Inside the wash plant swap that cost zero days of supply
Equip2's modular wash plant is doing 125 tonnes an hour at Oreti Aggregates, Invercargill - built without a single day of lost supply, and the standout stop at this year's Quarry Conference.
When the Quarry Conference wash plant tour pulled up at Oreti Beach this year, delegates saw something rarer than it should be: a brand-new wash plant in full production - not a concept, not a brochure render. Here's how it came together, and why the details matter to anyone weighing up their next plant.
The maths that ruled out mobile gear
With at least 20 years of quarry life ahead, mobile gear didn't stack up - most operations would replace it at least twice over that span. A fixed modular plant won on whole-of-life cost and gave operators a far easier plant to maintain. And rather than squeezing the new build into the old plant's footprint, Equip2 and Oreti Aggregates started with a clean slate, designing the wash plant's layout around site traffic flow and long-term management.
One feed in, five products out
Feed runs up a conveyor onto a three-deck screen, cutting three aggregate splits. The 0–7mm underflow drops to a split-deck dewatering screen: one side screens the aggregate fraction, while the 0–4mm is pumped through a hydrocyclone to strip out silts. The recovered sand lands back on the dewatering screen - pulled down to around 9% moisture - before a radial stacker carries it out to the stockpile.
The sand circuit runs at roughly 80 tonnes an hour of the plant’s 125 total. The product range spans P-gravel (5–7mm) through 13mm, 19mm and a Reject grade, with fines running at 50–60% natural sand yield. Early hours are already tracking ahead of expectations.
The unglamorous details that decide year ten
Equip2's scope ran from the concrete up, while Oreti Aggregates and SouthRoads covered the infrastructure and functionality of the build: hardstands and bins to prevent cross-contamination, and graded drainage engineered to keep salt water away from clean product. Wash-down hoses and drainage that actually goes somewhere - the kind of detail that makes daily operation easier for the life of the plant.
The changeover customers never noticed
Rather than demolish the old plant and lose supply through the rebuild, the team kept it running while the new wash plant went up alongside. The changeover took about three weeks - pulling the conveyor from under the old feeder bin, swapping the chute and drive direction, and completing final engineering including water connections and power supply. Zero days of lost supply.
Cleaner water, cleaner ponds
Feed water is drawn from a pond roughly 200 metres away, with waste water discharged to a settling pond. The circulating system runs at approximately 55 litres per second - and noticeably less silt is reaching the ponds now that saleable sand isn’t ending up in the waste stream.
A two-person crew runs the lot
Day to day, the wash plant is run predominantly by two women - Aliesha, several years into the industry and working toward her B-Grade, and Tayla, two years in - both taking full ownership of running the site.
Proof you can walk around
The build doubles as a proof point for Equip2’s turnkey capability - civils through to commissioning, delivered as one job. For everyone who made the trip out, the wash plant showed what a well-executed modular build looks like in practice: no supply interruption, a plant designed around the people running it, and results already ahead of expectations.
