A new excavator operator is attempting to learn the proper boom, stick, and bucket geometry for a trenching operation. They are observing a seasoned operator who is digging a 1.5 m deep trench. Which of the following describes an optimal digging geometry for this task?

Question: A new excavator operator is attempting to learn the proper boom, stick, and bucket geometry for a trenching operation. They are observing a seasoned operator who is digging a 1.5 m deep trench. Which of the following describes an optimal digging geometry for this task?

Answer options:

• The bucket teeth are at a 45-degree angle, the stick is fully extended, and the boom is at maximum height.
• The stick is curled inward as much as possible, with the boom lowered to allow the bucket to scrape the trench bottom. ✅ The bucket teeth are positioned perpendicular to the trench bottom, the stick is extended about two-thirds, and the boom is at a height that allows the bucket to cut effectively.
• The boom is fully lowered, the stick is fully extended, and the bucket is parallel to the ground, scraping the surface.

Correct answer: The bucket teeth are positioned perpendicular to the trench bottom, the stick is extended about two-thirds, and the boom is at a height that allows the bucket to cut effectively.

Explanation: Optimal digging geometry for trenching involves positioning the bucket teeth to cut effectively, typically perpendicular to the trench bottom. The stick extended about two-thirds provides good reach and digging force, while the boom height should allow for an effective cut without excessive strain on the machine. Fully extended or fully curled stick positions are generally inefficient for sustained trenching.