Scissor Lifts and Stage Floors.

SweetBennyFenton

SweetBennyFenton

Active Member
Hello all. Recently, my old Genie lift gave up the ghost. Now I am scrambling to replace it half way through my budget cycle. After reading a lot on this site about people's preferences and proper safety with lifts, I realized that a scissor lift would be the best way for me to go.

My question for all of you has to do with the weight of the lift. The lift I am looking at is 2400 lb. I'm wondering if anyone has had any problems with permanent stage floors failing under the weight of a scissor lift. Am I just being paranoid?

My stage floor is 1 1/2" of particle board on top of 1x sleepers on top of concrete.

Thanks in advance.
 
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From what you are describing, I would suspect that the floor might not take the load. I would run it past a structural engineer familiar with floors to find out, but it sounds a bit light to carry that load.

We dealt with this a few years ago as we listened to the floor boards creak under the weight of our JLG 20MVL, which weighs 2200 lbs.

As we had in the works a floor replacement, we modified the design to add a 2nd layer of 3/4 ply. Now the floor is original concrete subfloor with original-to-building embedded 2x4 sleepers, a 1/2 rubber pad then 2 layers of 3/4 ply with a 3/4 oak T&G on top of that. We added about 1/2" of height to the total floor, requiring metal ramps to be installed at 2 doors as well as at the loading door. The floor takes the weight very well with only occasional creaking as we roll across. The JLG has hard rubber tires that I suspect put slightly greater localized pressure then you'd see in a scissors, which typically from the models I've seen, have larger tires.

FWIW, using the self powered lift has saved us a TON of labor time (as compared to a standard Genie lift), possibly paying for itself in the 5 years we've had it. One in the bucket, one crew on deck as spotter. No crank-go up-come down-uncrank-move-repeat, etc.. as well as avoiding the dreaded "trick" of uncranking enough to move with the bucket up that is totally illegal and dangerous.

We also got the version with an extended bucket platform, that extends a couple of feet. Makes getting above and around scenic elements much easier. Also worth the extra expense.

And as a safety precaution, we do not use the JLG on our orchestra pit floor, even though it's essentially the same number and type of wood layers. Our pit has all that wood on a metal framework as part of the pit structure and we are concerned about the span between steel structural members not providing enough support. Thus we use the standard Genie AWP30S for those times we need access above the pit, or for heights above 25 ft.
 
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SteveB said:
....... as well as avoiding the dreaded "trick" of uncranking enough to move with the bucket up that is totally illegal and dangerous...........
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Actually, under the correct circumstances, this practice is not dangerous and not "illegal". While at the Meadowbrook Theatre in Michigan, I did the math, presented the case to OSHA and got an official exemption for that very practice. Currently a theatre in California is using the same method to apply to California OSHA and it looks like they will also be granted the same exemption. Long story short, the math proves that for a specific force pyramid, height (max working height at the facility in question), a specific weight at that height (use the max weight the lift will raise), a specific base width (dependent on the make and model of lift in question) it is not possible to generate enough speed to tip the lift over even if the outriggers strike an immovable object. In our particular case, the lift would have to be moving at over 20 MPH to generate enough force to tip over.

There were rules to follow that increase the safety factor. The lift may not be moved more than ten feet in a single move and must be stopped and both the floor path and the aerial path checked for obstacles or obstructions, before resuming motion. The lift can not be moved with a person in the basket when any part of the lift or outriggers are within 6' of a drop off such as a pit or stage edge. The lift can not be moved on a slopped surface. It should be noted that this exemption method will only work at low or moderate working heights as the force pyramid (base width/center of gravity for the entire structure/height/speed of travel) gets unbalanced very quickly as the height increases. At the Meadowbrook our working height was about (memory fades, it was a while ago) 18'-20', the California facility IIRC was about 24' which is probably about the maximum safe working height for this method.

This "movement" allowance is invaluable in dead hung houses and stages where a self propelled lift can not be used due to the weight issue. At the Meadowbrook, the time saved was a major issue as it was an IA house and labor costs added up fast.
 
MPowers said:
Actually, under the correct circumstances, this practice is not dangerous and not "illegal". While at the Meadowbrook Theatre in Michigan, I did the math, presented the case to OSHA and got an official exemption for that very practice.
Click to expand...

This is very interesting. Could you provide me with some of the data you used to make your case. At my school we have two genies, 20 and 25 feet respectively, and I'd like to present this to our TD as a potential change to our operating procedures. Since we are a state university we are already exempt from OSHA so we would not have to file for an exemption leaving the decision up to him and the respective department members opionion.
 
Contact me by PM and we'll talk.
 
Curious as well.

Does the caluculation take into effect how much the outriggers have been "un-cranked" - I.E. how high the outrigger foot/plate is off the floor ?. One would think that one factor is that even with the lift staionary, should the load in the bucket shift, the lift has the potential to tip if the outrigger feet are not firmly on the floor. I would think the buckets potential to tip is dependent on when the outrigger floor plate finally stops the motion.

Our Dept. of Theater uses our Genie and runs the lift in the manner described and I'm never happy about it, but if they are potentially OK to do this, I'll relay any information.
 
The height of the foot pad is relevant in that the base of the force pyramid is the Genie wheel base until the foot pad touches the floor. For The sake of the argument however and the "rules" of the exemption granted, the foot pad is assumed to be as close to the floor as possible and still permit motion without actually scraping the floor. If you are really interested, contact me off list ([email protected]) and I'll send the math figures.
 
One Thing about the lift situation that I did not mention because it is a connected issue but not directly connected with the exemption, except that the fact we already had it in place might have helped with the decision. The additional factor was we required everyone who used a lift to attend a short training session and then pass a test on the use and safety of the unit. This included the ground pushers and anyone in the basket. After passing the test a person was issued a Miosha card that verified passing the test and certified the person as a valid lift user for (IIRC) either 3 or 5 years, (memory fails) Really a fairly easy test, but it confirmed that anyone using a lift had been instructed in the safe use and procedures and understood them well enough to pass the test. This is not a bad idea for any institution that has a lift. If the local or state OSHA does not have a lift test in place, create one. It should cover a pre-use inspection, electrical/hydraulic/mechanical It should cover general lift safety rules as well as any local rules due to obstructions, drop offs etc.

Many places require a pre-use inspection with written check off sheet to be signed by the person making the start of shift inspection and a procedure for lock-out tag-out. Some venues require the same inspection at the end of the shift. For anyone not familiar with lock-out tag out, if anything is found wrong with the lift, the person making the inspection is required to put a lock on it and tag it as out of service (the same term is used for those safety lock tags that are used on electric panels and machinery in construction to prevent someone from turning a switch on or starting machinery while people are working on them.). Anyway, just thought I'd toss out this additional piece of the lift safety puzzle.
 
MPowers said:
One Thing about the lift situation that I did not mention because it is a connected issue but not directly connected with the exemption, except that the fact we already had it in place might have helped with the decision.
Click to expand...

[Snip]

Thanks for that Michael, as I was having trouble with the issue of how to apply what you've learned to an educational situation. In reality, I see no easy method to "certify" transient student labor in the proper use of the lift. Our Dept. of Theater has 3 full time staff members that can easily be certified as per NY State Dept. of Labor regulations (the governing authority in this case), but there has to be absolutely a new mind set in the use of the Genie in the Dept. of Theater space.

I admit that I have MAJOR issues with the concept of rolling a lift along with the outriggers raised to 1/4" to 1/2 inch or so with an extended bucket and a crew member inside - as practice, as it's somewhat a judgment call as to how high to crank, that depends greatly on the math formula you've described. In practice I'd rather see no usage in this manner. I would speculate that a call to Genie or JLG and describing this usage would end up with their legal departments having nightmares.

I will now describe a real life scenario one of my free-lance electricians found himself in at NYU recently (as an over-hire employee). He declined to continue a focus as the electrician in the bucket, when the Genie outriggers were cranked up to allow lift re-location. He indicated that he was uncomfortable with the practice and was subsequently replaced with another free-lance employee that was OK with the practice. He then subsequently observed the use of the Genie on a scenic platform, where the outriggers extended beyond the platform and where 4 electricians were used to "lift" the outriggers in such a manner that the lift sensors would be fooled into thinking that the outrigger pads were on the floor. He the observed the Genie being rolled along the platform with a wheel dropping into a square hole in the platform that caused the lift to nearly tip. The near fall was caught by the 4 crew members that were holding up the outriggers. All the employees present were over-hire, as all full time staff were off stage engaged in other duties.

This is the kind of stuff that makes my hair turn grayer then it already is, although I am proud of the fact that I recently initiated a move to usage of a safety harness and lanyard (as purchased from Sapsis) for use by crew (myself included) when using our JLG and Genie.
 
Well, as you know from my posts, those guys were violating not only standard safety usage, but also the rules that were in place to allow us the exemption. That was just plain stupid. As you say, they are lucky, very very lucky, the accident that will happen, didn't happen that time.

For your transient student labor. Create your own "certification". For those who are majors, have a required safety session at the start of each year that may last a couple of hours, independent of any show or rehearsal and which covers the basics of safety in the shop and on various crews. When I was teaching at U Mass we did that each year and students spent an hour in the scene shop, the costume shop and on stage. The safety training did not go into great depth in any one area but covered the basics and those not attending were not allowed to audition or participate on crews until the session was made up. For those who are not majors, require a 20 minute sit-down safety session for each crew they are on before the first call to cover the safety issues of that particular crew. Keep a current list of those who are "up to date" on their safety sessions. Not only will it make your stage safer, if anything does happen, you have a record of what was done to prevent it and a way to evaluate what could be done in the future to prevent a recurrence of the event. It can be done.

As for the height of the foot pad, no judgment, no math needed. If the lift could move, that was the height, no more. 1/2" would have been a No-No, way too high. What that meant was with most lifts the pad was actually still touching the floor but not taking weight. In addition, if the figures showed a condition that was even close to being close to the brink, it would not have passed. Like a design factor for rigging components, we made sure there was a very large margin for error before we presented our case to the OSHA people.

Also the way you talk, I suspect that you are generally using the lift beyond the height at which the practice is proven safe. As you may recall our working height was only about 18-20 feet. IIRC the gentleman in California applying for the exemption is only working at about 24'. As I mentioned earlier, the force pyramid gets out of range very quickly as the height increases. BTW, If you are interested, contact me off list and I'll send you the formulas and methodology used to determine the safety of the procedure.

While I applaud your use of harness and lanyard, just as a matter of information. While all boom lifts require a harness and clip off, OSHA does not require either when in a one man vertical lift or a scissors lift. In both those cases the lift railing is deemed the "safety" device. Some local jurisdictions may over ride that or require a "positioning device" which is not necessarily a harness but which prevents the worker from falling out of the lift should a slip occur or should the worker lose consciousness for any reason. Check your local jurisdiction for current rules.

Hope this helps.
 
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They put the Genie up on a raised platform with the legs hanging over? Wow. I'm nervous even putting a Genie on a raised deck where all the feet can touch. You have to be so careful about the construction and bracing underneath. A typical 4x8 platform that is fine for supporting actors may not support the concentrated forces that happen under a lift.

I did see a neat trick at one theatre. They put the outrigger feet on triple swivel piano casters, the kind you see under some grand pianos. That way the outriggers always had positive contact yet were still able to move. I thought that was an elegant solution.

I do subscribe to the practice of raising the Genie feet and moving, but I am careful to show everyone at the bottom of the lift just how high to raise the feet before I go up. I prefer that the feet are just about 1/8" off the floor, just high enough to not drag and catch on stuff on the deck. If I am not to high, say deck of Genie at about 21', then I don't see there being enough play in the outrigger leg to allow me to fall over. Also, the rails of the Genie are high enough that my body center of gravity is always within the platform and therefore over the base of the Genie. The real concern is not what the feet or outriggers might run into, it's what the Genie wheels might encounter since that is closer to the fulcrum of this giant lever you are rolling across the stage. Always remember that this big vertical stick is in fact a lever.

As for scissor lifts, in the summers I use one extensively. I find it a very efficient platform for working at height, whether carpenters, painters or electricians, although not my favorite tool for focus. In the civic center where I work we are not allowed to take the lift onto one of the stages because the sprung floor may not support it. I emphasize the word "may" because we don't want to risk damaging the floor. This is a stage where we would only be storing the lift, not working at height.

As for the particle board over 1X sleepers, would depend a lot on the spacing of the sleepers. Particle board is not a very good weight bearing substance. If you added a layer of plywood topped with a layer of masonite for finish you would improve your weight distribution. I'm not sure that would solve the issue as I am far from being an engineer or mathematician.
 
MPowers said:
While I applaud your use of harness and lanyard, just as a matter of information. While all boom lifts require a harness and clip off, OSHA does not require either when in a one man vertical lift or a scissors lift. In both those cases the lift railing is deemed the "safety" device.

Hope this helps.
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OK so now I'm totally confused. The searching I've done on the OSHA site yielded this:

"You ask us to describe the OSHA fall protection requirements for working from scissor lifts, aerial lifts and boom-type elevating work platforms. You also ask us to explain the difference between fall restraint systems, positioning systems, and fall arrest systems.

When Fall Protection On This Equipment Is Required in Construction Work

Aerial lifts/ boom-type platforms
Section 1926.453(b)(2)(v) of the Aerial Lift standard provides that workers in aerial lifts and boom-type platforms must be tied-off."

The article is in the form of a letter from OSHA in reply to a question on this topic. The way I'm reading it is that fall protection and/or a restraint system is required on "Aerial Lifts". FWIW, JLG as example, considers their vertical mast lifts to be aerial lifts. Genie as well call the typical lift we all use an "Aerial Work Platform". The OSHA letter is specific in differentiating a boom lift from an aerial lift.

What's got me confused is that the Google search had other sites (Non-OSHA) contradicting this rule.

Then I found this:

10. Aerial lifts -- 1926.453

a. Paragraph 1926.453(b)(2)(v) requires a body belt and lanyard attached to the boom or basket. As of January 1, 1998, Subpart M (1926.502(d)) provides that body belts will no longer be acceptable as part of a personal fall arrest system.

b. The use of a body belt in a tether system (i.e., to keep the employee from going over the guardrail) is acceptable, however, and is regulated under 1926.502(e).


Which I read as some type of fall protection is recommended - but not required due to a guardrail of 42" or higher being in place ?.

Thus I'm totally confused.
 
Steve,

Yes, the massive amount of information available through national, regional and local jurisdictions can be confusing.
A body belt is a positioning device, NOT a harness, NOT fall protection, especially NOT fall protection. If a worker were to fall backwards while while wearing only a belt, it could snap the spine. Side and front falls present other dangerous injury possibilities. The point of a body belt is to prevent a worker from needing fall protection. A belt device is intended to restrain the worker within the confines of the lift and the railing. If it is possible for the worker to fall out of an aerial lift (Genie, scissors, et al ) for any reason, then fall protection, i.e. harness, lanyard, is RECOMMENDED but not always required, check your local jurisdiction. The reason aerial lifts do not always require a harness is the very slow speed they can move, stop and accelerate. A boom lift on the other hand is a very long lever and when rotating sideways, the basket at the end of the boom can reach relatively high feet per second speeds. In addition when the swing stops there is often a tendency to snap back or oscillate a couple of times, thus presenting a strong possibility of ejecting the worker from the basket and thus the requirement to always harness and clip in.

Hope this helps a bit???
 
Scissor lifts and AWPs do not require fall protection. Some local venues do but not OSHA. Aerial lifts and boom lifts do require fall protection. Boom lifts are the Genie and JLG lifts, among others, that are self propelled and as MP says can sling you out of the lift. The aerial platforms are bucket trucks and towable lifts that are like boom lifts but aren't self propelled.
They all have a pretty good swing ability that can eject you in a heartbeat.
Nobody should ever use any of these pieces of equipment without some training in the safety and dangers of them, plus the PFP needed or not needed. The other thing, never belt off to a structure while in a basket. If it collapses for any reason you are now stranded.
 
mstaylor said:
Scissor lifts and AWPs do not require fall protection. Some local venues do but not OSHA. Aerial lifts and boom lifts do require fall protection. Boom lifts are the Genie and JLG lifts, among others, that are self propelled and as MP says can sling you out of the lift. The aerial platforms are bucket trucks and towable lifts that are like boom lifts but aren't self propelled.
They all have a pretty good swing ability that can eject you in a heartbeat.
Nobody should ever use any of these pieces of equipment without some training in the safety and dangers of them, plus the PFP needed or not needed. The other thing, never belt off to a structure while in a basket. If it collapses for any reason you are now stranded.
Click to expand...

Summary of Fall Protection Requirements 1 of 1
Subject: Fall Protection Requirements on Aerial Work Platforms​

This document summarizes the requirements of the standards pertaining to fall protection on aerial work platforms in the United States and Canada. It is important to note that the primary means of fall protection on
all aerial work platforms is provided by the guardrail system. However, there are some instances when a second level of fall protection is required by the standards for aerial work platforms in Canada and the United States as discussed below.​

Fall Protection Requirements on Booms:
Use of approved personal fall protection equipment (PFPE) in addition to a guardrail for operator fall protection is required in the United States and Canada for boom mounted aerial platforms. This requirement is mandated by the standards for
Boom-Supported Elevating Work Platforms (ANSI A92.5 and CSA B354.4) and
Vehicle-Mounted Elevating and Rotating Aerial Devices (ANSI
A92.2 and CSA C225) and enforced by OSHA (USA) and Provincial (Canadian) authorities.

Fall Protection Requirements on Manually Propelled and Scissor Lift Products:
Standards for Manually Propelled Elevating Work Platforms (ANSI A92.3 and CSA B354.1)
and Self Propelled Elevating Work Platforms (Scissor lifts) (ANSI A92.6 and CSA B354.2) do not require the use of PFPE in addition to guardrails. If a user (employer) or local government regulations requires an operator to use PFPE in addition to guardrails on these aerial platforms, lanyard attachment points are provided for this purpose by Genie Industries.

The platform guardrails are not approved attachment anchors for PFPE on any Genie aerial platforms. Only designated anchors may be used for PFPE.

All anchor locations on Genie Booms and Scissors are designed to hold 5000 pound static load.

Safe and appropriate use of personal fall protection equipment on any aerial lift is the responsibility of the operator and user (employer) and is accomplished by strict conformance to governing regulations, the operator’s manual, ANSI Manual of Responsibilities, and safety decals found on the machine.​

Summary of Fall Protection Requirements For Genie Products:

ANSI / CSA Standard Genie Products Affected Fall Protection Requirement​
ANSI A92.2 / CSA-C225
Vehicle Mounted Booms
TMZ, TZ trailer mounted booms
Use of approved harness and lanyard is required

ANSI A92.3 / CSA B354.1
Manually Propelled Elevating Platforms​
AWP, IWP,CWP, DPL, PLI, PLC,
EUP, EUM, PLP
The guardrail provides fall protection.
Personal fall protection Is Not required

ANSI A92.5 / CSA B354.4
Boom Supported Work Platforms
All self-propelled “S” and “Z” booms
Use of approved harness and lanyard is required

ANSI A92.6 / CSA B354.2
Self Propelled Elevating Work Platforms Scissors, Genie Runabout
The guardrail provides fall protection.​
Personal fall protection Is Not required

If you have questions regarding these requirements, please contact the Product Management Group

at 800-536-1800.​
 
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That a good document to support my designations for the various lifts and what is needed in each.
 
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