An apparatus includes a housing, at least one first gas-insulated circuit interrupter in the housing and at least one second gas-insulated circuit interrupter disposed in the housing above the at least one first gas-insulated circuit interrupter. The at least one first gas-insulated circuit interrupter and the at least one second gas-insulated circuit interrupter may be housed in respective ones of a first gas containment compartment and a second gas containment compartment vertically arranged in the housing. At least one first bus may be coupled to the at least one first gas-insulated circuit interrupter and at least one second bus may be coupled to the at least one second gas-insulated circuit interrupter. The buses may be disposed between the first and second gas-insulated circuit interrupters.