225B AND 229 TRACK-TYPE EXCAVATORS Operating Techniques Caterpillar

Operating Techniques
1.1. General
2.1. Backhoe Operation
3.2. Digging
4.2. Lifting
5.1. Clamshell Operation
6.2. Digging
7.2. Lifting


------ WARNING! ------

Serious injury or death by electrocution can result if the machine or attachments are not kept a safe distance from electrical power lines.

Keep the distance at least 3 m (10 feet) plus an additional 10 mm (.4 in) for each 1,000 volts over 50,000 volts. For safety, local or state codes or jobsite operating directives, may require a greater distance.

Never swing a load over a truck cab or workers.



When swinging into a ditch, do not use the ditch to stop the swinging motion. Inspect the machine for damage if the boom is swung into a bank or an object.

Repeated chopping can cause structural damage. Use a digging, scratching or peeling motion when trying to penetrate rock, frozen ground or hard surfaces.

Consult your AVSpare dealer for special teeth and side cutters available for use in severe applications.

With certain boom-stick-bucket combinations, the bucket can hit the cab or front of the machine. Always check for interference when first operating a new attachment.

Whenever the tracks of the machine raise off the ground while digging, lower the machine back to the ground smoothly. DO NOT DROP OR AVSCH IT WITH THE HYDRAULICS. Damage to the machine can result.

Keep the stick out, when moving a clamshell machine, to prevent the bucket from swinging into the cab. The bucket can swing in all directions.

Move the machine whenever the digging position is not efficient. The machine can be moved forward or backward anytime during the operating cycle.

To work in and out of close places, utilize the bucket, or other attachment to push or pull the machine, or to lift the tracks.

Use smooth, comfortable speeds while operating.

For efficient operation, use more than one control at a time when possible.

Spot a truck so the machine can load it from the rear or side. Load trucks evenly to avoid overloading the rear axles.

An oversized bucket or one equipped with bladetype side cutters, should not be used in rocky material. It slows down the cycle and damage to the bucket and other machine components could result.

When making turns in soft material, travel in a straight direction occasionally to clear the tracks.

Know the location of buried cables. Mark them clearly before digging.

Backhoe Operation


1. Position the stick at a 70° angle to the ground.

2. Position the bucket cutting edge at 120° angle to the ground. Maximum breakout force can now be exerted with the bucket.

3. Move the stick in and keep the bucket parallel with the ground.

4. If the stick travel stops due to the load, adjust the depth of cut by raising the boom and/or curling the bucket.
5. To apply the greatest force at the cutting edge, down pressure must be decreased as the stick moves in.
6. Maintain a bucket attitude that ensures a continuous flow of materials into the bucket.
7. Continue the pass with the bucket traveling in a horizontal direction, peeling material into it.

8. Close the bucket and raise the boom at pass completion.
9. Engage the swing control when the bucket is clear of the excavation.

10. To dump, move the stick out and open the bucket in one smooth motion.


------ WARNING! ------

To prevent injury, do not exceed the rated load capacity of the machine. If the machine is not on level ground, load capacities will vary.

Use short slings to prevent excessive load swing.



Damage to bucket cylinder, bucket or linkage could result if slings are placed incorrectly.

Use the lifting eye on the back of the bucket to sling objects. Lifting capacities are calculated from this point.

An unstable condition can exist if a load exceeds the machine load rating or, if a heavy load is swung over an end or side.

Picking up a load over a corner is the most stable position.

For the best stability, carry a load close to the machine and close to the ground.

Lift capacity decreases as the distance from the swing centerline is increased.

Clamshell Operation


------ WARNING! ------

The clamshell can swing in all directions. Personal injury can result if it swings into the cab, or a person in the work area.



When moving over a rough surface, keep the stick out to prevent the clamshell from swinging into the cab.

Use hydraulic controls smoothly to avoid excessive clamshell swing.

1. Lower the clamshell bucket into the excavation with the stick in a vertical position.

2. For best penetration, apply down pressure as the bucket is closed.
3. Raise the boom when the bucket is fully closed.

4. When the bucket clears the excavation, engage the swing control. Operate the control smoothly to avoid excessive clamshell swing.

5. Begin opening the bucket slowly when approaching the dump area. Stop the swing or stick motion slowly and open the bucket fully.
6. An experienced operator can use the swinging momentum of the load to cast material for a faster cycle, and to move material farther away from the excavation.



Using bucket teeth to pick up an object can result in tooth or bucket damage.

Trap objects in the bucket for a sure pickup.

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