⛏️ Draglines

Draglines are massive, long-reach excavation machines used primarily in mining (especially surface mining) and large-scale civil engineering projects like canal dredging or port construction. They use a drag bucket suspended from a boom to scoop and move large volumes of overburden or loose material.

🔧 Key Components of a Dragline

Component Description
Boom The long, lattice-type arm that supports the drag and hoist cables.
Drag Bucket A large open bucket used to scoop material by dragging it along the ground.
Drag Cable Pulls the bucket toward the machine (dragging action).
Hoist Cable Raises and lowers the bucket.
Slew System Rotates the upper structure to dump the material in designated areas.
Crawler Base Used for movement; due to size, many draglines are assembled on-site.

🏗️ Types of Draglines

Type Description
Crawler-Mounted Draglines Mobile, smaller; used in civil engineering and small mining sites.
Electric Walking Draglines Huge, used in open-pit mining; move by “walking” mechanism; often powered by electricity from the grid.

🏞️ Common Applications

  • Surface (strip) mining – particularly coal and phosphate
  • Overburden removal – clearing soil/rock above a mineral seam
  • Canal and river dredging
  • Harbor and dock construction
  • Large-scale excavation where other machinery is inefficient

✅ Advantages of Draglines

  • Exceptional reach – able to excavate materials far from the machine base
  • High productivity – can move massive amounts of material per pass
  • Low operating costs – especially electric-powered models
  • Minimal ground pressure – good for soft ground due to large footprint

⚖️ Limitations

  • Very large footprint – limited mobility, often assembled and disassembled on-site
  • High capital cost – especially for walking draglines
  • Slow cycle times – compared to hydraulic excavators in some tasks

🏷️ Major Dragline Manufacturers

  • Bucyrus-Erie (now part of Caterpillar)
  • P&H Mining Equipment (now part of Komatsu)
  • Marion Power Shovel Company (historic)
  • Liebherr (smaller-scale models)
  • Hitachi Construction Machinery

📊 Typical Specs (Electric Mining Draglines)

Feature Range (varies by model)
Boom Length 100 – 300+ feet (30 – 90+ meters)
Bucket Capacity 15 – 100+ cubic yards (11 – 76+ m³)
Operating Weight Up to 13 million lbs (6,000 metric tons)
Dig Depth Up to 200 feet (60+ meters)