Tractor overturns are a major cause of death in agriculture. Many variables are involved. To minimise the risks of driver injuries in an overturn a Roll-Over Protective Structure (ROPS) has been invented. Narrow track tractors for orchard and vineyard operations are mainly available with two different ROPS types: an enclosed cab frequently fitted with filters and air conditioning system or a simple front two post ROPS designed to be folded down allowing the tractor to operate in a reduced space. Concerning stability, the tractor unstable equilibrium angles are the result of the tractor configuration and position with respect to the ground slope. The aim of the paper was to study the effect of ROPS type on tractor stability performance. The tractor stability parameters were evaluated on 18 modern narrow track tractors measuring the mass, track width, wheelbase, Centre of Gravity (CoG) and Moments of Inertia (MoI). The evaluation considered pairs of tractors equipped with cab ROPS and two post ROPS. The cab fitment keeps the wheelbase and track width of the tractor unchanged with respect to the front foldable ROPS but affects the mass, position of the CoG and longitudinal and transversal MoI. Data show an increase of tractor mass and higher CoG and MoI for the cab fitment with respect to the two post ROPS. The recent debate on the safety performance of two post ROPS is consequent to the incorrect use of the foldable ROPS and the cab is often claimed to provide better driver protection. The investigation conducted denotes that on sloping fields narrow-track tractors fitted with a cab ROPS reach the unstable state at lower angle than two post ROPS tractors.
Tractor stability parameters as affected by ROPS type
FRANCESCHETTI, BRUNO;RONDELLI, VALDA;CAPACCI, ENRICO
2016
Abstract
Tractor overturns are a major cause of death in agriculture. Many variables are involved. To minimise the risks of driver injuries in an overturn a Roll-Over Protective Structure (ROPS) has been invented. Narrow track tractors for orchard and vineyard operations are mainly available with two different ROPS types: an enclosed cab frequently fitted with filters and air conditioning system or a simple front two post ROPS designed to be folded down allowing the tractor to operate in a reduced space. Concerning stability, the tractor unstable equilibrium angles are the result of the tractor configuration and position with respect to the ground slope. The aim of the paper was to study the effect of ROPS type on tractor stability performance. The tractor stability parameters were evaluated on 18 modern narrow track tractors measuring the mass, track width, wheelbase, Centre of Gravity (CoG) and Moments of Inertia (MoI). The evaluation considered pairs of tractors equipped with cab ROPS and two post ROPS. The cab fitment keeps the wheelbase and track width of the tractor unchanged with respect to the front foldable ROPS but affects the mass, position of the CoG and longitudinal and transversal MoI. Data show an increase of tractor mass and higher CoG and MoI for the cab fitment with respect to the two post ROPS. The recent debate on the safety performance of two post ROPS is consequent to the incorrect use of the foldable ROPS and the cab is often claimed to provide better driver protection. The investigation conducted denotes that on sloping fields narrow-track tractors fitted with a cab ROPS reach the unstable state at lower angle than two post ROPS tractors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
