Here's a clear breakdown based on practical tunnel and underground engineering use:
Why single-arm rock drilling jumbos are more flexible
1.Strong maneuverability
Compact structure and smaller turning radius
Easy to reposition in narrow tunnels, small cross-sections, and curved headings
Suitable for tunnel sections such as 3×3 m to medium-size tunnels
2.Simple operation
Only one drilling arm to control, reducing operator workload
Faster learning curve for operators
Easier coordination between positioning, drilling, and retracting
3.High adaptability
Can handle face drilling, anchor bolt drilling, forepoling, and auxiliary holes
Well suited for complex geological conditions where frequent adjustments are needed
4.Lower investment and operating cost
Lower purchase price compared with double-arm jumbos
Reduced maintenance, fuel, and spare-part costs
Ideal for projects with limited budgets or intermittent drilling needs
5.Convenient transport and site transfer
Easier to transport between working faces
Particularly useful in hydropower tunnels, mine roadways, and small municipal tunnels
When a single-arm jumbo is the best choice
Small or medium tunnel sections
Short-cycle excavation and support works
Projects requiring frequent bolting and auxiliary drilling
Sites with limited space or complex alignment
Comparison reminder
Single-arm jumbo → flexibility, ease of operation, cost-effective
Double-arm jumbo → higher drilling efficiency for large sections and long tunnels
If you want, we can also help you compare single-arm vs double-arm jumbos for a specific tunnel size or project type.
