Editing Aerial work platform (section)

==Lifting mechanisms==
[[File:JLG 450 AJ 2.jpg|thumb|right|200px|Articulated lift being demonstrated]]

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 [[Hydraulic machinery|hydraulics]] or possibly [[pneumatics]]. The different techniques also reflect in the pricing and availability of each type.

=== 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 devices are the closest in appearance to a crane – consisting of a number of jointed sections, which can be controlled to extend the lift in a number of different directions, which can often include "up and over" applications.<ref name= lift>{{cite web |title=Aerial Work Platforms |url=https://www.heavyliftgroup.co.uk/aerial-work-platforms.php |website=heavyliftgroup.co.uk}}</ref>

====Articulated====
The most common type of aerial device are known in the AWP industry as knuckle boom lifts or articulated boom lifts, due to their distinctive shape, providing easy access to awkward high reach positions.<ref name= lift/>

This type of AWP is the most likely of the types to be known as a "'''cherry picker'''", owing to its origins, where it was designed for use in [[orchard]]s (though not just cherry orchards). It lets the picker standing in the transport basket pick fruit high in a tree with relative ease (with the jointed design ensuring minimum damage to the tree). The term "cherry picker" has become generic, and is commonly used to describe articulated lifts (and more rarely all AWPs).

====Straight telescopic boom====
Another type of aerial device is a straight boom lift or telescopic boom lift, which as its name suggests has a boom that extends straight out for direct diagonal or vertical reach by the use of [[telescoping (mechanics)|telescoping]] sections, letting you take full advantage of the boom length range.

====Spider legs====
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. These legs can be manual or hydraulic (usually depending on size and price of the machine).

====Domains of use====
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. A specialist type of the articulated lift is the type of [[fire apparatus#Hydraulic platform|fire apparatus]] used by firefighters worldwide as a vehicle to provide high level or difficult access. These types of platforms often have additional features such as a piped water supply and [[water cannon]] to aid firefighters in their task.

=== Scissor lift ===
[[File:Hebebuehne Scissorlift.jpg|thumb|right|200px|An extended scissor lift]]
A scissor lift is a type of platform that can usually only move vertically. The mechanism to achieve this is the use of linked, folding supports in a criss-cross X pattern, known as a [[pantograph]] (or [[scissor mechanism]]). 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.
[[File:JCB S1930E Scissor Lift at Rajiv Gandhi International Airport, hyderabad.jpg|thumb|JCB S1930E Scissor Lift at [[Rajiv Gandhi International Airport]], [[Hyderabad]]]]
The contraction of the scissor action can be hydraulic, pneumatic or mechanical (via a [[leadscrew]] or [[rack and pinion]] system). Depending on the power system employed on the lift, it may require no power to descend, able to do so with a simple release of hydraulic or pneumatic pressure. 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.

Apart from the height and width variables, there are a few considerations required when choosing a scissor lift. Electric scissor lifts have smaller tyres and can be charged by a standard power point. These machines usually suit level ground surfaces and have zero or minimal fuel emissions. Diesel scissor lifts have larger rough terrain tyres with high ground clearance for uneven outdoor surface conditions. Many machines contain outriggers that can be deployed to stabilise the machine for operation.

=== Hotel lift ===
There are a number of smaller lifts that use mechanical devices to extend, such as [[rack and pinion]] or [[screw]] threads. These often have juxtaposed sections that move past each other in order to facilitate movement, usually in a vertical direction only. 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.