What type of installation requires a pit for the elevator?

The installation of hydraulic elevators necessitates a pit because this type of system operates using a hydraulic piston that extends and retracts to raise and lower the elevator car. This hydraulic cylinder is typically installed in a pit below the lowest landing of the elevator. The pit allows for the necessary space for the piston to move freely without obstructing the elevator car's travel, ensuring smooth operation.

In contrast, traction elevators use ropes and pulleys to lift the car, with the machinery located above the car, meaning they do not require a deep pit in the same way hydraulic systems do. Pneumatic elevators operate through air pressure and do not depend on a deep pit for their mechanics. Vacuum elevators, which also use air pressure for operation, are designed to function without a traditional pit.