Quarrying & Mining Magazine
Q&M Quarrying

Taranaki shell rock

A quarry nestled in the hills between the regions of Taranaki and Whanganui is one of only a few in the region to produce limestone. By NEIL RITCHIE.

The Ravensdown Windy Point Quarry has been operating for a little more than 30 years, producing a variety of what it refers to as ‘shell-rock’ products for a variety of customers.
“Despite the current downturns in the dairy and oil and gas industries, there’s still forestry, bee farms and road repairs, so we’re still pretty busy, flat out in fact,” says quarry manager Evan Mooney.

Ravensdown Windy Point Quarry manager Evan Mooney
Ravensdown Windy Point Quarry manager Evan Mooney.

The 64-year-old believes there’s another decade or so of economic life left in the small quarrying operation that is presently producing about 40,000 to 50,000 cubic metres of various limestone products every year.
“We would like to be doing about 60,000 cubic metres, as we were a few years ago, but that is going to depend on future demand.”
The Windy Point Quarry, right on the border between the South Taranaki and Whanganui District Councils, is one of very few quarries in either district to produce a range of aggregates from limestone.
“This is the only place we know in this area that produces shell rock and sometimes we still find whole fossilised mussel shells intact. It must have been one hell of a shake-up aeons ago,” says Evan.
Although the colour and composition of limestone varies considerably throughout the country, that quarried at Windy Point is yellowy brown and very hard. It is however still relatively soft compared to the usual volcanic andesite material found closer to Mount Taranaki.
Quarry worker Aaron Jackson operates the Hyundai R360 excavator.
Quarry worker Aaron Jackson operates the Hyundai R360 excavator.

“However, what we produce is approved by the Transport Agency for use. We have to get our product checked regularly, though, every few months or so, to make sure it meets their standards.
“And most of the rural and state highway roads in the Whanganui, Waverley and Waitotara areas have been built with shell rock and these have stood the test of time,” says Evan.
“At first it was dug out with a dozer, which we are still using, and no screening was required.
“Now the metal is ripped out by digger and our current digger, a Hyundai R360, is due for replacement. We’ve worn out two loaders since I’ve been here.
“But the old crusher, a Goodwin Barsby, she’s seen a few machines fade out in her time. And we are still using this crusher, which has being going since before 1985. It does the job perfectly for shell rock … we just scalp off the fines from off the crushed product.”
Evan has been the quarry manager at Ravensdown Windy Point Quarry for about 11 years.
“It’s just the same shit every day, but that’s okay because we know we are providing some valuable and extensively used products for the locals.”
The quarry employs two staff fulltime and a third part-time, produces a range of aggregates – from AP40 and AP65 to race fines, a larger rock as a base course and also offers an oversize material service.
Generally, end uses are as roading materials and for the burgeoning “bee metal” market. “Honey is the new gold,” says Evan, referring to the number of bee farms being established in the area.
“And there are a lot of repairs going on right now after last year’s floods,” he adds, referring to those events that occurred in and near Waitotara and the more northerly Taranaki town of Opunake last year. There was also flood damage to some of the Stratford district.
Towns and nearby farmland were inundated by the flooding, with houses and farmland damaged and millions of dollars of damage done to roads. A bridge on State Highway 3 was damaged, as well as numerous local roads being impacted by hundreds of slips and dropouts. The total estimated cost to repair and reinstate the affected roads is estimated to exceed $15 million and take well into 2017 or beyond to complete.
Regular quarry customers are “everybody really”, he says, from cow cockies and dairy farmers, for farm races and tanker tracks, to roading contractors and others. But the main customers are Fulton Hogan and Downer.
The quarry’s history is interesting. First Worsley Transport “discovered” the shell rock, says Evan. Then Waverley Bulk Transport (WBT) took over owning and operating the quarry. More recently WBT entered into a joint venture with the farmer-owned fertiliser company Ravensdown. And now New Plymouth’s Freight & Bulk Transport (FBT) is also involved.
And innovative technology is also entering quarry operations, including the Hyundai HL 770-9 wheel loader (featured on this issue’s cover) that sends “reports” of its operations back to Hyundai’s world headquarters in Seoul, South Korea, via satellite. Seoul then notifies the quarry, via the loader, of any likely faults that need to be repaired. “Remote monitoring at its best,” says Evan.
“And we have a new set of automated scales on the loader that does all the docket work for all the loads done in a day … this [information] is just downloaded to FBT’s New Plymouth head office every night and billing is automatic.
“So we no longer physically write out any dockets, it’s all done by computer.”

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