Design of a Sustainable, Locally Manufacturable, Agricultural Utility Vehicle for Developing Countries

Many areas of the developing world lack affordable transportation. Habitants spend a significant percentage of their time transporting agricultural products and water manually, over rough terrain and long distances, and it can be difficult to get fresh produce to markets where it can be sold before spoilage occurs. Through a partnership between universities, non-governmental agencies (NGOs), and local partners in Cameroon, a low-cost agricultural utility vehicle was designed and tested. The three-wheel vehicle was designed to use a low cost single cylinder 5-9kW engine, diesel or gas, and carry loads of 600kg at speeds up to 30km/h. The entire vehicle was designed to use locally available materials and resources, allowing for local manufacturing, maintenance, and employment. In 2011, Purdue University students travelled to Bangang, Cameroon and partnered with staff at the African Centre for Renewable Energy and Sustainable Technologies (ACREST) to build and test the basic utility vehicle (BUV). At the conclusion of a three week travel and building phase a working prototype was in operation. The design process, vehicle characteristics and performance, and field test results from the vehicle prototype are presented. The vehicle has a three speed transmission consisting entirely of standard V-belts and pulleys, and chains and sprockets. Maximum speeds are 6, 13, and 27 km/h for the three driveline ratios. Finished vehicle empty mass was measured at 450kg. A limited slip differential was designed using four Vbelts with a pair of belt tensioners. A steel truss frame can be constructed from square tubing or angle iron depending on local material availability. A rear trailing arm was designed for the rear suspension. A single airbag, multiple coil springs, or a leaf spring can all be utilized as the primary suspension. The one-piece trailing arm allows full vertical movement combined with very high roll stiffness. Wood is used to construct the cargo bed, engine cover, and seating for three people. The wood cargo bed rests on a steel frame with rear pivot points that allows for dumping the payload. The steering consists of a tiller handle connected to a single front wheel. Required skills for manufacturing the BUV include cutting metal (hacksaw, torch, or grinder), drilling holes, and welding. No machining or high tolerance components need to be fabricated. In summary, a low-cost, locally sustainable agricultural utility vehicle was designed and built, and a prototype constructed and tested in Africa.