Draglines are large excavation machines that use a bucket attached to cables to drag material against the ground. They have long reaches that allow them to dig softer materials below their tracks and are commonly used for excavating canals and depositing excavated material directly onto embankments without needing hauling equipment. Key factors that affect a dragline's output include its bucket size and type, the length of its crane boom, the type of material being excavated, the angle of its swing, digging depth, working conditions, and the operator's skill level. Draglines come in crawler, wheel, and truck mounted varieties for different terrain and job types.

1. DRAGLINES :
 Named : Its prominent operation of
dragging the bucket against the
material to be dug.
 Capacity – Size of the bucket (𝑚3).
 Applications :
 Digging softer material & below
its tracks.
 It has long reaches.
 Mostly used in excavation of
canals and depositing on
embankment without hauling
equipments.

2. Basic parts :
Hoist cable Hoisting cable
Crane boom Gantry
Hoist
Chain
Drag Cable Cab
Drag Chain Crawler
Bucket Mounting

3. Factors affecting the output:
 Size and type of bucket (0.38 to 3.06 𝑚3)
Light bucket – loose,dry.
Medium – clays,compacted gravel.
Heavy – hard materials
 Length of crane boom (50,60 and 70 ft)
 Type of material
 Angle of swing
 Depth of cut
 Working conditions,maintainance
 Size of hauling unit
 Operator skill

4. Types of draglines :
 Crawler mounted
- Low travel speed,soft ground,
large projects
 Wheel mounted
- high travel speed,firm ground &
scattered job
 Truck mounted
- high travel speed,firm ground &
scattered jobs
 Walking draglines

5. Output :
 Output = dragline capacity × C × F
where C = cycles/hr
F = correcting factor
Advantages Disadvantages
 Can work from the ground surface
while shovel has to be taken into
the pit.
 Hauling equipments need not to go
in the pit.
 Excavated material disposed in one
operation.
 High range than shovel.
 Less digging force.
 As the boom length increases the
bucket size must be decreased.
 Output is less than shovel.