What is one reason hydraulic elevators might require different door specifications compared to traction elevators?

Hydraulic elevators typically require different door specifications compared to traction elevators mainly due to the type of propulsion system they employ. Hydraulic elevators operate through a system that uses a piston to lift the cab, which introduces specific considerations for door operation and safety mechanisms.

This difference in propulsion technology influences various design factors such as door weight and the mechanism used for opening and closing the doors. Hydraulic systems often involve slower rates of travel and different force dynamics, which necessitate particular designs for the doors to ensure they operate effectively and safely under these conditions. Traction elevators, on the other hand, use cables and pulleys, allowing for different door requirements that align with their faster speed of travel and operational mechanics.

While speed of operation, weight capacity, and size of the hoistway are important considerations in elevator design, they are less directly tied to the fundamental differences in how the door systems must work based on the type of elevator propulsion system used. Thus, the reason relating to the type of propulsion system is the primary factor impacting door specification differences between hydraulic and traction elevators.