Page 154 - Moving the Earth_ The Workbook of Excavation

ROCK, SOIL, AND MUD

3.48 THE WORK

Overturning. If a crawler tractor is lying on its side, it may be rolled back on its tracks by pull
on a line fastened to the highest substantial structure near the center of the up side. If there is no
spot above the center of gravity which will take the pull, the line should be run across the up side
and what is usually the top of the tractor until a hold is found. Logs or other blocks under the line
should be used to protect the tractor parts
against crushing. An improvement on this is
to use a pulley in a tree, or in a heavy tripod,
so that the line will lift as well as pull.
If the machine is upside down, two pulls
may be necessary, one to get it on its side,
the other to right it. This is easiest down-
hill, but blocks must be arranged to prevent
it from rolling farther than planned. Power
should be applied slowly, to avoid bending
or crushing of parts.
If no power is available, hand jacks
should be obtained together with planks and
blocks. A jack placed on a plank should be
used to raise some portion of the tractor,
blocks placed to hold it at that height, the
jack released, blocks placed under the jack,
and the process repeated. One jack will do
it, but two are easier. It is good procedure
to start jacking the part of the machine
which will move the longest distance in
resuming upright position, and work the jacks
in as space opens up. If the tractor is dozer-
equipped, the dozer frame and blade will
safely take the strain of jacking. The dozer
may sometimes be moved advantageously,
using the starter for power.
The type of jack shown in Fig. 3.39 is
particularly useful in machine salvage. FIGURE 3.39 Equipment salvage jack.

SHOVELS

Planks. Power shovel tracks usually have flat shoes, so that it is difficult to get them to grip
poles or planks and drag them under, without excessive trenching, or bolting or cabling them on.
Before working a dragline or other shovel in risky places, it is a good plan to get a plank 2 inches
12 inches, 3 inches 12 inches or heavier, 2 feet longer than the shovel is wide, and drill holes
in it to match the holes in the track shoes so that it may be readily bolted, and carry it for use when
necessary as described under tractor rescue. Strain on plank and shovel will be reduced by trenching
deeply to the underslope of the idler if possible. If the shovel can climb up on this plank, saplings
or other helps can be placed in front of it to assist it to firm footing.
Hoisting Bucket. If a dragline is down on one end, logs or planks can be forced or dug under
the high end, and the low end raised by hooking the bucket or hoist cable to a stump or other
anchor, as in Fig. 3.40(A) and (B). Pulling in the hoist cable, or raising the boom, should tip the
shovel forward, lifting the rear sufficiently to allow shoring up with logs.
If the anchor is close, a low boom gives best leverage. If it is distant, a high boom is better.
However, a boom angle of over 45° may be dangerous, because if the hoist line breaks or comes
off the anchor, the reaction might throw the boom back on the cab.