1. Brief Description

    This is a tool used to probe the soundness of packing under the concrete sleepers. It is made up of a steel rod of about 1 m in length and about 25mm diameter fitted with a steel hemisphere cup at one end. This hemi-spherical hollow cup is fitted with rubber ball of 140 mm diameter made out of natural rubber. Its weight is about 5 to 6 Kg.
2. Use:

    The soundness of packing underneath a PSC sleeper can be estimated by using this tool by observing the rebound of the tool when dropped vertically on the edge of the sleeper from a height of about 60 cm.

    Note :

    The rebound is dependent on the quality of rubber, height of drop and packing under the sleeper. Thus, its efficacy and its inference can be relied upon only by ensuring that it is used regularly by an experienced trackman on soundly packed sleepers and comparing its rebound with the actual rebound at site (as in case of incipient buckling / buckled track).

      Fig.: Canne-A-Boule