Technodiversity Glossary

Functiogram

• capable of working in steep terrain
• less soil disturbance than for ground-based
• capable of pre-skidding loads (drop line)
• can work with limited road network

• Relatively long set-up and dismantle time
• Fixed set-up and dismantle time require relative intensive removal (ca. 0.5-1 m3/ m line)
• High planning effort
• Requires high operator skill

• Mountain operations
• Alpine forestry
• Developing on soft terrain as reduced-impact alternative to ground-based extraction

Economic suitability

Example:

• machine costs without personal costs: 100,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 3
• in total: 205,00 Euro/h
• regression line minutes per tree
  • b₀ = 1,0
  • b₁ (load volume) = 0,5
  • b₂ (logging distance) = 0,015
• plus costs for installation and dismantle of the cable system

Ecological suitability

Ecogram

Social suitability

• S-class: unloading full trees on forest road -> S3
• E-class: simple machine work, heavy and dangerous -> E3

Spinelli R.,  Marchi E., Visser R., Harrill H., Gallo R., Cambi M., Neri F., Lombardini C., Magagnotti N. (2017) The effect of carraige type on yarding productivity and cost. International Journal of Forest Engineering - Accepted paper.

Spinelli R., Magagnotti N., Visser R. (2015) Productivity models for cable yarding in Alpine forests. European Journal of Forest Engineering 1, p. 9-14.

Spinelli, R., Magagnotti, N. (2011) The effects of introducing modern technology on the financial, labour and energy performance of forest operations in the Italian Alps. Forest Policy and Economics, 13 (7), pp. 520-524.

Huyler, N., LeDoux, C., 1997. Cycle-time equation for the Koller K300 cable yarder operating on steep slopes in the Northeast. Res. Pap. NE-705, USDA Forest Service, Northeastern Forest Experiment Station 4 p.

Senturk, N., Ozturk, T., Demir, M., 2007. Productivity and costs in the course of timber transportation with the Koller K300 cable system in Turkey. Building and Environment 42: 2107-2113.

Stampfer, K., Visser, R., Kanzian, C., 2006. Cable corridor installation times for European yarders. International Journal of Forest Engineering 17: 71-77.

Zimbalatti, G., Proto, A., 2009. Cable logging opportunities for firewood in Calabrian forests. Biosystems Engineering 102: 63-68.

see SP-x2-x3 cross-cutting

After felling, delimbing, and topping, tree lengths are pre-skidded to a strip road using animals, and most commonly draught horses. Different breeds are available in different regions, but the most popular are heavy breeds like French Percherons, Belgian Ardennes, or Italian TPR.

Functiogram:

Advantages

• Capacity to work in dense stands and narrow corridors, inaccessible to mechanical vehicles.
• Capacity to handle soft or steep terrain (provided extraction proceeds downhill).
• Very low soil and stand impacts, because the animal has neither the size nor the power of a machine, and therefore it can never resort to brute force against an obstacle, but it must rather use brains and technique.
• Safety for the operator, who can control the horse at a distance through voice commands.
• Comfort for the operator, who is spared noise, vibration, exhaust gases, heavy cable pulls and tiresome walks on uphill grades (since he can ride the horse if the walk is too hard).
• Competitive cost on intermediate pulls (between 50 and 100 m), which are too long for direct winching and too short for cost-effective cable yarding.

Limitations, thresholds:

• The system is suitable for young trees only, as obtained from first and second thinnings, or to coppice harvesting operations. The size of older trees is generally too large for an animal to move them without preliminary crosscutting
• Distance must not exceed 200 m. Best results are obtained on shorter distances, between 25 and 100 m.
• Extraction must proceed on flat terrain or downhill slopes, with a maximum gradient of 50%. Experienced animals and drivers can safely handle steep terrain.
• Draught animals can only work 5 to 6 hours a day.  Operators working longer hours generally keep two animals and rotate them.

Main use

• Animal pre-skidding is still competitive with other mechanized pre-skidding systems (winches, mini-skidders etc.), but it is rarely used in industrialized countries, where it remains a specialist niche. The reason is in the small numbers of horse loggers, ready to accept the constant commitment imposed by animal care.

Economic suitability

Example:

• machine costs without personal costs: 10,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 1
• in total: 45,00 Euro/h
• regression line minutes pre log
  • b₀ = 3,0
  • b₁ (tree volume) = 8,0
  • b₂ (skidding distance) = 0,025

Ecological suitability:

• Ecogram 

Social suitability:

• S-class: no contact with forest road -> S5
• E-class: manual work, very heavy and dangerous -> E1

Felled and delimbed tree lengths are pulled to the trail with a cable winch that is mounted or attached to a tractor. 

Functiogram

Advantages

• extraction over long distance without driving on the ground 
• extracting in steep terrain (uphill)
• bringing trees to a site where machines for delimbing and cross-cutting can operate
• Compared with full trees, tree-lengths offer less resistance to drag and are easier to move within the stand
  
• Compared with full trees, no nutrient removal

Limitations, threshold

• distance limited by the length of the cable, often more than 100 m
• distance limited by the weight of the cable that must be pulled by the worker, so on flat terrain not more than 50 m, downhill wider distances are possible
• cable cannot be pulled uphill, therefore no downhill extraction over longer distance 

Main use

• in stands where fully mechanized methods are not applicable due to ground conditions, tree species (large broadleaf trees, e.g.)
• with wider distance of trails, where trees must be pulled into the reach of the crane of a machine
• in combination with extraction by means of a tractor 

Economic suitability

Example:

• machine costs without personal costs: 60,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 2
• in total: 130,00 Euro/h
• regression line time per tree
  • b₀ = 4,0
  • b₁ (tree volume) = 2,0
  • b₂ (skidding distance) = 0,1

Ecological suitability

Ecograms 

Social suitability

• S-class: no contact with forest road -> S5
• E-class: simple machine work, heavy and dangerous -> E3

Tree-lengths are dragged to the landing by a tractor equipped with a single or double-drum winch. The winch is used for assembling the load and for pre-skidding the tree-lengths to the skid trail if necessary.

Functiogram

• Independent pre-skidding and extraction capacity in one unit
• Can operate on steep terrain, if skid trails are available at a suitable spacing
• Can work in small lots if skidder is road legal

• Slow (pre-skidding)
• Need an assistant (chokerman) and/or the driver needs to leave the cab (uncomfortable)
• Limited load capacity

• Mountain operations
• Small-scale forestry
• Traditional extraction method when crosscutting should not be done before reaching the forest road (or the customer)

Economic suitability

Example:

• machine costs without personal costs: 65,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 2
• in total: 135,00 Euro/h
• regression line minutes per tree
  • b₀ = 4,0
  • b₁ (tree volume) = 2,0
  • b₂ (skidding distance) = 0,005

Ecological suitability

Ecograms 

Social suitability:

• S-class: unloading tree length on the road -> S3
• E-class: simple machine work, heavy and dangerous -> E3

Logging arch study for farm tractors - Merlo study etc.

Functiogram

• capable of working in steep terrain
• less soil disturbance than for ground-based
• capable of pre-skidding loads (drop line)
• can work with limited road network
• minimum of operations on the working site (safety)

• Relatively long set-up and dismantle time
• Fixed set-up and dismantle time require relative intensive removal (ca. 0.5-1 m3/ m line)
• High planning effort
• Requires high operator skill

• Mountain operations
• Alpine forestry
• Developing on soft terrain as reduced-impact alternative to ground-based extraction

Economic suitability

Example:

• machine costs without personal costs: 100,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 3
• in total: 205,00 Euro/h
• regression line minutes per tree
  • b₀ = 1,0
  • b₁ (tree volume) = 0,5
  • b₂ (skidding distance) = 0,015
• plus time for set-up and dismantle

Ecological suitability

Ecogram 

Social suitability

• S-class: unloading tree length on the road -> S3
  
• E-class: simple machine work, heavy and dangerous -> E3

Functiogram

• Capacity to deal with almost any terrain conditions 
  
• Limited impact

• Short distance only
• Animals need training and constant care
• Low productivity
• Only works with relatively small and short logs that are within the weight capacity of animal power

• Small scale forestry

Economic suitability

Example:

• machine costs without personal costs: 10,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 1
• in total: 45,00 Euro/h
• max. 0,4 m³ per log
• regression line minutes per tree
  • b₀ = 3,0
  • b₁ (tree volume) = 8,0
  • b₂ (skidding distance) = 0,025

Ecological suitability

Ecogram 

Social suitability:

• S-class: no contact with forest road -> S5
• E-class: manual work, very heavy and dangerous -> E1

Functiogram

Advantages

• Limited (or no) investment for manual sliding
• Capacity to deal with almost any terrain conditions 
• Limited impact

• Short distance only
• Downhill if sliding or throwing 
• Very low productivity
• Only works with relatively small and short logs that are within the weight capacity of human power

• Small scale forestry 

Economic suitability

Example:

• machine costs without personal costs: 0,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 1
• in total: 35,00 Euro/h
• regression line minutes per tree
  • max. load per cycle 0,1
    
  • b₀ = 2,0
  • b₁ (tree volume) = 1,0 
  • b₂ (skidding distance) = 0,025

Ecological suitability

Ecogram 

Social suitability:

• S-class: no contact with forest road -> S5
• E-class: manual work, very heavy and dangerous -> E1

When trees are cross-cut at the felling site, the logs must be pre-skidded to the trail separately. This is only rational when the weight of the tree length is too high. For example, the basic log can be separated from the rest of the stem before pre-skidding.     

Functiogram:

• low weights, lower damage in the stand

• low productivity

• Small scale forestry
• simple, light machines

Economic suitability:

Minutes per cycle

Example:

• machine costs without personal costs: 60,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 2
• in total: 130,00 Euro/h
• regression line time per tree
  • b₀ = 4,0
  • b₁ (log volume) =  2,0
  • b₂ (skidding distance) = 0,1

Ecological suitability

Ecograms 

Social suitability:

• S-class: no contact with forest road -> S5
• E-class: simple machine work, heavy and dangerous -> E3

see SP-x1-x2 delimbing