The Excavators are described in the Book of Ti'ana as being snake-like in appearance, with large, brutal-looking drill bits on the front of them. They are long, segmented crafts, self-contained and able to withstand massive collapses in the rock around them. At the head of the craft is the Guild Master's cabin and the chart room. Moving back from that point, one would come across the equipment room, the crew quarters, the refectory (kitchen/dining), the bathing quarters, the sample storage room, and finally the research room, which was located in the tail of the craft. Everything in all of the rooms in the craft was locked and secured, in the event of a sudden shift or jolt.
Two of these machines were used to carve the D'ni Path from the Southern Gate toward the Surface during the expedition to make contact with the people of Earth. This was by far not the first time these machines had been used; they were used for thousands of years prior for the excavation of new tunnels and caverns for habitation and mining.
During excavation, the two craft worked in shifts, one performing the actual digging and the other acting as a shelter to the rest of the crew. The excavator that was involved in the digging would be positioned in front of the rock it was supposed to channel through, with the other out of the way of most flying debris. Only when everything was in place did the digger begin its work, boring straight into the rock, lashing the sides of the tunnel it made with the tail of the craft, making it easier to remove the remaining material once the nara casing of the tunnel had been put into place.