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ŠUMARSKI LIST 13/2005 str. 89     <-- 89 -->        PDF

P. Horek, P. Mauer, L. Novak: LARIX FOREST CABLEWAYS - IMPLEMENT OF THE NATURE OR1KNTED ... Šumarski list SUPLHMENT (2005), 78-89
regeneration period. The present rotation period being
130 years, the first advance growths emerge as early as
at the stand age of 90 years. Therefore, it is necessary
that conditions are created for the rise of self-seedings
and subsequent shelterwood felling already at implementing
the last tending measure. The to-be regenerated
stands are to be divided by approximately 100 - 120 m
by inserting cableway routes, i.e. strip clear-fellings
whose width would be 4 to 5 m. There is a principle to
be observed at the measure implementation that the entire
strip width is not cut before the proper cableway
timber skidding takes place but it is only the narrowest
slit possible to enable the operation of an about 3 m wide
cableway which is going to be widened to the required
width of the strip felling by Polansky only after the
entire logging operation was accomplished. This is how
trees along the line can be removed, which were possibly
scratched while serving as fenders at skidding. Then
the felled strip-cut becomes a starting point for the natural
regeneration which shifts under the parent stand
from below. The logging is made in the context with
shelterwood felling the intensity of which is decreasing
from the cableway line edge into the stand inside. This
shelterwood treatment is made along the both sides of
the cableway route and results in the removal of mainly
large-diameter trees with ill-shaped stems or crowns
from the main stand level up to the distance of 20 - 30 m
from cableway reach. Qualitative individuals with perfect
crowns and good growing characteristics are left in
the stand for seed. By selecting the ill-shaped large-diameter
trees, we release main-level and sub-dominant


trees of smaller diameters, which respond to the release
with increased light increment on qualitative mass. Research
results indicate that the increment can fully compensate
production losses often recorded at the selection
of large-diameter trees. The consistent and timely selection
of large-diameter individuals together with the reduced
rotation period help to prevent the development
of false heart which can result in great economic losses.
At logging, we principally save the sub-dominant trees
which influence the stand microclimate for the sound
development of advance growths. After the stand has
been gradually felled and ensured, there are other fellings
inserted into the original system of strip fellings,
which gradually results in complete rgeneration of the
whole stand. The described system of beech stand management
is a good example of qualitative increment
management and there is a number of these examples in
the stands of TFE Krtiny, which can document correctness
of the above described method.


As to the technical aspects of cableway skidding
employed at the above mentioned silvicultural procedures,
it is the LARIX forest cableways which have
been exclusively used at the TFE Krtiny over the last 9
years, whose technical parameters and suitability correspond
the shelterwood system in individual selection
fellings. The following technical solutions of the LARIX
type cableways facilitate the application of mild
timber skidding methods in the conditions shelterwood
system in individual selection fellings.


3. TECHNICAL CHARACTERISTICS OF
LARIX FOREST


LARIX cableways produce the Czech firm Training
Forest Enterprise at Krtiny. The characteristic and parameters
of modern cableways LARIX and also carriages
are mentioned below.


LARIX 550 and LARIX 3T


The LARIX 550 and 3T cableways are designed as
trailed implements on agricultural tractor where the
tower and winches of the cableway are carried on the
rear three-point linkage, and another part drums with
running lines are carried on the front three-point linkage.


This means that the cableway´s weight is evenly
distributed onto the two axles, which makes the tractor
with the cableway mobile also in the difficult terrain.


The LARIX 550 and 3T is equipped with 5 cables:
skyline, running line, hoist line, slack- pulling line and
straw line.


The system with endless line make possible that
load during transport does not to be braked and there is


CABLEWAYS


very simple to direct the carriage with or without the
load, targeted automation of in hauling or out hauling
carriage is in standard equipment.


Cableways are radio-controlled right from the forest.


LARIX Hydro


Hydrostatic driven cable systems LARIX Hydro
are designed for timber transport, uphill as well as
downhill. The cable system is built either on a truck
with stationary motor (LARIX Hydro A) or on the special
trailer to a bigger agricultural tractor with minimum
engine power about 100 kW (LARIX Hydro P).


Between mainline and haulback line drum is an interlock
system with recuperation of braking power
what enables target automatic with storage commands
and programmed speed change of carriage with or without
the load. The set-up time is very short. Independence
of remote control - at landing place cable remote
control, at logging place radio control. Technical parameters
are as follow: