The old way of working at elevated heights too often requires scaffolding or staging. Putting up staging means coordinating crane operators, a crane crew, riggers, welders, and other support staff. It’s also material intensive. Lumber must be custom cut to fit and workers have to check out assembly tools from the yard’s tool crib. Even when reusable steel scaffolding is used, it takes a full crew to assemble the structure.
A better alternative, is mobile aerial work platforms. They are safer, less expensive and easier to use than erecting scaffolding or staging for elevated work. Whether the job is as simple as ceiling maintenance or as difficult as framing a new manufacturing facility, workers can safely and quickly get to work, whether they’re needed at 15 or 150 ft. (4.6 or 45.7 m) off the ground.
Choosing the right aerial work platform can be a challenging task. There are vertical personnel lifts that fit in the back of a van; scissor lifts with batteries, engines, or both; and straight and articulating boom lifts. Choosing the right lift can save money, increase productivity, and give workers a safe place to stand.
Each type of lift is designed to meet a particular set of needs, so the first step in choosing an aerial work platform is to determine your requirements (see questions box). Once the basic analysis is complete, you can consider the different types of mobile aerial work platforms that are available and find the one best suited to your needs.
Telescopic Boom Lifts
Telescopic boom lifts, also known as straight or stick booms, are especially useful for applications that require greater reach capability. From 40- through 120-ft. (12.2 through 36.6) models, telescopic booms can be raised or lowered from vertical to below horizontal and extended while the platform remains horizontal and stable. The turntable that houses the base of the boom can be rotated 360 degrees and the whole lift can be maneuvered forward and backward — and steered in any direction — even while the boom is extended.
Most telescopic boom lifts have restricted capacities of 1,000 lbs. (453.6 kg), meaning there are some restrictions to the extension and positioning of the boom while loaded. Unrestricted ratings of 500 lbs. (226.8 kg) provide sufficient capacity for most applications and allow full use of the lift’s flexibility. Some telescopic booms are equipped with an articulating jib, or arm between the boom and the platform, which provides additional reach up and over obstacles.
Power is generally provided by dual fuel or diesel engines and these lifts have top speeds in the 2.75 to 4.5 mph (4.43 to 7.24 kph) range. Most can handle 30 percent grades with ease and some models are designed to climb grades of up to 45 percent. This high gradeability makes telescopic boom lifts ideally suited for construction, especially on commercial or infrastructure sites. Mechanical, electrical, utility and painting contractors find the reach and mobility of telescopic booms useful, while automotive and aircraft assembly and maintenance facilities appreciate the same features.
Articulating Boom Lifts
Also known as knuckle booms, articulating boom lifts feature sectional booms, giving them the ability to reach up and over machinery, equipment and obstacles mounted on the floor. The articulating boom also allows the operator to reach elevated positions not easily approached by a straight or telescopic boom.
Articulating boom lifts, like telescopic boom machines, may be raised to vertical or lowered below horizontal. Some articulating models incorporate a telescoping section above the top knuckle to provide extended reach. Also like telescopic boom lifts, articulating models may be driven in any direction, even while the platform is elevated.
Electric articulating lifts are used primarily on slab and are powered by batteries that are rechargeable through a standard 110 VAC electric outlet. These clean-running, quiet lifts are ideal for facility maintenance including work in shopping malls, telecommunications centers, and entertainment facilities. Electric models generally extend to a maximum 45 to 50 ft. (13.7 to 15.2 m) of working height.
For outdoor or off-slab application, diesel, gasoline and dual fuel models provide freedom from battery rechargers and are available with platform heights up to 150 ft. (45.7 m). These lifts are suitable for building construction and maintenance, including applications on rugged terrain. The up-and-over capability also makes articulating boom lifts the aerial work platforms of choice in shipyards; aircraft hangars; petroleum and chemical refineries; and sports/entertainment facilities — all areas with many obstructions that preclude the use of other types of lifts.
Both electric and engine-powered articulating boom lifts can be equipped with options to increase their versatility, such as articulating jibs and proximity sensors to prevent the platform from contacting work areas.
Scissor Lifts
When the job requires more than two people, or involves larger equipment or materials, a scissor lift is the usual choice. These convenient machines move easily through double-width doors and some models fit easily through standard single doors. Scissor lifts are designed to provide large platform work areas up to 6 by 14 ft. (1.83 by 4.27 m) and lift capacities up to 2,500 lbs.(1,134 kg). Some platforms feature sliding deck extensions that increase the platform length by up to 6 ft. (1.83 m).
Scissor lifts are highly maneuverable and can be driven even when the platform is elevated. Because the platform rises straight from the base, they are best suited to applications that do not require up-and-over capabilities. Some specialty scissor lifts can extend as high as 100 ft. (30.5 m) but models with vertical reaches from 15 to 50 ft. (4.6 to 15.2 m) are more commonly available.
Pothole protection is essential when the lifts are to be driven while the platform is elevated. With these safety systems, the lift remains upright even if a wheel slips into a hole while the platform is elevated. Smaller vertical lifts also feature pothole protection or are designed to avoid the need for such a system.
Scissor lifts are often found on construction sites, where their reach and lifting capacity make them ideal for steelwork, mechanical systems installation and other tasks. In addition, their stable base and support system design allows rugged-terrain scissor lifts to climb grades of as much as 35 percent. Industrial, distribution and institutional users find that their mobility and maneuverability make maintenance and warehousing operations more cost effective. The scissor lifts’ versatility also appeals to hospitality, recreation and educational users.
Vertical Personnel Lifts
The simplest aerial work platforms, vertical personnel lifts, are ideal for jobs requiring a single operator. A work platform is typically attached to an aluminum mast that extends vertically up to 47 ft. (14.3 m) and is mounted to a steel base. Many models roll through standard single doors and fit into elevators or into the bed of a standard truck. Self-propelled and “push-around” models are available, both of which use rechargeable batteries to raise and lower the operator platform. Some models require outriggers for support.
Vertical personnel lifts are typically used for general commercial and institutional maintenance applications. Factories; retail centers and shopping malls; airports; public buildings; and entertainment facilities all rely on these easily transported, quiet lifts.
Safety First
Regardless of the type of aerial work platform selected, operator training is essential to ensure safe use. Safety equipment, including four-point harnesses, must be properly worn and anchored to the platform basket. Many lifts can be equipped with alarms to warn bystanders and coworkers that the lift, or just the platform, is in motion. Low-mount platforms are available for some lifts to ease operator access.
Once you know the type of aerial work platform that you need, you must consider where you’ll get it. For short-term or one-time use, a local rental company can probably supply both the lift and the training your operator will need. If a short-term rental is not appropriate, a local distributor can help determine your needs and make sure that they’re met with a quality lift. Some manufacturers also sell directly to end users and are willing to provide custom engineering and components.
High Reach, Higher Quality
While you’re looking, make sure that the aerial work platform you select is backed by a reputable manufacturer. You will need to select a brand that includes a promise for the best in terms of safety, reliability, productivity and ease of use for the operator.
As with any business decision, there are many factors to consider when renting or buying an aerial work platform. By considering the type of work the lift will support; special requirements such as quiet operation or freedom from recharging equipment; and the reputation of the manufacturer, you can be sure to make the right decision.
