Which of the following pieces of equipment is associated with a gantry?

The piece of equipment associated with a gantry is the dragline. A dragline operates using a suspended bucket that can be raised and lowered by a boom mounted on a gantry structure. This setup allows for the efficient lifting and moving of material, particularly in excavation and mining applications. The gantry provides the necessary support and movement range for the dragline's operations, making it an essential component for this type of machinery.

In contrast, bulldozers, caterpillars, and trenchers do not typically utilize a gantry. Instead, they each have their own unique operational mechanisms and structural designs suited for different types of earth-moving tasks. For example, bulldozers are equipped with a front blade for pushing material, caterpillars (often referring to tracked vehicles) are designed for stability and mobility across rough terrain, and trenchers are specifically developed for creating trenches in the ground.