A freight elevator is used to do just what its name implies: to elevate, or lift, freight, or goods. It is built to carry goods rather than people, though some do both to allow operators and those loading goods along for the ride.
Given its distinct purpose, a freight elevator is typically larger and can carry more weight than a passenger elevator. A freight elevator is often custom designed for the warehouse, shopping center or other large-scale facility it will serve. The designs are based on needed dimensions, the amount of weight it will carry and how goods will be loaded and unloaded, whether it be by hand, car or industrial truck. A heavy-duty freight elevator can hold a truck and can handle as much as 100,000 pounds (45, 359 kilograms), using a dual rope system for support.
A freight elevator often has a manual door, and sometimes multiple doors, to load from the front and rear or sides. The inside may be unfinished, so that it can take a beating from goods being pushed in and out daily.
As with passenger elevators, freight lifts can be hydraulic or traction. Traction elevators use steel ropes pulled along a deeply grooved pulley. Hydraulic elevators use a piston to push the elevator up from below. Both types require counter-weighting, which is typically accomplished by the placement of another elevator car on the other end of the ropes. Hydraulic lifts are cheaper, but often slower and cannot be built as high as traction elevators. Hydraulics can also leak oil into the earth, raising concerns for environmentalists.
Some of the earliest recorded uses of elevators were to move freight, with Egyptian and Roman civilizations using simple pulley systems to lift building materials. In the early 1800s, these designs took off, powering the lifts with newly discovered steam and hydraulic pistons. The new lifts became particularly popular to move goods onstage for plays and other performing arts events, with early installations at the Vienna Opera House.
The smallest freight elevators are often called dumbwaiters. They are typically used in two-story buildings to move household goods such as laundry or dishes up and down. Though older versions were operated by pulling on a rope, modern dumbwaiters include a small electric motor.
A freight elevator often has different code and fire requirements than passenger lifts, though these codes should still be clearly posted along with a certificate allowing the elevator’s operations.