The Caterpillar 345D is a hydraulic excavator in Caterpillar's 45-ton class, designed for heavy earthmoving, mass excavation, trenching, and material handling. It is commonly equipped with a Caterpillar diesel engine, hydraulic system, reinforced undercarriage, and a cab configured for operator visibility and control. The 345D is used in construction, quarrying, site development, and infrastructure work where high digging force and reach are required. Typical attachments may include buckets, hammers, and grapples. As part of the Caterpillar D-series excavator line, the 345D is known for its large operating capacity, durable structure, and compatibility with demanding jobsite applications.