FOPR 3 Module 6 Harvesting Systems

Question 1

Do you understand the Mechanics of Force Equlibrium calculations? (skidding)

Answer 1

Yes or NO

Question 2

2 line yarders

Answer 2

designed for high-lead yarding systems with a main line for inhaul and haul back line for outhaul.

Question 3

Running Skyline (2 line yarders)

Answer 3

Simplest form of carriage is Scab block. haulback block is hung on the haulback and connect to butt rigging.

Question 4

Gravity skyline (2 line yarders)

Answer 4

uses two yarders for uphill yarding. mainline yarder is used as the skyline. haulback line becomes the mainline for inhaul. outhaul is dependent on gravity.

Disadvantage: yarding road width is restricted by length of chokers. can use more complex carriages to overcome.

Question 5

3 line yarders

Answer 5

3rd working line on yarders may be a designated live skyline, or a second mainline intenede to add extra mechanical control of the carriage.

Question 6

Slack Skyline (3 line)

Answer 6

similar or identical to carriage used in shotgun system.

difference is additoinal haulback line which provides means of an outhaul for downhill yarding or if insufficent slope for gravity haulback.

slack puling carriages are used to allow for significatn lateral yarding distances. used for partial harvesting.

Question 7

Double Mainlines

Answer 7

tow mainlines move at the same rate in the same difrection on the inhaul and outhaul.

two lines will be moved in opposite directions to manipulate a function at the carriage.

Question 8

Guylines

Answer 8

elevates the working cables at landings. also known as a back spar.

They must counter act the forces from the working lines.

increased force on the lines means more and larger diameter guylines.

Question 9

Buckling

Answer 9

When an obstacle starts to collapse under pressure. Buckling designs consider the maximum load bearing

Question 10

critical compressive force for buckling

Answer 10

calculated value at which buckling could occur. based on Cross section area of column, length of column, compressive strength of the column.

Question 11

Production Variable elements

Answer 11

1. MGMT Decisions
2. Workers
3. Physical conditions
4. Type and conditions

examples:

Falling and bucking
 Yarding
 Loading
 Hauling
 Road maintenance
 “Expense” road construction

Question 12

Production Fixed/Non-controllable Elements

Answer 12

Stumpage, royalty, depletion
 Road use charges
 Administration and overhead
 Waste & residue stumpage and royalty
 Insurance

Question 13

Production Data Collection and Analysis

Answer 13

Logical and distinct components
 Measurable as an entity
 Useful in providing information for a purpose (e.g. control, planning, investment)
 You must consider the limitations of your resources to collect detailed data and the cost/benefit of going to that detail