North River Tunnels

The North River Tunnels are a pair of tunnels:52 that carry Amtrak and New Jersey Transit rail lines under the Hudson River between Weehawken, New Jersey and Pennsylvania Station in Manhattan, New York City. Built between 1904 and 1908 by the Pennsylvania Railroad (PRR) to allow its trains to reach Manhattan, they opened for passenger service in late 1910.

History

Context

The PRR had consolidated its control of railroads in New Jersey with the lease of United New Jersey Railroad and Canal Company in 1871, thereby extending its rail network from Philadelphia northward to Jersey City. Crossing the Hudson River, however, remained a major obstacle. To the east, the Long Island Rail Road (LIRR) ended at the East River. In both situations, passengers had to transfer to ferries to Manhattan. This put the PRR at a disadvantage relative to its arch competitor, the New York Central Railroad, which already served Manhattan.

After unsuccessfully trying to create a bridge over the Hudson River, the PRR and the LIRR developed several proposals for improved regional rail access in 1892 as part of the New York Tunnel Extension project. The proposals included new tunnels between Jersey City and Manhattan, and possibly one to Brooklyn; a new terminal in midtown Manhattan for both the PRR and LIRR, completion of the Hudson Tubes, and a bridge proposal. These proposals finally came to fruition at the turn of the century, when the PRR created subsidiaries to manage the project. The Pennsylvania, New Jersey and New York Railroad, incorporated on February 13, 1902, was to oversee construction of the North River Tunnels. The PNJ&NY would also be in charge of the Meadows Division, which would handle the construction of the North River Tunnel approaches on the New Jersey side.

The original proposal for the PRR and LIRR terminal in Midtown, which was published in June 1901, called for the construction of a bridge across Hudson River between 45th and 50th Streets in Manhattan, as well as two closely spaced terminals for the LIRR and PRR. This would allow passengers to travel between Long Island and New Jersey without having to switch trains. In December 1901, the plans were modified so that the PRR would construct the North River Tunnels under the Hudson River, instead of a bridge over it. The PRR cited costs and land value as a reason for constructing a tunnel rather than a bridge, since the cost of a tunnel would be one-third that of a bridge. The North River Tunnels themselves would consist of between two and four steel tubes with the diameter of 18.5 to 19.5 feet (5.6 to 5.9 m). The New York Tunnel Extension quickly gained opposition from the New York City Board of Rapid Transit Commissioners, who objected that they would not have jurisdiction over the new tunnels, as well as from the Interborough Rapid Transit Company, which saw the New York Tunnel Extension as a potential competitor to its as-yet-incomplete rapid transit service. The project was approved by the New York City Board of Aldermen in December 1902, on a 41-36 vote. The North and East River Tunnels were to be built under the riverbed of their respective rivers. The PRR and LIRR lines would converge at New York Penn Station, an expansive Beaux-Arts edifice between 31st and 33rd Streets in Manhattan. The entire project was expected to cost over $100 million.

Design and construction

Led by Chief Engineer Charles M. Jacobs, the tunnel design team began work in 1902. The contract for building the North River Tunnels was awarded to O'Rourke Engineering Construction Company in 1904. Originally, the tunnel would have comprised three tubes, but this was later downsized to two tubes. The first construction work comprised the digging of two shafts: one just east of 11th Avenue a few hundred yards east of the river's eastern shore; and a larger one in Weehawken, a few hundred yards west of the river's western shore. Construction on the Weehawken Shaft started in June 1903. It was completed in September 1904 as a concrete-walled rectangular pit, 56 by 116 ft (17.1 by 35.4 m) at the bottom and 76 ft (23.2 m) deep.

When the shafts were complete, O'Rourke began work on the tunnels proper. The project was divided into three parts, each managed by a resident engineer: the "Terminal Station" in Manhattan; the "River Tunnels", east from the Weehawken Shaft and under the Hudson River; and the Bergen Hill tunnels, west from the Weehawken Shaft to the tunnel portals on the west side of the Palisades.:45 The tunnels were built with drilling and blasting techniques and tunnelling shields, which were placed at three locations and driven towards each other. The shields proceeded west from Manhattan, east and west from Weehawken, and east from the Bergen portals.

Under the river itself, the tunnels started in rock, using drill and blast, but the strata under the river was pure mud for a considerable depth. As a result, this part was driven under compressed air, using 194-ton shields that met about 3,000 feet (910 m) from the Weehawken and Manhattan portals. The mud was such that the shield was shoved forward without taking any ground; however, it was found that the shield was easier to steer if some mud was taken in through holes at the front, since the mud had the consistency of toothpaste. After the tubes had been excavated, they were lined with 2.5-foot-wide (0.76 m) segmental cast-iron rings, each weighing 22 tons. The segments were bolted together and lined with 22-inch (56 cm) of concrete.:200 The two ends of the northern tube under the river met in September 1906; at that time it was the longest underwater tunnel in the world.

Meanwhile, the John Shields Construction Company had begun in 1905 to bore through Bergen Hill, the lower Hudson Palisades; William Bradley took over in 1906 and the tunnels to the Hackensack Meadows were completed in April 1908.

Opening and use

The tunnels opened November 27, 1910, when the New York Tunnel Extension to New York Penn Station opened.:37 Prior to the opening of the New York Tunnel Extension, PRR trains from points south and west continued on the PRR main line, which terminated at Exchange Place in Jersey City, New Jersey. The New York Tunnel Extension branched off from the original PRR line two miles northeast of Newark, then ran northeast across the Jersey Meadows to the North River Tunnels and New York Penn. The tunnel project was undertaken in conjunction with numerous other pieces of infrastructure, including the Portal Bridge over the Hackensack River and the Manhattan Transfer interchange with the Hudson and Manhattan Railroad (now PATH).:37, 39 The opening of the North River Tunnels and Penn Station made the PRR the first–and as it turned out, only–railroad with direct access to New York City from the south.

Since opening, the North River Tunnels have seen increased traffic due to various service changes. In 1967, the Aldene Plan was implemented, requiring the floundering Central Railroad of New Jersey (CNJ), Reading (RDG), and Lehigh Valley (LV) railroads, to travel into Newark Penn with continuing service to New York Penn.:61 The PRR went bankrupt shortly afterward, and its operations were subsumed first into the Penn Central Transportation Company,:61 then into Conrail in 1976, and finally NJ Transit in 1983. The PRR's long distance service (including part of today's Northeast Corridor and Empire Corridor) was taken over by Amtrak in 1976. Amtrak also took control of the North River Tunnels, and NJ Transit started operating trains through the tunnels under contract with Amtrak.

Portals

The west portals are in North Bergen, at the west edge of the New Jersey Palisades near the east end of Route 3 at U.S. Route 1/9. They run beneath North Bergen, Union City, and Weehawken, to the east portals at the east edge of 10th Avenue at 32nd Street in Manhattan. When the top of the Weehawken Shaft was covered is a mystery; the two tracks may have remained open to the sky until catenary was added circa 1932. The two portals on the Manhattan side fanned out into 21 tracks just underneath 10th Avenue, serving the platforms at Penn Station. 450 West 33rd Street (now Five Manhattan West), on the east side of 10th Avenue, was built above the east portals in 1969.

Except for a curve west of the west end of Pier 72 that totals just under a degree, the two tracks are straight (in plan view). They are 37 feet (11.3 m) apart from west of 11th Avenue to the Bergen Hill portals. The third rail now ends just west of the Bergen Hill portals.

Operation and useful life

The current North River Tunnels allow a maximum of 24 one-way crossings per hour. Since 2003, the tunnels have operated near capacity during peak hours. Between 1976 and 2010, the number of NJ Transit weekday trains crossing the Hudson using the North River Tunnels increased from 147 to 438.

Trains ordinarily travel west (to New Jersey) through the north tube and east (to Manhattan) through the south. During the busiest hour of morning rush, about 24 trains are scheduled through the south tube, and the same through the north tube in the afternoon.

The tubes run parallel to each other underneath the river. The center of each tube was separated by a distance of 37 feet (11 m). The two tracks fan out to 21 tracks just west of Penn Station.

Proposed Gateway capacity expansion

The existing North River Tunnels could carry a maximum of 24 trains per hour in each direction. If the new Hudson Tunnel is not built, the North River Tunnels will have to be closed one at a time, reducing weekday service below the existing level of 24 trains per hour. Due to the need to provide two-way service on a single track, service would be reduced by over 50 percent. In the best-case scenario, with perfect operating conditions, 9 trains per hour could be provided through the existing North River Tunnels, or a 63% reduction in service. During the duration of construction, passengers would have to use overcrowded PATH trains, buses, and ferries to get between New Jersey and New York.:1–7 On the other hand, if the new Gateway tunnel is built, it would allow an additional 24 trains per hour to travel under the Hudson River, supplementing the 24 trains per hour that could use the existing North River Tubes.

Text imported from Wikipedia article "North River Tunnels" and modified on July 23, 2019 according to the CC-BY-SA 4.0 International license.