True to the company's pioneering spirit, Bell Equipment will introduce its groundbreaking 60-tonne truck concept at Bauma Africa in September. The B60, as it is known, takes ADT design and innovation into a new league, opening up opportunities for the ADT specialist in a domain that was previously only contested by rigid haulers. 

According to Bell Equipment's Chief Engineer, Wynand van der Walt, the concept of a larger articulated truck is the realisation of a vision that Bell Equipment Director, Peter Bell, has held for many years. "It has been our intention to build a larger truck and concepts have been in development for some time but with the economic downturn the project was put on hold. At the beginning of last year it was revived and our Advanced Research and Development team started the full design process and developed prototypes for application testing." 

Explaining the B60 concept, Van der Walt says: "The idea is always to grow the size of the machine so that more dirt can be moved. We have identified a growing need amongst contractors who usually run rigid trucks in the 60 ton range. We have adopted the two-axle concept of a rigid truck, with the difference that the front axle is also driven and the front and rear chassis are independent. This makes the truck a complete 4x4, unlike the conventional rigid trucks, which are 4x2 with limited suspension and poor ability to negotiate unmaintained areas along the route or at the load and tip areas." 

"By combining the ADT concept as we know it with the single rear axle, we've come up with a unique machine configuration. It's a 4x4 with full articulation steering and oscillation joint and that gives us the ability to keep all four driving wheels on the ground and fully utilise the traction that's available. This gives the B60 more off-road capability than any conventional rigid truck." 

Continues Van der Walt: "An advantage of our truck would be the significant added flexibility from a single fleet. A contractor could use this truck on less maintained roads when starting a new mine; for the initial works before well maintained haul roads have been built. After establishment, when the mine is in operation, the capacity and performance of the truck would then allow for it to be placed directly into a production cycle. The off-road capability also means that, in a wet environment for example, a customer would benefit from quite a few extra days a year that he can operate, which would've otherwise been lost with a rigid truck." 

Bell Equipment's design philosophy has always been driven by creating lowest cost per tonne equipment solutions and the B60 is no different. "We saw with the increase from the B40D to the B50D that you don't pay the same proportion for fuel and other operating costs as you get in payload. We expect to achieve similar economies of scale with the B60 whereby customers will be moving 10 tonnes more than the B50D without the same increase in fuel consumption. We know our drivetrain is very efficient and we expect much lower fuel consumption than a traditional rigid truck." 

Bell engineers have stuck with the tried and tested B50D for the front end of the new truck. "We've deliberately chosen to go that route because the B50D has proven itself well and is running with proven componentry and systems. We've also made sure our weight distribution is such that we don't strain the front end any more than we do with the B50D minimising any risk with the new layout," says Van der Walt. 

The only tweaks to the front end are the engine and transmission. While the B50D and B60 share the same capacity V-8 turbocharged Mercedes Benz OM502LA engine, the power output has been increased from 380kW to 420kW in the B60. Engineers have also opted for a 7-speed Allison transmission rather than the 6-speed transmission of the B50D, finding the close ratio box better suited to the larger truck. 

The most visible differences are at the back end. The back axle is a dedicated 70t truck and haulage axle from Kessler, Germany in keeping with the Bell philosophy of selecting the best components and technology available on the market. 

To achieve the 60-tonne capacity the bin is much wider than an ADT and more resembles a conventional rigid-type bin. Telescopic cylinders tuck under the bin to push it up in stages during the tipping process. 

Says Van der Walt: "The rear chassis and suspension are distinctly different from an ADT concept. A cradle supports the rear axle with struts being used to create active shock absorption for a controlled ride." 

Testing has demonstrated that the chassis and suspension configuration creates a smooth ride, laden and unladen, that rivals the B50D in the operator comfort stakes. 

However, the B60 is aimed at a slightly different market then the flagship B50D. Bell Equipment Marketing Manager Llewellyn Roux says the B60 is better suited to hard ground applications typical of South Africa's hard mines and quarries with tight turns. He says: "In these applications you don't need the flotation of an ADT so the single rear axle can take the full load and deliver the benefits of having one less axle, such as no scuffing of tyres and improved manoeuvrability. 

"The real niche is where weather can change conditions significantly for shorter periods and the rigids would have to stop production. Additionally less maintenance of the ground conditions at the load and dump side, normally required to prevent rigid trucks from getting stuck, would also deliver significant savings to a customer. The fact that the machine has four wheel drive and the ability, through the incorporation of an independent front and rear chassis, to keep the wheels on the ground is a huge advantage for just about any high production application." 

Van der Walt says the B60 mule has been run extensively at Bell Equipment's off-road test track and at a mine in northern KwaZulu-Natal, giving engineers an opportunity to refine the concept. "During this time we invited customers to come and get a feel for the truck and make sure we're on the right track. We took their comments onboard and in general they were pleased with the concept and keen to test it on their own sites." 

After Bauma Africa the company aims to test the B60 further afield in Southern Africa and plans to build more units next year for testing on various customer sites. 

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