The words “aerial lift” are usually used in reference to elevated work platforms, which are platforms that can be raised and lowered in order to bring a person nearer to something that would otherwise be out of reach.
Elevated work platforms, which is another name for aerial lifts, are used to give municipal technicians access to utility wires; these kinds of aerial lifts are often known as cherry pickers and are usually mounted on specialized vehicles.
In the context of building construction and maintenance, aerial lifts like scissor lifts are used to allow access to light fixtures, HVAC equipment and other raised components.
Indoor scissor lifts are especially useful in theaters and television studios for the placement of lights and the dressing and construction of sets.
In churches, concert halls and other buildings with very high ceilings, aerial lifts can be used to create work platforms for repainting and refurbishing efforts. Aerial lifts make possible many tasks that would be impossible if stable, movable platforms were not available.
Aerial lifts operate in a number of ways. A hydraulic lift is a lift system that is raised and supported by compressed hydraulic fluid. Hydraulic fluid is a substance that, when placed on either side of a piston within a hydraulic cylinder, can cause that piston to move.
A hydraulic cylinder consists of an outer cylindrical casing, a piston, seals, flanges and hydraulic fluid. The piston is connected to a rod, which is connected to whatever machinery the hydraulic cylinder is intended to move. In the case of aerial lifts and other hydraulic lift configurations, hydraulic cylinder rods are connected to the platforms or the platforms’ load bearing elements.
A hydraulic pump changes the hydraulic pressure in the cylinder; when pressure on one side of the piston increases more than the pressure on the piston’s other side, the piston moves toward the area of negative pressure, forcing the connected rod in that direction.
These imbalances of pressure are capable of generating extraordinary force; in the case of lift systems, they can move heavy machinery and the people or equipment it bears.