5.2. Cycle Time for Scraper and Pusher

Try these first

1. 1.

   Define the term 'Swell Factor'.

   Hint

   Think about volume changes when excavating material.

2. 2.

   What does cycle time include?

   Hint

   Consider all the actions performed by the machinery during an operation.

3. 3.

   What is the purpose of the swell factor?

   • To calculate loading times
   • To determine volume change
   • To establish weight limits

   Hint

   Think about what happens when soil is excavated.

4. 4.

   True or False: The swelling of soil increases by 10% when move from bank to loose form.

   • True
   • False

   Hint

   Consider the effect of machinery versus natural properties.

5. 5.

   A construction project has determined that their scraper can carry a heaped capacity of 20 m³ at a swell factor of 0.78. If loaded to 92%, what would be the bank volume and weight of the material, given the unit weight is 1700 kg/m³?

   Hint

   Remember to convert first before calculating weight.

6. 6.

   Given a scraper’s cycle time of 10 minutes, can you suggest a workable number of scrapers if the pusher cycle time is 3 minutes? What are the operational cost benefits as the number of scrapers increases?

   Hint

   Consider the time and money dynamics with operations.