After the crane is installed for the customer, various tests need to be carried out before it is officially put into use, and load testing is one of them. Load testing is a necessary step to ensure the safe and stable operation of overhead cranes. During the installation process, whether it is a newly installed bridge crane, a crane that has been overhauled or modified, or even a crane that has suffered an accident, load testing is required before being put into production use. This is because the load test can verify the crane's performance, metal structure strength, stiffness, stability, welding quality, transmission smoothness and reliability of each working mechanism, safety devices, limit switches, and brake flexibility, reliability, and accuracy Whether all aspects of indicators such as sex meet the prescribed requirements.

In this article, we will demonstrate this process to customers through a case of using a water bag for load testing, and analyze in detail the problems and choices that may be faced during the load testing process.

The process of load testing of bridge crane

The crane installation, located at Tunnel Thames Water Site 4. This was positioned above the main tunnel shaft at the major infrastructure project and will utilise 80m height of lift and 37m travel to remove debris from beneath.

It uses hydration bladders to create 10% and 25% overload conditions, gradually filling the hydration bladder to achieve the desired weight. Graham Dawson, warehouse manager at the London office, explains: “We considered using board weights to complete the test, but access to the area was restricted by the trench being dug, so that ruled it out as a viable solution. Additionally, transporting board weights was The cost and environmental impact are far greater than a water bag mounted on a pallet."

“As the crane was newly installed, electrical issues arose on the first day. These were corrected before testing on the second day, but further on-site adjustments were required. The French representative requested that a static load be maintained for an hour to test the crane brakes, The UK department also wanted us to carry out deflection testing.” Calibrated 10-tonne load cells, shackles and slings were sourced from the crane manufacturer's stock, while water weight packages were also hired. Following successful testing, the crane was handed over to Thames Water.

What can we learn from this

We often hear the saying that what is suitable is the best. When traditional load testing encounters problems, water bag testing perfectly solves the issues of cost and environmental impact. When we develop crane solutions for our customers, we often give more priority to applicability than our customers.

In addition to understanding the working conditions, we also need to have a detailed understanding of various technologies. If our knowledge reserve is not enough, we are likely to have deviations in the process of formulating strategies for customers. For example, in the water bag test, we need to know the advantages of using a water bag and why we use a water bag. Generally speaking, hydration bags can adapt to various environments and usage scenarios, including indoor and outdoor environments, as well as different climate conditions. Additionally, hydration bags can be customized as needed to meet specific load testing needs. However, water bags may be less stable during load testing than solid weights. Because the shape and weight distribution of the water bag may be affected by the flow and distribution of water, resulting in unstable test results. In practical applications, the advantages and disadvantages of using water bags for load testing need to be comprehensively considered based on specific circumstances to select the most suitable testing method.

At the same time, we can also find that load testing plays an indispensable role and status in the installation process of overhead cranes. It is not only a necessary link to ensure the safe and stable operation of the crane, but also an important means to discover potential problems and make improvements. It is also an important way to ensure that the crane complies with relevant regulations and standards.

Understand the crane load testing process through practical cases