Page 153 - Moving the Earth_ The Workbook of Excavation

ROCK, SOIL, AND MUD

ROCK, SOIL, AND MUD 3.47

Front-End Loader. Front-end loaders equipped with flat or semigrouser shoes get stuck easily
in wet holes. The bucket can be used to push it out, preferably backward. Place it on the ground
in fully dumped position, apply down pressure, then rotate the floor forward to a flat position, usu-
ally turning the tracks slowly backward at the same time. See Fig. 3.38.
Poles may be placed under the bucket and behind the tracks, for extra bearing in very soft
ground.
A forward pull may be obtained by placing the bucket flat on the ground, applying enough
down pressure to raise the front slightly, and then dumping it slowly. It is not as effective as in
reverse.
The bucket can also be used for short-distance self-moving of a machine that cannot travel
because of clutch or transmission failure.
The front of the tracks can be raised off the ground by using down pressure with the bucket
floor vertical, and supported by poles or blocks. The rear can be raised by shoring up the front and
piling the bucket with heavy material.
Hanging Up. Tractors are frequently hung up on stumps or rocks in the absence of any mud at
all, usually through digging in the tracks while moving a heavy load. The first warning is liable
to be a failure of the tractor to keep its direction or to steer. The tractor should be stopped imme-
diately and the situation checked over. If the stump (or rock) is under the crankcase guard or other
smooth surface, the tractor may escape by backing or turning, or by climbing a rock or a stick
placed under one track. If the obstacle has wedged into a hole or raised section, then large rocks
or logs under the tracks, or even jacking, may be required to get free.
A crawler tractor may also be hung up by walking over a large flat stone or short log which
flips up and catches in the chassis or between the tracks. This situation deserves careful exami-
nation before working, as applying too much power in the wrong direction may break a track or
do other damage. Movement in the right direction, particularly turning one track only, may free
it; or climbing up on blocks or using another power source to pull the rock out the same way it
went in may work. Sterner measures are removing the track, or turning the machine on its side in
order to break up the stone, or to chop the log.

FIGURE 3.38 Pulling dozer shovel out with bucket.