Performance of a driven hitch-cart for draft animal power under different power take-off torque and ballast levels condition

The performance of a two-wheel driven hitch-cart designed for draft animal power has been assessed. The cart fits a three-point linkage system and a ground-driven power take-off (PTO). Conventional pneumatic tires and metallic wheels have been tested in dedicated draft trials with increasing torque applied to PTO (7.0 to 70 Nm) at two ballast levels (100 and 200 kg). Draft force varies from a minimum of about 760 N (pneumatic tires and the lowest ballast), up to about 4480 N (metallic wheels and the highest ballast), with a linear increase as a function of the PTO applied torque. In term of global efficiency the better performances was achieved in different conditions. The metallic wheels deliver greater power to the PTO than pneumatic tires. Furthermore, they had global efficiencies higher than pneumatic for high power requirements, while the pneumatics perform better when the required power is low. Slippage rises as a function of increasing torque and decreasing ballast, with metallic wheels allowing delivery of greater PTO torque at the same slippage extent. The performances of the cart are consistent with the use of implements designed for small tractors.