Railway Operations: Issues and Railway Operations: Issues and ObjectivesObjectives

Capacity managementCapacity management

Infrastructure planningInfrastructure planning

Timetable preparation Timetable preparation

Management of day-to-day movement Management of day-to-day movement of trains. of trains.

Objectives of the SimulatorObjectives of the Simulator Observing effects of making changes to the Observing effects of making changes to the

existing timetableexisting timetable

Estimating section capacityEstimating section capacity

Analyzing the effect of introducing extra Analyzing the effect of introducing extra scheduled trains in the sectionscheduled trains in the section

Objectives of the SimulatorObjectives of the Simulator

Visualizing the consequences of signal failure Visualizing the consequences of signal failure and delays of trains.and delays of trains.

To model and represent different arrival To model and represent different arrival patterns and compositions of traffic on section.patterns and compositions of traffic on section.

Evaluating investment proposals at local levelEvaluating investment proposals at local level

Objectives of the SimulatorObjectives of the SimulatorTo present the impact of changed operational To present the impact of changed operational

parameters such asparameters such asSpeed of trains Speed of trains Acceleration/DecelerationAcceleration/DecelerationLoop entry/exit velocitiesLoop entry/exit velocities

To experiment with different scheduling possibilities To experiment with different scheduling possibilities based on -based on -

ThroughputThroughputDelaysDelaysPrioritiesPrioritiesDue dates latenessDue dates latenessSlack in timetables.Slack in timetables.

Capacity PlanningCapacity Planning

Line /Section CapacityLine /Section Capacity::Number of (standardised) trains that can be run on Number of (standardised) trains that can be run on

a given sectiona given section

Estimated byEstimated by Scott’s FormulaScott’s Formula Master chart preparationMaster chart preparation

This can be done only for a static, known traffic This can be done only for a static, known traffic scenarioscenario

Current notion of capacityCurrent notion of capacity

The number of trains that can be handled with “reasonable” transit time (say, twice the bareminimum transit time).

This accounts for the prevailing traffic mixand congestion effects.

SoftwareSoftware Uses Uses Java 2Java 2 as development platform. as development platform. User specified data files are read and User specified data files are read and

station and blocks are modeled station and blocks are modeled accordinglyaccordingly

Trains are sorted in the order of their Trains are sorted in the order of their prioritiespriorities

Runs in ‘Runs in ‘one train at a time’one train at a time’ oror‘‘complete simulation’complete simulation’ modes modes

InputsInputs

Station detailsStation details Loop detailsLoop details Block detailsBlock details Scheduled trains data Scheduled trains data Freight train dataFreight train data Simulation parameter Simulation parameter

datadata

Gradient Gradient specification dataspecification data

Gradient’s effect Gradient’s effect detailsdetails

Signal failure detailsSignal failure details Delay specification Delay specification

datadata

In MS Excel or ASCII Text format

OutputOutputLoop /platform occupanciesLoop /platform occupanciesBlock occupanciesBlock occupanciesTraversal time of trains (timetabled Traversal time of trains (timetabled passenger as well as non-timetabled passenger as well as non-timetabled freight trains); Averages of such timesfreight trains); Averages of such timesPlot of distance vs. time in the master Plot of distance vs. time in the master chart formatchart formatVelocity profile and signal aspect displaysVelocity profile and signal aspect displaysSignal headway Signal headway

Start

Read The Data

Initialize all signals green, all sections Free

Sort Trains by Priority

Set signal failure

Get Train from sorted list

Schedule a train

Sort signals, prohibited intervals, set signal failure

Is any train left

Stop

Yes No

Algorithm

Departure Time Based Priority Departure Time Based Priority Scheduling of Passenger TrainsScheduling of Passenger TrainsThe train with The train with higher priorityhigher priority is scheduled first is scheduled first

If two trains have the same priorityIf two trains have the same priorityComparedCompared f for their or their departure times, departure times, for scheduled for scheduled passenger trains passenger trains 

Compared  for their Compared  for their arrival times,arrival times, for freight trains for freight trains

Passenger train with earliest departure or freight Passenger train with earliest departure or freight train with earliest arrival time is scheduled firsttrain with earliest arrival time is scheduled first

Preference Based Resource Preference Based Resource Allocation for Passenger TrainsAllocation for Passenger Trains

Exploring other Exploring other possible alternate pathspossible alternate paths through the station if the preferred loop is through the station if the preferred loop is not available by passenger trainnot available by passenger train

Ensures a much efficient use of available Ensures a much efficient use of available resourcesresources to facilitate a smooth passage to facilitate a smooth passage past the section.past the section.

Simulation Output without Simulation Output without searching alternate pathssearching alternate paths

Simulation Output with searching Simulation Output with searching alternate pathsalternate paths

Signal Spacing and Headway Signal Spacing and Headway Analysis on Suburban sectionsAnalysis on Suburban sections

Supports automatic signaling on mainline Supports automatic signaling on mainline sections and relevant track and train detail sections and relevant track and train detail in operation.in operation.

Study for Central Railway on signal spacinStudy for Central Railway on signal spacing and headway analysis.g and headway analysis.