. The New York improvement and tunnel extension of the Pennsylvania railroad. Issued October, 1910 . Pennsylvania Tunnels— Hackensack Portals of BergenHill Tunnel in New Jersey. Pennsylvania Tunnels— Interior, showing Signal Apparatus The Pennsylvania Railroads New York Improvement VIII The construction of the Pennsylvania Railroadtunnels under the North and East Rivers into NewYork and New Jersey, attaining a maximum depth of97 feet below mean high water, and built for a heavyand high-speed traffic of great volume, was an under-taking without precedent. The tunnels or tubes themselves consist
. The New York improvement and tunnel extension of the Pennsylvania railroad. Issued October, 1910 . Pennsylvania Tunnels— Hackensack Portals of BergenHill Tunnel in New Jersey. Pennsylvania Tunnels— Interior, showing Signal Apparatus The Pennsylvania Railroads New York Improvement VIII The construction of the Pennsylvania Railroadtunnels under the North and East Rivers into NewYork and New Jersey, attaining a maximum depth of97 feet below mean high water, and built for a heavyand high-speed traffic of great volume, was an under-taking without precedent. The tunnels or tubes themselves consist of a seriesof iron rings, and the installation of every ring meantan advance of two and a half feet. Eleven segmentsand a key piece at the top complete the circumfer-ence, and an entire ring weighs about fifteen cast-iron plates, or sections of the ring, haveflanges at right angles to the surface, and it is throughthese that the successive rings are held together withbolts. The record progress in one day of eight hourswas five of these rings, or twelve and one-half rams, placed against the flanges every fewinches around the tube, were used to p
Size: 1791px × 1395px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherphila, bookyear1910
