Two decades on, a Wheatbelt manufacturer builds up to take on the heaviest mine-spec water carts

Twenty-odd years after it started building trailers for farmers in the small Wheatbelt town of Dalwallinu, Shermac is now producing some of the largest mine-spec off-road water carts in the country, and it has built a dedicated heavy fabrication facility to do it.

The Western Australian manufacturer began in 2002 as a family business serving local Wheatbelt industries. Dust, rough roads, long distances, and demanding workloads meant the equipment had to be engineered properly rather than simply built to look good leaving the workshop, and that thinking shaped the company as it grew. Over two decades, Shermac evolved from trailer manufacturing into the design and production of mine-spec support vehicles, water carts, service trucks, service trailers, and diesel trailers, for mining, civil, and infrastructure operations across Australia.

The most demanding part of that range is the off-road water cart. Shermac's Roadserve 4000 and 5000 series are the largest builds it produces, mounted on articulated and rigid mining haul-truck chassis for sustained dust suppression and haul-road conditioning at full production scale. These are not light units. The modules on the biggest off-road builds weigh up to 40 tonnes, a different order of manufacturing to the trailers the business started with.

Meeting that demand required investment in capability, not just design. To support the move into off-road vehicles, Shermac built a specialist heavy fabrication workshop at its Dalwallinu site: a 1,400 square metre facility with a 220mm concrete floor engineered for 50-tonne point loads. A standout feature is a custom-engineered tank rotation system, mounted in a floor pit and connected to the tank, which lifts and rotates each tank as needed during the build. Because a water cart tank has to be turned several times as it is fabricated and coated, that system is central to producing the larger units to a consistent standard.

The engineering inside those tanks is where the years of building for harsh conditions show. Shermac tanks follow the slope of the chassis with curved sides that sit narrower at the top, keeping the centre of gravity low for stability and loading the carrier's axles correctly when full. Internally, the company applies what it describes as its most important build process: all surfaces are grit-blasted to class 2.5 and inspected before edges and seams are brushed with an epoxy liner and the tank receives two coats of tank liner, a corrosion-protection method aimed at long service life in wet, abrasive conditions. Pipework is hot-dip galvanised and mounted externally to prevent corrosion and simplify servicing, and every cart is built to Australian Standards with mine-spec compliance as standard, including access built to AS 1657, ROPS, high-visibility markings, and compliant lighting.

That end-to-end control is deliberate. Shermac carries its own design, engineering, procurement, and fabrication in house, through to assembly, testing, hydraulic engineering, auto electrics, blast and paint, commissioning, delivery, operator training, and after-sales parts and support. Handling the full build under one roof, the company says, gives it accountability for every stage and a more predictable outcome for the customer.

The approach has earned Shermac work with some of the largest operators in the country, including BHP, Rio Tinto, Fortescue, and Mineral Resources, and the company reports that around 75 per cent of its work is repeat business.

"Shermac has been providing customised, engineered-for-purpose service vehicles to the resource sector for two decades," said Steve Ray, Shermac's Chief Operating Officer.

The business now runs three divisions, Mining, Civil, and Commercial, from its Dalwallinu manufacturing base, with support offices in Perth and Queensland extending its reach beyond its home state. For a company that began building farm trailers in a country town, the shift to fabricating 40-tonne mine-spec modules marks how far the engineering has come. The stated priorities, though, have not changed: build reliable equipment, support customers properly, and keep improving.