As it stands, most mainline freight in the New York area either originates or terminates in New Jersey -- mainly in Newark. This is an artifact of the way American railroads were created and maintained: at one point, half a dozen railroads came up to the Hudson River's west shore, while half that lay on the east shore. Carfloats linked the two together. One still survives. At one time, a long-distance bypass of the city used a bridge at Poughkeepsie -- this is no longer in service -- requiring any train originating or departing New York City to clear what is known as the "Selkirk Hurdle," heading north to the first active rail crossing of the Hudson just south of Albany. (Making things worse is that the Hurdle is run by NS' competitor, CSX.) Unsurprisingly, this means that the vast majority of freight traffic either in the city, or transshipping it, goes by road: even with jams, crossing the George Washington or Tappan Zee is, by an order of magnitude, shorter.
So the idea is that a new freight terminal on the New York side of the Hudson from points west will help alleviate trucking congestion on the road Hudson crossings -- especially for trucks headed to Newark's vast land- and seaports. Carfloating, even significantly more intensive carfloating, would not be enough; a fixed link is what's needed.
This ... isn't really enough of a justification to drive an $11 billion investment. But something else is. To understand what is, though, first we must look at NS' and CSX's current Northeastern mainlines and traffic patterns.
Linking the Northeastern Markets
|Norfolk Southern's northeastern mainlines. Note relative circuitousness.|
CSX already had a mainline from DC and points south and west into Newark. This route runs through the hearts of the Northeastern cities -- DC, Baltimore, Philadelphia -- and connects to mainlines to the west and south. Augmenting this, CSX took control of the West Shore Line, Selkirk Yard, and the old Boston & Albany, as well as a new western mainline, the so-called "Water Level Route" from New York to Buffalo.
|The competition: CSX's Northeastern mainlines|
CSX got the more direct route and NS the more circuitous one. But the CSX line suffers one key competitive disadvantage: because of no fewer than three tunnels under city streets, CSX cannot, in fact, run Plate K-clearance (double-stacks, auto racks) trains north-south. One of these, in Philadelphia, conveniently came with a bypass in the Conrail purchase; another, in DC, is being rebuilt to expand capacity. The third, in Baltimore, continues to split CSX's mainline in two. It can't, in fact, run a double-stack train from New York to Newport News, VA, without an enormous detour through Ohio!
|Due to clearance restrictions, CSX is actually at a disadvantage when it comes to intermodal flows|
This brings up what does justify dropping $11 billion on the Cross Harbor Freight Tunnel: New traffic patterns. Specifically, one involving a direct route from Harrisburg to Boston via New York City.
How, exactly, does the NS get to Boston?
NS developed its Boston gateway -- the "Patriot Corridor" -- not on its own tracks but rather via what are known as trackage rights, which are (quelle surprise) the right for one company to run its train on another's railroad tracks. In this case, the trackage rights extended across two other railroads: the Canadian Pacific-owned Delaware & Hudson (D&H) from Sunbury, PA to the Albany area, and the Pan Am -- once an airline that went bankrupt whose branding got bought by a railroad -- from there on to Boston. Later, NS would buy the D&H portion outright as its owners culled what was, for them, non-core trackage.
There are several major problems with this alignment. First, it's really circuitous. And second, it's a mountain road: it follows the Susquehanna River all the way to Binghamton, NY, and from there runs along the back of the Catskills into the Mohawk Valley. And once there, getting into New England requires crossing another mountain range! Freight operators prefer low-grade routes, and the NS' is anything but.
|Linking up with the P&W (black) gives the Norfolk Southern a second way into New England|
Ah, but there is one more thing about the New York market that makes life complicated. It's the nation's largest and busiest passenger market, and while the NS doesn't really have to worry about it so much due to a convenient quirk of Victorian-era line placement, the P&W doesn't really have a choice. It isn't just the Hell Gate Bridge: the P&W's mainline and the Northeast Corridor are one and the same.
What that means is that -- while you get a straight, flat, fast route -- you also get one with limited freight slots and whose clearance is determined by overhead wire. And, just to make things all that much more annoying, the part with the greatest passenger-traffic density, New York to New Haven, has very limited, if any, bypass options. So, while the NS gets a nice shiny new tunnel and a new partner railroad, it also gets its partner railroad's baggage -- 10 tpd's worth of slots instead of 20 or so, and serious clearance restrictions to boot.
While double-stacks can be hauled under wire for short segments -- the Norfolk Southern does under SEPTA wire in Norristown, and CSX probably does (also under SEPTA wire) out around the Oxford Valley from time to time -- freight haulers generally prefer not to.* And this route has an unavoidable stretch of haulage under wire all the way into Connecticut, even if your New England intermodal terminal is Worcester.
What this means for NS is that they will have two partner railroads into New England, but both present inferior routes relative to the CSX's (a natural extension of the Water Level Route, albeit one requiring a stretch of mountain railroading). Despite the Cross Harbor Rail Tunnel's design allowing double-deck transit, the run-through unit trains an NS-P&W partnership would entail would have to be somewhat ... squatter.
What does this mean for passenger rail?
The effect for Amtrak, MNRR, and LIRR operations would be minimal. It's very likely NS-P&W trains would only be given night slots, due to the daytime congestion of the New Haven line.
But the biggest effect would be on Triborough RX. The Triborough RX proposal [i]as it stands[/i] requires half the Hell Gate's track capacity, and more importantly, the ramp connecting the bridge approach with the Bay Ridge branch.
While Triborough RX can be built at the edge of the Bay Ridge branch right-of-way, either as the Sea Beach Line is, the Canarsie Line (and also able to tie into both), it's very likely the freight requirements would conspire to eliminate the trackage available for Triborough RX. Remember, even though the freight connection can operate with a single track, the subway will need at least two, which means there is an unresolvable conflict of interest on the Long Island approach, where only two tracks are available.
If we agree the main purpose of Triborough RX is linking Brooklyn, Queens, and the Bronx together, then that erases the line's main advantage, at least in its current form; Triborough RX would need an entirely new connection over or under the East River to remain viable.
Finally, a freight connection directly linking the Norfolk Southern's Oak Island Yard with a P&W connection at Hell Gate would solve one major New York transportation problem -- it would finally surmount the Selkirk Hurdle -- but at the same time, it would bring into focus the next logical issue: inadequate infrastructure to support operations between New York and New Haven.
While several analyses of needed investments to improve that section have been done, a Cross Harbor Rail Tunnel would throw a new need into the mix: a freight route, preferably one that accommodates double-stacks. (The two potential solutions are to either widen the existing railroad or build a new alignment alongside I-95.) And that, in turn, would drive need for more slots across the East River -- a condition that would turn Hell Gate into a chokepoint.
The long-term effect of the Cross Harbor Rail Tunnel, therefore, would be the establishment of eight tracks of throughput demand across the East River at Hell Gate -- and while long distance, HSR, regional, and commuter trains can all be blended onto the same infrastructure, NS and P&W requiring 25 or 30 slots (instead of 10) per day may not be able to. And Triborough RX, requiring separated infrastructure, definitely can't.
* That said, there has long been the claim (which I haven't been able to substantiate) that double-deck intermodal trains run under wire in China.