Through this screen you can estimate the productivity and work time unit of the extraction system with skidding methods, under the operating conditions of the plot in question. At calculation procedure you can access through the Scrolling menu of the forestry managementSelecting the eighth item, that is "Extraction with tractor & forestry winch."
Even in this case the calculation is based on bibliographical data concerning the various stages of the extraction with skidding methods In particular, we have used the stacked time as a function of the distance between the point of attachment of the timber and the tractor. In this stage the skidding method is indirect, ie the tractor is switched off, while in the next step the skidding method is direct and times were then calculated according to the speed of the tractor. Were also taken into consideration different load capacity of tractors, the type of winch and systems of work that can be used.
Extraction with tractor & forestry winch
The calculation procedure provides you to enter the following parameters for the calculation of productivity and work time.
Parameters:
•  Timber volume sampling, expressed in m3, you can choose values between 10 and 300 (with intervals of ten unit). 
•  Average tree volume: expressed in m3, you can choose values between 1 and 10 (with intervals of one unit). 
•  Wood stacking average distance: expressed in kg, you can choose values between 5 and 100 (with intervals of 5 units). 
•  Average extraction distances off the striproad: expressed in meters, you can choose values between 25 and 500 (with intervals of 25 units). 
•  Average extraction distances on the striproad: expressed in meters, you can choose values between 50 and 1000 (with intervals of 50 units). 
•  extraction distance on the forestry road: expressed in meters, you can choose values between 50 and 500 (with intervals of 50 units). 
•  Number of log segments for tree: 
•  Equipments available for skidding: you can choose between: 
►  Small articulated tractor 
•  Extraction System: you can choose between: 
•  Forestry winch: you can choose between: 
The possibility to calculate working capacity (m3/h) and working times (h/m3) through the button is activated only when all required parameters are entered. If not shown on screen, the data is missing and then you could insert them.

