Aerial Lifts

Common or Unique?

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You think that a boom lift has little in common with a frame scaffold and you wonder why the US federal Occupational Safety & Health Administration, OSHA, combined the aerial lift standards with the scaffold standards in the same subpart.

You think it should be obvious that a stationary scaffold surrounding a building is nothing like a scissors lift or a mast climber. If that’s what you think, then you might be interested to know that they have a lot more in common than you think. Supported scaffolds, suspended scaffolds and aerial lifts are of the same cloth; there are strength issues, fall hazards, falling object hazards, stability concerns and access matters. It’s true—a boom lift has fall protection hazards just like a suspended scaffold does. Let’s face it, a fall is a fall. Who cares from what platform you fall. There is no doubt that there are unique circumstances for one piece of equipment that would not occur with another. For example, a boom lift can provide the operator with a catapult toss that one would not experience on a supported scaffold. Consequently, a boom lift operator needs fall restraint in addition to a guardrail system. Interestingly, besides the logical solutions to fall hazards, temporary elevated platforms have taken on a new dimension, mainly due to a misunderstanding of the hazards. Scissors lifts now have fall protection anchors, similar to boom lifts so that occupants can utilize fall arrest equipment in addition to a guardrail system that keeps them from walking off the platform. It appears to be an unnecessary inconvenience but some say that both suspenders and a belt are better. Simply stated, fall protection for temporary elevated platforms is determined by the type of equipment and the potential hazard: common hazard, unique solution.

It is unquestioned that all scaffolds must support the intended load. The common question asks how strong is strong enough. For supported and suspended scaffolds, each scaffold must be able to support four times the load applied while the suspension ropes for suspended scaffolds must be six times stronger than the intended load. That’s right, six times! Mast climbers have an interesting characteristic not often seen with other types of scaffolds. Unbalanced loads will tip the whole platform over, definitely not a good situation. Therefore it’s really important to follow the manufacturer’s recommendations regarding the placement of loads. This holds true for construction hoists where some people think that if the cage isn’t full, more load can be added. This is not a good idea.

Supported scaffolds can support thousands of pounds while boom lifts may be limited to a couple of workers. Suspended scaffolds can be designed for only a couple of workers and they can be designed for multiple personnel. The common thread is that all scaffolds, aerial lifts and construction hoists are designed to support loads; each exhibits a unique characteristic for doing so.

A proper foundation is required for any structure including construction hoists, aerial lifts and other scaffolds. Here a foundation is not the basement of the building but rather the support for the equipment. This foundation can be the ground, a floor, a roof, a beam, even water. That’s right; I saw a scaffold in a swimming pool supported by pontoons. Don’t ask!

A boom lift or scissors lift will apply its load through four wheels. As the machine drives around on the building floor it will exert loads in a way that may not have been anticipated by the design engineer. This may result in a damaged floor or worse. On the other hand, a mast climber typically applies its load to a very small base. Does the foundation have the capacity to support this type of concentrated load or does the load need to be spread out over a larger area? If the machine is setting on a floor, can the floor handle that type of load or will reshoring be required to transfer the load to a stronger foundation for the machine?

The common thread is that all scaffolds, aerial lifts and construction hoists require an adequate foundation. The unique attribute is how the load is applied to that foundation.

Access is necessary for any floor or platform, including temporary elevated platforms. However, what may work for a stationary scaffold won’t necessarily work for an aerial lift. Ladders are commonly used to access frame scaffolds although I cannot imagine using a portable ladder to access a boom lift. But I can imagine using a boom lift to access a frame scaffold. Its normally not a good idea to use a portable ladder to access a mast climber since the mast climber can exceed the height of the ladder, rendering it useless of worse; same thing with a suspended scaffold and an adjustable scaffold. Ramps work well with construction hoists and may also work well with a supported scaffold. Access is a common requirement, the solution is unique.

So, it does make sense to include supported scaffolds, those scaffolds whose platforms are supported by rigid means, suspended scaffolds, those scaffolds whose platforms are supported by non-rigid means, and aerial lifts in one set of standards. The hazards are common but the solutions are unique. Make sure you know both.

Why They Work: Engineering Principles of Aerial Work Platforms

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Aerial Work Platforms (AWP) are wonderful machines. They provide quick elevated access for workers to perform their tasks. They are mobile and safe to use. But how do they work? Why don’t they fall over? Well, they do fall over but it isn’t the machine’s fault—it’s the guy who forgot his training and screwed up.

Aerial Work Platforms encompass the various machines that are addressed in the 92 series of standards promulgated by the American National Standards Institute (ANSI). For example, these standards include Boom Supported Elevating Work Platforms (Boom Lifts), Self-Propelled Elevating Work Platforms (Scissors Lifts), Vehicle-Mounted Bridge Inspection and Maintenance Devices and Mast Climbers. Although the ANSI 92 series standards also address other machines, this article will focus on the engineering magic of boom lifts, scissors lifts, and mast climbers.

Mast Climber

Mast Climber


Scissors Lift

Scissors Lift


Boom lift

Boom Lift


While each of these three machines provides a platform that elevates, each machine does it best for specific conditions. For example, while a boom lift can provide access to the same locations as a scissors lift, a scissors lift typically can provide a larger platform. A scissors lift can provide access similar to a mast climber but a mast climber can support heavier loads and take the platform to a much higher elevation. However, in spite of these variations, the underlying engineering principles are the same.

Issues to Consider

When it comes to AWPs, the designer needs to address specific issues unique to the machine that is being designed while also addressing issues common to all machines. The most obvious issue is the strength of the machine. Each machine must be designed to support a certain load if it is expected to be functional. This load could be limited to one worker or it could be maximized to support heavy material loads such as pallets of brick or block. Typically steel is used as the material of choice for the load bearing elements, augmented by other materials chosen by the designer based on weight, economics, esthetics and suitability.

Stability is as important as strength. After all, what good is the elevated platform if it continues to fall over when you use it? In fact, the engineering property called the “center of gravity” should be of great concern to the designer as well as the user. Any AWP will do well provided the Center of Gravity (CofG) stays within the confines of the base of the machine. Once the CofG moves outside the base of the machine the operator will have a rather disconcerting experience if not a deadly one.

The CofG and its location are determined by the weight of the machine and the loads placed on the machine. As an illustration, picture a cube of concrete, or Styrofoam® (if you want to be a lightweight) that is 24 inches wide by 24 inches long by 24 inches high. The CofG is exactly in the center of the cube, 12 inches from each side. Now, place a six-pack of your favorite beverage on one edge of the cube. The CofG will shift towards the side of the cube where the six-pack is. Place it on the corner and the CofG will shift towards the corner. It will not shift all the way to the corner since the weight of the concrete is much greater than the six-pack, especially if you drank part of it! Now, since you drank all of the six-pack, place a twelve-pack at the opposite corner and the CofG will shift back past the center and towards the twelve-pack corner. The same phenomenon occurs in AWPs. For a scissors lift, the CofG easily stays within the wheelbase since the platform is never much bigger than the wheel base. However, for scissors lifts which have a cantilever platform, the CofG will shift towards the cantilever but will not move out of the wheelbase unless of course you stock the cantilever with enough six-packs to shift the CofG outside the wheelbase; now you have a problem – you just spilled your favorite beverage.

What about a boom lift where the basket is far from the wheelbase of the machine? Well, the CofG is still within the wheelbase because the designer made sure that no matter where you move the boom the CofG will never leave the wheelbase. Of course, should you overload the basket (that is loading it beyond the allowable load specified by the designer) or override the safety features that limit the boom extension, you will destabilize the boom resulting in some rather nasty results.

Mast Climbers operate under the same engineering restrictions but have another element that must be controlled. Since the platform is supported by a mast, the CofG must remain within the mast base. Because the mast base is typically rather small, like 2 feet by 2 feet, the mast must be supported at specific intervals to maintain the mast in plumb. Additionally, the platform loads must be carefully and continuously monitored to ensure the loads are balanced. That explains why there are loading charts on Mast Climber platforms.

Speaking of loads, boom lifts, mast climbers and scissors lifts must never be overloaded since the strength of the machine is based on the expected loads and the stability of the machine is based on the expected loads and use of the machine. Remember that overload does not mean collapse; it means that there is a safe load limit and anything above that will cause the machine to malfunction, stop working, fall over or fall down. None of these outcomes is healthy—believe what the manufacturer and the ANSI standards tell you!

What is the Foundation for the Foundation?

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Identification of the correct safety factors for scaffold foundations.

Foundations are a necessary part of any scaffold, whether it is a supported scaffold, a suspended scaffold, or an aerial lift.  Webster’s dictionary describes a foundation as “the natural or prepared ground or base on which some structure rests.”  Webster goes on to describe a base as “a bottom support; that on which a thing stands or rests.” Without a foundation, or base, the scaffold is useless.  Think about it: if a supported scaffold, that is a temporary elevated platform that is supported by rigid legs or posts, doesn’t have a solid foundation, it will collapse.  The same is true for aerial lifts such as scissors lifts or boom lifts, where it is very important that the foundation is strong enough to support the machine.

What about suspended scaffolds, those elevated temporary platforms that are supported by non-rigid means such as ropes?  Do they need foundations?  You may want to answer no since the rigging that supports the rope is typically on the roof of the structure.  But you would be wrong.  While the word foundation is typically used to describe the lowest level of a building and is usually in the ground, for scaffolding it means much more than that.  Think in terms of Webster’s definition for a base: “a bottom support; that on which a thing stands or rests.”  In the case of suspended scaffolds, the “thing” is the rigging, such as a cantilever beam, while the “bottom support” is the roof of the building or other structure supporting the rigging.  In other words, all scaffolds need foundations; it’s just that the foundation for suspended scaffold may be on the roof of the building.

This brings us to an interesting question about the strength of foundations: what safety factor is required for scaffold foundations?  Should it be adequate as specified in the federal Occupational Safety & Health Administration (OSHA) Construction Industry supported scaffold standards or should it have a safety factor of four as specified in the capacity standards?  But  wait, there’s more!  The OSHA Construction Industry suspended scaffold criteria specifies that “all suspension scaffold support devices, such as outrigger beams, cornice hooks, parapet clamps, and similar devices shall rest on surfaces capable of supporting at least 4 times the load imposed on them by the scaffold operating at the rated load of the hoist (or at least 1.5 times the load imposed on them by the scaffold at the stall capacity of the hoist, whichever is greater.)” [29 CFR 1926.451(d)(1)]  For suspended scaffolds this means the supporting surface, such as the roof of a building, should have a safety factor of 4.  For example, if you had a 1,000 pound load supported by a beam that cantilevered 18 inches past the edge of the roof, and the beam had a backspan of 10 feet, the fulcrum load would be 1,150 pounds while the required counterweight at the back of the beam for such a situation would have to be 600 pounds.  In our example the roof would have to support 1,750 pounds of actual weight.  This is like parking a couple of Harley Davidson Electra Glide Classics on the roof.  Picture that in your mind!  Frankly, my experience suggests that not too many suspended scaffold erectors give this loading thing much thought.  But then, they probably don’t think about parking Harleys on the roof either.  Applying a safety factor of 4, the roof would have to support 4,600 pounds at the fulcrum.  That’s a lot of load.  At the back end of the beam the roof would have to support 2,400 pounds meaning that the roof would have to support 4,000 pounds + 2,400 pounds for a total of 6,400 pounds.  In other words, the roof would have to hold the equivalent of a Chevy Crew Cab pickup truck.  Is this really necessary?  How many roofs do you think can hold a load of this magnitude?  Do the standards really require this?

While the snappy quick answer may be yes, the best way to answer this is to determine what the hazard is and what the intent of the standard is.  The hazard, of course, is that the roof collapses under the load of the hoist.  Therefore, the intent of the standard is to make sure you don’t collapse the roof while using a suspended scaffold; not a bad reason for having the regulation.  The tricky part is how to determine if the roof will have a 4 to 1 safety factor against collapse.  Related to that question is determining how much of the roof you can use to support the rigging.  Since the fulcrum is often a point load, there is a real possibility of having the fulcrum poke a hole in the roof.  That would not be good.  Therefore, this load has to be spread out.  The same may hold true for the back end, depending on how the counterweights are rigged.

Most outrigger applications are designed by “experience,” that is gut feel as to the strength of the roof.  If the roof happens to be new concrete, your gut just might be right.  On the other hand, if the roof is a hundred years old and decayed, your gut may not be right at all and you’ll get indigestion, not to mention what the roof might be doing.

The bottom line is that, just like the rigging, the supporting surface (the roof) must also have a safety factor of 4.  In our previously mentioned example, the actual load that has to be supported is 1,750 pounds, two Harleys.  Depending on the roof construction, for example the direction of the support beams and the design live load, you may be okay.  For illustration, if the roof design live load is 20 pounds per square foot (psf), and the outrigger beams are spaced at least 20 feet apart, the roof just might work with the required safety factor.  Of course, if the live load includes the design snow load, and it snows, your safety factor will melt away before the snow does!

In other words, if you have been guessing about the roof strength, you may have a correct safety factor —or not.

Complex Applicability

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An appraisal of the codes and standards that apply to aerial lifts, including boom lifts and scissors lifts.

Sometimes it’s simple, sometimes it isn’t.  When it comes to aerial platforms, such as boom lifts, scissors lifts, mast climbers and the like, the applicable OSHA standards get twisted, misapplied, and misused.  What causes this, you ask?  Well, maybe you don’t ask, but here it is anyway!

First a little history:  When OSHA decided to revise the Construction Industry scaffold standards, it was determined that aerial platforms (OSHA calls them aerial lifts), would be included.  Since aerial platforms are a very specific type of scaffold, OSHA acknowledges this fact by clearly stating in the Scope and Application [29 CFR 1926.450(2)] that “The criteria for aerial lifts are set out exclusively in §1926.453 of this subpart.” To further emphasize this exclusivity OSHA restates the obvious in the General Requirements, §1926.451, stating that “This section does not apply to aerial lifts, the criteria for which are set out exclusively in §1926.453.” What all this means is that none of the scaffold general requirements, including fall protection, access, platforms, and falling object protection to name a few, apply to aerial platforms.

In theory, for aerial platforms, all of this information is contained in §1926.453.  And this, in my opinion, is where the confusion begins.  §1926.453 references an American National Standards Institute standard, ANSI A92.2-1969.  Furthermore, OSHA describes the equipment it considers to be an aerial lift:

(i)                 Extensible boom platforms;

(ii)               Aerial ladders;

(iii)             Articulating boom platforms;

(iv)             Vertical towers; and

(v)               Any combination of any such devices.

The 1969 in the standard is the year 1969.  This was the current standard when the scaffold standards review began.  Consequently this is the standard that was used to establish the definition for an aerial lift.  And therein lays the problem since there has been a substantial growth of aerial platform types since 1969.  Fortunately OSHA recognized that new types of aerial platform equipment and ANSI standards have been introduced into the market since 1969. A note was added at the end of §1926.453 in the OSHA standards that recognizes the ineffective applicability of the 1969 ANSI standard by referring the reader to Non-mandatory Appendix C which “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.”  Non-mandatory Appendix C lists ANSI A92 Consensus Standards which apply to the aerial platforms that are familiar and common today.  Included in this list are familiar aerial platforms such as “Boom Supported Elevating Work Platforms” and “Mast Climbing Platforms.”

In practical terms, the referenced ANSI A92 standards are the best resources to use to ensure safe use of aerial platforms.  In fact, a review of OSHA §1926.453 will quickly illustrate the deficiencies of OSHA §1926.453.  This is said not to criticize the OSHA standards but rather is a statement of fact concerning the limitations of the OSHA standards regarding aerial platforms and the legal restraints that often stifle standards writers’ efforts.  The ramification of all this is confusion!  Interestingly, the scaffold General Requirements, §1926.451, are frequently cited as applicable to aerial platforms.  This is incorrect although common practice would indicate otherwise.  Additionally, OSHA §1926.452, Additional Requirements Applicable to Specific Types of Scaffolds, does not apply since aerial platforms are “exclusively set out in §1926.453.”   Clear to me; clear to you?

In legal or perhaps technical terms the outcome of standards application is a bit different.  This shows up in an OSHA Letter of Interpretation that opines that “Self Propelled Elevating Work Platforms” (ANSI A92.6), commonly known as scissors lifts, are not aerial platforms/lifts but rather “Mobile Scaffolds.”  Due to the constraints and wording of the language in §1926.453 and the ANSI A92.2-1969 standard, it is argued that scissors lifts are not included in the ANSI A92.2-1969 standard.  Thus, scissors lifts are not aerial platforms/lifts.  If they are not aerial platforms/lifts, they must be something else.  I guess since a scissors lift has an elevated platform and it has wheels, it can be concluded that scissors lifts are rolling scaffold towers.  Using this logic, helicopters, airplanes, forklifts, Airline Ground Support Vehicle-Mounted Vertical Lift Devices (ANSI A92-7), and boat trailers can be considered rolling scaffold towers!

What’s the bottom line?  The scaffold General Requirements do not apply to aerial platforms.  The scaffold Additional Requirements Applicable to Specific Types of Scaffolds  do not apply to aerial platforms.  In spite of OSHA’s opinion that scissors lifts are Mobile Scaffolds, scissors lifts are aerial platforms.  After all, I would think the industry should know what their equipment is; I hope you agree.

Aerial Lift or Mobile Scaffold?

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In the year 2000, at the turn of the century, the U.S. Federal Occupational Safety & Health Administration, OSHA, issued a Letter of Interpretation wherein it opined that aerial lifts known as scissors lifts (see illustration) are not aerial lifts but instead are mobile scaffolds.  The opinion was based on the fact that the revised OSHA scaffold standards for construction reference an American National Standards Institute, ANSI, standard that does not include scissors lifts.  This ANSI standard, known as ANSI A92.2-1969, was written in 1969, before the proliferation of aerial lifts that we have today.

Why was this outdated standard used, you ask?  Well, at the time the review of the original scaffold standard was initiated, A92.2-1969 was the ANSI standard that was applicable.  And since this was the only applicable standard, OSHA was required to work within the constraints of this standard to determine if scissors lifts were aerial lifts or not.  Since scissors lifts were not specifically mentioned in A92.2-1069, OSHA concluded that scissors lifts could not be included in the Aerial Lifts section of the revised standards.  However, OSHA also concluded that scissors lifts are scaffolds and therefore the other scaffold standards apply.  This includes 29 CFR 1926.451-General Requirements, and 29 CFR 1926.452-Additional Requirements for Specific Scaffolds.  Finally, OSHA concluded that since scissors lifts have wheels, they are Mobile Scaffolds and therefore must comply with 29 CFR 1926.452(w)-Mobile Scaffolds.  This interpretation of the standards relies on the accuracy of the assumption that scissors lifts are not aerial lifts and the assumption that scissors lifts are scaffolds.  Accepting these assumptions validates OSHA’s interpretation; not accepting these assumptions results in an entirely different conclusion.

I suggest an alternative interpretation to this dilemma since the industry generally recognizes that scissors lifts are aerial lifts and the Mobile Scaffold standards just don’t apply.  Here’s the argument:  The preponderance of information indicates that it was never intended for scissors lifts to be classified as Mobile Scaffolds.  A review of the preamble to the revised scaffold standards clearly indicates that the writers of the revised standard knew that additional ANSI standards existed: “OSHA recognizes that the A92 Committee has updated A92.2-1969 and has adopted other A92 standards which address technological advances and evolving safe industry practices regarding elevating and rotating work platforms.” (Federal Register, August 30, 1996, p 46095)  Furthermore, the writers also recognized the unique attributes of aerial lifts and the fact that they are just not the same as a typical supported or suspended scaffold.  How do I know that?  Besides stating in the preamble “…that the requirements of §1926.451 and §1926.452 do not apply to this type of equipment,”  the Scope and Application of Subpart L (29 CFR 1926.450(a)) clearly states that “The criteria for aerial lifts are set out exclusively in §1926.453 (Aerial Lifts) of this subpart.”  This exclusion is restated at the beginning of the General Requirements where it is confirmed that “This section does not apply to aerial lifts, the criteria for which are set out exclusively in § 1926.453.”  All this clarifies the applicability of standards but it does not necessarily clarify whether scissors lifts are scaffolds as described in § 1926.451 and §1926.452 or whether they are aerial lifts and consequently must comply with § 1926.453.  I believe the answer to this question exists within § 1926.453-Aerial Lifts and in the preamble for the revised standards.

1926.453-Aerial Lifts includes a note at the end of the section that points the reader to Non-mandatory Appendix C.  This appendix “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.”  Appendix C lists seven ANSI standards for aerial platforms, including ANSI A92.6-1990, Self Propelled Elevating Work Platforms. In case you are wondering, that’s the technical description for scissors lifts.  (See the illustration)  Furthermore, the OSHA writers explained in the preamble that “This Appendix is provided to serve as a guide to employers required to provide appropriate employee protection under § 1926.453, Aerial Lifts.  This Appendix reflects the proliferation of equipment-specific ANSI A92 standards since the adoption of ANSI A92.2-1969.”  Looks to me like a scissors lift is an aerial lift, not a Mobile Scaffold.

I can appreciate the constraints under which OSHA must operate.  The rulemaking process requires that the agency must comply with the legal restrictions that are in place to ensure that standards and regulations are not randomly (or intentionally) manipulated.  However, in this case, where it is clear in the industry that a scissors lift is an aerial lift, perhaps a little manipulation might be a good thing.  One last suggestion if I haven’t convinced you:  Read the Mobile Scaffold standards, § 1926.452(w)-Mobile Scaffolds and see how well they apply to a scissors lift.  The first standard requires that the scaffold “shall be braced by cross, horizontal, or diagonal braces, or combination thereof, to prevent  racking or collapse of the scaffold…Scaffolds shall be plumb, level, and squared.”  Does this make sense for a scissors lift?  How about “Where leveling of the scaffold is necessary, screw jacks or equivalent means shall be used.”  Or this one: “Caster stems and wheel stems shall be pinned or otherwise secured in scaffold legs or adjustment screws.”  And finally, “Before a scaffold is moved, each employee on the scaffold shall be made aware of the move.”  If you are operating the controls, do you talk to yourself?

The ANSI standard for scissors lifts, A92.6 is comprehensive, straightforward and very specific to scissors lifts.  Use this document.  You can purchase it directly from the Scaffold Industry Association at a very reasonable cost!

Common Sense – Does it Exist?

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What does this have to do with temporary structures such as scaffolding, aerial lifts, shoring and formwork?  Plenty since the decision by one can have a devastating life threatening effect on others.  I’m not being cynical or arrogant; plenty of opportunities lie ahead for me and you as we go about our daily lives.  Some of us will learn from these opportunities while some unfortunately will waste the chance to broaden their horizons and deepen their knowledge.  They will blow the chance to develop their common sense.  There is a saying that goes something like this:  Where does good judgment come from?  Well, it comes from experience.  Where does experience come from?  Well, that comes from bad judgment!

If you are the clerk at the local convenience store, chances are that your bad judgment, perhaps based on a lack of common sense, will not cause the death of a customer.  However, if you are a scaffold erector your decisions may result in another’s death.  This is serious.  Frankly, common sense drives many activities in the access and construction industry.  Daily decisions are made based on common sense, as they well should.  However, there is a fine line between common sense, based on “sound practical judgment,” and irresponsible actions that are just plain unjustifiable.  For example, why would a job superintendent not follow the shoring design prepared by a Professional Engineer?  Why would a scaffold erector not follow the qualified person’s scaffold plan?  Why would a carpenter choose a different formwork member although he has no “specialized knowledge or training” that would enable him to make the correct choice?

This common sense issue goes beyond engineering and construction.  Jobsite safety on many projects is held hostage to the phenomenon of poor common sense.  Where is the common sense when an employee must utilize personal fall protection while standing behind a properly constructed scaffold guardrail system?  Where is the common sense when it doesn’t matter what the user chooses as an anchor so long as she is “tied off?”  Common sense has obviously left the jobsite when the safety inspector ignores the advice of a qualified person and instead follows her own ill informed opinion of what is safe.  And certainly common sense never arrived at the jobsite when a signed piece of paper magically becomes the critical issue and not the practiced safety it is suppose to imply.

It seems common sense is no longer common.  In fact, the situation has morphed into a weird perverse alternate world where qualified workers are no longer allowed to make decisions yet the unqualified worker is allowed to act irresponsibly with no risk of having to accept the responsibility of his actions.  Why is it that a worker can modify a scaffold or incorrectly construct shoring without risking the consequences while those who have made the effort to understand the details of the activity are so severely punished, not because of their actions, but only because of their knowledge?  How can a shoring equipment supplier be held responsible for the customer’s superintendent’s poor decision when that superintendent didn’t even bother to learn how to use the equipment or even ask for help, help that is free for the asking?  Incredible.  And yet, those who lack common sense escape the wrath of the attorneys, OSHA and others because they can claim ignorance while those who do have the knowledge and expertise are held under the scrutiny of the legal microscope.

What is the solution?  It’s easy.  Common sense will tell you that you shouldn’t be involved with work activities that exceed your expertise.  The Code of Ethics for Professional Engineers requires that Professional Engineers practice only in their area of expertise.  Other professions have similar tenets in their codes.  Punishment for a breach can be severe.  Why not do the same for the Construction Industry?  Make the employee individually responsible for his actions.  You don’t comply with the OSHA Standards?  You get fined.  (Of course, if the employer is misbehaving, she should get fined too.) You make changes to the shoring layout, you are responsible; not the employer, not the designer, not the supplier, you.

Finally, my experience indicates that common sense disappears and intimidation replaces it.  In fact, intimidation, not common sense or knowledge, plays a huge role in the decision making process.  Safety inspectors can have incredible power over contractors and subcontractors.  Challenging a safety inspector’s incorrect requirement on a jobsite often results in the threat of continued harassment leading to trumped up accusations and stipulations that at a minimum wastes money and ultimately never increases safety.  Why, for example, would a safety inspector insist that a wall form scaffold bracket that has been safely used for over 50 years all of a sudden be dangerous?  Why would this same individual not trust the information that is offered to bolster the facts?  Why would the inspector not rely on the statements of numerous qualified individuals or the expertise of the professional consultants?  To me it is almost unbelievable that we have allowed individuals who lack any knowledge, or common sense, to dictate the actions of others.  I can only say it must be the lack of common sense.  Idle requirements without substantiation must stop.  Poor work habits that result in dangerous and fatal accidents must be stopped.  Common sense will tell you that.

Congratulations NOT in Order

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#1  Fall Protection – Residential construction 6’ or more: 1926.501(b)(13)

#2  Fall Protection – Unprotected sides and edges: 1926.501(b)(1)

#3  Aerial Lifts – Fall protection:  1926.453(b)(2)(v)

#4  Head Protection: 1926.100(a)

#5  Fall Hazards training program:  1926.503(a)(1)

#6  Scaffolds – Fall protection:  1926.451(g)(1)

#7  Portable ladders 3’ above landing surface:  1926.1053(b)(1)

#8  Scaffolds – Access:  1926.451(e)(1)

#9  Scaffolds – Platform construction:  1926.451(b)(1)

#10  Training for employees using scaffolds:  1926.454(a)

What is the significance of this list?  One factor is that some people just don’t get it.  For example, how can fall protection be a problem on scaffolding?  Fall protection has been required by federal OSHA since 1971 and it has been a consensus requirement for many years before that.  I fact, I have an illustration from an industry magazine published in the 1920’s that warns workers that guardrails are to be used on scaffolds.  It is difficult to imagine that a scaffold user doesn’t know that he/she is supposed to have fall protection at heights.  Some people just don’t get it.  Let’s face it:  Scaffolding isn’t so complicated that the typical user cannot grasp the concept of utilizing fall protection.  Rather it is the idea that “it won’t happen to me.”  Or perhaps the user lacks the training (Violation #10) that results in a false sense of security.  Do you know of anybody that has planned on going to work with the intent of falling off a scaffold?

#10 counters the efforts of the Scaffold Industry Association.  The association’s training programs have been available for a sufficient number of years that scaffold training violations shouldn’t be in the top 100 much less the top ten.  What gives?  I don’t have the answer to this one.  My experience suggests that employers and employees just don’t see the need for training.  They apparently do not recognize the direct relationship between training and a safe work environment.  This is very evident in this list of violations.  In all cases, except for # 5 and # 10, the equipment is available to eliminate the described hazard.  Obviously, it is the lack of training that really creates the hazards, not the lack of equipment or technology.

Check it out:  Do ladders exist that can extend more than 3 feet above the landing surface?  Of course.  Do scaffold suppliers have various components to provide safe access?  Of course.  Can platforms be constructed so they are safe?  Of course.  Can scaffolds be constructed with guardrail systems?  Of course.  Is it possible to use an aerial lift while wearing personal fall restraint?  Of course.  So what is the problem?  What must be done to get the industry off the top 10 list?

Again, I don’t have the answer but I can throw out a few thoughts that should be considered in developing a solution.  One of the basic problems is in communication.  As politically sensitive as the topic is, the language issue must be resolved.  There is no way that education and training can be effective if the recipient cannot read and write.  Signs, pictures and illustrations are nice but you can dumb down the situation only so far.  At some point the employee must have the skills to perform his or her task, even at the most basic level.  Directly related to this issue is the lack of a common language.  For safety issues, it is not nationalistic honor or pride.  It is safety, pure and simple.  How can safety be achieved when the workers on the jobsite speak English, German, Polish and Spanish, as occurred on a jobsite that I was recently on?

As we all know, the level of safety varies from country to country.  What happens when a worker, who is trained in a situation with sub-adequate conditions and rules, arrives in the United States to work at a jobsite that must comply with the federal OSHA standards?  Is it reasonable to assume that the worker will pick up the skills by practice and observation?  I think not.  This is an accident waiting to happen or at least a violation waiting to happen.  We owe the employee more than that and the employee owes himself more than that.

Personal and corporate responsibility must be considered/reconsidered.  Employers and employees must share in the responsibility for safe work practices.  It cannot be left to the employer any more than it can be left to the employee.  It cannot be left to technology or equipment; it must involve human actions, opinions, thought processes and attitudes.  It is time to make changes in the emphasis and it’s time to recognize the fundamental issues.  Let’s face it, a ladder not extending 3 feet above the landing surface isn’t causing 100 scaffold fatalities a year—it’s a lack of respect for the fragility of the human being.  Do you have ideas on how to fix it?  If you do, I’d like to hear about it.  Also, share your ideas at the upcoming SIA convention.  It is time to fix the entire system. Understand?

I’m Supposed to Know That?

By | Aerial Lifts, OSHA Standards & Regulations, Resources, Scaffolding | No Comments


(Answer the following true (T) or false (F) questions.  Place a (T) to the left of each true statement and a (F) to the left of each false statement.

____1.)  The allowable load on a scaffold is determined by testing or engineering analysis.

____2.)  OSHA requires scaffold competent persons to have training that deals with the loads that will be applied to the scaffold.

____3.)  OSHA Scaffold Standards are mandatory regulations.

____4.)  The subpart of the OSHA Construction Standard, 29 CFR 1926, that applies to scaffolding is Subpart M.

____5.)  The maximum height of the first step on a scaffold stairway is 24 inches.

____6.)  Scaffolds can only be erected, moved, dismantled or altered under the supervision of a competent person, qualified in scaffold erection.

____7.)  A typical stationary supported scaffold does not always need a base plate.

____8.)  Bracing is only required when the scaffold starts swaying.

____9.)  Scaffold users do not need scaffold training.

___10.)  Wood scaffold planks shall overlap a minimum of 12 inches or be secured from movement.

___11.)  Supported and Suspended Scaffolds shall be designed by a qualified person.

___12.)  Fall restraint must be utilized in all Articulated Aerial Lifts (Boom Lifts).

___13.)  OSHA requires that scaffold planks must either overhang their supports a minimum of 12 inches or be secured from movement.

___14.)  Cross braces on a Tubular Welded Frame Scaffold can never be used as part of the guardrail system.


15.)     The scaffold toprail height above the platform of a supported scaffold is:

a.)        38-45 inches

b.)        approximately 20 inches

c.)        approximately 42 inches

d.)        Whatever works

e.)        None of the above

16.)     The scaffold top rail strength, on a supported scaffold shall be:

a.)    75 pounds

b.)  100 pounds

c.)   150 pounds

d.)  200 pounds

e.)  None of the above

17.)     To comply with Federal OSHA Standards, what is the maximum erected height that a 3 ft. wide by 10 ft. long supported scaffold tower be built before it must be tied or guyed?

a.)  12′-0″

b.)  15′-0″

c.)  20′-0″

d.)  None of the above

18.) When utilizing personal fall arrest equipment the anchor must hold at least:

a.)  5,000 pounds unless it is designed by a qualified person

b.)  Depends on the individual

c.)  Three times the anticipated load

d.)  Four times the anticipated load

e.)  none of the above

19.)     What is the maximum erected height that a 7 ft. wide by 7 ft. long rolling tower can be built, according to Federal OSHA, if the scaffold does not have outriggers?  (Nobody will be ridingthe rolling tower.)

a.)        14′-0″

b.)        21′-0″

c.)        28′-0″

d.)        None of the above

20.) A competent person is designated by:

a.)           OSHA

b.)           The employer

c.)           A qualified person

d.)           All of the above

e.)           None of the above

21.)     A 60’-0” tall supported scaffold enclosed with tarps or plastic:

a.)        Shall withstand a wind of 110 mph

b.)        Shall be designed by a Qualified Professional Engineer

c.)        Shall be designed by a qualified person to withstand the anticipated wind force

d.)        None of the above

22.) A qualified person is required for:

a.)           The inspection of scaffolding

b.)           The design of scaffolding

c.)           The use of all scaffolds

d.)           Supported scaffolds only

e.)           All of the above

f.)            A,B and C above

g.)           B,C and D above

23.)  The maximum distance between rest platforms on a supported scaffold with a clamp on ladder is:

a.)           20’-0”

b.)           4 Tiers

c.)           26’-0”

d.)           35’-0”

e.)           It doesn’t matter if nobody is watching you

24.)  These people are exempt from Scaffold Training:

a.)          Scaffold Industry Association members

b.)          Scaffold inspectors

c.)           Scaffold users

d.)          A and b above

e.)          None of the above


  1. True
  2. True
  3. True
  4. False
  5. True
  6. True
  7. False
  8. False
  9. False
  10. True
  11. True
  12. True
  13. False
  14. False
  15. A
  16. D
  17. A
  18. A
  19. C
  20. B
  21. C
  22. B
  23. D
  24. E

If you have a perfect score, congratulations!  You know your standards.  If you scored 20 or more correctly, you will only receive 3 or 4 OSHA citations.  If you scored less than 20, go back and study up!

Number Logic

By | Aerial Lifts, OSHA Standards & Regulations, Resources, Scaffolding | No Comments

A standard is written this way:  29 CFR 1926.405(j)(4)(ii)(C).  (The example being used is an electrical standard addressing electrical equipment for general use.)  The “29” is the United States Code Title and defines the standards that are being referred to.  The “CFR” refers to the “Code of Federal Regulations.”  There are many codes of federal regulations that address a multitude of topics and activities.  We are interested in only a small portion of those regulations, and for this article, only those regulations that pertain to the OSHA standards that pertain to scaffolding.  Title 29, Chapter XVII is set aside for OSHA.  The “XVII” is a roman numeral and is “17” in English.

The OSHA standards encompass the various industries in the workplace.  To make it easier to find a specific standard, the regulations are divided into “parts;” the “1926” is a “part” that pertains to Construction.  You may be familiar with the part that pertains to General Industry which is Part 1910.  Maritime standards can be found in Parts 1915, 1917 and 1918 while Part 1904 includes information on “Recording and Reporting Occupational Injuries and Illness.”  In our example, your first look will tell you that it is a construction standard because of the 1926 designation.  If your work is in General Industry, this standard would not be applicable.

Each “Part” of the standards is divided into major “Subparts.”  In the case of the Construction Standards, 1926 is divided into 26 major Subparts and are designated by capitol letters, A through Z.  Subpart L addresses scaffolding.  Other examples include Subpart M, Fall Protection; Subpart X, Stairs and Ladders; Subpart K, Electrical, and; Subpart R, Steel Erection.

Within each of these subparts are “Sections.”  Sections become more specific.  For scaffolding, Subpart L, there are five sections:

Section 29 CFR 1926.450 is titled Scope Application and Definitions applicable to this subpart;

Section 29 CFR 1926.451 is titled General Requirements;

Section 29 CFR 1926.452 is titled Additional Requirements applicable to specific types of scaffolds;

Section 29 CFR 1926.453 is titled Aerial Lifts;

Section 29 CFR 1926.454 is titled Training Requirements.

Within each Section are major “Paragraphs.”  For example, in 29 CFR 1926.451, the General Requirements for Scaffolding, there are eight major Paragraphs, a through h.  Each one of these Paragraphs addresses a specific topic.  For example, “a” addresses scaffold capacity while “f” addresses the use of scaffolds.

The actual “Standard” or regulation exists within each “Paragraph.”  Each Standard is numbered, beginning obviously with 1 and continuing until the subject matter is adequately addressed.  Some Paragraphs have only a few standards while others have many.  In scaffolding, for example, the Capacity Paragraph has six Standards while the “Criteria for Suspension Scaffolds” Paragraph has 19 Standards.

Each “Paragraph” may also have “Subsections” instead of a single Standard.  Another way of looking at this is that a Standard may have additional information, making the Standard a “Subsection.”  This is where the roman numerals and letters come into play.  In our electrical example, 29 CFR 1926.405(j)(4)(ii)(C), the 4 is the Standard while the “ii” and the “C” are additional pieces of information for that specific Standard Number 4.  (You cannot take the information in “ii” and “C” and apply it to another Standard.  It is only applicable to Standard Number 4.)

So what does this all mean?  It means that the OSHA standards are systematic in their arrangement.  If you told me that I was in violation of 29 CFR 1926.451(a)(6) I would immediately know that you are talking about the requirement that all scaffolds shall be designed by a qualified person and built according to that design.  On the other hand, if you told me my scaffold was in violation of 29 CFR 1926.405(j)(4)(ii)(C), I would have to tell you that you are mistaken since those are standards addressing electrical hazards.

In summary, the system works like this:  If the standard is 29 CFR 1926.451(d)(12)(v), the 29 and the CFR tell us that we are dealing with US federal OSHA standards.  The 1926 tells use that it is the Construction Standards.  The 451 tells us that it is the Scaffold General Requirements.  The d tells us that it is the Criteria for Suspension Scaffolds.  The 12 tells us that it has to do with wire rope clips and finally the v tells us that “U-bolt clips shall not be used at the point of suspension for any scaffold hoist.”  If you are using u-bolts, you are in violation of 29 CFR 1926.451(d)(12)(v).

Are you expected to memorize all the standards?  Absolutely not.  But you can see that if you are working with scaffolds, and somebody tells you that you are in violation of 29 CFR 603(a)(1) you get to ask the accuser what the scaffold has to do with Pile Driving Equipment!  In other words, if 450 through 454 isn’t in there somewhere, it may be the wrong standard.

Only A Beginning

By | Aerial Lifts, OSHA Standards & Regulations, Resources, Scaffolding, Shoring | No Comments

So, what has the association been up to for the last 25years?  Back in the early 1980’s the big issues were insurance, OSHA, CAL-OSHA, liability exposure and membership.  Sounds familiar doesn’t it?  But wait a minute; it isn’t the same issues although the agencies may be the same.  Federal OSHA was only 13years old and the agency was in the process of revising the scaffold standards.  The scaffold industry was operating under the difficulties and confusion of the original specification standards.  Cal-OSHA’ relationship with the SIA was congenial (as far as I could tell from 1000 miles away) and the liability issues were being addressed through the development of Codes of Safe Practices.  The association was entering its second decade and the membership was growing.  Since that momentous occasion when I was the scribe of the Shoring Council, the association has certainly had its low points and high points.  But there is no doubt that the high points greatly exceed the low points.  The fact that the association has survived some of those low points illustrates not only the tenacity of its members but the value of its existence.  We were on a roll back then, just as we are now, but in a different way.  At that time, we were almost a decade away from initiating the SIA training program as we know it today.  But the foundation for that program was being laid through the development of 35 mm slide shows (remember those) and the Codes of Safe Practice.  Just as now, members donated countless hours to the SIA for the sake of those who use scaffolds.  There is no way to measure the effectiveness of those efforts since we only measure injuries and deaths and scaffolding still shows up on the “Top Ten” in OSHA fatality statistics.  But one has to wonder where we might be without the efforts of those early members who contributed so much to the industry.

It is a comfort to see a reinvigorated membership improving the safety of the industry.  Back in the early ‘80’s, frame scaffolds dominated the market.  Systems scaffold was a relatively new product and aerial lifts were in their infancy, at least compared to today.  Scaffold erector fall protection was just beginning to become an issue for the industry.  At that time the bigger issue was getting the scaffold users to use guardrails; some things never change.

Denver has changed since the early ‘80’s too.  We were known as a “cowtown” to some, the “QueenCityof the Plains” to others. Coloradohas added over a million folks to its population since 1983, greatly changing the size and feel of the city.  We have the Sixteenth Street Mall, which didn’t exist at the last convention.  The present convention center didn’t exist either.  There was a convention center but we tore it down because we didn’t like it.  I can’t promise perfect weather but it usually is pretty nice in July.  Besides, you can always head to the mountains if it gets too hot in the city.  (For those of you from locales that have an elevation less than 4000 feet, you’ll appreciate the lack of humidity—we have a law that doesn’t allow it to go above 50%.)

For those of you who like gambling, Colorado has a couple of towns not too far up the canyon that lets you leave money for us but my suggestion is don’t bother—just give me the money and I’ll save you the trip.  Just kidding, I don’t want the Chamber of Commerce to be mad at me.  Go to Blackhawk and Central City and gamble.  Take the “Oh myGod Road” out ofIdahoSprings up into Central City.  The drive is a thrill and a gamble.  When you get to Central City go gamble at the tables.  It may be low stakes but its fun.  (Russell and Gregory Gulches, where Central City is located, are where the big gold finds of the 1850’s occurred.   In fact, Central City is known as the “Richest Square Mile on Earth.”)   Or, if you don’t like the idea of gambling, try out driving the Lariat Trail up to Buffalo Bill’s grave.  The view of the city from Lookout Mountain is fabulous.  The road starts out in Golden, the gateway to the west, and home of the world’s largest brewery, Coors.  Speaking of beer, Denver is also home to more micro breweries than anywhere else in the country which, of course, should keep a few of you occupied for the entire convention.

If you like hiking, we have lots of opportunities.  If you are adventurous, try tackling a fourteener-we have 52 of them.  These are mountains over 14,000 feet high.  Not so adventurous?  Then drive to the top ofMt.Evans, one of the fourteeners and the highest paved road inNorth America. You can say you did a fourteener; I won’t tell.

By the way, we have lots of construction going on.  Admire how we do scaffolds inDenver.  They are unique because they are always much taller than the rest of the scaffolds inNorth America; we start out a mile high!  Welcome to theMileHighCity, theQueenCityof the Plains, and the host city for the Scaffold Industry Association 2008 Convention; we the proudColoradomembers of the Scaffold Industry Association are pleased to have you.  Let’s continue what was started in California in 1973, added to in Denver in 1983, and goes on today, better than ever!