BRUSH AND TREES.- To clear brush and small trees with a dozer, travel forward at a slow speed with the blade lowered several inches below grade, as shown in figure 11-22. When cleared in this manner, make one pass to knock over small trees and brush, then make another pass to clear them away.

Medium trees are 4 to 10 inches in diameter. To push trees of this size, raise the blade as high as possible

Figure _11-22.-Clearing brush and small trees.

Figure 11-23.-Pushing over a medium-size tree.

to gain added leverage and push the tree over slowly, as shown in figure 11-23.

As the tree falls, backup quickly to clear the rising root mass. Lower the blade, travel forward, and dig the roots free with a lifting and pushing action. The felled trees are then ready to be pushed to a dismissal area.

Large trees are over 10 inches in diameter. For large trees, the removal is slower, more difficult, and takes more time. Approach the tree on foot and inspect it for dead limbs that could break off and fall on the dozer, possibly hitting the operator. Then make sure the dozer blade contacts the tree high and centered for the most leverage. Before pushing over a large tree, determine the direction of the fall, which is usually in the direction of lean. If the tree can be pushed over in the manner described for medium trees, do so.

CAUTION

When removing trees, be careful not to injure personnel or damage equipment. See that the dozer has side covers for [he engine. These covers help prevent limbs, sticks, and other debris from entering the engine area.

Dozers should never be worked close together when clearing trees, because one dozer could push a tree over on the other. Do not follow too closely when the tree starts to fall, since the stump may catch under the front of the dozer. The dozer will then need help backing off, and the bottom of the dozer could be damaged. As the operator, you should have a plan of how you are going to accomplish clearing the trees so they do not tangle with one another when they fall. You will probably be pushing green trees. They bend and snap back when free and may damage equipment or injure personnel. When making contact or releasing pressure on the tree, do it slowly so the top of the tree does not sway or shake, causing dead limbs to break off and fall on the dozer, possibly hitting you.

Know the ground on which you are working. Do not high center the dozer on stumps or trees. This problem is tougher when you are working in a wooded area and need help from another dozer. Existing trees could interfere. When you are clearing brush and trees, remember that the most common cause of damage to a machine is a stick or limb puncturing the radiator, breaking a hydraulic line, or damaging the exhaust stack. Pay attention. Know the capabilities of your dozer and what you need to do from start to finish.

STUMPING.- Pushing down a whole tree with a dozer is easier than removing the tree first by cutting it down and then removing the stump. The stump is usually too short to gain any pushing leverage or to provide a good swaying action for breaking out the roots.

When removing a stump, side cut deep enough to get the blade well under the roots. You can break up the roots by placing the blade well under the stump, traveling forward and raising the blade.

For a stump that will not yield to dozing, hauling it out with chains and grab hooks pulled by several dozers may work; or the stump may be hauled out by a wire leading to the winch on a winch-equipped dozer. If the ground around the stump is not to be disturbed, you may only need to saw the stump off level with the surface grade, rather than removing it.

Figure 11-24.-Large tree removal.

If the tree has a large root system, the following method may be used: A cut is made on the side opposite the direction of fall of the tree to a depth sufficient to cut some of the larger roots (fig. 11-24, view A). The roots on both adjacent sides are cut in a similar manner (fig. 11-24, view B). Build an earth ramp above the original cut, so a greater pushing leverage can be obtained to push the tree over (fig. 11-24, view C).

As it starts to fall, back quickly to get away from the rising root mass. It may be necessary to cut the roots on the fourth side when large- or well-rooted trees are being removed. The cut around the tree should have a "V" ditch shape, made with the blade angled downward laterally toward the tree to cut the roots. The stump holes should be filled so water cannot collect.

REMOVING ROCKS AND BOULDERS.- A dozer with a tilted blade is the most effective piece of equipment for removing rocks and boulders. With the left lower corner of the blade hooked well under the boulder, the best way to exert maximum uprooting pressure is to combine raising the blade with a right turn of the dozer. With the right lower corner of the blade hooked well under the boulder, the best way to exert maximum uprooting pressure is to combine raising the blade with a left turn of the dozer. A boulder that is deeply embedded should beside cut, like a stump. Some boulders, like some stumps, must be broken up some other way for removal. If the dozer is not equipped with a hydraulic tilt control, the dozer blade can be tilted by adjusting the pitch braces on the blade of the dozer to lower either corner of the blade. To increase the digging action of a straight-blade dozer working in hard ground, tilt the top of the blade forward.

WORKING IN WET MATERIAL.- Wet material is quite difficult to move with a dozer. When the material is too soft to hold up the weight of the dozer, each successive pass should be the full depth of the wet material. This places the dozer on a firmer footing. The mud should be pushed far enough so it will not flow back into the cut. Provide for rescue of the dozer if the dozer gets stuck.

NOTE: Never pull a dozer forward by hooking onto the blade. The blade is made for pushing, not pulling, _{Hook the towing} wire rope to the hook under the front of the tractor or to the drawbar on the rear of the tractor. Some dozers are equipped with wider track shoes for better flotation when working in mud or soft materials. These tractors with wide track shoes are called low ground pressure (LGP) tractors.

The extremely low ground bearing pressure is one of many reasons the dozer is highly recommended for working in wet materials.