In my overview of Regional Rail New York core stations, I mentioned several stops shared between RRNY and a Triboro Rx using the same equipment. This latter requirement, a conclusion which I arrived at in this post (and which the RPA policy brief seems to tacitly agree with), results in a route that–like the New York Subway–would lie entirely, or almost entirely, within city limits, yet would need the same equipment as the broader regional network.
In this sense, the interaction between the subway, RRNY, and the Triboro mirrors London’s. There, major projects like Thameslink, its expansion, Crossrail, and the proposed Crossrail 2 are slowly linking London’s vast commuter rail net into an S-Bahn-like system,* while the London Overground mainly provides circumferential service on the mainlines.
Considering a Quadboro Network
Indeed, since RRNY Lines 3 and 6 share a tunnel between St. George and the planned Triboro Rx terminus at Bay Ridge, and since under this system the Triboro Rx uses RRNY-standard equipment anyway, we can see that it can easily be connected across the Verrazano Narrows and directly connected to the Staten Island Railway.
Here we have a Quadboro Rx, a line that runs from Tottenville to Co-Op City, following the SIR, the Narrows tunnel, Bay Ridge Branch, and Hell Gate Line–the Triboro Rx and SIR joined end-to-end. But the beauty of Quadboro is that it invites us to consider other underutilized rail infrastructure in the region. Suddenly it’s not just “Quadboro Rx” but Line Q1 of a Quadboro network.
Take for example Line Q2. Once the infrastructure to create the Q1 is in place, it is a short branch line reactivation–in this case, the Port Morris Branch, linking Line 4’s Harlem Route mainline with Line 2’s Northeast corridor–a reactivation that the earlier Triboro Rx routing to Yankees Stadium suggests–creates a circumferential that follows uses parts of Lines 2, 3, and 4, and follows the original Q1’s mainline across Brooklyn and Queens. At St. George, then, the line follows the North Shore Line, offering local service to Old Place, and then diverging along the Travis Branch to Fresh Kills.
But that reference to Yankees Stadium also suggests that there is promise in a Jamaica-Yankees service, linking together Queens’ and the Bronx’s biggest hubs. We’ll call this line Q3, and it utilizes the underutilized Bushwick Branch to connect to the Hell Gate Line and then heads up the Port Morris Branch to snake through the interlockings over to Yankees Stadium.
Using the Bushwick Branch, in its turn, suggests Q4, a reactivation of former LIRR service on same between Long Island City and Jamaica. Remember how I wanted to explore the opportunity for a station around the Long Island City area, replacing Hunterspoint Avenue? This is why. An LIC complex that links together Lines 1 and 2, the Q1, and the 7 train (via Vernon Blvd – Jackson Ave) complements a Queensboro complex about a kilometer up the L1/L2 trunk.
Finally, let’s take a look at a Q5 linking the Brooklyn Army Terminal, via a track that would almost certainly be the original Triboro Rx terminus, with Jamaica via the Bay Ridge and Bushwick branches.
The network as a whole looks like this, handsome circumferential network covering New York’s four outer boroughs.
Right now these Quadboro ideas are very preliminary. The main thing they have in common is that they are circumferential lines that utilize the same basic equipment as the RRNY network. So far I haven’t refined things as much; nor have I even come close I do, however, know that I want them to operate at “subway-like” frequency.
I’ll have to do more work to understand the infrastructure commitments, as well as to see whether any more lines can be developed. Off the top of my head, I think the Chemical Coast route between Perth Amboy and Portal is viable, and may be split into three lines with a trunk linking into the Bay Ridge route (to Jamaica?) via the Cross Harbor Tunnel, making that piece of infrastructure useful for both freight and passenger trains.
Another consideration is the Montauk and Atlantic branches between Jamaica and Valley Stream. The short reverse branching on them can be eliminated simply by running Quadboro service out to Valley Stream on the Atlantic Branch, moving the L1 Far Rockaway Branch and all L4 service to the Montauk Branch. (I had briefly considered an L1 branch via the Bushwick and Far Rockaway branches prior to beginning this series, but had tossed it when it became clear it was too detrimental on mainline frequencies.)
However, Quadboro’s purpose is very clear — Much like the London Overground, it serves the densest parts of the metro outside Manhattan and as such functions (also like the Overground) more like an extension of the subway network than like a large regional rail net–even in the S-Bahn/RER style–that RRNY does.
Next up: The equipment
* Although one can argue that the London example, like most other examples from across the Commonwealth, take more from Paris’ RER system. The phrase gaining wider use, “Regional Express Rail,” even seems to be a reuse of the French acronym (although réseau express régional technically means “regional express network”). That said, the original RER is itself still modeled on the the same changes to commuter rail in Germany that drove the development of the S-Bahnen. Interestingly, Buenos Aires’ own plan fits Spanish inside the same basic acronym: Red de expresos regionales translates to “regional express route”.