🔹 1. Introduction

Shovel excavators are the primary loading machines in surface mining operations.
They load fragmented rock into:

• Dump trucks
  
• Tippers
  
• Crushers
  
• In-pit conveyors
  

Modern surface mines rely heavily on:

• Electric Rope Shovels (ERS) for large production
  
• Hydraulic Shovels for high flexibility
  
• Front-End Loaders for quick mobility
  

Shovel performance determines overall mine productivity and cost per tonne.

🔹 2. Types of Shovel Excavators in Surface Mines

2.1 Electric Rope Shovel (ERS)ERS is the workhorse of large open-pit mines, especially in hard rock.Features

• Bucket capacity: 20–42 m³
  
• Extremely powerful digging capability
  
• High reliability
  
• Best for blasting fragmentation
  

Advantages

✔ Very high productivity
✔ Long life (20–25 years)
✔ Ideal for hard rock

2.2 Hydraulic ShovelUsed widely due to flexibility and mobility.Features

• Bucket size: 5–25 m³
  
• Powered by hydraulics
  
• Superior digging in soft/medium rock
  

Advantages

✔ Quick relocation
✔ Precise control
✔ Works in tight spaces
2.3 Front-End Loader (FEL)

High mobility loading machine.Features

• Bucket size: 3–15 m³
  
• Tyre-mounted
  
• Excellent for short-distance loading
  

Advantages

✔ Very flexible
✔ Fast cycle
✔ Good for stockpiles

🔹 3. Components of a ShovelMain Parts

• Boom
  
• Stick/Arm
  
• Bucket
  
• Hoist rope
  
• Swing mechanism
  
• Propel system (tracks)
  
• Cab & controls
  

🔹 4. Shovel Working Cycle

A shovel cycle consists of:

1. Digging/Crowding
   
2. Hoisting
   
3. Swinging (loaded)
   
4. Dumping
   
5. Swinging back (empty)
   

Cycle time affects productivity directly.
🔹 5. Shovel Productivity

Productivity of a shovel is:Q=3600×Cb×F×ηtcQ = \frac{3600 \times C_b \times F \times \eta}{t_c}Q=tc 3600×Cb ×F×ηWhere:

• Cb = Bucket capacity (m³)
  
• F = Fill factor (0.8–1.2)
  
• η = Job efficiency (0.7–0.85)
  
• tc = Cycle time (seconds)
  

5.1 Fill Factor (F)

Extent to which bucket is filled.

• Hard rock → 0.8
  
• Soft rock → 1.0
  
• Fine material → 1.1–1.2
  

5.2 Job Efficiency

Reflects delays, operator skill, and conditions.Typical values:

• Excellent: 0.85
  
• Average: 0.75
  
• Poor: 0.65
  

5.3 Ideal Match Between Shovel & TruckRule of thumb:

No. of passes=Truck body volumeShovel bucket volume\text{No. of passes} = \frac{\text{Truck body volume}}{\text{Shovel bucket volume}}No. of passes=Shovel bucket volumeTruck body volumeIdeal = 3–5 passesExample:

• 20 m³ bucket → suits 100 T truck
  
• 40 m³ bucket → suits 220–240 T truck
  

🔹 6. Factors Affecting Shovel Performance

• Bench geometry
  
• Fragmentation quality
  
• Operator skill
  
• Weather conditions
  
• Machine condition
  
• Swing angle
  
• Positioning of truck
  

🔹 7. Diagram (Text Format)
Shovel Loading Operation (Side View)
Bucket ┌───┐Boom | |<——— Fragmented Rock ─────┘ | \ \__ Truck Body

🔹 8. Advantages & LimitationsAdvantages

✔ Huge productivity
✔ Durable
✔ Ideal for hard rock
✔ Low cost per tonneLimitations

✘ High capital cost
✘ Requires blasting
✘ Limited mobility
✘ High power consumption

🔥 25 MCQs (DGMS Machinery Pattern)

1) Electric rope shovel bucket capacity is typically —

a) 2–5 m³
b) 5–15 m³
c) 20–42 m³
d) 50–100 m³
e) None
Answer: c
2) Shovel cycle time includes —

a) Swinging only
b) Dumping only
c) Dig–Hoist–Swing–Dump–Return
d) Travel only
e) None
Answer: c
3) Fill factor represents —

a) Rock hardness
b) Bench height
c) Bucket filling efficiency
d) Sub-grade control
e) Truck size
Answer: c
4) Shovel job efficiency typically —

a) 0.2–0.3
b) 0.7–0.85
c) 1.5
d) 2.0
e) None
Answer: b
5) Hydraulic shovels are powered by —

a) Steam pressure
b) Pneumatic pistons
c) Hydraulic systems
d) Fuel pumps
e) None
Answer: c
6) Best loading machine for hard rock —

a) Backhoe
b) Loader
c) Electric rope shovel
d) Skid-steer
e) Dozer
Answer: c
7) No. of passes depends on —

a) Rock quality
b) Bench width
c) Shovel bucket vs truck body size
d) Explosive type
e) None
Answer: c
8) Swing angle affects —

a) Explosive quantity
b) Bit wear
c) Cycle time
d) Bench height
e) None
Answer: c
9) Front-end loaders are —

a) Track-mounted
b) Tyre-mounted
c) Electric
d) Chain-driven
e) None
Answer: b
10) ERS stands for —

a) Excavator rope system
b) Electric Rope Shovel
c) Engine rod shovel
d) Energy rope system
e) None
Answer: b
11) High fill factor occurs in —

a) Oversize muck
b) Hard bands
c) Soft, fine material
d) Wet clay
e) None
Answer: c
12) Productivity formula includes —

a) Truck hours
b) Spacing
c) Bucket capacity
d) Drill diameter
e) Face slope
Answer: c
13) Wrong truck positioning causes —

a) Good swings
b) Longer cycle time
c) Better fragmentation
d) Low blast energy
e) None
Answer: b
14) Modern mines prefer —

a) Manual pickaxes

b) Horse carts
c) Electric rope shovels
d) Hand shovels
e) None
Answer: c
15) Ideal passes per truck —

a) 1–2
b) 3–5
c) 6–10
d) 12–14
e) None
Answer: b
16) Shovels work best with —

a) Unblasted rock
b) Fine powder
c) Well-blasted fragmented muck
d) Wet clay
e) None
Answer: c
17) Hydraulic shovels advantage —

a) Poor mobility
b) High precision
c) Very heavy
d) Limited working range
e) None
Answer: b
18) Crawler-mounted shovels provide —

a) High speed
b) Low traction
c) Stability
d) High tyre cost
e) None
Answer: c
19) Operator skill affects —

a) Explosive weight
b) Bench width
c) Cycle time
d) Truck RPM
e) None
Answer: c
20) Job efficiency decreases with —

a) Good maintenance
b) Skilled operator
c) Frequent delays
d) Proper blasting
e) None
Answer: c
21) ERS is best for —

a) Soft alluvium
b) Hard rock excavation
c) Sand dunes
d) Clay pits
e) None
Answer: b
22) Fill factor of 0.8 indicates —

a) Full bucket
b) Partial fill
c) Overloaded bucket
d) Zero productivity
e) None
Answer: b
23) Shovel life is typically —

a) 2 years
b) 5 years
c) 10 years
d) 20–25 years
e) None
Answer: d
24) Truck-shovel matching improves —

a) Vibration
b) Blasting
c) Production
d) Bench height
e) None
Answer: c
25) Shovels operate mainly on —

a) Vertical faces
b) Inclined slopes
c) Bench faces
d) Stopes
e) Drifts
Answer: c
                                🔚 Conclusion

Shovel excavators form the backbone of surface mining.
Their performance directly influences cost, productivity, and mine output.
Proper selection, truck matching, maintenance, and blasting quality are essential for DGMS-compliant efficient mining.

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