shovel productivity

1. Shovel Dumper Productivity
Calculations
• Compute the productivity of a 4.6 m3 shovel
with 35 Tonne Dumper having a struck
capacity of 16.97 m3. Also calculate the no. of
shovel and dumpers required to handle 3 MT
of overburden material. Assume suitable data
and loading conditions.

2. Assumptions of data
• Swell factor-0.7
• Fill factor of dumper as well as shovel-0.9
• Shovel efficiency-70%
• Shovel cycle time-30 s
• Positioning time of dumper-30 s
• Availability and utilization- 0.8x0.8=0.64
• No. of shifts-2
• Hours in shift-8
• No. of working days in a year-300
• Hauling distance- 5 km
• Dumper speed- 20 km/h
• Density of coal-1.5t/m3
• Rock density-2.5t/m3

3. 1. Volumetric Capacity of Dumper (Solid)-
Dumper Pay load Capacity in Tonnes x fill factor/ Density
of coal, ore, rock
35 x 0.9/2.5 = 12.6 m3 (For OB or limestone)
35 x 0.9/1.5 = 21 m3 (For Coal)
35 x 0.9/3.5 = 9 m3 (for Iron ore)
2. Volumetric Capacity of Dumper (Loose)-
Solid volumetric Dumper Capacity/swell factor
12.6/ 0.7 = 18 m3 (For OB or limestone)
21 /0.7 = 30 m3 (For Coal)
9/0.7 = 12.85 m3 (for Iron ore)

4. • Actual struck capacity of dumper given is
16.97 m3.
3. Hence solid capacity of dumper= Actual struck
capacity x Swell factor = 16.97 x 0.7 = 11.9 m3
The above check is essential to ensure that
neither the dumper should not get overloaded
(more than its payload) nor there should be
any spillage during transport (more than its
struck capacity).

5. • Solid bucket capacity of shovel- Nominal bucket
capacity x swell factor x Fill factor
• 4.6 x 0.9 x 0.7 = 2.89 m3
• Average working hours in a year-
• 300x2x8x0.64=3072 hrs
• No. of passes required to fill the dumper – solid
capacity of dumper/solid bucket cap. of shovel
• 11.9/2.89 = 4 buckets

6. • Loading time of shovel – 0.5 min. X 4 +
positioning time of dumper= 2 min + 0.5 min=
2.5 min
• Hourly productivity of shovel –
= 60 x shovel capacity x no. of passes x efficiency
/ shovel cycle time in min.
= 60 x 2.89 x 4 x 0.7 /2.5
= 187 m3

7. • Annual production capacity of shovel-
• Hourly production capacity of shovel x no. of
hours in a year
=187x 3072
= 574464 m3
Annual production in tonnes-
574464 x 2.5 = 1436160 = 1.4 MT

8. • Dumper cycle time- loading time of dumper
+ hauling time to and fro+ unloading time including
positioning time for dumping
= 2.5 + (5x60/20) + 1 =18.5 min
No. of dumpers required- Total time/loading time x
availability
= 18.5/2.5 x 0.64 = 12 dumpers
Productivity of Dumpers = 1.4 MT/12= 0.1116 MT

9. • No. of Shovel required= 3 MT/1.4 MT=2
shovels
• Total no. of dumpers required- 3 MT/0.1166
• = 26 dumpers

10. Synchronization of Shovel dumper
combination
• The production capacity of shovel dumper
operated faces can be optimized by allocating
required number of dumpers against each shovel
so that shovel need not have to wait for the
dumpers and also dumper waiting times is not
excessive.
• If shovel needs to wait for dumpers, its
production capacity decreases.
• If dumper waiting time is more, it increases the
ownership and maintanence cost and hence cost
of production.

11. Synchronization of Shovel dumper
combination
• Therefore proper synchronization of shovel
dumper faces is a must for optimizing the
capacity as well as cost of production.
• For this purpose, an index known as Match
Factor is checked for shovel dumper operated
Face.
• Match Factor = Number of dumpers per
shovel x shovel loading time for filling the
dumper / Dumper cycle time

12. Synchronization of Shovel dumper
combination
• Match Factor should not be less than 1.
• If match factor is less than 1 then either
number of dumpers or its capacity should be
increased.
• If it is not possible to increase the dumper size
or its numbers, then reducing haulage
distance is another option.
Q. In a mine for one shovel, six trucks are assigned. The shovel
loading time per dumper is 5 min. and dumper cycle time is 20
min.. Calculate the match factor.

13. Assignment
• Calculate the productivity of a 10 m3 shovel with 85
tonne dumper having struck capacity of 37 m3. Also
calculate the no. of shovel and dumpers required to
handle 10 million m3 of overburden material. Assume
suitable data and loading conditions?
• Compute the productivity of a 42 m3 Shovel with 350
tonnes Dumper having a struck capacity of 165 m3.
Also calculate the no. of shovel and dumpers required
to handle 25 million m3 of overburden material.
Assume suitable data and loading conditions.