Isolation mounting system for railroad car steps and running boards

In a mounting system for securing a metal support surface to a metal bracket on a railroad car, the improvement comprising:

• a compressible, energy absorbing arrangement having a non-metallic bushing secured intermediate the support surface and the bracket for preventing metal to metal contact between the support surface and the bracket and absorbing vibrational energy caused by movement of the railroad car,
• wherein the bushing has an upstanding neck protruding through a hole formed in the support surface and a bottom surface having an enlarged central opening provided therein, the enlarged central opening being in communication with a throughbore passing through the neck of the bushing, wherein the enlarged central opening receives an expanded head of an insert having an internally threaded bore and threaded shaft depending from the head and secured to the metal bracket,
• wherein the arrangement includes a fastening device passing through the bushing and isolated from the support surface, the fastening device being received within the internally threaded bore of the insert.