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Features to look for in skidding winches TYPES OF WINCHES The two types of
winches that are available are the single drum winch and the double drum winch. The single
drum winch totally dominates the market, it is used for winching and skidding worldwide. The double drum winch is used to power
high lead systems in Alpine terrain. WINCH SIZES Skidding winches
are available for farm tractors that range in size from 17 HP to 200 HP. The pulling
capacities of the winches range from 6000 lb. to 18.000 lb.. The pulling capacity is measured when the winch
drum wraps the cable for the first time on an empty drum. The pulling capacity reflects
the weight that the winch can lift clear off the ground. How much weight the
winch can actually pull out depends on many factors such as the amount of cable on the
drum, the leaning of the terrain and how much the logs dig into the ground when winching. There should be some relation between the pulling
capacity and the size of the tractor that the winch is used on. The table below gives some direction for you when
you are selecting a winch for your tractor.
FEATURES TO LOOK
FOR IN A SKIDDING WINCH Separate Frame for
the Winch Mechanism The winch
mechanism should have its own, separate frame which is detachable from the rest of the
winch. The separate frame makes it easy to take out the entire
winch mechanism for service and repair. Winches where the winch mechanism does not come out in one piece are very difficult
to work on. The winch
mechanism should be totally covered so the components of the winch are not exposed to
water, snow, ice or branches. The controls for
the clutch engagement and the brake must be accessible from the operator's seat on the
tractor. The operator usually stands on the
ground in a safe place 6-8 feet on the side of the winch when winching in a load. The load
is then skidded out and it is common that one comes to a wet spot on the skid trail. The
operator should be able to drop the load before the wet spot, drive the tractor through
the mud and then winch in the load from dry ground on the other side without climbing off
and on the tractor. To enable all this to be
done from the tractor seat one should choose a winch where the clutch
engagement control rope and the drum brake control is accessible from the cab of the
tractor. Winches which can be operated from the driver's seat have the clutch control rope
in the center on top of the winch. The control rope runs through a swivel pulley which
enables operation from any direction. Clutch
Protected From Burnout The winching
process creates a lot of heat in the clutch mechanism. The clutch pads will eventually
burn and glaze if the heat is not pulled away
from the clutch. Top of the line equipment have heat sinks built into the clutch which
will absorb the heat that has been generated. That prevents glazing of the clutch. Those winches can be identified by the 5 year
warranty the manufacturer gives to the clutch. If
there is no warranty on the clutch and there is warnings against slipping the clutch in
the operator's manual, move on. The Upper Pulley. The winch is
pushed toward the ground when the cable is pulled through the upper cable pulley. This
down pressure anchors the winch in place when winching.
It is therefore advantageous to choose a winch where the upper pulley is
higher above the ground because that will increase down pressure and anchorage. The diameter of
the upper pulley is also a factor to observe. The cable will wear out faster if the pulley
diameter is very small.
The Lower
Snatchblock The cable is run through the lower snatchblock when skidding.
This lowers the center of gravity, so larger loads can be winched out. The lower snatchblock also functions as a hinge,
so that the tractor turns easier. The snatchblock must be constructed so that the cable is
easy to place in it and easy to remove from it. The cable must stay securely in place when
skidding. The common method to achieve the
above requirements is the design where the cable goes into the snatchblock only when it is
turned sharply to the right. The cable stays securely in the snatchblock because the
tractor can not turn sharp enough to release the cable.
Height Of The
Winch The upper pulley
is usually on the top of the winch, so the needed down pressure for anchorage comes from the height of the winch. Weight Of The
Winch. The winch must be built to withstand the stresses
of logging. The weight of the winch is one indication of
durability. Another indication of durability is the design of the winch. Is
the design durable because the form of the material provides strength to it? If, for
example you are comparing two winch frames. One has a deep frame with many folds the other
had a shallow frame with less folds. You should choose the deep frame with the folds. The
strength comes from the form. The Main Frame Of
The Winch. The frame should
provide a rigid base for the winch mechanism. A blade on the bottom of the frame will dig
into the ground and thus anchor the winch and tractor in place. The blade can also be used
for stacking the logs in the landing. THE CABLE The cable that works best in
skidding winches is steel core wire rope. There is other types of cable being sold to this
use and one should especially avoid "aircraft cable" which is a cheap quality cable too stiff for use
in a skidding winch. Aircraft cable has a tendency to retain the form of the winch drum,
so after a while it looks like one is pulling out a slinky from the drum. Wire rope of 6X25 type is suitable
for use in skidding winches. The wires on the outside should be thicker than the wires on
the inside. The thicker outside wires provide longer wear and the thinner inside wires
keeps the cable flexible. The cable clamps should put equal
pressure on both sides of the cable. " Iron Grip" clamps are the most popular. They have a round form so they do not get hooked
onto roots and branches. They have 2 bolts
which tighten the lock which enables repairs at the work site. Iron Grip cable clamps are
very expensive, but you can use them a long time if you replace the bolts when needed. Cables which has been terminated by
pressing a metal bushing on the ends can not be repaired in the field, and should
therefore be avoided. For information on commercially available winches, click here. |