Belmont Quarry is certainly one of the oldest and probably one of the largest in the region. It’s had several owners and been the site for a number of ‘colourful’ activities besides quarrying. RICHARD SILCOCK profiles its current operation.
It may not have the glitz of a Hollywood sound stage but the Belmont Quarry was used as one of the filming locations for the Peter Jackson, multi-million dollar, 2009 movie The Lovely Bones. It was also the site of a gold mine at the turn of the 20th century and old prospecting tunnels are still often unearthed. In the 1920s it was a source of rock which was used for ballast when constructing Wellington’s rail network.
From 1935 until 1977 the quarry was operated by River Sand and Shingle until it was taken over by Firth Industries (a subsidiary of Winstone Aggregates).
These days and since 1988 this 195-acre quarry alongside SH2 and the Hutt River is owned and operated by Winstone Aggregates, now a part of the Fletcher Building group of companies. Winstones’ itself has a history dating back to the mid-1800s and was started by William Winstone in Auckland when he began transporting and selling coal and scoria from a horse and cart to early settlers.
Some 1.2 million tonnes of fractured greywacke rock is extracted annually at the Belmont site, processed and used primarily for road and construction purposes.
Situated in the Hutt Valley, the quarry is well located for the supply of high-grade aggregate for some large roading projects in the region, including the under-construction Transmission Gully, and recently completed upgrade of the Wellington Motorway, Inner City Bypass and the Haywards SH2/SH58 Interchange. Customers include NZTA, contractors and local councils.
“This need has driven demand upwards of 20 percent,” says Shane Hagai, Wellington quarries manager for Winstones.
“Last year was a very busy year for us, with the size and number of the road projects under construction demanding a constant supply of crushed aggregate from the quarry and sand from our dredging operation on the lower tidal reaches of the Hutt River,” he says. “That demand is expected to be sustained over the coming three to four years at least as the road projects progress.
“We are presently working 6am to 6pm shifts Monday to Saturday, with all maintenance carried out at night so that we do not lose any production time during the day.
“We also run a concrete and asphalt production plant at Belmont which in 1995 underwent a major redevelopment to enable the production of a full range of high quality products.”
Rock at the quarry is initially ‘loosened’ through blasting and is sub-contracted out to the Red Bull Powder Company that carries out a controlled blast every two or three months. The rock is then extracted using 75 tonne CAT 374 excavators and conveyed to HP300 cone and Goodwin jaw crushers and the screening plant via a series of electrically driven aerial conveyors (there are 52, 170 metre long conveyors in the quarry), or by Komatsu dump trucks, where it is crushed and processed before being transported to stock piles. From there the aggregate is loaded onto customers’ trucks for transportation to construction sites. Rigid control is maintained through weigh bridges and computers mounted in the loaders which display to the operator the weight of the product in the bucket.
The quarry is well benched to maintain stability, with the highest point reaching 160-metres from the top to the bottom of the pit. Three faces are worked and on average 450 tonnes of rock is extracted every working hour.
“It’s a pretty tidy operation for a quarry,” says Shane. “We are very mindful about safety and about running an economic operation. All of our staff regularly attend safety briefings and we run a ‘tool box chat’ each work-day morning at 6am to discuss the day’s programme and any safety awareness issues. We believe in a two-way consultative approach with our managers and supervisors listening to staff so that together we can produce and document work plans and ways of working effectively and efficiently.”
Twenty-five, full-time staff are employed to manage and operate the quarry and they are often assisted at peak times by contract workers.
“Some of the staff here have been with us for a considerable number of years, so we have a pretty experienced team,” says Shane. “We employ five women who operate our Volvo L250 loaders or drive our dump trucks and water carts. Most of our guys are largely in their 30s and come from a variety of backgrounds but they all work well together as a close knit team,” says Shane.
“The ‘girls’ are a core part of our operation, really hard workers and they keep the guys in order,” he quips. “There may be some friendly banter in the lunch room but they all get along pretty well.”
The sand and shingle is extracted from the bed of the Hutt River by a 20-tonne Hitachi excavator mounted on a barge upstream from the mouth of the river which flows into Wellington Harbour at Petone. Extraction is down to a depth of 4.25 metres below the water level.
The sand is then transported via a conveyor belt to a screening plant for processing, resulting in a fine, rounded product suitable for building and use in concrete manufacture.
“It is a win win situation,” says Shane. “It provides us with the base aggregate and also keeps the river mouth from forming a sand bar which could cause the river to flood at times of high rainfall, inundating the lower part of the Hutt Valley, the surrounding housing and light industry.
“The quarry and the sand plant, along with our concrete and asphalt production plants are well placed to continue meeting the wider region’s needs for a high quality product well into the future and the quarry itself plays a key role in supplying seal chip to the local market.
“After all,” says Shane, “this quarry has some good bones and is expected to keep producing rock for a further 30-40 years.”