PPD Practice Exam - Hydraulic freight elevators


I’d like to get more clarification on the reference to this question. Can someone please elaborate why a hydraulic elevator cannot be for freight use? I re-read MEEB Ch. 32 again, and hydraulic direct plunger types are appropriate for “low-speed, low-rise applications up to four stories in height… and freight applications of all sorts - in particular, those intended for very heavy loads” (MEEB pg 1452).

My follow up question would be, what would be the best elevator option for a two-story factory?

Thank you!


Hi @samantha.lee . @coachlizschneider can you clarify this reference?

Hi @samantha.lee thank you for your question.

There are four main types of elevators to consider when choosing an appropriate elevator for your building. Gearless traction elevators, geared traction elevators, machine room-less elevators, and hydraulic elevators. Gearless traction elevators are traditionally used for very tall buildings as they are faster than the other types. Geared traction elevators are often used for mid-sized office and residential buildings. Machine room-less elevators are commonly used for low to mid-rise buildings and can save quit a bit of space because as the name suggests no machine room is required. And finally hydraulic elevators which, as you pointed out, are used for low-rise applications such as offices, residential, parking garages, and also freight.

One of the advantages of a hydraulic elevator is that the load of the elevator is carried by the ground and not the building structure. This allows them to lift very heavy loads, making it the ideal elevator for freight applications. So for this question while a hydraulic elevator would be appropriate for a four-story department store, it would also be appropriate for a two-story factory.