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State what words have been substituted by THAT (THOSE).

1. Latest automobile engines are more powerful than those of previous makes.

2. Central areas of the USA differ greatly in topography, climate and forest composition from those lying along the Atlantic coast.

3. Sawmills operated all year round are not so dependent on timber supply as those working seasonally.

4. Tractor skidding is more productive than that done by oxen.

5. Logs loaded on trucks get to the mills quicker than those driven by water.

14. Guess the words by definitions and translate them into Russian:

1.the backcut; 2. to buck; 3. a bucker; 4. a bullbuck; 5. to clear cut; 6. a cutting pattern; 7.day wages; 8. a double-action shear; 9. the face; 10. to fell; 11. ground skidding; 12. to hang-up; 13. a head lean; 14. to limb; 15.measuring; 16. residual stand; 17. a set; 18. to singlejack; 19. a skid road; 20. stand density; 21. a strip; 22. topping; 23. tree-length; 24. to yard; 25.a yarder;

 

1. Compensation on a day rate; 2. to cut a felled tree into smaller segments; 3. a cutting supervisor; 4. the undercut made in a tree on the side facing the direction in which the tree is to fall; 5. to sever a standing tree from its stump; 6. to trim the limbs off the bole of a tree either by hand or machine; 7. moving trees on the ground either by crawler tractor or wheel skidder; 8. a crew member who cuts felled trees into shorter lengths; 9. to fell and buck all the merchantable trees in a given area;10. the pattern to which trees are felled during a cutting operation; 11. a mechanized cutting tool for felling trees that works like a pair of scissors; 12. to move logs from the stump to a landing area; 13. a machine equipped with powered winches and used to haul logs to the skid road or landing; 14. trees remaining in an area after the cutting operation has been completed; 15. a cutting crew, generally composed of two men; 16. to work alone on a setting, felling and bucking the trees; 17. to fell a tree so that it lodges in a second tree instead of falling to the ground; 18. the downhill lean of a standing tree, this is the most pronounced type of lean occurring in trees; 19. a method employed before bucking to ensure that proper log lengths are cut for the end use desired; 20. the final cut made in a tree to remove or sever the wood on its back side and allow it to fall; 21. a road on which logs are skidded; 22. the number of merchantable trees per acre; 23. the area in which a set of cutters works; 24. one cut is made to remove the top from a felled tree at a predetermined merchantable diameter; 25. a log which has been topped only.

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Cable logging

Cable loggingis a logging method primarily used on the West Coast of North America with yarder, loaders and grapple yarders.

The cables can be rigged in several configurations.

There are two classes.

  1. High lead logging, in which a simple loop of cable runs from the yarder out through pulley blocks anchored to stumps at the far end of the cut.
  2. Skyline, in which a carriage, pulled by hauling cables, runs along a skyline cable, providing vertical lift to the logs.

Into this there are varieties of loading systems. While skyline logging requires additional setup time, the vertical lift of the skyline allows faster yarding, which can outweigh the additional labor costs, especially on larger harvest units. Since the 1980's Grapple Yarders have become popular.



Skyline and grapple yarding, however, require more complex and expensive equipment. A traditional highlead or gravity system will function with just two cables, a skidding line and a haulback line. As the names imply the skidding line is used to drag the logs in, and the haulback line is used to drag the skidding line back out for the next turn (or group of logs). A skyline system will add a third line---the skyline whose function is to hold the skidding line and the haulback line off the ground or 'in the sky'. The yarder itself is located on a landing, a flat area on top of the ridge that is being logged. After the trees are retrieved by the yarder, the limbs are bucked (removed) and the logs are then placed in piles awaiting transport.

A yarder is piece of logging equipment which uses a system of cables to pull or fly logs from the stump to the landing. It generally consists of an engine, drums, and spar, but has a range of configurations and variations such as the Swing yarder. A loader is a heavy equipment machine often used in construction, primarily used to load material (such as asphalt, demolition debris, dirt, snow, feed, gravel, logs, raw minerals, recycled material, rock, sand, and woodchips) into or onto another type of machinery (sich as a dump truck, conveyor belt, feed-hopper, or railcar).

A grapple yarder is a piece of large crawler tracked logging equipment with tongs used to move logs. It is used primarily on the Pacific West Coast of North America. They have since replaced yarders. Some units are made by Madill of Nanaimo, British Columbia.

High lead logging is a method of cable logging using a spar (tree), yarder and loader. It was developed by Oscar Wirkkala. It is accomplished with 2 lines (cables) and 2 winches. The mainline or yarding line extends out from one winch, while a second usually lighter line called the haulback line extends out from the other winch to a 'tail block' or pulley at the tail (back) end of the logging site, and passes through the tail block and connects to the main line. Butt rigging is installed where the two lines join and the logs are hooked to the butt rigging with chokers. --- Wind up the main line and the logs are pulled in, wind up the haulback and the butt rigging is pulled out for more logs or another 'turn'.

The "high lead" feature is added by elevating both lines near the winch or 'head' end. This is accomplished by running the lines through a block (pulley to non-loggers) called the "head block" because it is on the head end of the project. Early on, it was customary to trim and top a tree making it into a 'spar pole' or 'spar tree' for the purpose of supporting the head blocks but gradually the use of wooden spars gave way over the 20 century to the use of steel spars stood up for the purpose. In any event the spars were supported by a number of 'guy wires'.

The reason for elevating the lines (cables) at the head end is to assist in pulling the logs free of obstructions on the ground. Also if the trees are being partially lifted as they are transported it is less disruptive to the ground which can be an environmental issue.

A popular method of logging on the West Coast of America. First used in 1904, with Lidgerwood winches, and a spar tree.

In skyline logging (or skyline yarding), logs are transported on a suspended steel cable from where the trees are felled to a central area, which is typically next to a road. Logs are attached to the suspended cable by means of choker cables and carriages. A skyline yarder can pull in 5 to 10 logs (on separate chokers) at a time. The suspended cable is a loop that wraps around a pulley at each end; one of the pulleys is the drive pulley. The pulleys are mounted on towers or cranes or, in rare cases, helium balloons.


Date: 2015-12-17; view: 871


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