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420EL
Руководство по эксплуатации Страница: 22

Husqvarna 420EL [22/28] Working techniques

WORKING TECHNIQUES

22 – English

Cut all the way through the log from above. Avoid letting

the chain touch the ground as you ﬁnish the cut. Maintain

full throttle but be prepared for what might happen.

If it is possible (can you turn the log?) stop cutting about

2/3 of the way through the log.

Turn the log and ﬁnish the cut from the opposite side. (53)

The log is supported at one end. There is a high risk

that it will split.

Start by cutting from below (about 1/3 of the way through).

Finish by cutting from above so that the two cuts meet.

(53)

The log is supported at both ends. There is a high risk

that the chain will jam.

Start by cutting from above (about 1/3 of the way through).

Finish by cutting from below so that the two cuts meet.

(54)

Tree felling technique

Safe distance

The safe distance between a tree that is to be felled and

anyone else working nearby is at least 2 1/2 tree lengths.

Make sure that no-one else is in this ”risk zone” before or

during felling. (55)

Felling direction

The aim is to fell the tree in a position where you can limb

and cross-cut the log as easily as possible. You want it to

fall in a location where you can stand and move about

safely.

Once you have decided which way you want the tree to fall

you must judge which way the tree would fall naturally.

Several factors affect this:

• Lean of the tree

• Bend

• Wind direction

• Arrangement of branches

• Weight of snow

• Obstacles within the reach of the tree: for example,

other trees, power lines, roads and buildings.

• Look for signs of damage and rot in the stem, this

makes it more probably that the tree will break and

start to fall before you expect it to.

You may ﬁnd you are forced to let the tree fall in its natural

direction because it is impossible or dangerous to try to

make it fall in the direction you ﬁrst intended.

Another very important factor, which does not affect the

felling direction but does affect your safety, is to make sure

the tree has no damaged or dead branches that might

break off and hit you during felling.

The main point to avoid is letting the tree fall onto another

tree. It is very dangerous to remove a trapped tree and

there is high accident risk. See instructions under the

heading Freeing a tree that has fallen badly.

Clearing the trunk and preparing your retreat

Delimb the stem up to shoulder height. It is safer to work

from the top down and to have the tree between you and

the saw. (56)

Remove any undergrowth from the base of the tree and

check the area for obstacles (stones, branches, holes,

etc.) so that you have a clear path of retreat when the tree

starts to fall. Your path of retreat should be roughly 135

degrees away from the intended felling direction. (57)

1 Danger zone

2 Retreat path

3 Felling direction

Felling

Felling is done using three cuts. First you make the

directional cuts, which consist of the top cut and the

bottom cut, then you ﬁnish with the felling cut. By placing

these cuts correctly you can control the felling direction

very accurately.

Directional cuts

To make the directional cut you begin with the top cut. Aim

using to the saw’s felling direction mark (1) toward a goal

further forward in the terrain, where you would like the tree

to fall (2). Stand on the right-hand side of the tree, behind

the saw, and cut with a pull stroke.

Next make the bottom cut so that it ﬁnishes exactly at the

end of the top cut. (58)

The directional cuts should run 1/4 of the diameter

through the trunk and the angle between the top cut and

bottom cut should be 45°.

The line where the two cuts meet is called the directional

cut line. This line should be perfectly horizontal and at

right angles (90°) to the chosen felling direction. (59)

Felling cut

The felling cut is made from the opposite side of the tree

and it must be perfectly horizontal. Stand on the left side

of the tree and cut on the pull stroke.

Make the felling cut about 3-5 cm (1.5-2 inches) above the

bottom directional cut. (60)

IMPORTANT! It takes a lot of experience to fell a tree.

Inexperienced users of chain saws should not fell trees.

Do not attempt any task that you feel unsure of!

IMPORTANT! During critical felling operations, hearing

protectors should be lifted immediately when sawing is

completed so that sounds and warning signals can be

heard.

WARNING! Unless you have special

training we advise you not to fell trees

with a diameter larger than the bar length

of your saw!

Husqvarna 420EL [22/28] Working techniques

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