holeless hydraulic
Hydraulic elevators lifted by paired telescoping cylinders at the shaft base, without an underground cylinder hole.
Holeless hydraulic elevators are vertical transportation cabs lifted by a pair of hydraulic cylinders with telescoping pistons which rest on the ground or the foundation at the base of the shaft, obviating the need for an underground hole (as used by traditional hydraulic elevators).
This system is practical in low-rise buildings from 2 to 4 floors. Keeping the cylinders above ground avoids the buried-cylinder arrangement and its associated risk of underground oil leakage. Energy use depends on the particular drive and installation.
The cylinders rest at the shaft base instead of extending into a bore below it. The lifting mechanism remains hydraulic even though its installation avoids the traditional below-ground cylinder hole.