Heavy Truck Load Check A


Overview: Computes Articulated Vehicle axle weights and three-axis center of gravity based on information about vehicle and load (Bill of Lading).


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 Load Check A 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 an .LCA 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:


Load Check A


Configuration: Tractor / Trailer / Loads

              Length: Overall Length of Tractor/Trailer (Computed from Input Values)

              Height: Overall Height of Tractor/Trailer (Computed from Input Values)



              Wheelbase: Wheelbase of Tractor

              Front-SA: Distance from the Front of the Vehicle to the Steer Axle

              5W-cDA: Distance from the Fifth Wheel to the Centerline of the Drive Axle(s)

              Drive Axles: Number of Drive Axles

              Tire Radius: Distance from the Center of the Axle to the Road Surface

              TR CG (Lng): Distance (Longitudinal) from the Front to the CG (Tractor)

              TR CG (Ver): Distance (Vertical) from the Road Surface to the CG (Tractor)

              TR Weight: Weight of the Tractor



              Length: Overall Length of Trailer

              Height: Overall Height of Trailer

              Width: Overall Width of Trailer

              TL (hBed): Bed Height of Trailer


              TL CG (Lng): Distance (Longitudinal) from the Front to the CG (Trailer)

              TL CG (Ver): Distance (Vertical) from the Road Surface to the CG (Trailer)

              TL Weight: Weight of the Trailer without Load

              Front-KP: Distance from the Front of the Trailer to the Kingpin

              KP - cRA: Distance from the Kingpin to the Centerline of the Trailer Axle(s)

              TL Axles: Number of Trailer Axles

              Tire Radius: Distance from the Center of the Axle to the Road Surface


Load Note: When inputting the Load information:

1.          Disregard the Total number of Loads in Loads (#) it should be 1 at the start. To delete all loads, enter a Zero (0) for Total number of Loads

2.          If necessary, Click the Right (or Left) Arrow button at Current (#) to bring up the (next) appropriate Load number in the Current Load box (Start with Load # 1)

3.          After entering all of the data for the Load, click on the DO button

4.          Go to Step 2 until you have entered information for all of the Loads

5.          If the Graphics are not displayed, Click on Graphics

              Loads (#): Number of Individual Loads

              Current (#): Number of Current Load (Enter or use Arrows to Change)

              Height (Ver): Vertical Height of Current Load

              Length (Lng): Longitudinal Length of Current Load

              Depth (Lat): Lateral Depth of Current Load

              Weight: Weight of Current Load


CG Location of Current Load

              CG% (Btm): Location of CG from Bottom of Current Load

              CG% (Frt): Location of CG from Front of Current Load

              CG% (Lft): Location of CG from Left Side of Current Load


Position of Current Load

              Lng (X): Longitudinal Distance: Front of Trailer to Front of Current Load

              Lat (Y): Lateral Distance: Left of Trailer to Left of Current Load

              Vrt (Z): Vertical Distance: Bottom of Trailer to Bottom of Current Load




The output from this module consists a graphics screen showing a side view of the Tractor/Trailer and an overhead view of the Bed of the Trailer showing the placement of the individual Loads (1-99) and their individual weights.


Data displayed on the screen includes:



              Empty Weight Empty Weight of Tractor/Trailer

              Load Weight Load Weight

              Total Weight Combined Weight of Tractor/Trailer and Load


Position of CG of Load

              Load CG(lng) Longitudinal Position of Entire Load from Front of Tractor

              Load CG(vrt) Vertical Position of Entire Load

              Load CG(lat) Lateral Position of Entire Load from Left of Trailer



Trailer + Load CG Position

              TRL +L CG(lng) Longitudinal Position of Trailer +Load from Front of Tractor

              TRL +L CG(vrt) Vertical Position of Trailer +Load

              TRL +L CG(lat) Lateral Position of Trailer + Load from Left of Trailer


Tractor + Trailer + Load CG Position

              T +T +L CG(Lng) Longitudinal Position of Tractor +Trailer +Load from Front of Tractor

              T +T +L CG(Lng) Vertical Position of Tractor +Trailer +Load

              T +T +L CG(Lng) Lateral Position of Trailer + Load from Left of Trailer


Axle Weights

              SA Weight Weight on Steer Axle

              DA Weight Weight on Drive Axle(s)

              RA Weight Weight on Rear Axle(s)


              Total Weight Total Weight of Vehicle


CG Markers Toggles CG lines on the Graphics display




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


              Save .LCA 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.LCA of the data at the close of this module or the close of the program.


              Graphics Toggles a Graphic display showing the Load configuration on the vehicle as well as the output data including the Weights on the Axles.


              Adjustments Displays Adjustment bars allowing the Vehicles to be scaled and repositioned on the screen preventing interference with Output data.


              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.