How to give a crane a leg lift
The cranes at the Port of Los Angeles are definitely going up in the world. No less than 10 ship-to-shore Noell cranes needed to be raised a further 33 feet, to accommodate lager ships calling at the American port.
Longer legged cranes
Each crane needed longer leg sections, which had been pre-fabricated in China by Shanghai Zhenhua Port Machinery Company (ZPMC). The operation required the use of 16 wireless 150 tonne capacity load cells to weigh a single raised crane to properly benchmark its new weight and centre of gravity.
According to American Cranes and Transport magazine:
“The weighing procedure included lifting the crane utilizing ZPMC’s self-propelled modular trailers, placing the load cells in pairs under the eight intermediate gantry equalizers on specially designed pedestals, and lowering the crane down to rest on the load cells. The crane was lifted off the load cells between trials to allow for three distinct weighing evolutions.”
The use of such an array of load cells showed that the extra leg sections added an additional 193te to the structure. When the concrete ballast was added, it shifted the operational centre of gravity backwards approximately 1 metre.
Rising and falling
Another major engineering project has to content with fluctuations in working heights. The team constructing the new Zezelj bridge across the iconic River Danube in Serbia have to cope with changing water levels over 4 metres. So, a system was devised to maintain schedules around these fluctuations, and reduce cost variations. The constructor ALE used load cells in various operations, including the weighing and launching of two arches and two span sections, thus completing the first stage in this impressive €45.3m project.
Taking the strain in Manchester
Load cells are also a crucial component in another icon bridge project, the new Ordsall Chord bridge across the River Irwell in Manchester, UK. This time, they have been used in the initial stressing and ongoing monitoring of the 46 solid steel hangers on each side of the bridge. Real time monitoring ensures that if a pair of hangers do fail, they can be removed and replaced without restricting traffic allowed on the bridge.
If you have a complex engineering project, using our high quality, UK-manufactured load cells could really take a eight off your mind. Call us with details of your project, and we can help design a solution that is both efficient and cost-effective.
