Developed as a joint venture (JV) between mining equipment group Bell Equipment and South Africa-based mining equipment company Aard Mining Equipment, a new underground haul truck (UHT), the B33L (Bell branding) or A33 (Aard branding) is expected to be fully operational by the beginning of April, after undergoing months of testwork.

The B33L/A33 UHT, which was launched at international trade fair for construction machinery bauma Africa, in Johannesburg, last year, features a low-height design, enabling the underground transportation of up to 33 t of mined ore.

The dumper completes Bell’s underground hauling complement as the biggest in the range.

Prior to manufacture, Bell conducted research that involved garnering customer input and listening to their requirements, notes Bell Equipment senior design engineer Dawid Ras.

“Although this was a clean-slate design, lessons learnt from previous designs were taken into consideration,” he states, adding that the timeline for developing the first machine was about nine months, excluding testing.

Ras notes that the design philosophy was in line with Bell’s policy of designing strong, reliable machines.

The B33L/A33 is fitted with a fail-safe braking system, which showcases a spring-applied hydraulic release brake and automatic-stop park brake app- lication.

The truck’s electronics include an inclinometer to determine the correct amount of torque required before the park brake is released. This prevents the truck from rolling backwards on inclines.

When moving forward, the dumper uses eight light-emitting diode (LED) clusters of lights, with reverse lighting being provided by four rear-facing LED clusters of lights.

A rear-mounted video camera also assists the driver in reversing manoeuvres. An automatic fire-suppression system is also available on request.

Engine
The UHT is powered by a turbocharged 12 ℓ V6 Mercedes-Benz OM 501 LA series engine that prod- uces 389 hp. Bell says the engine has proven its reliability to Bell engineers, as it is also installed in Bell’s B40D series of surface articulated dump trucks (ADTs).

The engine is mated to an Allison 4000 series auto- matic transmission, with six forward gears and one reverse gear. “Depending on customer requirements and mine site regulations, the transmission can be locked to use the first three or first four forward gears to limit top speeds,” he says.

“The engine and transmission are similar to our surface ADT range,” says Ras, adding that these components have proven durability and offer significant advantage to Bell customers with regard to the pricing of parts and their availability.

The machine uses Kessler axles, which are designed to carry loads of up to 40 t, while there are large-capacity braking systems with forced cooling at each wheel-end for improved reliability and endurance.

Further, exhaust emissions on the B33L/A33 pass through a catalytic converter for purification and through a large sil- encer for noise reduction. Exhaust gases meet Tier 2 emissions regulations of the US Environmental Protection Agency.

Maintenance Made Easy

Ras explains that the layout of the truck was designed to provide easy access for maintenance procedures, such as fluid and component checks.

“The electrical, pneumatics and fuel systems can be accessed from the left side of the vehicle, while the hydraulic valve blocks are positioned centrally, behind the cab, for easy access,” he says. Hydraulic tanks are also positioned behind the cab.

Unique to this UHT, however, is the centrally mounted operator’s cab, which provides significantly increased visibility. The cab is also air-conditioned, adding to operator comfort, and is fitted with a trainer seat for use when instructing new drivers.

“Leaning on the surface ADT’s legacy, this locally produced product is priced more competitively than the imported competitor products,” says Ras.

Joint Venture
Bell Equipment product manager Stephen McNeill says the JV was established as a result of Bell’s extensive experience in producing 25 t and 30 t underground dump trucks, coupled with Aard Mining Equipment’s vast underground experience and comprehensive range of underground machines, which excludes dump trucks.

“In November 2011, Bell approached Aard with the intention of understanding similarities between the two organisations’ underground product offering,” he says. It was found that Bell and Aard share similar design and manufacturing approaches and that both companies understand the value of working together to offer a complete range of locally manufactured, robust and reliable underground machines for the mining market,” says McNeill.

He believes that Bell has proven to be a leading worldwide ADT designer and distributor, with a focus on surface mining and construction applications. “However, as Bell was able to offer only dump trucks to underground mining customers, we were initially unable to infiltrate and effectively support this sector of the market with a full complement of underground machines.

“With Aard’s ground application experience and Bell’s expertise in the design and manufacture of trucks, the JV has proven its value with the launch of the new A33 haul truck from Bell to match the new 10 t load haul dumper (LHD) from Aard,” adds McNeill.

“As a dedicated equipment supplier with a full range of underground machinery, Aard is well positioned to include the Bell underground trucks and rock scalers in its product portfolio,” he notes.

With the establishment of the JV, Bell and Aard entered into a supply and distribution agreement for these products to be Aard branded, as well as sold and supported by Aard, which has taken over the aftermarket support of the existing Bell underground in-field units.

The agreement awards Aard the rights to sell and support these products throughout Southern Africa, excluding Namibia and Botswana.

“Although Bell loses a portion of the sales revenue per product sold, the Bell group bene- fits from an increased volume of underground units sold owing to Aard’s dedicated focus on the underground mining sector,” McNeill concludes.

Aard sales manager Pierre Roche says that the Aard 10 t LHD was designed last year; one unit is undergoing tests while another unit is on their production line.

He adds that the Aard LHD is equipped with a catalytic convertor and emissions dilutor for exhaust emissions cleaning.