The Inexpugnable-class tactical command ship was disc-shaped, with an opening in its center.[1][2] At 3,100 meters in diameter, it was often described as a mobile space station.[1] The bridge was innovative in design; holograms were projected over a transparent deck on the bridge, providing a merger of electronic and visual data and facilitating command.[1][2] This bridge design, referred to as the "wishing well" by Republic helmsmen, could sometimes produce vertigo.[2] The Inexpugnable-class was operated by a crew of 4,300 Republic officers and enlisted personnel. It also carried a total of 2,000 troops. The class could carry up to 50,000 metric tons of cargo and enough consumables for optimal ship and crew operations for two years.[1]