The Accu-Tread roller was chosen for this application to reduce contact stress for a safe segmental launch.
Hilman Rollers designed the AccuTread for this application. This is a special roller designed to reduce contact stress accomplished by integrating a steel or neoprene tread with Hilman's endless chain principle working simultaneously. When in compression, it spreads the load over the greater area effectively reducing the contact stress over the given area.
This project used the 20 metric ton capacity Hilman AccuTread rollers inverted to interface with the heavy precast concrete segments so as not to mark the structure in any way.
An Accu-Tread was chosen for this application due to the high stresses that would have damaged the concrete segments had only standard rollers been used. The recirculating treads minimized the chance of point loading as well as maximized the safety and contact area of the segmental launch.
Standard Hilman Rollers with Rocker Assembly were also used for maintaining the alignment of the concrete segments. The project utilized a 'balanced cantilever construction process' and was deemed very successful.
