Since the fastener had to be delivered as a single unit, it had to be assembled on a steel plate that in turn is bolted to the wooden sleepers. The thickness of the steel plate was determined as ½" (12 mm) to provide a secure anchor for the 1" (25 mm) diameter studs that form the backbone of the pre-load system. This meant that there was only room for ¾" (19 mm) of vibration damping material. The solution consists of a 3 mm thick rubber sheet studded with natural rubber discs with a diameter of 35 mm and a height of 19 mm.
Comparison of ground borne vibration levels between standard NYCTA track and track with the D2S fastener at Grand Street Station.
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