Which two categories of devices are used for pile installation with cranes?

• A. Pile hammers and vibratory pile drivers
• B. Hydraulic hammers and diesel hammers
• C. Rotary drills and augers
• D. Gantry and jib cranes

Answer: (A)

Pile installation with cranes relies on two main device categories: pile hammers and vibratory pile drivers. A pile hammer delivers a percussive blow to drive the pile into the ground, while a vibratory pile driver uses high-frequency vibration to overcome soil resistance and seat the pile more easily. The other options either represent subtypes within a single category (hydraulic and diesel hammers are both hammers), refer to drilling methods for drilled piles (rotary drills and augers), or are crane types rather than installation devices (gantry and jib cranes). So the best match is pile hammers and vibratory pile drivers.