Railway Operations: Issues and
Objectives
Capacity management
Infrastructure planning
Timetable preparation
Management of day-to-day movement
of trains.
Objectives of the Simulator
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Observing effects of making changes to the
existing timetable
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Estimating section capacity
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Analyzing the effect of introducing extra
scheduled trains in the section
Objectives of the Simulator
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Visualizing the consequences of signal failure
and delays of trains.
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To model and represent different arrival
patterns and compositions of traffic on section.
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Evaluating investment proposals at local level
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.
Capacity Planning
Line /Section Capacity:
Number of (standardised) trains that can be run on
a given section
Estimated by
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Scott’s Formula
Master chart preparation
This can be done only for a static, known traffic
scenario
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.
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
Inputs
In MS Excel or ASCII Text format
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Station details
Loop details
Block details
Scheduled trains data
Freight train data
Simulation parameter
data
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Gradient
specification data
Gradient’s effect
details
Signal failure details
Delay specification
data
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
Algorithm
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
Yes
No
Stop
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
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
resources to facilitate a smooth passage
past the section.
Simulation Output without
searching alternate paths
Simulation Output with searching
alternate paths
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.