14.06.2007

Unattached superstructure caused Croydon accident

The UK Health and Safety Executive (HSE) has established that the superstructure of the tower crane that collapsed in Croydon 10 days ago was not attached to the tower or the climbing frame thus causing the accident.

In other words the crew had lifted the first of six extra sections to be inserted into the tower balancing the crane, the bolts attaching the top of the crane to its tower were then removed without attaching it to the climbing frame, leaving it simply balancing on top of the tower. As soon as the operator started to trolley the section into the tower the top became back heavy causing it to literally flip over backwards.

As a result of its initial findings the HSE has placed a prohibition notice on the owner of the crane - Select plant preventing it from carrying out the climbing of any tower crane unless it is done by people who have adequate training specific to the particular crane and climbing frame.

The nature of the prohibition order suggest that crew involved in the Croydon accident were not trained or experienced with climbing Terex Comedil tower cranes.

Select Plant issued a statement saying: “We take this extremely seriously.
Safety is absolutely critical and we are determined to understand all the causes of this accident to ensure that we can prevent anything like this happening again.
We believe our crane crews are adequately trained and accumulate extensive on-site experience before taking part in any crane climbing operations”.

“Clearly, however, there are lessons to be learned from this incident and we are determined to learn those lessons fast. We will not prejudge the outcome of the investigation and we continue to cooperate fully with the appropriate authorities.
We are continuing to undertake climbing operations in accordance with the notice issued by the Health and Safety Executive and with their agreement.”

Vertikal Comment

Climbing a tower crane is not particularly complex, it is more about knowing the precise sequence of what needs to be done and then scrupulously following the steps one by one making sure that each step has been successfully completed before moving onto the next.

It is almost down to a checklist type process with experience required so that the team knows what to do when a step does not go as per the manual.

One wonders A) if the crew involved in this incident had the manual to hand and if they had a clear checklist to follow?
And B) if the team ran through what they had to do, how to do and who was going to be responsible for each action before they climbed up the tower.

Given the disastrous results of a mistake when erecting or dismantling a tower crane, such ‘toolbox talks’ or briefings before ascending the tower are essential, in order to make sure everyone knows exactly what is going on and what the dangers are if certain stages are not done in sequence.

Everyone involved with this particular accident was very very lucky, at least five or six men could easily have lost their lives that day.

Finally congratulations to the HSE for issuing its preliminary findings of the cause of the accident so quickly. Hopefully this will serve as a wake up call for all tower crane comanies, their erection teams and tower crane operators who assist with climbing, erection or dismantling.