enclosed shaft

covered shaft

An interior enclosed space that extends through one or more stories of a building, connecting openings in successive floors, or the floors and roof; must be covered at the top.
References in periodicals archive ?
Specific tasks required: pull the motor, pull discharge head, pull enclosed shaft column and pump, replace two 1" PVC monitoring access port pipes with pvc 11/4" x10 LF pipes.
Their 10,000-sq-ft operation in the marine manufacturing mecca of Southern Florida produces watertight, enclosed shaft systems that run through low-friction thrust bearings.
A residential elevator requires an enclosed shaft, as does a commercial elevator, albeit with a smaller mechanical room and overrun space at the top of the unit.