RAILSIM TPC Train Plot of Acceleration Components over chainage/stationing location (in this case, in feet).  Other possible selections for the horizontal axis are many, such as time (in hours, minutes or seconds), distance traveled, velocity, and speed restriction.

Railroads, transit agencies, rail systems suppliers, consulting engineers and planners rely on RAILSIM® Simulation Software Suite for rail systems planning, analysis and design. RAILSIM Train Performance Calculator (TPC) provides simulation of one train on a single track rail alignment, and is the ideal tool for:

• Travel time predictions,
• Train control attainable speed and safe braking distance analysis,
• Alternative rail alignment analysis, and
• Rolling stock evaluation.

Rail Network Planning Applications

Planners develop trip times predictions for new rail alignments and assignment of new rolling stock to existing rail lines with RAILSIM TPC. These are used to support ridership prediction models, operations planning and fleet size requirements analyses. RAILSIM TPC includes many automated features to support planning applications, including realistic interstation coasting for inclusion of schedule recovery margin and calculation of curve speed limits where engineering calculations are not available.

RAILSIM TPC supports analysis of skip-stop operations, alternative stopping patterns and the impacts of global or station-specific dwell time improvements. RAILSIM TPC’s energy consumption calculations are useful in predicting fossil fuel-powered train emissions and their environmental impacts on a location-specific basis.

RAILSIM TPC reports on the progress of every run as it processes.

Rail Systems Engineering Applications

Rail Systems Engineers calculate safe braking distances for train control design purposes with RAILSIM TPC. Attainable speed calculations using the TPC support train control design and rail track design, where higher design speeds (and their associated costs) may not be required for normal operations. RAILSIM TPC’s peak power and energy consumption calculations are used by Rail Systems Engineers to support electrical components sizing and to evaluate energy savings attributable to coasting strategies and more energy-efficient rolling stock.

Rolling Stock Design and Evaluation Applications

Engineers and planners use RAILSIM TPC (with our extensive Rolling Stock Libraries) to compare the performance and trip times of alternative rolling stock types, including “off-the-shelf” versus custom-built models. Where severe grades and curves are an issue, RAILSIM TPC is used to determine optimal power to weight ratios under a variety of adhesion conditions. RAILSIM TPC can be used to evaluate trip time adjustments when low adhesion conditions prevail, and to assess the likelihood of train stalling.

TPC Run Types

RAILSIM TPC supports eight different run types:

• END TO END RUN — TPC run from terminal to terminal with station stopping as required
• FLYING SPEED RUN — maximum attainable speed run,
• ALL OUT SPEED RUN — station to station run with no coasting or train pacing,
• SCHEDULED SPEED RUN — station to station run with coasting as required,
• ACCELERATE — can be combined with other run types, such as for the “run-away” portion of safe braking distance calculations,
• MAINTAIN SPEED — can be combined with other run types, such as for the reaction time period for safe braking distance calculations,
• COAST — can be combined with other run types, such as for the brake build-up time of safe braking distance calculations, and
• BRAKE — can be combined with other run types, and includes friction service braking, combined braking (friction and dynamic/regenerative), blended braking (dynamic/regenerative with friction at low velocities) and emergency braking options.

Using the RAILSIM TPC Station Stops page shown here, you can easily vary
station dwells and stopping patterns for any simulated train run.

Highly Accurate Train Performance Modeling

RAILSIM TPC accurately calculates train performance for all types of operations and analyses, including:

• Variable calculation time step from 0.01 to 10.0 seconds,
• Detailed tractive effort/braking effort curve inputs or simplified calculations based on horsepower,
• Support for user-specified train loads (freight or passenger) by location,
• Support for user-specified schedule margin by station,
• Support for different train performance strategies to achieve schedule margin, including coasting without a reduced speed limit, coasting with a reduced speed limit and linear velocity reduction
• Support for rotational mass inertia processing,
• Derating of locomotive horsepower for head-end power, where applicable,
• Distributed mass and center of mass processing options,
• Jerk rate limiting where applicable,
• Accurate modeling of grade and curve effects, and
• Adherence to an unlimited number of user-specified speed restrictions.

Schedule margin can be specified in percent, in time per distance, or in actual run time.

Sophisticated Train Braking Algorithms

RAILSIM TPC supports many different types of train braking modeling, ensuring that its results are appropriate for the specific type of train being simulated. These features include:

• Brake build-up time where applicable,
• Support for either air or electric brake propagation through the train,
• Air brake propagation times which are specific to each locomotive and car in the train,
• Accurate modeling of helper and mid-train locomotives where air brake propagation is in effect,
• Support for friction braking, blended braking (transition from dynamic/regenerative braking to friction braking at a user-specified transition speed), and combined braking (combined dynamic/regenerative and friction braking),
• Support for emergency braking (concurrent application of friction, dynamic/regenerative braking and track braking, where applicable).

The User Experience

RAILSIM TPC provides convenient data editing, train performance modeling and report generation in a single software package. Its easy-to-use features include:

• A "point and click" user interface,
• Trains can be assembled using pop-up menus with lists of locomotives, freight cars, passenger coaches and multiple unit vehicles,
• Support of both metric and imperial (American) measurement systems,
• Extensive user documentation providing specific information on data formats, program commands and output interpretation, including color user manual with graphic "snapshots" of all RAILSIM menus and displays, and
• Context-sensitive online help that is a browsable version of the user manual and is continuously updated and delivered with each software update.

RAILSIM TPC supports convenient tab controls for all train performance options, parameters, station stopping patterns and dwell times, schedule margins, and train loads selections.

TPC Typical Output

RAILSIM Report Generator produces detailed, formatted reports from TPC run output data. Each report reflects a user-specified computational time step. Reports can be displayed on-screen, stored in a disk file or sent directly to any Microsoft Windows-compatible printer. Spreadsheet, relational database (Microsoft Access *.MDB file) and CAD (AutoCAD *.DXF file) formats are also supported:

• TRAIN REPORT — time, distance, chainage (engineering stationing), velocity, acceleration, deceleration, rolling resistance, effective track grade, effective track curve and data input summary, in text format,
• TRAIN SUMMARY REPORT — station arrive, leave and pass (non-stop) times (either time of day or cumulative running time) as well as distance operated, average velocity (with and without station stops), peak power demand and energy consumption for an End to End run,
• TRAIN PLOT — graphical representation of any two or three groups of TPC output variables, including time, distance, acceleration, tractive/braking effort, chainage (engineering stationing), grade, curvature, and maximum authorized speed. Separate colors are user-selectable for multiple variables and zoom/pan functions are included,

TPC Train Plot of Rolling Resistance versus Velocity

• ENERGY/POWER PLOT — graphical representation of computed peak power demand and energy consumption for an End to End TPC run, including tractive effort, hotel (lights, air conditioning and heating) power and power consumption during dynamic braking. Where applicable, regenerative power and energy produced during braking are shown. Energy consumption and instantaneous power demand are reported in kWh and kW for electrical vehicles, and in gallons or liters of diesel fuel for fossil fuel powered trains, and
• ACCELERATION COMPONENTS PLOT (shown at the top of this page) — graphical representation of a TPC run showing a multi-color plot of the simulated components which make up train acceleration and deceleration — tractive effort, braking effort, rolling resistance due to curvature, the effects of gradient and train rolling resistance (including aerodynamic resistance).

Click any image below to see full size.