Masonry Magazine June 2002 Page. 28
Mast Climbers Reach for the Sky
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Mast climbers can safely work up to nearly 100 feet (30m) indoors and 65 feet (20m) outdoors without being tied to the building. Overall, heights are not a problem with some projects reaching more than 800 feet. According to Jean Robillard, president of Bennu, "Some people want to go 35 feet free standing. It's legal to do it, it's technically acceptable to do it; I don't personally like it. I think once you reach 30 feet, you should start tying to the wall. If you're going more than 30 feet, we ask that you tie every 20 feet."
Robillard's comments are, as he indicated, his opinion. Other manufacturers disagree and cite the fact that 35 feet free-standing is quite common and will give you an average working height required for low jobs like a warehouse or strip mall. In these cases, you can complete the wall without using any anchoring point, so installation and movement are faster.
Since many factors, such as ground condition, slope and worker comfort might come into play in determining the proper free-standing height, and keeping safety in mind, it might just make sense to resort to tie-offs whenever approaching the manufacturer's stated upper limit.
Many platforms are built of a modular design, enabling the machine to be constructed to suit the project. St-Pierre says, "Some models features side wings with counterweights, which allows long corner returns but decreases the load capacity. Plenty of accessories are available in order to increase the productivity, such as wheel chassis, mini-chassis, railings, wall anchoring, weather and overhead protection, etc. This gives added flexibility and efficiency when contouring buildings is required while allowing distributors to stock a wide range of platform capabilities in a reasonable area."
Single platforms lengths can be from 7 feet (2.1m) up to more than 60 feet (18.3m), providing an efficient working area. Bennu's Robillard explains, "You will find people using them with short segments of 20 to 25 feet, up to indefinite length. As much as people thought originally that platforms would be used only on high-er walls, they are extensively used on strip malls and lower build-ings, depending on the geographic area where they're working. In this case, they don't tie to the wall at all you just set your plat-forms to go up to 20 feet or so, and then move the whole thing down the wall and do another section."
Many models are equipped with precision leveling to help reduce repetitive strain injuries, a factor that constitutes a strong technical advantages associated with the mast climber concept.
Most manufacturers now use high quality components and surface treatment, like hot dip galvanizing, giving extended life to the structure, especially the mast sections, anchors and railings. Actually, less damage usually is done to components when compared to traditional scaffolding equipment even though the units are much larger and complex.
Adding modular components, called wings or bridges, to provide a more efficient working area means single platforms lengths can be adjusted to suit the job. The bridge junctions allow a level inclination between two units. According to Robillard, there can be a delta or variation of about 1/12 the length of the platform between sections and the overlapping bridge unit will compensate to maintain level working conditions.
Mast climbers often allow projects to be done faster, with reduced labor and plant costs. One of the main reasons is quick and easy erection and dismantling. Generally set-up time is 30 percent faster than conventional scaffold depending on the manufacturer. Also, the fact that material and other equipment can be lifted on the platform with a hoist at the same time that the workers do their job shortens downtime significantly. Obviously, long platforms also speed up work on wide facades since less erection and movement is necessary for workers to span the full length of the wall.
The platform can be brought to the ground for restocking so masonry material like brick and blocks can be placed where needed by a forklift, eliminating more costly high-reach material movers. And since mast climbers can always be positioned at the most ergonomic and efficient working position by the touch of a button, they have proven to reduce labor by more than 30 percent, a considerable savings.
The safety of mast climbers hasn't been neglected in either their design or manufacture. All the products are designed with the safety of the worker on the platform and those working near-especially underneath the platform foremost in mind. Although regulations vary from country to country, all units have to be equipped with braking and fall arrest systems, limit switch-es, and guard rails to ensure work areas are kept safe at all times. Unlike conventional scaffold, the entire platform moves with the workers so the person in charge can spend more time doing pro-ductive tasks instead of constantly verifying that planks and struc-tures are securely in place at all times.
All in all, mast climbing work platforms can be a positive addi-tion to the mason contractor's equipment inventory. If you haven't used one, and you have a long wall in your future, check out the option of renting a unit for the job. Once you try it, you might find you'll want one available in your equipment yard full time.
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