Unique Group has carried out proof load testing and operational verification of a Konecranes 8t overhead crane system at a municipal water production facility in California, using its Water Weights suspended load testing technology.
The work took place inside an active utility environment, with lifting operations performed above key water production infrastructure, including large diameter piping systems, pumps and associated process equipment.
The facility’s layout meant the team had to work within confined structural conditions, with recessed access points and limited space to handle conventional solid test weights.
According to the company, many utility operators face similar constraints when upgrading or maintaining ageing infrastructure in buildings not originally designed for current crane maintenance and proof load testing requirements.
Operators may need to validate lifting systems while also protecting nearby assets and keeping operations running.
To manage the restrictions at the California site, the test team used a low headroom Water Weights suspended load testing bag along with calibrated tension load measurement equipment.
The arrangement allowed the proof load to be applied gradually while maintaining control throughout the lift. Unique Group said the low headroom configuration helped maximise lifting height in the confined structure and enabled the required load to be introduced safely within the available space.
Using suspended water weights also reduced logistical and handling challenges and helped avoid concentrated floor loading issues associated with traditional solid test weights, the company said.
It added that controlled suspended loading allows test teams to observe rigging, crane performance, structural response and operational clearances during the lifting process.
Unique Group field technician Roger Herrera said the job required detailed planning before any loading began.
Herrera said: “Projects like this are about understanding the environment before rigging begins.
“You work inside an active facility with limited access, critical infrastructure beneath the lift zone, and almost no space for extra movement. Every step must be controlled and deliberate.”
Herrera also compared the approach to conventional methods.
He said: “With traditional solid weights, logistics become very challenging in confined structures. Being able to bring in the equipment efficiently, rig it safely, and gradually apply the load gives the client more control over the process and reduces unnecessary strain on the facility.”
Unique Group said overhead crane proof load testing in active utility and infrastructure environments requires compliance with standards including OSHA 1910.179, relevant ASME B30 standards, and site-specific safety procedures set by the facility owner and crane manufacturer.
The company said equipment used on the project included the overhead crane, calibrated load measurement devices, rigging assemblies and a suspended low headroom twelve and a half ton Water Weights test bag positioned above essential utility equipment.
