Narrow-Track Agricultural Tractors: A Survey on the Load of the Hand-Operated Foldable Rollbar.
To protect the driver in case of a tractor overturn, narrow-track tractors (used in vineyards and orchards) can be equipped with a rollover protective structure (ROPS) consisting of a two-pillar front-mounted foldable rollbar. The transition from the horizontal (rest) to the vertical (protection) position of this ROPS is performed manually by the driver. In addition to the time spent performing this task many times each day, a moderate physical load is required, given that these rollbars often have a mass of some tens of kilograms. In practice, neglect and poor attention to safety lead to the foldable rollbar remaining continuously in the rest position rather than being moved to the vertical (protection) position. Several rollover accidents have been fatal for the driver because the tractor, although equipped with a two-pillar front-mounted ROPS, had the rollbar in the horizontal position at the time of the event, thus assuring no protection to the driver. This issue is quite serious. To remove at least one of the problems for the proper management of this type of ROPS, the OECD has recently updated its Code 6 by introducing an optional test addressing the manual handling of front-mounted rollbars, providing a maximum load of 100 N. Several tests were conducted on new rollbars to ascertain the accuracy of this limit. The 100 N value was generally exceeded, which is cause for criticism. Indeed, a more appropriate reference for manual handling in this case would be the higher loads (up to 250 N) already provided by other standards for non-continuous tasks.
Comparing the influence of Roll-Over Protective Structure type on tractor lateral stability
Abstract Tractor overturns are a major cause of death in agriculture. Many variables are involved. The Roll-Over Protective Structure (ROPS) has been invented to minimise the risks of driver injuries in a tractor overturn. 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 two post ROPS designed to be folded down to allow the tractor to operate in a reduced surrounding space. Concerning stability, the tractor lateral stability angle is the result of the tractor configuration and its 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 22 modern narrow-track tractors measuring mass, track-width, wheelbase, Centre of Gravity (CoG) and Moments of Inertia (MoI). The evaluation considered pairs of tractors equipped with two post ROPS and cab ROPS. In the design of compact narrow-track tractors 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 in tractor mass and higher CoG and MoI for the cab fitment with respect to the two post ROPS. A recent international debate on the safety performance of two post ROPS was consequent to the incorrect use of the foldable ROPS in field operations. Cab ROPS is thus often claimed to provide higher protection to the driver. This investigation denotes that on sloping fields narrow-track tractors fitted with a cab ROPS reach the lateral unstable state at a lower angle than two post ROPS tractors; consequently, the stability performance of the tractor worsens.
Ergonomics and psycho-sociological quality indexes in greenhouses, Almería (Spain)
This study investigates the use of the Labour Economics and Sociology Laboratory of France (LEST) method to analyse work posts among greenhouse workers in the Almeria region of South-Eastern Spain. The aim is to improve the health of the labourers. Data were gathered from 110 greenhouses, 73 of the Almeria parral plano type and 37 raspa and amagado. Crops studied were 63 greenhouses of tomatoes, 31 of watermelons, and 16 of courgette, examining the physical environment, physical load, psycho-social aspects, and time worked by the labourers. The main conclusion was that this type of crop protective structure, typical in South-Eastern Spain, does not guarantee a comfortable working environment, as defined by the norm UNE-EN 13031-1 reference. The results also associate the different types of greenhouses and their crops with the ergonomic and psycho-sociological conditions of the workers. Improvements are proposed.