Austin, Texas

January 2018 Austin, Texas

Project Cranes The Outcome Key Learning

Tilt-up construction of commercial building

Crawler crane • Overturned crane • Minor injuries • Quality assurance must be undertaken on site • Lifting clutches must be thoroughly and regularly inspected. • Riggers must be properly trained and where required qualified in tilt-up construction • Unnecessary personnel should not be permitted in the lifting vicinity

Nearly a dozen workers were lucky to escape major injuries in January 2018 when a crawler crane lifting a concrete panel overturned in Austin, Texas. The crane was erecting a large panel as part of the tilt-up construction of a commercial building when a cable at the top of the panel broke free.

A dogman standing on one end of the panel as it was being lifted at the opposite end, was thrown to the ground from the force of the tilt panel as it lost footing on the ground. He quickly regained his balance and escaped clear of the slipping panel. As he did so, the remaining workers in the vicinity also fled as the concrete slab pivoted and then came crashing to the ground, pulling the crane over with it.

The panel had eight attachment points embedded in the concrete, with a series of cables and pulleys allowing the angle of the panel to be adjusted as it was lifted. Dave Ritchie, a crane operator for 17 years and a safety consultant for the Occupational Safety and Health Administration, said that either the attachment insert came out of the concrete (which is dependent on the quality of the concrete), or there was a problem with the rigging (either with the assembly of the rigging or failing to identify a defect during inspection).

Once the cable broke free, excess stress was placed on the remaining attachment points shifting the load distribution, and ultimately pulling the crane over.

It was reported that one worker was trapped beneath the fallen crane, before later being freed. Two workers suffered non-life-threatening injuries, including the crane operator who broke his ankle when exiting the crane cab.

Key learnings from this incident

Whilst we were unable to locate official findings of this investigation, there are a number of measures that should be considered to prevent an incident of this nature:

Quality assurance must be undertaken on site to verify the quality of the surrounding concrete including the strength and curing times. Additionally, the lifting inserts and clutches must be in line with the engineer’s design. Lifting clutches must be thoroughly and regularly inspected.

Riggers must be properly trained and where required qualified in tilt-up construction

Unnecessary personnel should not be permitted in the lifting vicinity. An exclusion zone should be established, and only suitable trained and qualified personnel allowed within the exclusion zone.