Pick and carry cranes, commonly known as Frannas, are one of the most used cranes on worksites, making up approximately 50% of all mobile cranes in Australia. This ingenious invention has both the benefits of a truck and the powerful lifting capacity of a crane, meaning these machines can travel long distances with their load already picked. Another feature that makes Franna cranes different from others lies in its articulation, a quality that enables it to rotate on its base, offering greater manoeuvrability and the ability to work in confined spaces. Although these machines are highly beneficial to jobsites, there is the danger of your crane overturning if not correctly operated.
In this article we explore some of the contributing factors that can lead to articulated mobile cranes rolling and how you can mitigate these risks.
What causes pick and carry cranes to overturn (and how to avoid them)?
Correctly inflated tyres are critical for the stabilisation of pick and carry cranes. A deflated tyre on one side of the machine can destabilise the crane, having the same effect as a pothole or soft ground. While the lack of stabilising legs enables its superior manoeuvrability compared to other cranes, it renders these machines completely dependent on suspension and tyres to remain upright.
HOW TO AVOID THIS: Frequently check that your crane tyres are properly inflated and in good condition. A regular inspection and maintenance schedule with a heavy equipment specialist like SuperService™ can ensure that any issues that arise with your tyres are quickly rectified.
- Safe working loads are exceeded
Lifting capacity depends on the individual crane and the radius of the lift. Exceeding the safe working load for your pick and carry crane can cause it to overturn.
HOW TO AVOID THIS: All operations should be carried out according to the manufacturer’s instructions. It is also vital to take into account the impact factors such as sloping ground or strong winds will have on the safe rated capacity of the machine.
- Lifting and/or travelling on uneven ground
Changing ground conditions, like potholes or uneven road surfaces, can affect the stability and rated capacity of articulated mobile cranes when they are carrying a load.
HOW TO AVOID THIS: Operators should plan the travel path (any slopes, or changes in surface gradient, etc.) and inspect the ground conditions, particularly after wet weather, before lifting and moving loads. As pick and carry cranes require level ground for safe operation, it may be necessary to improve ground conditions before carrying out required work.
- Excessive boom angle and extension
Loads carried beyond safe boom length and angle run the risk of overturning the crane.
HOW TO AVOID THIS: With all pick and carry operations, ensure that the load is carried with the minimum boom length and keeping the boom tip as low as possible.
- Changing direction or manoeuvring around barriers
Both articulating and manoeuvring movements have the potential to destabilise the pick and carry crane.
HOW TO AVOID THIS: Use multiple point turns when changing direction to keep the articulation angle to a minimum or land the load and reposition the crane instead of manoeuvring with the load.
- The crane has been poorly maintained
Without regular maintenance, the safety, longevity, and performance of your pick and carry crane is greatly inhibited, leading to a higher risk of accidents, such as overturning.
HOW TO AVOID THIS: Scheduling routine maintenance with a specialist mechanic like SuperService™ will ensure your Franna/pick and carry crane is performing optimally.
Pick and carry cranes overturning can expose workers and the public to the risk of grievous bodily injury or even death. Safe operation of these machines, including proper maintenance and being mindful of boom angles and extensions, is critical to reduce the risk of your crane rolling.