Nobles crane servicing repair a jib crane damaged in service

Wednesday, 30 January 2019

Our technicians responded to a call out for an inspection of a jib crane that had been damaged in service. The crane had been ‘Tagged Out of Service’ and could not be used or placed back in service until assessment or repair was completed by a competent person, in this case, Nobles crane service technicians.

Once onsite our technician conducted an inspection and it was apparent that the jib crane was knocked and the jib mounting plate was now slightly dislodged from the concrete. The anchors were loose and the base plate had moved away from the floor showing a gap between the underside of the plate and the concrete floor (see image 1). Further discussions with the customer indicated that the jib crane was knocked by a forklift when trying to unload a pallet.

Image 1

Working in tight space restrictions it was initially thought that the jib base plate could be moved slightly and new holes could be drilled and new anchors fitted. This was decided against as the new holes needed to be at least 120mm from the existing holes or voids. This would have also decreased the integrity of the concrete therefore causing an unsafe working environment. After discussions it was then decided to replace the concrete under the jib to ensure the floor was structurally sound and the jib crane cold be mounted back in its original position.

Nobles crane technicians first removed the jib from the floor to see what damage was done to the concrete and if any damage was done the jib crane itself. As it was only a slight knock the jib crane itself was not damaged and could be reused.

The first step was to repair the concrete floor, Nobles outsourced this to an approved local concrete company. The original concrete area was cut out and removed and replaced with new concrete as per engineering specification. Previous engineer reports were also used to assist in providing the correct strength and mix of the concrete. Once the concrete was completed it was left to set and strengthen to ensure a strong foundation for the jib crane to be mounted on.

When our crane technicians returned to site they prepared the area for the jib crane to be refitted. New mounting holes were drilled into the concrete for anchors, chemical anchors were used to hold the rods in place. Levelling nuts were then fitted prior to jib base plate being fitted in the original position. This allowed the jib base plate to be adjusted if the floor was not level. The jib was then fitted and fixed into place with nuts to the top of the base plate. The levelling nuts were used to ensure the base plate and jib were level and grout was used and left to dry (see image 2).

Image 2

Once complete the original hoist was installed, commissioned and tested and put back into service. Test certification and commissioning reports were issued to the customer in accordance with Australian Standards. The end result was that the customer could use their equipment again in a timely manner to meet their deadlines and could rest assured the equipment was safe to use.

Our Crane Services division inspect, repair and replace all hoist brands and models for mining, defence and industrial clients. We offer expert advice and a range of in house products to assist you with your lifting and rigging requirements. For more information or to book a crane service please call 1300 711 559 or email us at sales@nobles.com.au.

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