Crane experts: human error to blame for Croydon collapse?

The training of tower crane erectors has been thrown into the spotlight after it emerged the recent collapse in Croydon could have been caused by human error.

When CJ showed its exclusive photographs of the accident to a tower crane engineer with years of industry experience, he was surprised at the absence of any damage to the underside of the crane top and the minimal damage to the top of the tower and climbing frame.

He said the lack of damage to the Terex Comedil CTT 181 crane, which belonged to Laing O'Rourke's Select Plant arm, suggested the connection was not made correctly or broke cleanly. "Looking at the photographs, you have to question whether the connection was properly made in the first place."

He said it was also significant that the accident occurred when erectors were preparing to insert the first of six sections into the mast.

Another senior industry source who saw the photos agreed with his findings. The expert, who did not wish to be named, said: "It appears that basic errors were made involving the bolts."

He said a heavy workload and not enough skilled erectors could lead to similar accidents in the future. "It takes five years to become a competent tower crane erector and with so much work on at the moment the industry is naturally under pressure."

Alan Ritchie, general secretary of construction trade union UCATT, said: "The latest information about this accident is deeply troubling. It will increase safety concerns involving cranes for all construction workers and members of the public.

"The industry needs to act swiftly to ensure the highest levels of safety and training are both created and applied for all crane operations."

Haydn Steele of the Construction Plant-hire Association Tower Crane Interest Group said the message on training is getting through, but can only change as legislation does.

At the time of the accident the crane was lifting a tower section as a known weight at the specified radius to balance the top of the crane for the climb, and a mast section was on the platform ready to be inserted.

The balancing is done to ensure there is only minimal stress placed on the temporary head bolts securing the crane top to the climbing frame.

During the operation the top of the crane toppled backwards injuring the operator and trapping some of the rigging crew.

This sequence of events fits with photographic evidence, eyewitness reports of the crane lifting a steel beam, and Haymills Construction's technical director Dean Murphy, who said the crane wasn't working and the only thing it would be lifting was mast sections.

Laing O'Rourke was unavailable for comment when CJ asked it about the experience and training of the Select erectors. The Health & Safety Executive investigation continues.