1. CE403Construction Methodology Loaders & Haulers

5. Estimating Loader Production • The product of average bucket load multiplied by cycles per hour for EQ 2-1. Production = Volume per Cycle x Cycles per Hour

6. Basic Loader Cycle Time • Cycle time includes: • Loading • Dumping • Making four reversals of directions • Travel

7. Basic Loader Cycle Time, min Includes time for: loading, dumping, and four reversals of direction.

8. One Way Haul Distance vs. Time, min, Fig. 4-15

9. Loader Production Example Problem Estimate the hourly production (LCY/h) of a 3.5 CY wheeled loader excavating sand and gravel from a pit and moving it to a stockpile. The average haul distance is 200 ft, the effective grade is 6%, the bucket fill factor is 1.00, and the job efficiency is 50 min/h.

10. Basic Loader Cycle Time, min Includes time for: loading, dumping, and four reversals of direction.

11. One Way Haul Distance vs. Time, min, Fig. 4-15

12. Loader Production Example (Fig. 4-14)

13. Loader Job Management • Prevent cutting of tires. • (Use L-5 Tires) • Bucket weight is limited due to tipping. • Optimal positioning of loader & haul units.

14. Haulers ~ Trucks & Wagons.

17. Total Cycle Time Fixed Time + Variable Time

18. Load Time = Haul Unit Capacity Loader Production @ 100% Efficiency = Number of Bucket Loads x Excavator Cycle Time Number of Haulers Req’d.

19. Haulers and Loaders • Typically assume Loader will operate at 100% efficiency. • At least, this is the operation’s goal. • Daily Cost Comparisons (Means 2011) • 2.5 CY Loader - $1251.87 • 16 Ton Dump Truck - $855.20

20. Total Cycle Time Fixed Time + Variable Time

21. No of Haulers Req’d (N) = = Haul Unit Cycle Time Load Time Number of Haulers Req’d. Equation designed to keep loader fully occupied Round N to nearest integer – Eg. N=9.1 round to 10 trucks.

22. Total Cycle Time Fixed Time + Variable Time

23. Expected Production = = Actual Number of Units No. of Haulers Req’d (N) x Excavator Production Number of Haulers Req’d. Designed to estimate production if less than theoretically required number of trucks are used.

24. Haul Unit Example Problem Given the following information on a shovel & truck operation, a) calculate the number of trucks theoretically required and the production of this combination; b) calculate the expected production if two trucks are removed from the fleet.

25. Haul Unit Example

26. Haul Unit Job Management • Stager Start-Stop Times. • Do not Overload Haul Units. • Maintain Haul Roads. • Develop Efficient Traffic Pattern for Loading, Hauling & Dumping. • Provide Backup Units ~ As Needed. • No Speeding.