Gauge conversion in Mayiladuthurai-Thiruvarur – Pattakottai- Karaikudi section – Material modification to gauge conversion in Tiruthuraipundi – Agastyampalli section: 50 mm machine-crushed stone ballast at Tiruthuraipundi and Agastyampalli station including loading and unloading into BKH between Tiruthuraipundi (Excl) and Agastyampalli (Incl) stations. Proposed collection, supply and stacking.