Thinking outside the box

Since 1971 Auckland-based Spiral Drillers Civil has earned a reputation for tackling some difficult piling work. Richard Silcock profiles the company and finds out why it has been so successful.

“AS CLICHÉD AS it may sound, I attribute the success of the business to maintaining a high standard of work, finding a solution for our clients and thinking outside the box when it comes to difficult jobs,” says Andrew Hannah, co-owner and managing director of Spiral Drillers Civil.

Andrew’s father Brian founded the business back in 1971, primarily to provide a service for local farmers in South Auckland and North Waikato who required offal holes to be excavated.

“My father saw an opportunity and very quickly progressed from drilling offal holes to drilling holes for house and building piles, which after all is just an offal hole filled with concrete instead of shit and sheep guts,” says Andrew.

“I took over the business in 2010 along with my business partner and the other co-owner of the business, Jon Faber, who has a background in civil engineering project work. Our aim has always been to be the best specialist piling company in New Zealand.”

Spiral Drillers’ bread and butter work revolves around piling and all its permutations, including concrete piles,concrete piles, screw piles, sheet piling and micro piles for clients all around greater Auckland and the Waikato region.

“Our core business is essentially for large commercial projects and we do a substantial amount of work in difficult situations where there is restricted access and/or not much headroom. But we do work for domestic customers as well, particularly at difficult sites such as where there is a sloping section or a steep bank,” he says. “While most modern homes these days are built on a concrete pad, with flat sections becoming increasingly more difficult to find around Auckland, people are building on these difficult sites, often to gain a view, so we see a good future for house piling going forward.

“Ninety percent of our work is around greater Auckland and the northern part of the Waikato, however from time to time we travel out of the area. For example, we recently did some work in Wellington and in the South Island drilling methane wells at landfills.

The company operates from its office and base in Pukekohe, South Auckland where it has a fully equipped workshop for maintaining, adapting and manufacturing specialist equipment.

“With our range of equipment we can drill almost any natural material including Waitemata sandstone, Parnell grit, greywacke and basalt rock.

“We have the usual standard, fixed-mast piling rigs and through some adaptations we have made to some of the rigs we are able to drill up to four-metre diameter holes for access shafts for micro tunnelling companies.

“We also have a variety of ‘micro-rigs’ which have been designed to allow access in tight, height restrictive areas and these can be further adapted to work around on-site obstacles,” says Andrew. “One of these rigs, which only weighs a mere 900 kilograms can drill a hole 450mm in diameter to a depth of 12 metres under a head height of only 2.2 metres.”

Asked about some of their most recent and unusual projects, Andrew cites the work they are doing for the refurbishment and repiling of the International Hotel in Princes Street, Auckland.

“We have been subcontracted by Dominion Contractors to carry out this work which requires a 450mm pile drilled to a depth of 21.2 metres. Straightforward in itself, but the problem was the head height, with the basement and levels one, two and three only having a 2.2-metre head space. Fortunately level four had a head height of 3.6  metres which was sufficient for us to install our rig and drill down using a series of ‘kelly-bar’ extensions. We were working nine metres above ground level and had to extensively prop up various floors beneath to avoid a collapse.”

A Spiral Drillers TC7 rig drilling 15-metre deep pile holes in a confined space of only 2.4 metres high.

Another project Spiral Drillers Civil is currently working on for North Power and Top Energy involves drilling four, 1.2-metre diameter, four-metre deep pile holes for power transmission pylons at a site near Kaeo in Northland.

“As the site is in extremely steep inaccessible bush-clad country our solution was to modify a stand-alone rig that can be dismantled and helicoptered to the site and reassembled at each drilling location,” says Andrew. “Lifting the rig mast, which weighs 1180 kilograms, into the rig base is a pretty tricky operation and requires a very skilful pilot and no wind. Once the foundation holes are drilled, the helicopter lifts the pylons into place and the holes are backfilled with concrete.

“As the pylon foundations are on separate ridges there is a fair amount of tramping required by our guys to get to each site so they have to be pretty fit.”

Staff safety is an important component of how the team work and each project is measured by a formal risk assessment and task analysis procedure before any work commences.

“The well-being of our employees comes first and no deadline or project requirement will ever come before our people’s safety,” says Andrew.

Looking ahead, Andrew says they see more and more work coming their way from the seismic strengthening of older buildings.

“With the new regulations and the need to upgrade buildings, particularly the older ones that are not up to ‘code standards’, owners will need to get seismic strengthening work done to bring them up to standard, able to withstand moderate earthquakes and meet their insurer’s requirements – so I see continuing opportunities there.

“We see this as a further phase in the development of the business, providing a wider range of services and undoubtedly employing more staff,” he says.

Spiral Drillers Civil currently has a full-time staff of 39. Andrew says they all regularly attend training sessions and industry conferences to keep abreast of changes in the technology, which he says is again another reason for their success, as is the ‘one big happy family’ work atmosphere they have created.

Putting it another way,” says Andrew, “we know each other well and we know the drill.”

This article was first published in Contractor‘s May issue.

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