Page 32 - Moving the Earth_ The Workbook of Excavation

LAND CLEARING AND CONTROLS

1.32 THE WORK

tightening cable may lift the tractor and turn it over sideward. In (B) the downward pull may blow
the tires, unless the axle housing is blocked up, as in (C).
If a wheel tractor is not anchored, a rear winch must be underwound, and care must be taken that
the machine does not overturn through rising on the front, a danger which is particularly serious
if the tractor is driven to move the load.

Truck Winches. A truck winch is usually of the horizontal drum type. It may be mounted in the
front bumper, on a flatbed body, or between the body and the cab.
Rotation may be for underwinding, overwinding, or both. Power is from the power takeoff,
controlled by the truck engine clutch pedal.
The principal handicap of a truck winch is the difficulty of maneuvering it into position for a
straight pull. One or more pulleys may be required to obtain a proper direction of pull and a straight
line onto the winch. The truck should have all the wheels blocked, or be anchored by a line from a
frame member near the winch.
A gypsy spool or capstan winch (Fig. 1.24) may be mounted vertically on the forward end of
a flat body, chiefly for dragging loads onto the truck. A hemp rope is looped around it two or three
times, with one end attached to the work and the other end held by the operator. If the operator
leaves it slack, the spool will turn inside the rope; if she or he pulls it tight, the working end of the
rope will be pulled with great force. The slippage on the spool absorbs shocks that would break
the rope and enables it to do very heavy pulling, under exact control. However, the gypsy is not
ordinarily used for stumping.

Hand Winches. Hand winches are turned by a hand crank, operating through one or more sets
of reduction gears. Under most conditions, it is not possible to make a full turn of the handle because
it strikes obstructions, or passes through awkward positions. A large part of the work of winching
consists in removing and replacing this handle, and if much work is to be done, a ratchet handle
should be purchased, or made up by adapting one from a heavy socket set.
The winch is usually equipped with a friction brake and a pawl that can be engaged to prevent
it from turning backward when the handle is released.
Operation of these devices is tedious because of the number of crank turns which must be made
to reel in the cable; and exhausting because of the force which must be applied to the handle to
develop the rated pull of the winch. It is important that it be thoroughly lubricated.
Hand winches can be used in places inaccessible to power equipment, are comparatively inex-
pensive, and are surprisingly powerful. Sometimes they can take out tougher stumps than a power
winch of the same pull, because the line can be left taut and tightened gradually or from time to
time as the stump yields. Their weight, with cable, may be from 75 to 300 pounds, so that carry-
ing one of them any distance is at least a two-person job. It can often be transported in a loader
bucket.
Hand winches are sometimes mounted on a truck, in which case they serve largely as a spool
to carry cable, most of the pulling being done by the power of the truck. If the job is too heavy for
the truck, it may be anchored or blocked and the work done with the winch handle.

FIGURE 1.24 Capstan winch.