The Terra-Grader can improve and maintain deteriorating roads in African countries.
This will help solve the problems poor infrastructure causes for farmers, writes Chris Nel.
The Terra-grader multi-purpose road construction and maintenance grader was developed locally. It was awarded the 2006 South African Bureau of Standards Design Excellence Award and the SAICE-SANRAL-Sanlam SMART Award. It’s the brainchild of Luigi Quaroni and Johan Wessels. They had first-hand experience of deteriorating infrastructure in poor, war-ravaged African communities. “We realised unless something practical was done to maintain or upgrade rural roads for access to markets, the downward spiral would continue,” says Luigi. “Standard road construction and maintenance equipment isn’t suitable because infrastructure for access to fuel supplies often doesn’t exist.”
The manufacturers worked with the University of Johannesburg’s Department of Mechanical Engineering Technology. Postgraduate engineering lecturer Francisco Lardin Martinez was assigned to do his Masters in Technology dissertation on the design and development of a proposed towed grader. This was named the Terra-Grader.
With a ballast tank filled with water, the Terra-Grader weighs 14t, similar to a conventional motorised grader.
The blade-cutting edge is a standard 3 650mm. Blade extensions on both sides can increase to 4 360mm.
The blade operates on an articulation system allowing up-down movement to a depth of 150mm. It angles at 24º and tilts 12º up and down on both sides. It displays a 600mm lateral shift to both sides. All operations are hydraulic.
A hydraulic-powered spray-bar operates through a hydraulic fire pump. It discharges water from a 6 000â„“ baffled and rust-proof water tank at 80â„“/min, at 12 bar, through spray nozzles. The pump’s fire-hydrant coupling valve allows the use of a lay-flat fire hose with a delivery rate of 550â„“/min. A suction hose fitted to the pump allows refilling from open water at 600â„“/m.
The scarifier uses standard off-the-shelf ripper tips. It’s hydraulically operated to rip the soil up to 95mm deep.
The static compaction roller is a steel drum the full width of the Terra-Grader. During operation it remains under constant weight from 8t to 14t, depending on the content of the water tank. A spring-loaded scraper along the length of the roller ensures the roller remains clean.
The hydraulically operated wheels at the rear are fitted with pneumatic brakes. They can be lowered quickly to raise the road-building equipment, converting the Terra-Grader into a tow-trailer, while the tyres are foam-filled and puncture proof.
A 100kW four-wheel drive powershift tractor tows the Terra-Grader. Maximum fuel consumption is 100â„“ in a 10-hour working day. The price has yet to be established. |fw