The Caterpillar D6 track-type tractor is a medium bulldozer manufactured by Caterpillar Inc. The D6 is primarily used to move material short distances or through challenging terrain. The vehicle is powerful, yet small and light, weighing 16 to 20 tons (18 to 23 short tons) depending on configuration (recent models). This makes it ideal for working on very steep slopes, in forests, and for backfilling pipelines safely without risking damage to the pipe.