Haul Truck Specifications

To access this screen:

Activate the Schedule ribbon and select Setup. Select any haul truck item on the left.
On the Update Schedule screen, enable the Haul Trucks option and click Browse.

This screen is used to define the haul truck mass, drive wheel load distribution and traction parameters. These settings form part of the General Settings screen for each truck.

Activity steps:

Display the Haul Truck Specifications screen.
In Vehicle Weight (tonnes), enter a value for the Empty state.
In Load Distribution on Wheels (%), enter values for both Empty and Loaded states.
In Coefficient of Traction, enter a value.
To construct the schedule based on an acceleration formula, select Compute Accelerations. To use a static speed for the distance travelled for EFH, clear Compute Accelerations (see below).

How Acceleration Is Calculated

The maximum force without slipping is calculated using the load distribution, weight, gradient and traction coefficient.

maximum force without slipping = cos ( atan ( gradient / 100 ) ) * weight * traction coefficient * load distribution / 100

The rimpull force is calculated as follows.

If using the rimpull and retardation model, rimpull force is looked up on the chart using the current speed.

If using the linear model, rimpull force = gross weight * sin ( atan ( effective gradient / 100 ) ).

The force of gravity is calculated.

force of gravity = sin ( atan ( gradient / 100 ) ) * weight

The accelerating force is calculated.

accelerating force = ( smallest of rimpull force and maximum force without slipping ) - force of gravity

The acceleration rate is calculated.

acceleration rate = accelerating force * 9.81 / weight

The acceleration time is calculated.

acceleration time = ( max speed - current speed ) / acceleration rate

The acceleration distance is calculated.

acceleration distance = acceleration rate * acceleration time * acceleration time / 2