14 tph: both tracks on the North River Tubes can handle that much, as can the East River Tubes’ inbound tracks; their outbound tracks handle 9.5 tph. (Interestingly, this suggests that the Grand Central approach’s signalling is better than the river tubes’.)
So what does this all mean for Scenario B? Well, from our previous post, we know that:
- The East River Tubes must handle 40 trains, plus Amtrak’s, on four tracks at peak
- Approaches to the new Old Fulton Avenue tunnel (i.e. the New Hudson Tunnel, Manhattan Spine, 4th Avenue Tunnel, and Atlantic Avenue Tunnel) must be able to handle 32 tph, also on four tracks
- The new Old Fulton Avenue tunnel proper must handle 64 tph, on six or eight tracks
From this, we can see that:
- The East River Tubes will have the highest capacity need, at 10 tph per track
- The Old Fulton Avenue Tunnel’s approaches need to support 8 tph
- The Old Fulton Avenue Tunnel proper needs to have 8-10.67 tph
If we assume moderate Amtrak capacity growth, to 8 tph, and a Penn Station – Grand Central connector, we can signal the entire system at 10 tph per track: Amtrak deadheads can use ESA to Sunnyside, while revenue trains can use the now-underutilized Mt. Vernon connection. Amtrak growth that much exceeds this, however, may need its own dedicated infrastructure; this is something worth looking at later. Likewise, a Triboro Rx that uses RRNY rolling stock can easily fit across Hell Gate under this proposal, perhaps with dedicated passenger tracks for it and Line B and a freight crossover at some point in the crossing.
This trunk runs from Newark to the Bronx, and is the spine of Lines 1 and 2. It is almost entirely extant, including the Hell Gate Bridge and approaches, East River Tubes, and North River Tubes and approaches; once Gateway is completed, the full extent should be quad-tracked.
Beyond the extant stations at Secaucus Jct. and New York Penn, new stations are provided at Portal, where it crosses Line 6; Midtown East, where it crosses the Manhattan Spine, and Sunnyside, where it crosses Queens Blvd. In addition to this, investigations should be made into the closure of the Hunterspoint Ave. station and its replacement with a direct transfer facility at Long Island City. A Bergenline Avenue station is also a future possibility.
The Midtown Trunk has a standard of 10 tph per track, as a Penn-Grand Central connection would alleviate pressure through the East River Tubes. (This is because the Yonkers-Port Washington service does not use North River/Gateway.) This connection would convert ESA’s LIRR concourse into an Amtrak concourse; depending on connections made, either all Amtrak trains or Amtrak deadheads would run through ESA.
This trunk is the natural extension of the Grand Central approach. The spine of Lines 3 and 4, it runs from the station’s lower level (the upper level will be closed to through traffic and most likely malled) down Lexington Avenue to Broadway, and then down Broadway to Fulton.
There are three new stations on this line: Midtown East, where it meets the East River Tubes; Union Square; and Houston Street.
At Fulton it meets the Pavonia Tunnel, where they form a two-level deep-level station box accessed from the Fulton Street oculus. They then segue into the Old Fulton Street Tunnel under the East River.
The Pavonia Tunnel
The Pavonia Tunnel is a new 4-track crossing of the Hudson River, and the spine of Lines 5 and 6. It encompasses the Bergen Arches, and a new route connecting at their base down I-78 to Newark Ave. and then 2nd St., crossing the Hudson and running down Vesey Street and then curving under the old St. Paul’s graveyard to Fulton Street, where it meets the Manhattan Spine.
Its major stations include Jersey City, where it runs along Newark Avenue, and Exchange Place, where it meets the HBLR. Another station site to be investigated might be Bergen Arches between Central and Summit avenues.
Where it meets the Manhattan spine is a large new Lower Manhattan station, a deep level fully integrated into the existing MTA Fulton Street Station facility. This station has two track levels, and the tunnels continue into the Old Fulton Street Tunnel.
Old Fulton Street Tunnel
Lines 3, 4, 5, and 6’s crossing of the East River, the Old Fulton Street Tunnel runs from Fulton Street in Manhattan to Old Fulton Street in Brooklyn (hence the name), curving down either the BQE green space, Poplar Street, or Sands Street to the underside of the Manhattan Bridge approaches and thence Flatbush Avenue.
A DUMBO station is provided along the section between Old Fulton Street and Flatbush Avenue.
This tunnel is a two-level facility, and is bounded by stations on either end. In Manhattan, the Fulton Street Station box marks its connection with the Pavonia Tunnel and Manhattan Spine; in Brooklyn, the University Place station marks its connection with the 3rd Ave. tunnel and Atlantic Terminal spur.
At Fulton Street, Lines 3 and 4 are on the upper level, and Lines 5 and 6, the lower; at University Place, Lines 4 and 5 are on the upper level, and Lines 3 and 6, the lower. In between — either under the East or under Flatbush — lies a transfer junction for lines 3 and 5 to change levels, one of the most complex parts of the entire system.
3rd Avenue Tunnel
This tunnel, part of the spines of Lines 3 and 6, runs under 3rd Ave. in Brooklyn. At Flatbush, it meets the upper-level Atlantic Terminal Spur and runs concurrently with it to University Place station.
At its far end, it meets the Staten Island Connection group at Brooklyn Army Terminal station; near its junction with the Atlantic Terminal Spur lies an Atlantic Avenue station. Otherwise, it closely parallels the 4th Street Subway.
A final note: a bellmouth junction connects it to the Bay Ridge Branch, as a possible Triboro Rx continuation.
Staten Island Connection
Also part of Lines 3 and 6, the Staten Island Connection is a group of three projects that bring RRNY service to Staten Island. These projects are a new Narrows Tunnel under Upper New York Bay, a rehabilitation of the North Shore Line into a quad-tracked main, and a new double-track bridge (or tunnel) used by Line 6 across Arthur Kill just north of Pralls Island.
The Narrows Tunnel links Lines 3 and 6 to the North Shore Line, as well as Triboro Rx to the SIR; a Triboro branch provides local service along the North Shore Line. At Old Place, Lines 5 and 6 split; Line 5 crosses Arthur Kill at either the Arthur Kill Lift Bridge or on the transit portion of the Goethals Bridge. Using the lift bridge, however, runs a risk of causing cascade delays throughout the system if the bridge is open when a train is supposed to cross.
Finally, the Pralls Island fixed link links Line 6 to the Chemical Coast Line, its core mainline north from Perth Amboy.
Next up: We’ll take a look at some of RRNY’s core stations in Brooklyn, Manhattan, and New Jersey.