Slip Sidings and Catch sidings :
For all gauges, the maximum gradient permitted is 1: 400, whereas 1: 1200 is usually allowed within the station yard. No station yard should be steeper than 1: 260 except due to geographic conditions, where such a gradient cannot be avoided within the station yard, CRS condonation has to be obtained and special arrangements like “Slip Sliding” has to be provided.
Slip Sliding due to gradient steeper than 1: 100 falling away from the station in the close neighborhood.
If the gradient is steeper than 1: 80 falling towards the station. The arrangement of Catch siding is to be provided. It is to trap vehicles coming uncontrolled from the block section and trying to enter into the station.
- Catch siding due to falling gradient while approaching the station if steeper than 1: 80.
- Slip Sliding and Catch Siding points must be interlocked with the block instruments and such sidings should not be used for shunting or stabling purposes.