Straddle tractors were created to meet specific needs, linked to the performance of particular operations in the fruit growing field and, above all, in the vineyards. They literally "scramble" the row, passing through it, along its longitudinal direction. Since they are designed to perform particular operations, to optimize their yield it is necessary to use them in vineyards that have been bred with techniques such as to size the plants in the right way. These models consist of a load-bearing frame on which all the other components, such as the engine and driver's cab, are placed and are equipped with front and rear attachments. The engines can be 4 or 6 cylinders, generally turbo; able to develop powers between 50 and 130 Kw. They are equipped with hydrostatic transmission, due to the particular conformation of the vehicle and the wheels are generally isodiametric.
Mainly, straddle tractors are divided into some types, consisting of the frame that carries a specific operating equipment: frame with the function of tying machine equipped with front attachment; frame with pruning function, with front attachment; frame with trimming function, with front attachment; frame with fertilizer distributor function, carrying a rear attachment; frame with sprayer function, also with rear attachment and the frame with grape harvester function with rear attachment. The track width of the frame varies from 1.20 to 2.90 meters, to be able to adapt to the various space requirements, even small ones, that characterize the vineyards. The vehicles, at least in the most modern versions, are hydraulically self-leveling; while the straddle element is built with variable height, also hydraulically adjustable.
Since they are machines designed to carry out special processes that require intervention precision, the use of electronics is the norm. The operations that are carried out under the control of computers, sensors and detectors that coordinate the work of the mechanical and hydraulic organs are numerous. It is worth mentioning some models, to give an idea of what these means are. In some cases, the automotor for precision viticulture (this is the most technical definition) can be equipped with a cartography or a visual identification system. This grape harvester (geolocalized among other things) is able to carry out the work of sorting the grapes directly in the vineyard independently and automatically: depending on the criteria of maturity or quality of the bunches, these are sorted into the bin on the right or in the one of left.
Straddle tractors: Technical solutions on straddle tractors
Stability is also of great importance, especially for the conformation of the terrain where these machines operate, which is not always flat, on the contrary. Some models, to better adhere to the conformation of the ground, have the supporting frame divided into two halves, connected to each other by a longitudinal pin. In this way, the support on the ground of all four wheels is guaranteed, with great stability and traction of the vehicle. It should also be remembered that, although for some operations these vehicles are combined with specific attached equipment, straddle tractors are able to operate in all respects as a normal tractor to which various implements are combined. In this way the tractor will perform particular tasks, but can also simply plow.