How to Operate a Knuckle Boom Crane


If you’ve ever wondered how to operate a knuckle boom crane, you’ve come to the right place. In this comprehensive guide, we will walk you through the step-by-step process of operating a knuckle boom crane. Whether you’re a beginner or someone looking to refresh your knowledge, this guide will provide you with all the information you need to safely and efficiently operate a knuckle boom crane.


What is a Knuckle Boom Crane?

A knuckle boom crane, also known as an articulated crane or a loader crane, is a type of crane that is mounted on a truck or a trailer. It is characterized by its articulated arm or boom, which consists of multiple folding sections connected by hinges. This design allows the boom to bend or “knuckle” at various points, giving the crane increased flexibility and reach.


Safety Precautions Before Operating a Knuckle Boom Crane

Safety should always be the top priority when operating any type of crane. Before you begin operating a knuckle boom crane, it is essential to take the following safety precautions:

  • Conduct a thorough inspection of the crane and ensure that it is in proper working condition.
  • Check the weather conditions to ensure safe operation.
  • Clear the work area of any potential hazards or obstacles.
  • Wear the appropriate personal protective equipment, including a hard hat, safety glasses, and high-visibility clothing.
  • Familiarize yourself with the crane’s load capacity and limitations.
  • Communicate with coworkers and establish clear signals for crane operations.


Familiarizing Yourself with the Knuckle Boom Crane Controls

Before you start operating a knuckle boom crane, it’s important to familiarize yourself with the controls. The specific controls may vary depending on the make and model of the crane, but here are some common controls you should know:

  • Boom control: This control extends or retracts the boom.
  • Main winch control: This control operates the main winch for lifting and lowering loads.
  • Outrigger control: This control extends or retracts the outriggers for stability.
  • Slewing control: This control rotates the crane horizontally.
  • Auxiliary winch control: This control operates the auxiliary winch for additional lifting tasks.


Pre-Operational Checks and Inspections

Before you start operating the knuckle boom crane, it is crucial to perform pre-operational checks and inspections. These checks help ensure that the crane is in good working condition and ready for operation. Here are some key areas to inspect:

  • Check the hydraulic system for leaks or damage.
  • Inspect the cables and wire ropes for any signs of wear or fraying.
  • Test the emergency stop button to ensure it is functioning correctly.
  • Verify that all safety devices, such as limit switches and overload protection systems, are operational.
  • Examine the boom and outriggers for any structural damage or defects.


Starting and Shutting Down the Knuckle Boom Crane

To start the knuckle boom crane, follow these steps:

  1. Ensure that the crane is parked on a level surface and engage the parking brake.
  2. Turn on the ignition and wait for all the warning lights to go off.
  3. Activate the hydraulic system by flipping the corresponding switch.
  4. Test the controls to ensure that they are functioning properly.

To shut down the crane, follow these steps:

  1. Place the boom in its stowed position and retract the outriggers.
  2. Turn off the ignition and remove the key.
  3. Deactivate the hydraulic system by flipping the corresponding switch.
  4. Perform a final walk-around inspection to ensure that the crane is secure and ready for transport or storage.


Basic Maneuvering Techniques

When operating a knuckle boom crane, it’s important to master basic manoeuvring techniques to ensure smooth and controlled movements. Here are some techniques to keep in mind:

  • Use smooth and gradual movements when operating the controls to avoid sudden jolts or jerks.
  • Keep a safe distance from obstacles or other workers to prevent collisions.
  • Always maintain clear visibility of the load and the surrounding area.
  • Use a spotter when manoeuvring in tight spaces or areas with limited visibility.
  • Practice operating the crane in different scenarios to improve your manoeuvring skills.


Lifting and Lowering Loads

Lifting and lowering loads is one of the primary functions of a knuckle boom crane. Follow these steps for safe and efficient load operations:

  1. Verify the weight of the load and ensure that it falls within the crane’s load capacity.
  2. Attach the appropriate lifting device, such as a hook or a sling, to the load.
  3. Use the main winch control to lift the load smoothly and steadily.
  4. Position the load to the desired location and lower it gently using the main winch control.
  5. Ensure that the load is stable and secure before releasing it from the lifting device.


Rotating the Crane

The ability to rotate the crane is essential for reaching different areas on the job site. Follow these steps to rotate the knuckle boom crane:

  1. Ensure that the area around the crane is clear of any obstructions.
  2. Use the slewing control to rotate the crane in the desired direction.
  3. Maintain a slow and controlled rotation to avoid swinging the load or causing sudden movements.


Extending and Retracting the Boom

The boom’s ability to extend and retract allows the crane to reach varying distances. Follow these steps to extend and retract the boom:

  1. Activate the boom control to extend the boom to the desired length.
  2. Ensure that the boom is fully extended and locked into position before lifting any loads.
  3. Use the boom control to retract the boom back to its stowed position after completing the task.


Operating the Outriggers

The outriggers provide stability to the knuckle boom crane during lifting operations. Here’s how to operate the outriggers:

  1. Identify the appropriate location to extend the outriggers for optimal stability.
  2. Use the outrigger control to extend the outriggers until they firmly contact the ground.
  3. Verify that the outriggers are fully extended and locked into position before operating the crane.


Understanding Load Charts

Load charts provide valuable information about a crane’s lifting capacity based on its configuration and boom length. It’s crucial to understand load charts to prevent overloading and ensure safe lifting operations. Refer to the crane’s load chart and consider the following factors:

  • Boom length
  • Boom angle
  • Radius or distance from the crane’s centre to the load
  • Load weight and distribution
  • Outrigger configuration


Working Near Power Lines

Working near power lines poses significant hazards when operating a knuckle boom crane. To ensure safety, follow these guidelines:

  • Maintain a minimum safe distance from power lines as mandated by local regulations.
  • Use proximity warning devices to alert you if the crane approaches a dangerous distance from power lines.
  • Implement an exclusion zone around the power lines and ensure that it is marked.
  • Conduct a thorough site assessment to identify potential power line hazards before starting work.


Communicating with Signal Persons

Clear communication between the crane operator and signal persons is essential for safe and efficient crane operations. Establish standard hand signals or radio communication protocols to relay instructions accurately. Some common hand signals include:

  • Extend arm horizontally: Extend the boom or move the load away from the signal person.
  • Raise arm vertically: Raise the boom or move the load higher.
  • Lower arm vertically: Lower the boom or move the load lower.
  • Move the arm in a circular motion: Rotate the crane.


Crane Maintenance and Inspections

Regular maintenance and inspections are vital for keeping the knuckle boom crane in optimal condition. Follow these maintenance guidelines:

  • Conduct daily visual inspections for signs of wear, damage, or leaks.
  • Lubricate moving parts as recommended by the manufacturer.
  • Schedule regular servicing and maintenance checks by qualified technicians.
  • Keep a record of maintenance activities and inspections for future reference.


Common Mistakes to Avoid

When operating a knuckle boom crane, it’s crucial to be aware of common mistakes and take steps to avoid them. Here are some mistakes to watch out for:

  • Overloading the crane beyond its rated capacity.
  • Ignoring safety precautions and guidelines.
  • Failing to conduct proper pre-operational checks and inspections.
  • Improperly securing loads, leading to accidents or dropped loads.
  • Lack of communication with signal persons or coworkers.



Operating a knuckle boom crane requires knowledge, skill, and a commitment to safety. By following this step-by-step guide, beginners can gain a solid understanding of the operation and safety considerations associated with knuckle boom cranes. Remember to prioritize safety, conduct proper inspections, and adhere to industry regulations for a successful and accident-free crane operation.


Frequently Asked Questions (FAQs)

Q: How long does it take to learn how to operate a knuckle boom crane?

A: The time it takes to learn how to operate a knuckle boom crane can vary depending on the individual’s aptitude and the level of training received. Generally, it takes several weeks to gain proficiency in operating a knuckle boom crane.


Q: Do I need a license to operate a knuckle boom crane?

A: Yes, operating a knuckle boom crane typically requires a specialized license or certification. The specific requirements may vary depending on your location and local regulations. It is important to check with the relevant authorities to ensure compliance.


Q: Can a knuckle boom crane be used for different types of lifting tasks?

A: Yes, a knuckle boom crane is versatile and can be used for various lifting tasks. It is commonly used in construction, forestry, shipping, and other industries that require the lifting and positioning of heavy loads.


Q: What are the main advantages of using a knuckle boom crane?

A: Knuckle boom cranes offer several advantages, including enhanced manoeuvrability, increased reach and flexibility, and the ability to work in tight spaces. The articulated boom design allows for precise positioning of loads, making it ideal for complex lifting operations.


Q: Are there any safety considerations when operating a knuckle boom crane in windy conditions?

A: Yes, windy conditions can affect the stability of the crane and increase the risk of accidents. It is important to follow the manufacturer’s guidelines and local regulations regarding wind speed limitations for crane operations. Additionally, taking extra precautions such as reducing the load capacity and maintaining a wider working radius can help ensure safe operation.


Q: How often should a knuckle boom crane be inspected?

A: Regular inspections should be conducted on a daily, weekly, monthly, and annual basis, as recommended by the manufacturer and local regulations. Daily visual inspections should be performed by the crane operator before each use, while more detailed inspections should be carried out by qualified technicians at regular intervals.

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