What is Track renewal?
Complete Track Renewal (CTR)refers to the most thorough track replacement regime where rails, sleepers, etc., are fully replaced. Through Rail Renewal (TRR) refers to the replacement of rails in a given section of track. Through Sleeper Renewal (TSR) refers to the replacement of sleepers. There are Through Turnout Renewal (TRR), Through Fitting Renewal (TFR), Through Weld Renewal (TWR), and Through Bridge Timber Renewal (TBTR).
Each of these has a more thorough (‘primary’) and less thorough (‘secondary’) version, hence you see the acronyms like ‘CTR(P)’ for ‘Complete Track Renewal – Primary’, or ‘TSR(S)’ for ‘Through Sleeper Renewal- Secondary. Additionally, there are ‘Casual’ renewals, which refers to renewals of any kind that happen not on a predetermined schedule but as determined based on patrolling and inspection of tracks, in small continuous stretches. Finally, ‘Scattered’ Rail renewal (SR) refers to ad hoc replacements that happen at isolated points.