Efficient Dragline Operation

Other uses of the dragline operation include the following:

1. Although the dragline bucket can be readily cast beyond the length of the boom, the machine should be positioned to eliminate casting.

2. Use heavy timber mats for work on soft ground. The mats should be kept level and clean.

3. When setting up for a dragline operation, you should have access for maintenance, operating personnel, and hauling equipment.

4. Excavate the working area in layers, not in trenches, and keep the slope upward toward the crane.

5. Do not drag the bucket in so close to the crane that it builds piles and ridges of material in front of the crane.

Figure 12-48.-In-line approach with dragline.

6. Salvage pieces of hoist wire rope for use as the dump rope.

PILE-DRIVING OPERATIONS

Pile driving in the NCF is done with crawler- or truck-mounted cranes rigged with pile-driving attachments, as shown in figure 12-49. The pile-driving hammer is categorized under the 36-00000 USN number registration series.

NOTE: The combined weight of all the pile-driving attachments reduces the capacity of the crane. Additionally, the crane capacity must be able to support the combined weight of all of the pile-driving attachments.

LEADS

Pile-driving leads serve as tracks along which the pile-driving hammer runs and as guides for positioning and steadying the pile during driving operations. The leads come in 10-, 15-, and 20-foot sections bolted together to form various lengths, as shown in figure 12-50.

NOTE: Because of the vibrations created during pile-driving operations, you must check all the lead

Figure 12-49.-Typical pile-driving operation.

section bolts for tightness at the beginning of each pile-driving shift.

The types of leads used in the NCF are swinging, underhung, extended four-way, and spud leads.