TYPICAL DIGGING CYCLE

TYPICAL DIGGING CYCLE

Start a digging cycle with the bucket - on the ground, in the pit, and under the boom point. If the machine tends to rotate freely, apply just enough swing effort with the RIGHT controller in the opposite the direction of machine movement, to hold the machine steady.

Operator’s Controls

Begin dragging the bucket in by pulling back on the drag (left) controller. The more the controller is moved off its neutral position, the faster the bucket will be pulled toward the machine. As the bucket is dragged in, take care to remove any slack from the hoist rigging. Do not allow the spreader bar to rest on the bucket. Additional hoist pull can be applied to reduce the cutting depth and wear on the bucket heel. Do not drag the bucket any further than necessary to fill it. Dragging a full bucket wastes time and energy.

With the bucket full, a correct combination of hoist and drag controller movement will increase the hoist speed (right controller back) and decrease the drag speed (left controller forward) to lift the bucket out of the pit. Keep just enough tension on the drag ropes to prevent the bucket from dumping. Too much rope tension tightens the “line of bucket carry” and positions the bucket close to the boom. This adds strain to the boom and slows down the hoist speed.

As soon as the bucket clears the digging face, slowly move the swing lever in the desired direction of machine rotation. A correct combination of hoist and drag effort with swing motion added avoids any excessive bucket and rope swing. Swing the machine and lift the bucket at the same time so that the bucket reaches the dump height and spoil location at the same time.

CAUTION: USE EXTREME CARE WHEN SWINGING TO INSURE THE BUCKET CLEARS ALL OBSTRUCTIONS AND THAT CLEARANCE EXISTS AROUND THE MACHINE.

Upon approaching the dump point, reverse the swing motion to bring the machine to a smooth and accurate stop. Coordinate the hoist and pay-out so that the bucket dumps as the machine stops swinging, and the bucket is empty as it starts back to the pit.

All the drives are “plugged” while digging to bring each motion to a stop and control the bucket as desired. There are no “operating” brakes on this machine. All the brakes on the drives are “parking” brakes only.

Release the drag rope tension by paying out some rope off the drum. This dumps the bucket. As the bucket dumps, move the right controller just slightly forward of its neutral position. Be cautious - do not allow an excessive amount of drag rope to pay out.

Never hold the load any longer than necessary to complete the dumping cycle. Once the material clears the bucket, slowly swing the machine back over the work area and lower the bucket into the pit, using a combined effort of the hoist and drag motions to place the bucket at its new dig site.

CAUTION: NEVER LOWER A FULL BUCKET OVER AN EXTENDED DISTANCE. DOING SO COULD CAUSE SEVERE DAMAGE TO THE ELECTRIC DRIVE COMPONENTS ON THIS DRAGLINE.

While operating the machine, observe its components for problems. Look for loose bucket pins; broken or frayed strands on the boom support, hoist, drag, and dump ropes; and bucket and rigging damage or wear. Keep an eye on the boom and the boom point. Report any maintenance requirements promptly to the appropriate personnel for attention so that unnecessary downtime can be minimized.