Typical engineering scenarios include the following:
1. Small and Medium Tunnel Excavation
Single-arm jumbos are very suitable for tunnels with limited cross-sections, such as:
Hydropower diversion tunnels
Municipal utility tunnels (water supply, drainage, power, communication)
Mine roadways and access drifts
Transportation tunnels with small profiles
They can efficiently drill blast holes in tunnel sections such as:
3 × 3 m
4 × 4 m
5 × 5 m
Up to about 6 × 6 m (depending on boom reach)
2. Tunnel Support and Rock Bolting
Because of their flexible boom movement, single-arm jumbos are widely used for:
Rock bolt drilling
Anchor bolt and cable bolt hole drilling
Systematic bolting after blasting
Temporary support holes
They are especially effective when frequent repositioning is required.
3. Complex Geological Conditions
Single-arm jumbos perform well in:
Soft to medium-hard surrounding rock (Class II–IV)
Broken or fractured rock zones
Irregular tunnel faces
The operator can easily adjust drilling angles and positions to adapt to changing rock conditions.
4. Projects with Limited Space and Access
They are ideal for sites where space is restricted:
Narrow tunnels
Low-headroom underground works
Construction sites with tight turning radius
Renovation or expansion of existing tunnels
Compact dimensions make transport and maneuvering easier.
5. Cost-Sensitive Projects
Compared with double-arm jumbos, single-arm machines offer:
Lower purchase cost
Lower operating and maintenance cost
Reduced energy consumption
Smaller crew requirement
This makes them suitable for small contractors or short-length tunnel projects.
6. Auxiliary and Secondary Excavation Works
Single-arm jumbos are commonly used for:
Pilot tunnels
Cross passages
Ventilation tunnels
Emergency exits
Drainage galleries
They are often used alongside larger jumbos as support equipment.
Summary
Single-arm rock drilling jumbos are best suited for:
Small to medium tunnel sections
Rock bolting and support drilling
Restricted or complex construction environments
Projects requiring high flexibility and lower investment
If you want, we can recommend typical configurations (boom type, propulsion beam length, rock drill power) based on your tunnel size and rock class.
