Up and Down – And Around Too!

By David H. Glabe, P.E. / April 1, 2010

Mast Climbing Work Platforms are marvelous pieces of equipment.  And safe too, provided you behave yourself.  Actually it isn’t very difficult to use these platforms—provided you have been trained.  That isn’t unusual.  After all, if you want to use any scaffold or aerial platform you have to be trained.

Mast Climbing Work Platforms are Aerial Platforms.  That is, they are a unique type of aerial platform, designed to provide access at heights.  Aerial platforms include nine types of unique platforms including “Boom Supported Elevating Work Platforms,” commonly known as cherry pickers or boom lifts, “Self-Propelled Elevating Work Platforms,” also known as scissors lifts, and “Vehicle-Mounted Elevating and Rotating Aerial Devices.”  These are commonly used by power companies and typically have a boom and basket mounted to a truck.  Mast Climbing Work Platforms, as the name suggests, has a platform that is supported by a mast or masts, depending on the design of the platform and the length of the platform.  The platform rides up and down the mast by hydraulics or motors.  The platform is enclosed with a guardrail system and access can be by ladder or direct access to the building.  These machines are rather robust in that they carry substantial loads to great heights.  As I said earlier, if you behave yourself, these platforms pose no hazards to the user.

The US federal OSHA construction standards that apply to aerial work platforms are found exclusively in 29 CFR 1926.453.  Unfortunately, the OSHA standards are not clear or very effective.  Since mandatory OSHA standards cannot reference non existing consensus standards, the only ANSI standard that was available at the time the revised scaffold standards were promulgated was ANSI A92.2-1969.  That was a pretty long time ago.  And back then there was not the plethora of aerial platforms that we have today.  To compensate for this deficiency, OSHA provided Non-mandatory Appendix C which lists ANSI standards that are more current.  Furthermore, OSHA states in 29 CFR 1926.453 that “Non-mandatory Appendix C lists examples of national consensus standards that are considered to provide employee protection equivalent to that provided through the application of ANSI A92.2-1969, where appropriate.”  If you have ever read A92.2-1969, this is the understatement of the year.  Your best bet is to use the applicable ANSI standard and not worry about 29 CFR 1926.453.

So, what is in the ANSI standards that make them so much more effective?  First, each of the standards is specific to the type of aerial platform you are using.  For Mast Climbing Platforms, A92.9 is very specific in the obligations and responsibilities of the various parties who are involved with these machines.  For example, there are requirements that manufacturers must meet in the design and manufacture of the machine.  The company renting the equipment must meet requirements that are specific to their part of the work.  And of course, the erectors and users must have training.

As a user of a mast climbing platform, you must understand the safety issues including fall protection, falling object protection and access to mention a few.  The user must also understand the loading limits and criteria for the platform being used.  A single mast platform, that is a mast climber that has a platform supported by only one mast, must be loaded carefully so that the load isn’t out of balance due to the platform cantilever on both sides of the mast.  That doesn’t mean that a two mast platform can be loaded any way you want; you need to know the limitations no matter whether it is a single or two mast platform.  Guardrails can be removed so the platform can be loaded.  This means the user must utilize personal fall protection or restraint equipment while exposed to a fall.

Erectors require a deeper understanding of the equipment.  The base of the mast climber must set on a firm foundation.  It is not uncommon for the mast climber to set on a roof or upper floor of a building.  When this occurs, the supporting structure must be analyzed for capacity.  Don’t guess on this; get a qualified engineer to help you.  Mast climbing platforms can be free standing for a certain height, depending on the base and the design.  However, there is a limit to how height they can free stand, typically in the range of 25 to 40 feet.  Once the mast exceeds the design limit for a freestanding installation, the mast must be secured, or tied, to the adjacent structure.  These ties are not your typical #9 wire but rather are a structural connection that has to support a considerable load.  As a matter of fact, they are critical to the safe operation of the climber.  If you are not an erector, don’t even think about messing with the ties.  If you are an erector, make sure you understand that the first tie must remain connected until a crane is connected to the mast or the mast is otherwise stabilized to prevent tip over.

So what else can go wrong?  Let’s see, besides the mast falling over, workers have climbed up and over the guardrail in an attempt to climb onto an adjacent building floor.  Workers have bypassed the safety switches and run the platform off the top of the mast.  Workers have overloaded the platform to the point of wearing out the gears and rollers and just plain knocking the platform over.  Suppliers have not properly maintained the platform before renting it to the end user.  And, the end user has not maintained it in the field.The solution to all this is easy.  Know what you are doing when you use mast climbing platforms.  If you haven’t been trained don’t get on one.  If you aren’t trained in the proper assembly and disassembly keep your hands off.  Don’t rely on the OSHA aerial platform standards for an education; they won’t help you.  Go to the ANSI Standards and get the training.  In fact the SIA can help in the training!

Tags: Scaffolding Scaffolding Platforms aerial platforms ANSI Mast Climber mast climbing mast climbing work platforms OSHA Standards & Regulations Resources work platforms

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