Railway Track & Structures - July 2008 - (Page 37)

strengths of 75,000 psi minimum. The spike was developed with coordination from spike machinery manufacturers to make it compatible with the equipment. Both Harsco and Nordco have kits available to convert late-model spike drivers to accept the Evergrip. “Evergrip first was adopted and saw widespread use with CSXT in 2003 and several million have been installed since. Canadian Pacific switched to the part in 2007. The CPR version is 1030 steel with tensile strength of 80,000 psi minimum. As of mid-2007, no report had been received of an Evergrip being found loose or broken in the field.” Austin added: “The increased loads and traffic have been especially demanding on special trackwork. In the past 10 years, more attention has been paid to the fasteners. As more bolts were broken or loosened in trackwork, the practice has been to increase the strength and size of the bolts. Other conditions within the trackwork that can cause bolt failure are more frequently considered.” Evergrip drive-in screw spike. Many bolts in special trackwork are now SAE J429 Grade 8. AREMA included recommendations for Grade 8 bolts in special trackwork in plan 100 of the trackwork plans in 1999. The recommendations also include torque values and guidance to use lubrication. “The railroad engineering community has begun to recognize that other aspects of the track can cause fastener failures,” he said. “It has been common in the past for a broken bolt to be written off as ‘bad’ and just discarded and replaced. When several bolts break in the same location and not in other places, the likelihood of it being a ‘bad’ bolt problem becomes remote. It is now more commonly recognized that ballast and subgrade issues, installation deficiencies, joint design, and maintenance practices can have fatal consequences for otherwise sound fasteners. Bolts are best used to clamp things together by tension. When they are loose and expected to hold trackwork together by resisting bending and shear, the result is usually a broken bolt. “The past several years have seen many changes in the fasteners used in track,” Austin said. “The higher axle loads and increased traffic have forced railroads to move to different fastener systems, higher strength and larger parts. Different railroads have taken different strategies to address the issues, but nearly all have made some upgrades to fasteners and changes in installation and maintenance practices. There will, no doubt, continue to be changes in the fasteners and methods used in railroad track.” http://www.plasseramerican.com http://www.plasseramerican.com

Table of Contents Feed for the Digital Edition of Railway Track & Structures - July 2008

Railway Track & Structures - July 2008 On Track Industry Today Supplier News AREMA News NRC News TTCI R&D Products and Literature People Calendar Sales Representatives Website Directory Advertisers Index Professional Directory Classified Advertising Chicago Perspective Extending Service Life for Costly Special Trackwork Rail Welding Gets Act Together Premium Fasteners, Rail Steels Help Meet Strain of Heavy Haul

Railway Track & Structures - July 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.