Skidders

Purpose built tractors, which extract by lifting one end of full-length trees clear of the ground and pulling them to roadside. Variations include All terrain vehicle (ATV) based units and mini/midi tractor variants

Farm skidders
Availability Widespread
Costs Relatively low capital cost, but only gives competitive unit costs over short extraction distances
Terrain ability Not suited to wet sites or slopes > 30%. Good manoeuvrability in crops
Potential site impact High ground damage risk on sensitive sites
Potential crop impact High crop damage risk
Access and transportation Easy transportation and access
Other operational considerations Not suited to shortwood systems. Best suited to extraction distances of less than 150 m. Requires conversion space at roadside. Can be used for other agricultural activities. Generally low load capacity
Ergonomics Some manual handling is required

 

Purpose built skidders
Availability Widespread
Costs Relatively low capital cost, but only gives competitive unit costs over short extraction distances
Terrain ability Not suited to wet sites or slopes > 30%. Good manoeuvrability in crops
Potential site impact High ground damage risk on sensitive sites
Potential crop impact Higher crop damage risk than other systems
Access and transportation Easy transportation and access
Other operational considerations Not suited to shortwood systems. Best suited to extraction distances of less than 250 m. Requires conversion space at roadside. Can be used for other agricultural activities. Generally low load capacity (up to around 5 m3).  Careful planning of extraction routes is essential to avoid site and crop damage
Ergonomics Some manual handling is required

 

Small tracked skidders
Availability Not widespread
Costs Relatively low capital cost, achieving low unit costs over shorter extraction distances
Terrain ability The tracks improve traction on slopes and make the crossing of narrow ditches possible, however stability is more affected by slope than with wheeled vehicles
Potential site impact Lower ground pressure than many other tractors, but high ground damage risk on sensitive sites. Track damage sensitivity on rough sites
Potential crop impact High crop damage risk
Access and transportation Easy transportation and access
Other operational considerations Not suited to shortwood systems. Best suited to extraction distances of less than 150 m. Generally low load capacity
Ergonomics Some manual handling is required

 

Skid arch sulky
Availability Not widespread
Costs Capital costs vary, with generally low cost of attachments. Unit costs generally high
Terrain ability Good manoeuvrability, but trailed load constraint turning. Ability to cope with some steep ground. Terrain roughness can be an issue. Brash and waste on the ground can impede travelling
Potential site impact Low risk from the arch itself but high traction force and low weight from ATC can cause ground damage if not properly used
Potential crop impact High crop damage risk
Access and transportation Easy transportation and access
Other operational considerations Best suited to extraction distances of less than 150 m. Low load capacity, most suited to small operations
Ergonomics Some manual handling is required