Local original-equipment manufacturer (OEM) Bell Equipment has developed the Bell M350 Mulcher, which caters to the forestry industry and has been specially geared for South Africa’s hot and dusty climate.
This niche solution was developed in consultation with the company’s customer base.
The development of the machine is in response to foresters moving away from the slash and burn practice of land clearing in favour of mulching as a more environmentally responsible method of removing biomass, explains Bell Equipment agricultural and alliance products chief engineer Ian Kramer.
He says there are tangible business benefits to mulching, which reduces the time between harvesting and replanting. Moreover, the mulch provides nutrients for young trees.
“We were approached by some of our customers who have tried traditional mulchers developed for the wetter climates of Europe and North America. These units typically don’t cope well with our harsh, dry conditions, where the combination of wood fibre and dust tends to clog up the cooling pack, causing overheating.”
Therefore, Bell Equipment was asked to develop a solution better suited to local applications.
“Working with our customers, we adapted the mulcher for our conditions by repositioning the cooling pack at the back of the machine, incorporating screening to keep the debris out and fitting a filtration system to filter out the dust and prevent it from reaching the cooling pack,” Kramer explains.
He says Bell Equipment demonstrated that the new machine can operate in ambient temperatures of 45 °C, having worked in the Kwambonambi area of northern KwaZulu-Natal, in the middle of summer.
“Temperatures often peaked higher than 45 °C, with no incidents of overheating.”
Like traditional mulchers, the cab is enclosed and filtered through the air conditioner to keep the workspace dust-free. The cab is mounted further forward for better visibility of the head, similar to a combine harvester. Bell Equipment chose to incorporate a head from Italian mulcher manufacturer FAE, because the prominent manufacturer is well recognised and spares are readily available in South Africa.
The Bell M350 generates 261 kW of power.
“During the design phase, we interacted with customers and looked at competitor machines. We found that these machines were fitted with larger mulching heads that required more power. However, the heads weren’t being supplied with the full power requirement so the performance wasn’t as good as it could be,” Kramer notes.
Therefore, Bell Equipment chose to use a slightly smaller head so that the machine could supply the head with the full power that the head manufacturer requires.
“By allowing the head to run at more optimal performance levels, our machine is more effective at mulching,” he claims.
The Mulcher is a four-wheel-drive machine with a solidly mounted front axle and a steering rear axle that pivots to keep all wheels on the ground on undulating terrain. The engine, located just behind the cab, drives three hydraulic pumps that are mounted underneath the cab.
During the design phase, the design team led by Kramer focused on service accessibility. Therefore, the hydraulic charge filters, fuel filter and air conditioner intake filter are all easily accessed through the bonnet side doors. The engine oil filter and air intake filter are also within easy reach inside the engine compartment.
The engine and air conditioner pre-cleaner are above the bonnet, while coolant filling is performed through the top of the bonnet.
Another important design consideration was the width of the machine. Imported units are about 2.8 m wide and have to be transported as an abnormal load, requiring special load permits and increased transport costs. However, the width of the Bell M350 is less than 2.6 m and can be transported on a normal low bed.
“Small details like this make a huge difference to our customers,” says Kramer.
He claims that independent studies by a large forestry company have shown that, depending on the operating conditions, the Bell M350 delivers between 18% and 23% better fuel burn than competitor machines, while productivity is on a par, from about 1.8 ha a day to 2.5 ha a day.
“At a lower capital investment, this means that our machine has a lower total cost of ownership while providing a solution uniquely suited to local conditions and backed by Bell as the OEM,” Kramer concludes.