A Grav Shaft consists of a pair of square tubes that propel matter either upward or downward.
Grav Shafts play a similiar role in System Shock 2 as elevators in real life. They are present both in public areas and military settings, including the umbilical tunnels between the spaceships Von Braun and UNN Rickenbacker.
When faced with variable G situations, it quickly became clear that conventional lifts would not be suitable for deep space travel. The first prototype Grav Lift, developed by TriOp in '34, actually interfaces with the gravometric generators aboard the ship to either increase or decrease gravity in the lift area. The essential design was so elegant that it has remained essentially unchanged.