These powerful trucks combine the function of a boom lift and a digger for hole digging and material handling.
What is a digger derrick? A common sight on roads and highways, a digger derrick is a specialized truck used by utility companies, construction crews and telecommunications providers. With a boom and hydraulic auger mounted on a vehicle base, it combines the capabilities of a boom truck or crane and a digger for digging holes, setting utility poles, lifting heavy objects and hoisting crew to tasks at height.
Take a closer look at digger derricks, their benefits and how to choose one for your application.
Digger derrick components
Sometimes called digger trucks or auger cranes, digger derricks use a hydraulic auger for drilling holes and a boom for lifting and positioning loads. The main components are:
- Truck chassis: The vehicle's base provides mobility and stability. Most have wheels, but tracked vehicles are available for rough or inclined terrain.
- Boom: This extendable arm can be lifted, lowered and rotated. You can add a winch and hook or a bucket for lifting and positioning materials. Booms are available in a variety of lengths and configurations.
- Auger: A powerful hydraulic rotating drill bit creates holes in a variety of soil types.
- Outriggers: These stabilizers extend outward from the chassis to prevent the vehicle from tipping over during operation.
- Controls: Controls are located in the truck cab or at an operator control station at the rear of the truck, depending on the model.
Common uses for digger derricks
Digger derrick trucks are used for a variety of applications across several industries, including the utility, telecom, construction and mining industries. Here are some the most common uses:
- Digging utility pole holes, setting poles and maintaining utility infrastructure.
- Installing and maintaining cell towers, antennas and communication lines.
- Stringing electrical lines, setting transformers and maintaining power distribution systems.
- Tree trimming and pruning (requires an aerial bucket attachment).
- Drilling holes for installing foundations, anchors and footings.
- Installing road signs, traffic signals and streetlights.
- Geotechnical drilling, including soil sampling and testing.
- Placing equipment, lifting building materials and handling large loads.
- Clearing debris, restoring power lines and performing infrastructure repairs during disaster response and recovery.
- Mining and exploration drilling and support tasks, such as setting roof bolts in underground mines and handling materials in surface mining operations.
Benefits of digger derricks
Digger derrick trucks offer numerous benefits on a variety of projects.
- Versatility and efficiency: Digger derricks dig rapidly and perform the function of several machines, reducing the need for other equipment, cutting costs and enabling faster project completion.
- Enhanced safety: Advanced controls, stability systems and safety mechanisms minimize the risk of accidents and injuries.
- Precision and accuracy: Hydraulic controls and attachments allow for precise hole digging and placement, essential in utility installations and other applications where accuracy is crucial.
- Accessibility: A derrick digger can access remote or challenging jobsites that an equipment trailer or larger truck might not be able to.
Choosing a digger derrick
When buying or renting a digger derrick, the diameter of the holes you need to dig, the soil conditions and the required lifting capacity will determine the best size and model. These trucks have a maximum digging radius of anywhere from 22 feet to 40 feet and a maximum lifting capacity of anywhere from 5,500 pounds to 50,000 pounds.
Make sure the sheave height (the maximum height of the boom when fully extended and elevated) is high enough to lift the poles you need to install and that the machine has sufficient lifting capacity to lift them at the boom angle you want. (Ideally, you want to dig the hole and lift and set the pole without moving the truck.) Sheave heights range from 25 feet to 95 feet.
Light-duty models are compact, with a shorter boom reach and lower lifting capacity. They are suitable for setting small utility poles or digging holes for signs, especially in areas with limited space to maneuver.
Medium-duty digger trucks have a moderate boom reach and more lifting capacity to handle tasks such as setting large utility poles and backfilling.
Extra-heavy-duty digger derricks are workhorses with the longest reach and greatest lifting capacity. These are used for the most demanding tasks such as setting tall transmission towers, handling oversized loads and heavy-duty construction projects.
When in doubt, talk with your equipment vendor to determine the best digger derrick for your application. The right machine can help you get the job done better, faster and cheaper while increasing worker safety.