Auckland City’s Quay Street is getting a makeover as part of the Downtown Transformation project. Last year, in conjunction with JFC, our AirX trucks were used to remove five mature Pohutukawa trees from along Princes Wharf. After 30-40 years, the trees were a pretty decent size: they ranged between 8-10m tall and one had a canopy spread of 5m. The rootballs alone were around 3.8m wide by 60cm deep.

The plan was to move the trees off-site for a year before reinstating them once the transformation is complete, so extreme care was necessary when digging out. Before work started on each tree, a meeting was held with expert arborists to discuss strategy, mainly around avoiding the main tap root.

To add to the challenge, at some point the trees had large amounts of concrete poured around their base, constricting their growth. This needed to be carefully broken away with jackhammers, without affecting the roots.

Complicating things further, there were large services running through the concrete and tree roots — both power and gas — that would be catastrophic if hit.

“This was definitely a job for our AirX,” says the HydroVac project manager overseeing the job.  “The stakes were too high to have a digger doing the work, and flooding the hole with water with hydro-excavation wasn’t an option with the services running through the job.”

An air lance was used first, to locate all the roots – an air lance is a bit like a waterblaster but using compressed air instead. Once the main roots were exposed by the air lance, the arborist would determine the best place to fit the 10-inch boom in. Air-excavation was employed until the root ball was exposed, about 1.5-2m deep, before a crane carefully pulled each tree from the site and put it on the back of a truck.

Excavation and removal took between 1-3 days per tree.

Watch this cool short video on the process HERE