18.11.2009

Another AT crane tips while on wheels

Another All Terrain tipped over as it as being relocated while fully rigged last week, the accident occurred in Cedar Rapids, Iowa, on the site of the new courthouse.

The crane a 550 ton Grove GMK 7550, owned and operated by Milwaukee, Wisconsin based Dawes Rigging and Crane Rental, was rigged with its counterweight and a long fixed jib.
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The fallen crane

It was moving across the yard, from where it had been rigged, in order to set up closer to the new building to erect a tower crane. The boom was fully retracted and at a sensible angle to provide some balance to the axle weights, Local reports say that the ground was sufficiently uneven or out of level to cause the crane to tip over sideways.

The crane cab fortunately fell uppermost and the 45 year old operator was not injured and no one else was affected.

The crane’s jib demolished the corner of a low level site building, narrowly missing the guard hut and landed on the rear end of a parked pick up truck belonging to a CAT dealer. The crane was working for Ryan Companies which will investigate the accident along with Dawes.

Vertikal Comment

Moving a large All Terrain crane while rigged is riskier than usual crane operations with numerous factors to consider and set up correctly. One wonders if cranes such as this can still be travelled with the outriggers beams extended?

While somewhat old hat and primitive, in jobs like this, where space does not seem to be an issue, moving the crane with the outriggers extended and close to the ground, so they act like stabilisers on a child’s bike, may one assumes, have prevented the crane from tipping?

It could be of course that the lighter weight, more engineered chassis structures of modern road going cranes like this will not take the use of the outriggers for something they are not designed to for?

We would be interested to hear from you crane engineers on this issue..