 an aerial work platform (awp), also known as an aerial device, elevating work platform (ewp), or mobile elevating work platform (mewp) is a mechanical device used to provide temporary access for people or equipment to inaccessible areas, usually at height. there are distinct types of mechanized access platforms and the individual types may also be known as a "cherry picker" or a "scissor lift". they are generally used for temporary, flexible access purposes such as maintenance and construction work or by firefighters for emergency access, which distinguishes them from permanent access equipment such as elevators. they are designed to lift limited weights&nbsp;â usually less than a ton, although some have a higher safe working load (swl)&nbsp;â distinguishing them from most types of cranes. they are usually capable of being set up and operated by a single person. 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. they may also be equipped with specialist equipment, such as carrying frames for window glass.specialized aerial work platforms stretch makers' market share (from www.constructionequipment.com, thursday 1 february 2007) underbridge units are also available to lift operators down to a work area.universal access platform guide(from www.universalplatforms.co.uk, thursday 4 october 2012)  ==lifting mechanisms== there are several distinct types of aerial work platforms, which all have specific features which make them more or less desirable for different applications. the key difference is in the drive mechanism which propels the working platform to the desired location. most are powered by either hydraulics or possibly pneumatics. the different techniques also reflect in the pricing and availability of each type. thumb|right|200px|articulated lift being demonstrated. === aerial device ===  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. aerial device
Vertical_transport_devices