Line Capacity Simulator

1. Line Capacity Simulator

2. Railway Operations: Issues and Objectives • Capacity management • Infrastructure planning • Timetable preparation • Management of day-to-day movement of trains.

3. Objectives of the Simulator • Observing effects of making changes to the existing timetable • Estimating section capacity • Analyzing the effect of introducing extra scheduled trains in the section

4. Objectives of the Simulator • Visualizing the consequences of signal failure and delays of trains. • To model and represent different arrival patterns and compositions of traffic on section. • Evaluating investment proposals at local level

5. Objectives of the Simulator • To present the impact of changed operational parameters such as • Speed of trains • Acceleration/Deceleration • Loop entry/exit velocities • To experiment with different scheduling possibilities based on - • Throughput • Delays • Priorities • Due dates lateness • Slack in timetables.

6. Capacity Planning Line /Section Capacity: Number of (standardised) trains that can be run on a given section Estimated by • Scott’s Formula • Master chart preparation This can be done only for a static, known traffic scenario

7. Current notion of capacity The number of trains that can be handled with “reasonable” transit time (say, twice the bare minimum transit time). This accounts for the prevailing traffic mix and congestion effects.

8. Software • Uses Java 2 as development platform. • User specified data files are read and station and blocks are modeled accordingly • Trains are sorted in the order of their priorities • Runs in ‘one train at a time’ or‘complete simulation’ modes

9. Station details Loop details Block details Scheduled trains data Freight train data Simulation parameter data Gradient specification data Gradient’s effect details Signal failure details Delay specification data Inputs In MS Excel or ASCII Text format

10. Output • Loop /platform occupancies • Block occupancies • Traversal time of trains (timetabled passenger as well as non-timetabled freight trains); Averages of such times • Plot of distance vs. time in the master chart format • Velocity profile and signal aspect displays • Signal headway

11. Algorithm

12. Departure Time Based Priority Scheduling of Passenger Trains • The train with higher priority is scheduled first • If two trains have the same priority • Compared for their departure times, for scheduled passenger trains  • Compared  for their arrival times, for freight trains • Passenger train with earliest departure or freight train with earliest arrival time is scheduled first

13. Preference Based Resource Allocation for Passenger Trains • Exploring other possible alternate paths through the station if the preferred loop is not available by passenger train • Ensures a much efficient use of available resourcesto facilitate a smooth passage past the section.

14. Simulation Output without searching alternate paths

15. Simulation Output with searching alternate paths

21. Signal Spacing and Headway Analysis on Suburban sections • Supports automatic signaling on mainline sections and relevant track and train detail in operation. • Study for Central Railway on signal spacing and headway analysis.