Q. Explain Gap Survey and adjustment of Gap?

Gap survey and rectification of gaps is to be carried out, in stretches where track develops excessive creep jammed joints, sun kinks, buckling, wide gaps, battered and hogged joints, fractures at joints and bending of bolts etc. In SWR the gap survey and adjustment should normally be done before the end of February once a year (i.e., before onset of Summer).

The gap survey shall be conducted on a clear and sunny day in the cool hours of the day.

The length over which gap survey is to be done should, wherever possible, be divided into suitable sub-sections, each bounded by fixed points such as level crossings, points and crossings etc. The survey should be completed during as short a time as possible, by employing adequate number of parties so that the rail temperature is not likely to vary appreciably.

The joint gaps shall be measured by taper gauge in mm. and the readings entered in the pro forma.