Aerial work platform
They are designed to lift limited weights — usually less than a ton, although some have a higher safe working load (SWL)[1] — distinguishing them from most types of cranes.
Regardless of the task they are used for, aerial work platforms may provide additional features beyond transport and access, including being equipped with electrical outlets or compressed air connectors for power tools.
Jay Eitel invented the device in 1944 after a frustrating day spent picking cherries using a ladder.
[6] There are several distinct types of aerial work platforms, which all have specific features which make them more or less desirable for different applications.
Aerial devices were once exclusively operated by hydraulic pistons, powered by diesel or gasoline motors on the base unit.
Lightweight electrically powered units are gaining popularity for window-cleaning or other maintenance operations, especially indoors and in isolated courtyards, where heavier hydraulic equipment cannot be used.
Some AWPS are classified as spider lifts due to the appearance of their legs as they unfold, extend and stabilise, providing a wide supportive base to operate safely.
AWPs are widely used for maintenance and construction of all types, including extensively in the power and telecommunications industries to service overhead lines, and in arboriculture to provide an independent work platform on difficult or dangerous trees.
The upward motion is achieved by the application of pressure to the outside of the lowest set of supports, elongating the crossing pattern, and propelling the work platform vertically.
The platform may also have an extending deck to allow closer access to the work area, because of the inherent limits of vertical-only movement.
This is the main reason that these methods of powering the lifts are preferred, as it allows a fail-safe option of returning the platform to the ground by release of a manual valve.
Diesel scissor lifts have larger rough terrain tyres with high ground clearance for uneven outdoor surface conditions.
These lifts usually have limited capability in terms of weight and extension, and are most often used for internal maintenance tasks, such as changing light bulbs.
Small non-powered AWPs can be light enough to be transported in a pickup truck bed, and can usually be moved through a standard doorway.
When using AWPs in the vicinity of overhead power lines, users may be electrocuted if the lift comes into contact with electrical wiring.
The industry began a strong growth period again in 2003 that resulted in peak shipments in 2007 prior to the economic crash in 2008.
The 2008 crash has caused a strong consolidation amongst rental companies and the industry reached high unit shipment levels again in 2018.
