Fall Protection in Tower Tray Manways:
This issue comes up frequently and wanted to get input.
We have tower interiors that must be inspected prior to startup and during turnarounds. Often these towers have narrow tray manways (e.g. 19 inches x 30 inches) with the distance between the trays anywhere from 18 inches to 24 inches. Arguments are presented that climbing inside towers with these dimensions should require fall protection harnesses and lanyards, especially when the distance traveled can be 30 or 40 feet (vertical). There are also rescue considerations.
The opposing argument is that harnesses and lanyards present the greater hazard to climbing inside a tower than falling. Experience with having harnesses getting caught on internals has shaped those beliefs. Additionally, the argument notes that the dimensions of the climb space are not terribly different from the interior of a fixed ladder with a ladder cage, for which fall protection is not required (i.e., the cage provides fall protection).
I am interested in your advice regarding this type of activity.
This has come up over the past twenty years regularly regarding catalyst trays. Such towers can be climbed from the bottom up or top down based on tray installation design. Easiest for fall protection anchorages is top
Fall protection and rescue facility is always required. The objections are always to be considered and solutions offered to neutralize the complaint.
Thus harnesses can be worn inside coveralls to avoid snagging tendency. There are several designs available including Yokee from Frenchcreek Production. I would use an SRL with two-way retieval capability anchored
directly overhead. In this way snagging can be minimized.
The analogy of a cage is patently wrong and ill-advised in my opinion. Cages do not work except psychologically to avoid agoraphobia and acrophobia and
offer no physical falling protection. Furthermore they cannot be demonstrated or tested. Any person falling inside a tower could be jammed and might take the destruction of the tower to get that person out much in the same way as 737 and 747 wing fuel tanks require destructive rescue; the
777 was designed around rescue from the start and the plane was built from the seat belt back to the wing tips.
Access into and out of towers with a vertical accessway requires the
GrabSafe (see the products section of this web site) to provide horizontal handholds that are vital in dynamic fall conditions.
I suggest preparing sketched to help generate solutions for the various types of towers.
EFSS designed a fall protection system while erecting/installing
an oil tank fixed roof because the jig-saw shaped pieces are highly
dangerous to lay and tip suddenly if the spokes do not support the tank piece sufficiently when the pivot point is exceeded.
I have run across several contractors using rigging(cable chokers, nylon slings) for fall protection. Either by hanging retractable lanyards from them or tying off to them directly. What is the proper answer? I believe that rigging is for material handling and that’s all. They make D-ring straps for these applications.
Use of material slings is a good idea for anchorage connectors when:
1. They are committed for fall arrest application only with strength exceeding OSHA requirements when new.
2. They are permanently marked as to purpose (never any mixed use).
3. They are permanently labeled for fall arrest use only per Z359 2007 Fall Protection Code.
4. The connection to the fall arrest connector is compatible per manufacturer’s instructions, also see 9.
5. The attachment to the anchorage is compatible and not cutting, and choking is acceptable per manufacturer’s instructions.
6. The sling is part of an approved fall arrest system endorsed by a Competent Person and a Qualified Person compliant with 1926.32 and 1926.500 series.
7. The sling is inspected regularly for damage and replaced when necessary with another sling meeting items 1-6.
8. The sling is polyester in acid environments; wire cable in abrasive environments.
9. The application has been reviewed for possible vibration damage over a few months period of time.
10. Portable applications are treated as a system with approved anchorage meeting 1926.500 series or equivalent for 1910 applications.
11. Choose a fall equipment manufacturer’s sling with D-ring and loop for choking preferably if the above conditions 1-10 are met.
Note: Watch for revised and new ANSI Z359.0-4 in the next year.
I always have been under the impression that workplaces that fall under the general industry category were required to use fall arrest equipment that conforms with ANSI Z359.1.
I am in discussions with a group that disagrees and has contacted manufacturers who have told them that this is not true. If this is the case, is it acceptable to utilize ANSI A10.14 marked equipment in a general industry setting?
In your book (“Introduction to Fall Protection, 3rd Edition”) it states that OSHA can reference an ANSI standard when issuing a citation. Is this ammunition I can use in support of my argument or am I just totally incorrect?
There is a new draft Z359 standard relating to independent testing. Some manufacturers are concerned that test houses do not have the equipment to properly test to Z359 and would like to conduct in-house witnessed by a Competent Person in the Z359 standards.
How do you handle workers that are out of the standard weight range for PFAS, meaning those who either weigh less than 130 pounds (usually women) or those over 310 pounds?
The Z359 committee as of 2008 is staying with the 130-310 lbs because of lack of biomechanical and anthropometric information about larger workers particularly. Lighter workers are exposed to higher G forces. Above 400 lbs there is concern for whether the tissues supporting the body on 1-5/8 to 2 inch straps is viable without interrupting circulation. The industry needs a grant to research or model these extreme weight and shape issues. Also be aware that the test torso use of 220 lbs may disappear in favor of a 282 lbs torso or dummy (divide 310 by 1.1) because it has been concluded from some joint manufacturer testing that there is a more accurate 1.1:1 ratio for torso to the human body and the 1.4:1 is not valid. See the ASSE By Design newsletter for 2007 final issue which provides the test report for extensive work done in this field including live drops. The method of testing equipment is changing significantly.
What sort of fall protection system or program is required for workers that spend 4 hours or more on a platform every two weeks?
This is controlled by OSHA Instruction 01-01-013 that indicates a guardrail is necessary for work less than 4 hours, an alternative fall protection system is OK.
Use of the proposed general industry standard dated 4/10/90 would be acceptable. Washington State has a connection to the equivalent of 1910.66 App. C (soon to beome a horizontal standard in that state, like ladders). You also can use 1910.66 App. C as policy.
I have a case where they were using retractables in a horizontal
position hooked to an engineered life line. I do not see anything about this in your chapter in the ASSE book.
Do retractables have to be overhead and within a 45 degree angle? The lanyards were also hooked to the retractable. Does your book cover these issues?
All SRL’s (retractables) are used overhead in this country. Any unit positioned at an angle for example on a residential roof is fine unless you fall off the gable end.
Lanyards should not be hooked to SRL unless a D-ring extender from same manufacturer is used.
SRLs for use in two dimensions are a recent innovation and are called Double SRLs used only in Australia so far. The tarping flatbed truck loads is a great application for this. See the Professional Safety article in May 2008 on Tarping Flatbed Safety and look for an expanded web page on this www.FallSafety.com site in truck/trailer fall protection which provides information regarding on-board trailer fall protection for use at destinations.
I am an investigator for OSHA in Tampa. I have your first and second edition book on fall protection.
I am trying to find a product or manufacturer of a horizontal lifeline system on a tripod system.
The system is needed for residential roofing to prevent a swing fall hazard. Generally roofers use a roofing anchor, however, that obviously creates a swing fall hazard.
On page 107, second edition, figure 7.25 shows a tripod system. If that system could be used with a horizontal lifeline it could solve a lot of problems.
The problem for manufacturers is that without Competent and Qualified Person authority the systems can be misused so easily that injury is virtually a certainty if a fall occurs. For example a HLL with a s/a lanyard fall energy input causes 10,000 lbf at each anchor. Too much for wood roofs and wood screws. Labels and warnings are increasingly sophisticated but it is hard to cover every geometry when you don’t work on a roof every day.
Try DBI Sala’s roofing components page for ideas of stands that get the line off the roof, www.capitalsafety.com.
If the employer wants a custom design post system for one or more foreseeable uses, then our engineers can definetly design it, fabricate it and test it to meet sound work practices. One example is bridge builders – we regularly test and improve construction company HLL concepts.
Thank you for your investment in the book 1 and 2. The third edition still has lots of information in it (2x 2nd ed.). The 4th ed just started to review, will contain the new Z359 info. Missing fall protection information should come to our attention as soon as possible.
Where would I find rules about not hooking a retractable to a horizontal life line and then to a lanyard? Is this covered in your book, Introduction to Fall Protection?
The key question is a SRL with additional lanyard attached which weighs down the SRL line or has an unsafe attachment. The HLL is incidental I think.
Under proper usage comes the requirements to follow manufacturer’s instructions. This is addressed on page 321 of the third edition.
While no manufacturer will recommend attaching a generic 6 ft lanyard to a SRL or any snaphook to another snaphook, there are two foot connector lanyards that are lightweight for easy reach, made by some manufacturers with one snaphook and a D-ring. These devices weigh 1-2 pounds or less than what it takes to keep the SRL line taut. That is the key. Keep the line taut to reduce the fall distance. Keep the SRL above head height and at least 5 ft or shoulder height at 25 ft payout range. Beyond 25 ft distance keep overhead. Danger here is the arc of the fall which swings you over an edge. See the sketch on page 326.
Let me know if you think something more specific is needed for the 4th edition underway currently.
As a company, we require employees on ladders to be tied off over 4 feet. Is this an OSHA requirement or a safe working practice adopted by our company? Also in normal office environments with a suspended ceiling with no tie off points, what is the normal industry practice to meet this requirement if one is working above the four foot level.
To give you a little background, I am referring to work on commercial step ladders in an office environment with furniture, cubicles, and obstructions throughout. We decided that it is not an OSHA requirement to be tied off while working on a step ladder above the 4’ height. We have used scaffolds with the required fall protection in some instances, but aerial lifts and scissor lifts are not practical in most cases due to the obstructions. Our heights are 11’-3” from top of floor to acoustical ceiling and it’s approximately 14’-6” from top of floor to bottom of slab above. I was really looking for info on how other companies dealt with this issue since it should be a common issue throughout the US in office environments. In industrial setting, we could and do use the lifts and build scaffolding. But if you are changing out a light bulb, we try to work it from a step ladder.
Please define the word ladder (e.g. stepladder?) and what height ladder, and what is ceiling height and typical ladder standing step. Also the “tieing off” process for stepladders is more problematic for stepladders in the middle of a space, than portable ladders which lean against a solid surface in plant or office conditions.
General Industry is normally four feet trigger height for fall protection. Agreed. What devices have you considered to do work with fall protection above drop ceilings? Does that work anywhere?
Aerial lifts: Have you used scissor lifts or small aerial devices?
EFSS was hired by a pharma packaging company to address this type problem a couple of years ago. We specifically looked at filter changes for HVAC units in a clean room environment. We provided an engineered horizontal lifeline to attach a distance from the drop ceiling access to the AC unit. The worker used a step ladder or small lift to access the opening and then attached to the HLL using a first man up device from the ground or the lift. The access in the processing area was pre-set so that the small aerial lift was able to predictably access the several AC units with about ten feet of travel climbing in the 12 ft drop ceiling. In that case the height above the drop ceiling was about 7 ft and pipes and other footholds were present.
Other applications were at a plant where fall protection was mandatory on a stepladder to reach lighting in a plant environment again using first man up devices (Introduction to Fall Protection 3rd ed).
We looked at the fall exposure not the OSHA ladder rules from 1971 based on management input. The access to corridor utilities with numerous wires and cords plus ducting, sprinkler, nitrogen, oxygen, water pipes etc is an increasing problem in the USA and probably world wide. IT wires are a particular problem with little or no discipline for travel routes and cable trays which should be pre-planned in new buildings. Changing fluorescent lighting strips should follow a program designed before construction of office space. Likewise installation of alarm and security system wiring from inside to outside must be integrated with worker exposure traveling in unstable ceilings.
Picture this: we have an old concrete pit in a field. The edges of the pit stick up 28″ above the ground, not high enough to count as a guardrail. There is a chain link fence surrounding the pit to keep people out, approximately 3 or 4′ from the edge of the pit (30ftx30ft). We
have some people who want to do some maintenance in the area between the fence and the pit (e.g. cut weeds). How do I protect those workers?
There is nothing substantial enough to use as a fall arrest anchorage.
I can have them put up a guard rail around the edge of the pit, but that will actually expose them to the hazard for a longer period of time.
Filling it with dirt is great; more permanent the better if the
pit has no further purpose. Maybe this is the time to do it.
Throwing in a couple of short-term additional ideas to the many offered already:
1. A weedwhacker could be a remote tool with a monitor for the entrance area to cut weeds. If the whole fence comes down temporarily then you could weedwhack the enire edge area.
2. A net vertically or horizontal could be engineer rigged over or to the side of the 30 ft square pit – however, is there enough room to move
3. A 14″ overlap edge (how wide is the wall?) or box 28″ tall such that it is impossible to fall over but merely flop. The goal is 30″ high and 12″ wall – a carpenter could make some pieces to go over the wall and provide this profile (see OSHA proposal 4 10 90 or Introduction to Fall
Protection 3rd edition for details).
This is a great question for an engineer who fancies him(her)self as a Qualified Person! We have structural engineers that could engineer any solution including horizontal cable lifelines on each side well away from the edge. It is a cost and time and degree of protection and permanent solution desire that rules here.
How can you solve this problem once and for all?? Stop using SRL’s over any edge which is sharp and has an anchor point less than 5 ft high. Reason: too many cutting cable incidents are occurring because the SRL now has a free fall of about 6-7
ft eg decking.Above 5 ft the free fal is typically 6-10″ with no edge
contact. Consider higher anchorages procedures or leading edge SRL models with 5000 lbs cables (7/32″ diameter).
We are looking to install a temporary horizontal lifeline system in our theatre. It is outdoors so we are would prefer the line to be galvanized aircraft cable instead of synthetic rope. The run would be roughly 40 feet long. We were wondering if the use of rated aircraft cable and hardware along with the correct anchorage points would be safe and meet the necessary standards.
As far as component types are concerned. There will be less stretch so less fall distance and reduce collisions so that is good. But the real question is what is the fall protection system are you intending 5/16 or 3/8 dia. aircraft cable and swaged terminations, and then what is the application involving how many people? Are you attaching SRLs or lanyards and what hardware is being used such as large snaphooks compliant with Z359.1-2007 with 3600 lbs gates and are you using shackles attached to an anchorage capable of 16,000 lbs.
How do you rig fall protection where there is no access between HVAC, Conduit and 40 ft above?
The question is how to approach a cable tray filled with conduit also the HVAC unit when there is no obvious anchor point. HVAC unit and trapeze hold the cable tray.
Assume that the cable tray is 15 ft above the ground. In this case inside a building there are numerous types of aerial lift to access and where the lift can provide an anchor for in-the-bucket work above head height
Above a corridor drop ceiling, we can access the area by catwalk then build a scaffold for certain types of work.
Voltages unknown and if electric can be shut down. Frequency of work unknown. Duration of work unknown. Specific work and work method unknown. Number in crew unknown.
Can a HLL be placed up to 40 ft up? EFSS can engineer that if requested for the people specified.
Concerning the design installing and use of fall protection systems on structural steel construction, my organization has some challenges and questions on which we are seeking clarification.
The situation / condition:
1.Concerning the definition(s) of the term engineered. There is a question about the idea that a crew of seasoned professionals, certainly meeting the definitions of competent and/or qualified by years of experience, training and even professional license holders in their field can design a fall restraint / fall arrest system. The condition present is that we have adequate body harnesses, lanyard and/or self retracting lifelines, snap hooks, etc. but anchorage is an issue. Our welders (with a combined working experience of around 200 years working at heights and in fall hazard situations) and superintendant (who is a 30 plus year licensed contractor) feel that they can in fact fabricate and install (read: weld / bolt / attach) eye bolts to existing steel beams, and attach a horizontal cable to each point of this anchorage, connect their retractable lifelines and set about to do their work.
2.BUT& we have a compliance element that is adamant that field fabricated welds affixing eyebolts to steel MUST be engineered (read: PE designed and somehow certified) that those anchorage points are in fact able to achieve the minimum support weights of 5k pounds.
3.The counter position from the crew and superintendant is actually more one of difference in definition and application of the term engineered. They contend that the term engineered means designed/created/ and put into use by competent/qualified persons and that something does not need to be professionally designed and stamped with some sort of approval to be engineered. (one example was that a guy can engineer (design, and build) a tree house in his back yard for his kids and not need any professional engineer to be involved for the entire structure, such that it may turn out, to have been engineered)
4.There is a sentiment that engineered is a term used and applied to a specific design of something if the design/product is going to be advertised, marketed publicly and sold. Engineered in that case, is a liability issue in that if an organization does create, design, manufacture and sell an object, that it must be engineered and professionally guaranteed in some manner.
The question buried at the bottom of the difference in definition and application of the term engineered&
Since the situation above is local, employer specific, and the employer assumes the risk in the event that a field designed (engineered) system is created and used does the term engineered really apply?
If they weld eyebolts to structural steel members, attach a horizontal cable and lanyards to that cable, don and attached body harnesses (essentially the whole system as a sum of its components), and there is a failure of any part of the fall protection system that results in a loss event the employer is responsible no matter what.
Essentially, is the crew and superintendant correct or is the compliance entity correct with their definition and application of the term engineered?
Fall Protection is easiest to answer case by specific case to assess the hazards present in each case.
General fall protection principles are harder without going to the other end of the spectrum.
If engineered is defined as the mathematical certainty of fall arrest or function in a pristine environment then it must be reduced to writing.
To guess fall arrest force at the termination of a horizontal lifeline is not possible by a lay or field experience there must be a calculation in the file to refer to. It must be by a Qualified Person. Presently this is often a Qualified Person Registered Structural Engineer from the outside who work every day on Fall Protection systems.
Each fall protection horizontal lifeline system should theoretically have its engineer. This done through creation of templates.
The relief from a new person in the fall protection process is the use of systems which are like. You build that up then when a new system arises that a Competent Person recognizes has no equivalent, the engineer is again brought in to create a model.
If the recognition of these templates in the field is accurate then the engineer will not be needed except on a few occasions over a one-two year period. Geometries are sometimes complicated and change moment to moment so the recognition of fall hazards up front needs some time to work out related solutions following your engineered models.
Is it acceptable a worker using a leading-edge self-retracting device for installing steel decking to use an 18’’ D-ring extension on his harness? Using the extension would result in the energy absorbing pack on the SLR being further away from the user’s body. I don’t know if that would negate the extra protection of the leading–edge SRL. Thank you, and by the way, I love the 4th edition of your book.
Yes, I believe your suggestion is acceptable. This is based on the likelihood of the fall impact at edge being between the EA and the SLR.
Is an SRL allowed in combination with a lanyard extension?
Yes the idea, of course, is to make the attachment feasible and compatible for those workers having difficulty reaching the SRL snaphook to attach to the harness back D-ring. Free fall should not be increased. Ideally the manufacturer of each component should be the same. Note that SRL extension is allowed to 48″ unless you are using a 24″ total extension model ref Z359.14.
Any question please let me know. Thanks Tony: