Tennessee quarry tests the mettle of the Rokbak RA40  

A Rokbak RA40 articulated hauler is tackling the tough terrain of a quarry in Cookville, the largest city of Putnam County, Tennessee, to transport overburden, shot rock and finished crushed limestone products for UC Materials, as part of a large multi-group project.

Nestled directly between Nashville and Knoxville, the limestone rock quarry provides material to customers in the local area and feeds other sites within the group in which the quarry operates. UC Materials rents the RA40 from Ironclad Equipment LLC, which purchased the articulated hauler in January 2023 from long-term Rokbak dealer Diamond Equipment, a family-owned construction equipment dealership providing sales, service, parts, and rentals from five locations across four states in the Midwest and South.

“The reason we went with Rokbak is uptime and price,” says Ironclad Equipment LLC general manager and co-founder Barry Reese. “I personally prioritize profitability and knowing that the truck will always be working, and the RA40 ticked the boxes.

“The fact that the RA40 is performing really well, our operators like it and it does everything other haulers do but for a lot less money, shows why we’re very satisfied!”

Since being acquired by Ironclad at the start of the year, the RA40 had already clocked up over 1600 hours of operation [at time of writing]. The truck has been on this site since September 2023 and has been working at around 40 hours a week for UC Materials at the quarry. This isn’t Ironclad’s only Rokbak truck – the company has one tasked with land-clearing on a residential site near Nashville, and a third RA40 has also just been bought, signaling clear satisfaction with the hauler and the brand.

“The RA40 has really been a hit,” says Barry. “We’ve seen what it’s brought to the construction site and UC Materials quarry, so it makes sense to add to our fleet and choose a proven performer. We know what we’ve got, and we know the benefits this particular dump truck offers our expansive operations.”

Tough tasks in Tennessee
UC Materials uses the RA40 to move topsoil at the top of the quarry, as well as large amounts of rock from the face down to the base and stockpile it in the yard. Operating conditions can vary daily depending on the weather, but the ADT powers on and works between eight to ten hours a day.

Three to four passes via wheel loader fill up the RA40’s all-welded body. The RA40 has a haul capacity of 38 tonnes (41.9 US ton) and a heaped capacity of 23.0m3 (30.3 yd3), making it ideal for transporting the volumes of materials required by the quarry. Fabricated from high hardness 1,000 Mpa (1450,000 lbf/ in²) yield strength steel, a dual slope tailchute eases the material ejection from the RA40 body.

The RA40 can travel easily up the dusty, steep incline of the quarry’s haul route and an effective power-to-weight ratio ensures material is moved as quickly as possible in all conditions, with the adaptable drivetrain maintaining traction and speed on the toughest sites.

“The quarry has the ability to continue for a very long time, so there is lots of hard work ahead for our Rokbak dump truck,” explains site manager Matt Davidson. “There is 1000ft to go back from the current wall face.

“The operators are happy with the truck, and we plan on operating it within the quarry indefinitely, with low manual maintenance and cab comfort two particular strengths that have impressed the team.”

Stateside success continues
The RA40 has a spacious, ergonomically designed cab with pressurized properties, which ensures operators are comfortable when behind the wheel. Acoustic insulation helps to minimize noise levels inside the cab while a high performance and easily adjusted heating, ventilation, and air conditioning (HVAC) system ensures a stable temperature. Other features that help to deliver a comfortable work environment include a tilt/telescopic steering wheel, an adaptive air suspension operator’s seat with adjustable armrests, anti-vibration mounts for the engine and cab, and cushioned stops on the steering cylinders. The sharp reverse-camera is also useful for maintaining site safety.

The RA40 has ground-level test points, a fully tilting cab and an electronically raised hood that provides safe and easy access to the drivetrain components. Only two grease fittings must be greased manually on Ironclad’s RA40 every 250 hours. A full suite of on-dash diagnostic and machine health check data maximizes uptime by reducing intervention time. This includes prognostics for the transmission whereby the operator can immediately check the health of the component, including fluid level, fluid life, filter life, clutch life and more. Again, this reduces intervention time, boosting uptime for owners.

“Success stories such as this in Tennessee emphasize that the Rokbak rebrand has led to accelerated demand in North America,” says Rokbak regional sales manager Dan Meara. “Our trucks are out working across the United States and Canada, helping to generate further interest in the brand and contributing to the RA30 and RA40 being used on multiple large projects in this dynamic market.”

Rokbak is a manufacturer of off-highway articulated haulers that are used in mining, quarrying, and construction applications around the world. A member of the Volvo Group and headquartered in Motherwell, Scotland, UK, Rokbak has two models of articulated haulers, with payloads ranging from 28 to 38 tonnes (30.9 to 41.9 US tons).