Which of the following is NOT a common tool used in excavation?

The chipper is not commonly used in excavation work. Excavation typically involves moving large amounts of earth and soil, and the tools most commonly associated with this task are heavy machinery such as excavators, backhoes, and bulldozers. Each of these tools is designed for specific functions related to digging, lifting, and grading soil.

Excavators are versatile machines equipped with a bucket for digging and can be used for a variety of excavation tasks. Backhoes, which have both a digging arm and a loader bucket, are also essential for excavation and can handle smaller, more precise tasks. Bulldozers are designed for pushing large quantities of soil, making them suitable for grading and site preparation.

On the other hand, a chipper is primarily a tool used for reducing wood and brush into mulch and is more related to landscaping or forestry activities than to excavation. Therefore, the presence of a chipper in the context of excavation is not typical, affirming that the correct choice is the chipper.