03.12.2008

Structural failure

Several of you have sent us the following set of photographs of a rare structural failure on a crane over the weekend at Ipswich Docks in the UK. The crane, a Demag AC650/AC2000 with 800 tonne rating, was being rigged at the time, with its counterweights being installed, when the superstructure frame failed and came crashing down onto the unsupported front end of the carrier chassis, breaking its back.
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A structural failure dumped the counterweight

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The back end of the superstructure sheared off

The crane was due to lift replacement flood gates into place in the docks.The new gates, constructed by Ravestein in Holland, arrived in Ipswich at the end of last week and were due to be installed over the weekend as part of the Environment Agency's policy to protect 2,320 properties in Ipswich.

Each flood gate measures nine metres by 11 metres and weigh 45 tonnes each.

We have been talking to Ainscough the crane’s owner and Terex Demag, the manufacturer, but given the nature of accident we have – understandably not yet received a detailed response.
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The superstructure bottom plate struck the crane chassis

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The impact on the unsupported rear end of the chassis broke its back

Thankfully no one was hurt in the incident, but the crane may prove to be a write off given the amount of damage and its age?

Terex and Ainscough are carrying out an investigation and we understand that owners of similar cranes have been alerted.

We had hoped to leave the publication of these photos until the full details were available along with a comment from the manufacturer, but such is the speed of the internet that since the first information arrived on Sunday we have been inundated with requests for confirmation and information and details, and the story began to be stretched and distorted. We have therefore decided to provide this preliminary report.

Vertikal Comment

Structural failures are a very rare occurrence on lifting equipment, with most accidents due to operator error. While we are keen to comment, given the nature of this accident we feel it more sensible and prudent to wait and hear what comes out of the investigations.

And please do stop sending the photographs now, many thanks indeed to those who have.