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Lowering a 30 ton excavator down a 35 metre cliff face on the Mahia Peninsula. That doesn't happen every day.
Lattey group 80 tonne track-mounted crawler crane used on the Rangatahi drop out repair project
Lattey group Liebherr LTM 1055 crane in action
Lattey group Liebherr LTM 1055 crane on the Mahia peninsula
Lattey group 80 tonne track-mounted crawler crane used on the Rangatahi drop out repair project
COMPLETED LATE 2020
Rangitahi drop out repair
In late 2020 we were engaged by QRS to undertake the first stage of the Rangitahi drop out repair in Mahia. This involved remediation of a large slip that had undermined a section of East Coast Road on the North side of the peninsula. The drop out had occurred after years of coastal erosion undermined a wooden crib wall that was helping to hold the road 35 metres above the Pacific Ocean.
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The scope for us was to mobilise our 80 tonne track-mounted crawler crane to site and assist QRS in the reclamation of land that had slipped away. To do this we first had to get our smaller 20 tonne rough-terrain crane (‘roughie’) on site to assemble the larger 80 tonne unit.
The big crane was used each day to lower a 14 tonne excavator down to the beach below. The excavator was used to place 204 enormous Redi-Rock blocks onto a large new retaining wall being built into the cliff face. The rocks were lifted down in large bins throughout the day. Before high tide, the excavator was lifted back up onto dry land.
Fast forward to now - and stage two of the project came online. This involved lifting a smaller excavator down onto the beach and repeating the process of lifting rocks, but this time with a smaller capacity bin.
Due to the lower weights involved and a shorter timeframe required on site, we decided our new Liebherr LTM 1055 all-terrain crane was best suited for the job. This crane could power itself to Mahia without the need for a support vehicle - a big cost saving on the project.
The smaller physical size of the crane and its variobase outrigger system meant we could operate at full 55 tonne capacity, but with less outrigger length extended. This allowed QRS to keep one lane of the road open while we completed the work, limiting disruption to local road users.
This was another great partnership with QRS who won a regional construction award from Civil Construction New Zealand (CCNZ) for their management of this demanding project.