The century-old PATH subway tunnels underneath the Hudson River were not excavated through bedrock, but rather under a thick layer of silt and clay. Apparently there is a a sufficient security concern to warrant protecting the tops of the tunnels with some form of blanket to protect against bomb blasts. [Source: NYPOST.com via ASCE SmartBrief. Image: NYPOST.com]
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Historic Pennsylvania Tunnel Reopens with Help From NCFI’s TerraThane Polyurethane Foam
MOUNT AIRY, NC—A $2 million tunnel construction project on the Great Alleghany Passage (GAP) is reopened to the public with help from a geotechnical polyurethane foam called TerraThane, by US company, NCFI Polyurethanes.
The GAP rail-trail is 150 miles of hiking and biking between Cumberland, Md, and Pittsburgh, Pa. created along the former railway line. In Cumberland, the GAP joins the C&O Canal Towpath, creating a continuous 335-mile long trail experience all the way to Washington, DC. It’s become a favorite biking destination for people from around the Mid-Atlantic states. One of its main tunnels, the Pinkerton Tunnel, an 849-foot former Western Maryland Railway tunnel, has been closed since 1975 due to erosion and unstable conditions. The Allegheny Trail Alliance, the organization that built and now maintains the 150-mile GAP, and the Somerset County Rails-to-Trails Association (SCRTA), wanted the tunnel reopened and helped fund the project.
[Editor] Click through for the rest of the press release from GeoPrac sponsor, NCFI Polyurethanes (makers of TerraThane). [/Editor]