Heavy Truck Rollover


Overview: Computes the Rollover Speeds of a vehicle based on vehicle dimensional data.


Entry into Module:


This module of the program is normally entered by clicking on the REC-TEC block in the upper left of the REC-TEC Window causing the drop-down menu to appear. Place the cursor on the Heavy Truck block and click on Rollover on the sub-menu to initiate this module.


Under certain circumstances, the user may choose to use the Files block instead of the drop-down menu approach. Selecting any file with a .ROL extension in the Dialog box accessed from either the Open Single File or Open Multiple Files block opens this module.


Selecting AutoLoad [ON] from either the Setup Menu or the AutoLoad Icon on the upper right side (third line) of the REC-TEC Window automatically loads the two-vehicle scenario that was on the screen when the module was closed, either individually, or when the program was closed. With AutoLoad [OFF] on the main REC-TEC Window, modules will start without loading a file.


Data Entry:


This module contains the following data entry blocks:




             Track Width Track Width (Ctr to Ctr)

             Bed Width Vehicle Bed Width

             Suspension Vertical Displacement of Bed Edge

             Roll Center Vehicle Height of Roll Center


             C/M Vertical Enter 0 (Zero) to Compute C/M

o Number of Loads (Not including Trailer)

o Weight Trailer

Vertical C/M from Road

Lateral C/M from Left


o Weight Load (N)

Vertical C/M from Road

Lateral C/M from Left

             C/M Lateral Enter 0 (Zero) to Compute C/M


             Superelevation Superelevation of Roadway

             Turn Radius Vehicle Turn Radius due to Steering




The output from this module consists of the repeated input variables plus the Rollover Thresholds (Left and Right) and the Rollover Speeds (Left and Right) expressed in the primary and secondary configurations.


             Rollover Threshold

o Left: If Rollover Threshold is greater than friction then no Rollover Something caused the Vehicle to Trip.

o Right: If Rollover Threshold is greater than friction then no Rollover Something caused the Vehicle to Trip.


             Rollover Left Rollover Speed to the Left in Primary and Secondary configuration.


             Rollover Right Rollover Speed to the Right in Primary and Secondary configuration.




Several Command Buttons appear in a frame located at the lower right corner of the module Window. The Command Buttons allow the user to engage options including the option to Open and Save the data required to generate the scenario shown on the screen at the time the file was saved.


             Open .ROL File Calls up a Dialog box, which Opens any pre-existing .ROL file and displays the output results.


             Save .ROL File Calls up a Dialog box, which Saves data on the screen to files with any user-selectable filenames. This is independent of the automatic saving as LastFile.ROL of the data at the close of this module or the close of the program.


             Graphics Toggles a Graphic display of the Rear End of a Trailer showing the specifics of the Unit. [Esc] to Exit


             Formulae Opens a word processor (set by the user in Setup) with a file showing the basic formulae used in this module of the program. While the user may add to or modify the information in this file, it does not change the formulae imbedded into the program.


             N This button toggles a graphical number pad on the screen that can be used to enter data into the input boxes without using your keyboard number pad. This may be useful for presentations as data entry can be accomplished using a wired/wireless mouse.