Calculation model of the tractor transport set - Economic and environmental indicators

Abstract

This contribution presents a calculation method of indicators in agricultural transport. The tractor Zetor Forterra 8641 with a silage trailer was used. Calculations were performed with various weights of transported material: 2.5, 3.6, 5.8, 7.4 and 9.0 tons. The model was created concerning significant parameters of the transport set, engine characteristics and route. It considered splitting of the route into elementary sections, in which important route parameters were regarded as constant. Indicators were defined in every section (fuel consumption, emissions, etc.) and overall values were calculated as a sum. The set with 7.4 t of load reached the lowest unit costs 20.62 CZK·tkm<sup>–1</sup>, transport output 79.51 tkm·h<sup>–1</sup> and unit consumption 0.14 L·tkm<sup>–1</sup>. The set with the maximum load 9.0 t reached output 86.05 tkm·h<sup>–1</sup> but unit costs were 20.68 CZK·tkm<sup>–1</sup>. Using the maximum capacity was not the most effective option. When the weight of a load increased (from 2.5 to 9.0 t), driving time extended from 0.28 to 0.46 h and hourly transportation output increased from 38.60 to 86.05 tkm·h<sup>–1</sup>, unit consumption decreased from 0.24 to 0.13 L·tkm<sup>–1</sup>. Total emissions significantly increased, but unit emissions decreased in average two times for each pollutant.