Amtrak’s Place in RRNY

Screenshot 2016-05-28 at 2.42.55 PM
Current Amtrak paths through New York’s core

As we have developed the RRNY system, we’re finding that there is one last part to consider: Amtrak. Compared to the main RRNY routes, which is generally scaled reach a peak throughput of 32 tph (and can easily double that if 20 tph per track signalling is implemented), Amtrak’s services seem, well, minuscule.

Currently there are 4 tph total across Hell Gate in the peak hours, and the Keystone Service is scheduled around the 8:00 crunch through the North River Tubes. As daily trains (such as the Lake Shore Limited, Silver Meteor, and Vermonter) can be assumed to depart off-peak, they will not be counted towards Amtrak’s peak runs–only hourly trains will.

RRNY has two potential Amtrak paths: a modest-growth route that fits Amtrak around other services, and a high-growth route that gives Amtrak more dedicated infrastructure. Both programs, however, have some shared features.

Key Amtrak Features

Clearly, East Side Access is not going to be particularly useful under RRNY. Most LIRR trains (2/3) are diverted down the Atlantic Branch, heading to Midtown via Lower Manhattan if on Line 4, or bypassing Midtown altogether if on Line 5. The remaining trains use the East River trunk. But it represents a lot of emplaced concrete and should not just be left abandoned in the ground.

The key shared features are these:

  1. A Penn Station-Grand Central access tunnel that utilizes the ESA cavern
  2. Medium-speed Amtrak trains use ESA and the Hell Gate line
  3. High-speed Amtrak trains use the New Haven Line, on extra slots in the core and a pair of tracks between Mt. Vernon and New Rochelle that Line 2 leaves superfluous

The idea here is to split Amtrak services along different paths, particularly in the core. Only Line 2 and Quadboro services use Hell Gate at peak, and this leaves more available slots for more-frequent medium-speed runs; a slight gap between services and available frequency on the Manhattan Spine’s upper part gives high-speed trains a faster, more direct run out of Manhattan than by Hell Gate.

Meanwhile, the West Side Line remains the Empire Service’s home.

A Modest-Growth Scenario

Screenshot 2016-05-28 at 2.44.18 PM
Amtrak routes through the core under a modest-growth RRNY scenario. This plan allots Amtrak 16 slots (8 services) across the Hudson

This scenario is limited by potential Amtrak movements through the North River Tubes complex (which includes Gateway). This is because of arbitrage between them and the East River Tubes: between Lines 1 and 2, 32 tph cross the North River Tubes at peak, while, due to the 8 tph Line 1 receives from the West Side Line at Penn Station, 40 tph cross the East River Tubes.

That means that the East River Tubes are the most congested part of the entire network, congested to the point where they set 12 tph as the upper per-track throughput limit of, again, the entire network. (If you don’t think that’s enough slots to handle the demand, recall here that these estimates are scalable, and can easily double due to the way the system is structured: the only limit is the signalling system’s throughput capacity.)

But it also means there are 16 slots available through the North River Tubes–4x the amount Amtrak currently uses. Or: there are enough slots for 8 distinct hourly services of any type heading west from New York. (Recall that a service needs two slots, one for the train coming and a second for the train going.)

Finally, because the LIRR vacates the Hudson Yards, Amtrak can also take over that space. This means that corridor services can develop between New York and various New England points, with the Hudson Yards being their terminal facility.

Under the modest-growth scenario, 8 Northeast Corridor trains per hour, reckoned directionally, meet 4 Empire Corridor trains at Penn Station. These 12 trains (i.e. 24 tph) are then routed through the Penn Station-Grand Central Connector, a graceful spiral helix linking into Grand Central’s East Side Access station cavern.

From here, trains like the Empire and Keystone corridor services that terminate in New York are deadheaded through ESA to the Sunnyside Yards. Regional services are likewise sent along the Hell Gate Line (may change if Quadboro vacuums up all the slots Line 2 isn’t using), while high-speed trains use spare slots along the Manhattan Spine to the New Haven Line. Line 4 only needs 2 tracks between Mt. Vernon and New Rochelle for its New Canaan branch; the two tracks it doesn’t use mark the start of the Boston-New York HSL.

Developing a More Extensive Service Portfolio…

Screenshot 2016-05-28 at 3.16.06 PM
A significantly less modest block of services. Here, 11 services (22 slots) are needed across the Hudson. This compliments 5 services (10 slots) along the Hudson Line and 4 services (8 slots) terminating at Penn Station

But…where can corridor Amtrak trains go? And how many of them do we need?

One way of looking at it is to develop a corridor/service breakdown. Since we know that four high speed lines converge on New York, two linked together end-to-end, we can say that each has a high-speed medium-speed service pair. In other, similarly dense, parts of the world, there are often crack “super-high-speed” expresses on top of that. So in the New York market, we have:

Northeast Corridor

  1. Boston-DC super-express
  2. Boston-DC HSR
  3. Boston-DC medium-speed
  4. New York-Philadelphia medium-speed

Keystone Corridor

  1. New York-Pittsburgh super-express
  2. New York-Pittsburgh HSR
  3. New York-Pittsburgh medium-speed

Empire Corridor

  1. New York-Toronto super-express
  2. New York-Buffalo HSR
  3. New York-Niagara Falls medium-speed

for the major corridors. We can add to that three secondary blocks of (mostly) medium-speed services, essentially supercommuter corridors reaching out from Manhattan to snare the parts of its vast commute shed RRNY can’t reach. These include:

New England Service Area

  1. New York-Portland via Worcester
  2. New York-Boston via Springfield
  3. New York-Amherst
  4. New York-Albany via Pittsfield

Mid-Atlantic Service Area

  1. New York-Buffalo via Binghamton
  2. New York-Binghamton
  3. New York-Roanoke
  4. New York-Harrisburg

Champlain “Corridor”

  1. New York-Montréal HSR
  2. New York-Montréal medium-speed

From all of this we get 16 distinct hourly runs that either originate or terminate in New York, and three that pass through the city. Breaking out the part that requires a Hudson River crossing, we find 11 services, i.e. 22 slots required. This is obviously a fair bit more than the North River Tubes’ available capacity under the more modest assumptions allowing Amtrak to use RRNY’s spare capacity.

…And The Core Infrastructure To Go With It

Screenshot 2016-05-28 at 2.46.48 PM
As Amtrak service density goes up, the need for dedicated infrastructure becomes unavoidable.  This example uses a two-track HSL tunnel to bypass the North River Tubes bottleneck; the drill is continued to the far side of the Hudson-Harlem convergence

There are two potential solutions available here–and remember, at this point, we’ve added enough capacity demands to make seeking a new solution worthwhile. The first is to do more or less the same thing that we are already doing with Gateway, i.e. making the line between Penn Stations Newark and New York six-track to handle Amtrak’s new capacity demands.

The second solution is a bit more interesting. This comes about as a reflection that the Penn Station-Grand Central connection, at two tracks, is also nearing capacity, handling nine services (18 slots) between the Empire/Champlain and New England groups alone. Essentially, Amtrak now needs four New York tracks of its own.

(Aside: This also pushes RRNY closer and closer towards a true S-Bahn, even if it’d be a very large example by German standards: S-Bahn routes are generally decoupled from intercity ones through the core.)

To provide this, I propose using the now-disused Hoboken Station throat (remember, services that used to call at Hoboken are now mostly bundled into Lines 2 and 5) as a launch box for a wide-bore two-track tunnel, where the use of a wide bore futureproofs the tunnel. This tunnel gently curves until it runs under Park Avenue, passing through Amtrak’s deep-level Grand Central station box and continuing up to the Bronx, where it surfaces just past the junction with the Port Morris Line.

Under this plan, Grand Central becomes Amtrak’s main Manhattan hub: Mid-Atlantic, Keystone Corridor, and most Northeast Corridor trains stop only there (the lone exceptions are Grand Central-Penn Station-30th Street Clockers). Penn Station continues to be important, however, as the terminus of the New England service block as well as one of the Empire Corridor’s two Midtown stations.

Capacity Breakdown

Under the service portfolio outlined above, Amtrak needs:

  • 22 slots under the Hudson
  • 18 slots off the Empire Corridor
  • 14 slots into New England

The HSR components of the Northeast and Empire corridors do not begin until one passes Newark, Mt. Vernon, or Yonkers. This allows Amtrak to use its available slots in the core for every service. But it does also mean that there may be significant chokepoints on the Hudson and New Haven lines as well–on the former, between Spuyten Duyvil and Yonkers; the latter, New Rochelle and Stamford. These may be worth investigating.

Service Allocation

The general allocation of service is thus:

  • Northeast Corridor – Super-Express, HSR, Regional: ← Newark Penn – New Hudson River Crossing – Grand Central – Amtrak Manhattan Spine – Mt. Vernon →
  • New York-Philadelphia Clockers: Newark Penn – North River Tubes – Penn Station – Penn-Grand Central Connection – East Side Access – Sunnyside Yard ⊣
  • Keystone Corridor – Super-Express, HSR, Regional: ← Newark Penn – New Hudson River Crossing – Grand Central – East Side Access – Sunnyside Yard ⊣
  • Mid-Atlantic – Harrisburg, Roanoke: ← Newark Penn – New Hudson River Crossing – Grand Central – East Side Access – Sunnyside Yard ⊣
  • Mid-Atlantic – Buffalo, Binghamton: ← Paterson – New Hudson River Crossing – Grand Central – East Side Access – Sunnyside Yard 
  • Empire Corridor – Super-Express, HSR, Regional; Champlain – HSR, Regional: ← West Side Line – Penn Station – Penn-Grand Central Connection – Grand Central – East Side Access – Sunnyside Yard 
  • New England – Portland, Boston, Amherst, Albany: ← Mt. Vernon – Amtrak Manhattan Spine – Grand Central – Penn-Grand Central Connection – Penn Station – Hudson Yard 

where and → means “service continues” and ⊣ means “end of service”, i.e. the yard where the train is stored. Note that the Mid-Atlantic, Keystone, and Empire trains are stored in Sunnyside Yards (now given over entirely to Amtrak and most likely decked over and redeveloped), while New England trains are stored in Hudson Yards. Note also that (a) the Hell Gate Line has been bypassed entirely by the new Amtrak tunnel, allowing RRNY and Quadboro (Crossboro?) services to occupy all its slots, and (b) that, due to the Penn Station-Grand Central Connection’s congestion, the Clocker is the only Amtrak service still using the North River Tubes. Any further service growth along the Empire and Champlain corridors, like, say, an hourly train to Burlington via Rutland, would require shifting the Clocker down through the New Hudson Crossing (which, remember, is futureproofed to be quad-tracked!).

Remarks

RRNY is turning out to be a deeper series than I first expected. There is still one more subject I need to explore: the core tunnels proper. After that, I have some things to talk about.

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