Ground Based Harvesting

Question 1

What kind of horses are logging horses? How are logging horses classified?

Answer 1

Draft horses. Classified by weight.

Question 2

What are 6 reasons that horse logging is not common?

Answer 2

• ground lead only
• slow
• expensive to maintain horses
• not capable of adverse slopes
• logs can’t exceed 1 cubic meter.
• less than 100m skidding distance

Question 3

What are some characteristics of tractor logging?

Answer 3

• utilize pony arch with choker to skid logs with front end lift
• can be outfitted with hydraulic grapple
• can be outfitted with a winch to pull logs up steep slopes (30-40 m reach)

Question 4

What is the point of the integral or pony arch?

Answer 4

• generate lift on the front end of the log to reduce “hang ups” and site degradation.

Question 5

With crawler skidders, what is the maximum adverse slope?

Answer 5

15%

Question 6

What is the maximum favourable slope for a crawler?

Answer 6

40%

Question 7

What are the best applications for the crawler (2).

Answer 7

• Deep snow, frozen ground, dry sites or high coarse frag

- has a very short turning radius, making it good for partial cuts if the blade is removed.

Question 8

What defines flex track skidders?

Answer 8

• Tracks are flexible, making it more stable when driving over obstacles.
• can be outfitted with arch grapples, swing grapples or choker arch configurations.

Question 9

What separates flex track skidders from tractors? 4 things

Answer 9

• Faster
• More stable
• can work on slightly steeper slopes
• not as heavy of an impact on soils

Question 10

What are the limitations of the flex track? (5)

Answer 10

• High cost due to carriage maintenance
• Rocky ground can damage undercarriage
• High operating cost (maintenance)
• 20% adverse max
• 50% favourable max

Question 11

What are some characteristics of rubber tired skidders?

Answer 11

• The cheapest harvesting system to operate
• AWD with articulating frame
• Hydraulic grapple or winch line / chokers
• High soil disturbance

Question 12

What are the preferred applications of rubber tire skidders?

Answer 12

• Low cost, High productivity
• grapple with feller bunched or chokers for hand felled
• short skidding distance of 200m or less

Question 13

What are the limitations of rubber tire skidders? (5)

Answer 13

• 10% max adverse
• 30% max favourable
• not a good option on fine textured or wet soils
• unstable on obstacles and hills
• needs trail

Question 14

What is the legal expectation of skidder trails?

Answer 14

They are required to be deactivated by digging them up and reducing compaction so trees can grow.

Question 15

What are some characteristics of the clam bunk?

Answer 15

• grapple arm lifts trees onto a bunk
• hydraulic arms clamp the load
• big loads (take full length logs to roadside)

Question 16

What are the limitations of the clam bunk?

Answer 16

• 10% max adverse
• 50-60% favourable
• low maneuverability and slow operation where there are obstacles.

Question 17

What is a crucial part of designing plans for ground based harvesting?

Answer 17

• Engineer skidding trails for minimal site impact and be sure to educate the contractor and hold him accountable to these plans.

Question 18

What is a “rub tree”

Answer 18

A tree that is sacrificed to be used as a pivot point for logs being skidded in order to minimize damage to leave trees.

Question 19

What is the relationship between road density and skidding cost?

Answer 19

Inverse. The higher the road density, the lower the cost of skidding. But remember also the cost of deactivation post harvest.

Question 20

What are the characteristics of forwarders?

Answer 20

• self loading, rough terrain carrier
• haul overland to landing
• unload themselves onto roadside log decks
• articulating chassis, self loading grapple, oversized towers.

Question 21

What are the limitations of forwarders?

Answer 21

• 15% max adverse

- 35% max favourable