Mount Airy, North Carolina – TerraThane geotechnical polyurethane foam from NCFI Polyurethanes played a key role in the recent $2m (EUR1.8m) restoration of an old railway tunnel on the route of a bike rail-trail in Pennsylvania.
The 849 ft (259m) Pinkerton Tunnel on the former Western Maryland Railway had been closed since 1975, having become unsafe as a result of erosion.
A new tunnel was created inside the old one using a structural steel plate tunnel lining system, and TerraThane was pumped into the gap between the two tunnels to create a single, monolithic structure.
According to Kirk Roberts, manager of geotechnical contractor CJGeo which ran the project, TerraThane was chosen as it is a viscous, high-density liquid that was easy to pump into the space, where it expanded to fill the gap. Once cured, it adhered to both the concrete and steel surfaces, tying them together.
“NCFI’s formulation is structurally sound and provides excellent waterproofing for the steel,” Roberts said. “We took two weeks pumping in more than 120,000 lbs of TerraThane. This was by far the largest structural steel plate tunnel reline grouted with polyurethane the liner manufacturer has ever seen, and the TerraThane worked great.”
XE Currency conversion:29 February, 2016