A flat-bed trailer was making a delivery of a counterbalance lifting beam (Combi-Steker) to a construction site in London. On arrival, the driver was instructed to proceed to an area that was designated as an unloading bay.  The unloading bay was part pavement and part road, so the vehicle was not level. There was an exclusion zone around the bay to prevent access by public or other contractors.

The driver was informed that the tower crane, that would be used to unload the trailer, was already in use by another contractor on-site. It was estimated that the crane would be available within circa 10 minutes to unload his trailer.  Due to this delay, the driver decided to remove two straps which he had added to the Combi-Steker to ensure its stability during transportation to the construction site.

Having removed these straps, he then asked two trained lifting operatives, who were on the back of the trailer bed and were standing on the driver side of the bed, to release a third strap that was attached to the Combi-Steker through the master link. When the final strap was released by one of these operatives, it tipped over to the off side of the trailer. Its fall was arrested when it contacted the edge protection top rail. Fortunately, nobody was hit by the beam and the edge protection did not give way which could have resulted in a more serious outcome. The images below were taken at the site.

KEY FINDINGS

• The immediate cause of the NMI was the release of the transport retaining straps from the Combi-Steker counterbalance lifting beam before it was connected to the site tower crane. This allowed the Combi-Steker to rotate in an uncontrolled manner.
• It was established that the load had shifted during transport.
• The route cause of the incident was that there was no loading process/method in place for the counterbalance beam.
• The operative who loaded the Combi Steker onto the flat bed did what he believed to be correct without knowing what the site team would do when unloading.
• There were no instructions provided by the original supplier of the Combi Steker that showed how it should be safely loaded and how it should be secured it to a trailer.

• After the incident, the supplier was contacted, and an SOP was created that would show how to load and unload safely the counter balance beam.


• Training was given to the loading operatives and the site team operatives for unloading and reloading when returning it back to the yard once the task was completed.