OVERVIEW OF FALL PROTECTION STANDARDS
There are multiple factors to consider when implementing a fall protection system. These can include ANSI and OSHA regulations, structural integrity, system usability and more. While we provide as much information as we can via our website, there’s no substitute to having a fall protection expert review your specific application. Speaking with an FLS expert is also the simplest way to be sure all fall safety considerations have been met. Our experts are a ready to answer your fall protection questions.
Fall Protection 101
Heavy industry and construction work has many hazards. Whether the hazard is moving equipment, thermal, explosive, or contaminated atmosphere, they are all dangerous.
Workers are trained to recognize most hazards in their work places and take appropriate measure to ensure their safety. This is normally accomplished by wearing Personal Protective Equipment (PPE) and through training in the proper way to deal with the hazard. Unfortunately individuals largely overlook one of the most common hazards, in any workplace or home, because it seems too trivial or it takes longer to be safe than the job takes.
What is the hazard? FALLS!
How prevalent is this fall hazard?
Falls from elevation are, according to the National Safety Council, one of the highest causes of death in the workplace. A study by the United Roofers Union conducted between 1985 and 1989 reported 297 fatalities from heights six feet or less. In Maine, between 1997-1998, 31% of all industrial fatalities were fall related. The cost? The pay out made by employers and insurance companies averaged out to 1 million dollars per episode.
Fall related accidents are complex events involving multiple factors. A number of issues both human and equipment related should be addressed to educate employees on fall hazards both in general and specific to their work environment.
These issues include:
- Where and when protection is required
- Establishment and implementation of a fall protection plan, including provision for rescue
- Proper selection of fall protection systems
- Correct construction and installation of these systems
- Proper training in selection, use and maintenance of the selected equipmentThe key to preventing falls is through education and skill proficiency. A thorough knowledge of the hazards, available equipment, application and limitations of the appliances along with a program to implement learned skills will further the goal of reducing and minimizing workplace injuries and fatalities due to falls.What are the chances of surviving a fall?
From an 11 foot fall the chances of surviving are 15%. That means there is an 85% chance of becoming a fatality. This course is designed to keep you from becoming one of the 85% by giving you a better understanding of what is required to protect workers at elevation and the tools to work safely at heights.
For some individuals working at heights is a thrill, while for others it can be a nightmare due to fear of falling. It can be enjoyable on a nice day, but miserable on a cold windy day. Hazards working at heights are normally much the same as working on the ground with the exception of falling and either being injured or requiring some form of rescue.
There are four general categories of hazards while working at heights:
Psychological / Medical
The body’s normal core temperature is 98.6 F. When this temperature increases, the body tries to maintain the proper core temperature through perspiration. As the core temperature continues to rise, heat cramps, heat exhaustion or heat stroke can occur.
Heat cramps are painful spasms of muscles usually in the calf or abdomen. A fluid and salt loss resulting from heavy exercise or work outdoors in warm or even moderate temperatures cause these.
Signs and Symptoms
- Severe muscle contractions, usually in the legs and the abdomen
- Usually normal body temperature
- Moist skin
This is the most common heat illness leading to fluid depletion and is caused by exercise or work in a hot environment. The cause is fluid loss from excess sweating, which is not adequately replaced. This loss leads to low blood volume. Blood flow is reduced to vital organs as the body tries to give off heat by increasing blood flow to the skin.
Signs and Symptoms
- Normal or slightly elevated body temperature
- Cool, moist, pale, or red skin
- Dizziness and weakness
This is the least common, yet the most serious heat illness. Heat stroke develops when the body cannot cool itself and gradually stops working. Sweating stops because the body tissues have a lower fluid content. The body then cannot cool itself and body temperature rapidly rises. It soon reaches a level at which the brain and other vital organs, such as the heart and kidneys, cannot function properly.
Signs and Symptoms
- High body temperature, often as high as 106F
- Red, hot, dry skin – especially in the elderly
- Irritable, bizarre or combative behavior
- Progressive loss of consciousness
- Rapid, weak pulse becoming irregular
- Rapid breathing
Some people find working outdoors in the cold invigorating and some don’t. A couple things occur in the winter, one being the worker must dress in heavy cloths, which makes movement awkward. The other is the lowering of the body’s core temperature causing hypothermia.
This condition is caused by exposure to the cold to a point that the body cannot keep itself warm. Air temperature, the humidity, whether the skin is wet or dry, and wind all affect how the body maintains it’s temperature and how much exposure is needed before hypothermia begins. The air temperature does not have to be below freezing to cause hypothermia.
Signs and Symptoms
- Shivering (may be absent in later stages)
- Lack of coordination
- Confused or unusual behavior
- Body temperature below 95F
Wind is an indirect hazard as it can cause wind chill factors leading to hypothermia and frostbite. Stronger winds can move the staging or structure causing unsteady work surfaces. The wind can also blow loose material around which could hit workers or cause them to avoid flying objects.
1.2.2 Medical Problems
Fear of heights is the first thing most people think about when discussing medical problems that relate to work involving heights. This isn’t that large of a problem, as people with this fear either have overcome it enough to work at heights or they don’t go up. Vertigo is a disorder that can happen to anyone, anytime.
Vertigo is a disorder of balance that gives a person the sensation of spinning around in space when at rest. Alternatively, objects may appear to be spinning around the person.
Vertigo is caused by a disorder of the ear the affects balance. Infections of the inner and middle ear or blockages of the Eustachian Tube can cause vertigo. A build up of wax in the outer ear can also cause the disruption of balance. Drugs, alcohol, or food poisoning as well as sudden disturbances of the eye will have a great affect on vertigo. Thus, if a person shows up to work with an ear infection or hung over, there is a possibility of vertigo.
Signs and Symptoms
- Nausea and vomiting is common
- Difficulty walking with a tendency to fall side ways
- Eyes may flicker
- Buzz in ears
- Hearing loss
The above are symptoms that may occur, but not always.
Complacency is one of the leading causes of falls due to the worker becoming careless. Due to experience, lack of training, or other factors, many workers become unconcerned with the hazards and fail to take appropriate action to protect them from a fall.
Fooling around at heights can be very dangerous and must not be tolerated. It can take many forms from pushing and shoving to playing with others safety gear. Horseplay can result in serious injury for which participants may be held responsible.
Although overlooked on many occasions, housekeeping is very important. The more equipment, tools and left over material left lying about, the more hazards that are available for slips, trips and falls.
To avoid injury from falls or falling objects, practice good housekeeping. Dispose of scrap and waste materials promptly in approved containers. Return tools and equipment to storage as soon as you are finished with them. Obtain and use a good tool belt to avoid dropped tools.
Basic fall protection systems can be as simple as a guardrail, a ladder cage or a handrail. All provide basic protection but, as in the case of a ladder cage, imperfect protection. Fall protection systems can be divided into three types:
- Fall Restraint
- Work Positioning
- Fall Arrest
1.3.1 Fall Restraint
A fall restraint system is designed to eliminate the possibility of falling to the next level whether it is a floor or suspended obstructions such as pipes or conduit. The simplest form would be a guardrail. Properly constructed and secured the rail will give more than adequate protection for a worker performing his task or transiting the area. Guardrails that are poorly made and designed lend a false sense of security and may be more hazardous then having no rail at all.
Hand or stair rails are there to be used to assist a worker to ascend or descend stairs. They may not prevent a scraped knee or banged shinbone, but they can stop a person from tumbling down a flight of stairs or falling into the risers if the rail is used in a safe and contentious manner.
Ladder cages are the least effective of all. In fact, OSHA is studying the elimination of cages as a protective device. Loosing your grip on a ladder and falling within the interior of a cage can cause serious injury and if it does arrest a fall, it does so by entangling the workers body within it’s framework. If it does not, then the worker merely tumbles within the cage till they strike the ground.
Constructed restraint systems are necessary when there are no guardrails and in many more cases the task to be completed may be a one-time exercise or due to other variables it is not possible to erect a rail or properly secure it.
Designed properly, a restraint system allows a worker to perform their task without the possibility of loosing contact with the walking/working surface. This means the anchor point will not be subjected to an impact load. Because of this the anchor strength requirements are limited to four times the intended load. For example, a 200 lb. worker would need an anchor point capable of sustaining an 800 lb load. Equipment for restraint systems should be compatible and in good working order. Although a waist belt can still be used for restraint, it is highly recommended that a full body harness be worn.
1.3.2 Work Positioning
Work positioning allows a worker to perform their task in the vertical plane while being exposed to a minimal free fall, two feet or less. Two examples of this would be a construction worker assembling or performing a task on a metal form structure or a window washer.
Anchor points for a work-positioning device are rated at 3,000 lbs because of the possibility of a 2-foot free fall. Many of these devices are simple chain devices with a specialized hook or carabiner. The connection points to a worker will be on each hip. The workers feet are in contact with the structure they are working on. In the case of a window washer, this would be the powered swing stage. A device such as a DBI RPD 1 would be used as a back up or as a primary device utilizing a vertical lifeline with a rope grab as a redundant system.
A worker using a work-positioning device should employ a backup system in case the primary system should fail. This is especially true for a window washer or any worker employing the use of a swing stage or powered platform. Make sure that the device is inspected and is compatible with the task. Jury rig systems using old lanyards, pieces of chain and a collection of snap hooks are an invitation to trouble.
1.3.3 Fall Arrest Systems
Fall protection is addressed within OSHA 1910 General Industry Standards but only draw attention to guardrail, handrails and related matters. Fall protection for floor and wall openings in this standard are governed by the four-foot rule. Simply stated, if the floor or wall opening is four feet above the next level then that opening shall be guarded by use of rails or other appropriate measures. This standard is weak and OSHA is in the process of rewriting the rules to make them conform to the 1926 Standards.
OSHA addresses fall protection within the 1926 Construction Standards. Anchor points, connectors, shock absorbers, in fact all the components that establish the parameters of restraint, positioning and fall arrest systems are contained in this standard. The Construction Standard follows the six-foot rule. Any worker exposed to a six-foot free fall is required to have fall protection whether it is restraint, positioning, or a combination of components that would comprise a fall protection system.
When a fall arrest system is in place there is a high probability of a worker sustaining a fall. This system is not designed to prevent a fall but to arrest the fall with minimal injury to the worker.
The components of a fall arrest system are as follows:
- Anchor Point
- Connecting Means
- Energy Absorbers
- Body Holding Devices
As part of any fall arrest or work positioning system there must be a provision for rescue and / or retrieval. This component is part of a required plan as stipulated by this standard. Planning for the worst may also facilitate identification of hazards and could help in removing the need for fall protection by using other means of production or assembly.
Anchors fall into two categories, certified and improvised. But exactly what constitutes an anchor? By simple definition it is any secure structure that can withstand and absorb the impact and / or static forces exerted by fall protection equipment. They can be a beam, girder, floor or column. Certified anchors are rated at a minimum of 3,600 lbs., improvised at a minimum of 5,000 lbs. Some points that should be considered in selecting or designing an anchorage would be: work area access, potential fall distance, utilization of shock absorbing equipment and ease of rescue.
1.4.1 Certified Anchors
These are specifically designed and tested products or points prominently marked and labeled for use with fall protection products or systems. Although most certified anchors are built and designed for site-specific applications such products as tripods, davit arms, eye bolts and beam clamps fall into the same category. All engineered anchor points and related products should be rated at a minimum of 3,600 lbs. and distinguished by paint or markings to insure they are not used as material handling load points. Routine inspections of these points should be carried out to insure they have not been damaged or compromised by virtue of accident or misuse.
1.4.2 Improvised Anchors
Often there are no engineered anchor points within the work area. It is now up to the employee to select the correct engineered product and determine whether the area has a hard point capable of withstanding a 5,000-lb. impact.
Before making the selection the employee should remember these points:
- The hard point should be unquestionably strong
- It does not show excessive wear or deterioration
- Has no sharp edges
- Is not electrical in nature (electrical conduit or trays) (if it is imperative that a hard point such as a crane rail be utilized lock out/tag out becomes an absolute necessity)
- Is not mobile or capable of movement
- Is not subject to high temperature, contact with solvents or corrosives (Steam or air lines, fire suppression systems, intake or drain lines)
If the anchorage does not appear to be secure, multiple anchorage points meeting the above criteria must be utilized. While it may be difficult to mark improvised anchorage’s, if one is identified and used on a regular basis certification and / or testing would be prudent to eliminate uncertainty.
1.4.3 Anchorage Connectors
Once it has been determined that an improvised anchorage is to be used the next step is the identification and proper use of an appropriate anchorage connector. All of the products on the market today have practical applications and range from a simple eyebolt or sling to self-locking hooks and sophisticated quadruped assemblies. Some of the more common types are belt type connectors, tripods, slings both synthetic and cable and beam clamps of various types.
The synthetic belt type connectors are either a simple basket type or a pass through. In either case the belt should have an integrated softener pad so that any blunt edge or undiscovered burr does not compromise the load-bearing portion of the strap. There are many belt types available that do not have a pad and routinely advise users to provide one if there is concern with abrasion. Manufacturers instruction on the use, care and maintenance of these appliances should be followed. Slings should not be configured in a girth or choke style hitch unless the product is so designed by the manufacturer. Improper configuration could cause the sling to fail in the event of a fall.
When faced with high temperature, such as welding or areas that may have contact with chemicals or solvents an effective alternative to synthetic slings would be 1/4-inch aircraft cable with Flemish eye splices. These slings are rated at roughly 7,600 lbs. and it is recommended that two be used in tandem and hung in a basket configuration. Proper training in the use and configuration of these type slings should be done by certified personnel, as there are certain considerations to be addressed with these appliances. Never girth or choke hitch steel cable. This type of configuration allows for undue stress on the slings and in the case of a fall the impact forces may cause the slings to part.
1.4.4 Inspection, Care, and Maintenance
All the above-mentioned appliances should be inspected on a daily basis by the end user and periodically by competent personnel. Cuts, tears, abrasions, discoloration, kinks, burrs, deformations should be noted. Serious wear or damage would preclude the use of the appliance as would a fall. One hazard often overlooked in relation to synthetic slings is UV exposure. Slings left out in direct sunlight for long periods of time will degrade and loose their tensile strength. Discoloration and brittleness are two immediate symptoms of UV damage. Synthetics can be cleaned. Refer to manufacturers recommendations in the area.
Connecting means for fall protection systems are divided into four main sections. Snap hooks, carabiners, lanyards and shock absorbing lanyards. In this section we are going to examine each of these connector types so that the employee will have a better working knowledge of the equipment available and it’s use.
1.5.1 Snap Hooks
In the past non-locking snap hooks have been the rule however, as of January 1st, 1998 OSHA requires self – locking snap hooks to be used. The use of self – locking snap hooks reduces the probability of accidental roll out (disengagement of connectors) however, there is still the possibility of a forced roll out disengagement especially if the connectors are improperly used, mated or poorly maintained.
ANSI requires that the hooks be either drop forged, stamped or machined from high tensile steel, proof tested to 3,600 lbs and are capable of withstanding a 5,000lb-impact force. A quality hook should have its rating, country of origin and either in writing or by symbol a drop forged manufacture notation. While the hook itself is rated for 5,000 lbs it should be important to note that the weakest point of the hook is the gate. Side gate loading of the device is dangerous when you consider that only 350 to 400 pounds of impact force is needed to ” blow” the gate.
Snap hooks come in various designs and it is crucial that the hook be user friendly in all types of environments and weather conditions. Hooks that are easy to use in mild conditions may be found to be difficult to open with a gloved hand while others may tend to jam up if not cleaned on a regular basis.
Other types of hooks available are ladder or scaffold hooks. While these types offer larger mouth openings and are very easy to open, there is always the possibility of accidental unlocking of the hook if the device becomes wedged between the employee and a work surface. Some snap hook variants incorporate integral swivels which allows for an attached lanyard to align itself eliminating the possibility of twisting the lanyard or cross gate loading if the hook is connected to an eye bolt.
Inspection, Care, and Maintenance
Hooks should be inspected by the end user on a per use basis. Deformations, cracks, burrs, discoloration and improper alignment of the gate should be notated and the hook retired. Broken springs or excessive slop in the gate would also mandate retirement of the device. Hooks exposed to harsh environments such as acids and metal particulate contamination and are subject to heavy use where they are dropped or banged against machinery are prime candidates for early replacement. Note: On some occasions workers have compromised hooks by grinding out the locking mechanism or merely taping the lock open. Not only is this dangerous but borders on the criminal if the hook is being used by someone unaware that the hook has been “altered”. Further, many times a hook sewn into a shock-absorbing lanyard has been involved in a fall, taken out of service then cut from the lanyard and used for other purposes. This is poor practice. There is no practical avenue to determine whether that particular hook’s capabilities have been compromised. Once a hook is involved in a fall, identify and destroy.
Keeping a hook clean is a simple affair. Gates should be cleaned with WD-40 or similar type solvent, then cleaned with a soft, dry clothe. Greases or oils may lubricate but if not completely removed have a tendency to attract dirt. Lubrication can be accomplished with a dry lubricant such as graphite. Again, consult the manufacturers recommendations if unsure as to the correct process for the appliance.
Carabiners by definition are connector components comprised of an oval, elliptical or trapezoidal shaped body with a normally closed gate that may be opened to permit the body to receive an object. In the case of OSHA approved devices the gate must be self-locking. ANSI does not recognize non-locking types. In the recent past manual or screw gate carabiners were accepted however, there were legitimate concerns on the advisability of using these devices in the workplace. Fire and rescue personnel are still allowed the use of screw gate carabiners for rescue purposes since OSHA does not specifically address rescue services or equipment.
Carabiners have their origin in mountain climbing and the earliest versions were in steel, then aluminum. All were non- locking to allow for quick access and egress of the climbing rope however care and attention was needed to ensure that roll out did not occur as it did many times because of negligence or oversight.
Screw Gate or Manual Lock Carabiners
The need to have a secured carabiner led to the screw gate carabiner, a device that requires the user to manually screw or lock the carabiner. The carabiners were available in either aluminum or steel. The major concerns over using these types centered on proper loading of the device and the whether an employee could be counted on to lock the device each and every time. Other problems arose when the device was exposed to continuous vibration and would occasionally “unlock” itself. In other cases, under load the carabiner would stretch and the screw gate slip down. When the load was released in would be almost impossible to unlock the device by hand.
Auto – Locking Carabiners
In response to the concerns with the screw gate types auto – locking carabiners were introduced. These devices could be opened with one hand and when the sleeve was released, would lock without any further assistance. Since the gate did not have to be screwed shut these carabiners would not jam closed after a load was not released nor would they open because of excessive vibration. Loading or proper positioning of the carabiner ceased to be a concern since the device would load itself along its spine. There is one cautionary the user should be aware of, if the sleeve of the carabiner is allowed to come into close contact with clothing, harnesses and equipment the sleeve may be forced open effectively unlocking the carbine.
Aluminum vs. Steel
There has been a continual debate over the use of these two materials. OSHA allows for the use of aluminum by stating that the connector can be made of ” materials of equivalent strength.” The controversy over aluminum stems from the question of durability and whether aluminum carabiners could sustain an impact from height without compromising their tensile or impact strength ratings. On the question of durability steel wins out. Steel carabiners are capable of absorbing a tremendous amount of wear and tear and continue to function. Dropping them or having them tossed into tool bins is not recommended but the reality is this is the type of treatment most of the devices are subject to. Admittedly, aluminum is not as durable as steel but on the question on their ability to absorb impact it appears that the concern is not over the body of the carabiner but rather the sleeve.
If the carabiner is dropped any deformation of, or difficulty opening and closing of the gate would be the criteria for removal of the device from use. From the industrial standpoint steel, auto – locking carabiners are still the best choice.
Cross Gate Loading
Although this condition has been mitigated by the self-loading design of modern industrial carabiners employees should be aware of the possibility and it’s consequences. This condition is exemplified by the carabiner being loaded across it’s gate rather than along it’s axis or spine. A carabiner that is rated at 5,000lbs along its spine is rated at less than half the rating when cross gate loaded. This condition can be caused by having too many slings in the carabiner or having the load rotate and catch the sleeve of the carabiner.
Types of Carabiners:
The basic designs for industrial use can be reduced to three basic types.
- The standard D
- The Offset D
The major point of the D type carabiners is the great strength that this device is capable of. They are also prone to load properly which relates to less probability of cross gate loading.
The scaffold type carabiners are much larger and have large mouth openings some as wide as 2 inches. This allows workers to secure them to larger structural members that their smaller cousins cannot do. These scaffold carabiners are available in three shapes, pear, triangle, and offset triangle. Another type would be a captive eye with a swivel designed to allow full movement of the worker without twisting the lanyard. These carabiners rarely exceed the 5,000lb rating because of the pin that has been drilled into the spine to allow the 360-degree movement however, if used properly these devices are extremely versatile especially if used with self-retracting lifelines.
The minimum rating for carabiners is 5,000lbs. Most will exceed these ratings however, one should be careful and read the rating that is stamped on the device. There are carabiners that are rated at 3,600lb and these do not fulfill the OSHA requirements.
Inspection, Care and Maintenance
Inspection of carabiners should be done on a daily basis. Carabiners that have significant dents, gouges discoloration, improper alignment of the gate or gates that are stiff and difficult to open or close should be taken out of service. Carabiners involved in falls should also be removed and destroyed with the view that if allowed to be used for other purposes there is always the possibility of catastrophic failure of the device. Like snap hooks, carabiners should be serviced with a dry lubricant and cleaned with a soft, dry cloth.
The ANSI definition of a lanyard is as follows: A component consisting of a flexible line of rope, wire rope or strap which generally has a connector at each end for connecting the body support to a fall arrestor, energy absorber, anchorage connector or anchorage. (ANSI Z359.1)
Lanyards are typically three to six feet in length however; some lanyards are adjustable in length and in some specialized applications may be as much as 12 feet in length. OSHA only allows a maximum free fall of six feet for the vast majority of industries. The major exception would be those people involved in the erection of steel.
Other types of lanyards that are available would the dual lanyard that is actually two lanyards attached to a specially designed shock absorber. This type would be used as a 100% tie off for those workers moving in a horizontal direction while involved in their work tasks.
There are three basic types of lanyards, based on the materials used for their construction.
Laid Rope: This type was the most common until the introduction of the synthetic, web style lanyard. It consisted of three strands of nylon with a minimum total diameter of 1/2 inch. The nylon construction gave this type high strength and elasticity. The downside of a nylon lanyard was its propensity to absorb water and thus loose up to 30% of its strength while wet. With the laid rope construction, foreign material such as grit, sand, and any type of particulate matter could find it’s way in between the strands and so degrade the lanyard from the inside out. Nylon also did not fare well in the areas of hot work or where there was exposure to corrosives or acids.
Flat Synthetics: These types of synthetics are very strong and compare very favorably with nylon and unlike nylon are not affected by rain or water. They have high resistance to abrasion but are, like nylon, suspect around areas of high temperature, hot work and corrosive exposure. Another factor to consider with synthetics is UV degradation. Leaving them exposed for long periods to strong sunlight has a detrimental effect on their strength and durability. Synthetics also have very little in the way of elasticity.
Stainless Steel and Galvanized Cable: This type of lanyard is usually found in very unique work areas. High strength, excellent abrasion resistance, and affected by only the most extreme temperatures. They are used in welding, hot work and any type of environment that would be hostile to the other types. One caution would be in the area of electrical work for obvious reasons. One point to keep in mind, these types have no elasticity.
Along with these three there is a fourth type commonly referred to as a manyard. This type incorporates an internal shock absorber within the nylon core of its construction. While very popular because of it’s relatively lightweight and absence of a pouch – type shock absorber there are concerns with this style. There are variants on the market that show impact on the lanyard but do so in reverse. The Miller Manyard and the DBI product exemplify this problem, which operate exactly the same with the exception of their impact indicators. Mixing these lanyards is apt to cause confusion even if personnel are highly trained in their use.
All the lanyard types previously described with the exception of the manyard should be used in conjunction with a shock absorber, preferably one that is integrally attached to the lanyard. Cable lanyards, if used in a fall protection system should always be used in conjunction with a shock absorber!
The reason is the amount of impact force that can be generated on a human body during a fall. Medical studies show that the human body cannot sustain impacts of 2,500lbs and above. Tests have shown that dropping a 220lb test weight six feet can generate as much as 6,000 lb. of impact if a steel cable is used and 2,800 lb. with a flat web synthetic. Nylon lanyards generated between 1,700 and 1,900lbs of impact force due to nylon’s elastic capabilities. Even so, OSHA mandates that the maximum impact force that a worker can be exposed to is 1,800lbs while wearing a full body harness. The inconsistency of a nylon lanyard mandates the use of a shock absorber if the lanyard is part of a fall protection system.
One of the most common abuses of lanyards is girth hitching, which is tying the lanyard back onto itself by utilizing the snap hook. Many times workers will use this method to tie themselves off. This is an extremely dangerous practice because of the pressure being exerted against the gate of the snap hook. While discussing snap hooks we noted that the gate of the hook could only sustain 350 – 400 lb. worth of force. Further, the amount of pressure being exerted against the lanyard material itself could cause the material to break even if it’s steel cable. There are now devices with an integrated shock absorber that will allow for tie offs but these use steel D-ring sewn directly to the lanyard itself. We will examine this type and other variants in the next section.
Inspection, Care, and Maintenance
Lanyards should be routinely inspected for cuts, tears, abrasions and discoloration. Brown or black spots in flat synthetic webbing may be indicative of splatter burns from grinding or welding work. Discoloration may stem from UV degradation or exposure to chemicals. Laid rope lanyards should be inspected inside and out. Opening the weave to see if the lanyard has grit, stones or other foreign matter that may degrade the interior portion of the lanyard. In cable lanyards fraying of the cable, or signs of excessive wear at the point of connection with the hook or the shock absorber would dictate removal of the lanyard from service. Synthetics that may be unusually stiff or soft may indicate exposure to petroleum products such as gasoline, diesel fuel, turpentine or kerosene. Lastly, any lanyard that has seen service for any other reason other than fall protection should be taken out of service for that purpose and so labeled or if it has seen an impacted fall it should be removed and destroyed.
1.5.4 Shock Absorbers
Shock absorbers or as referred to by ANSI, energy absorbers, is a component whose primary function is to dissipate energy and limit deceleration forces imposed on the body during fall arrest. A personal energy absorber is one that is attached to the harness.
There are three basic types of energy absorbers defined by their construction. One is made of flat webbing folded over on itself and stitched in a pattern that upon activation will break the stitching in a controlled manner thereby dissipating the energy.
The second form is a woven pattern with a designed fault that upon activation will tear the material up the middle at set rate of speed.
The third is a loomed effect; this type has often been referred to as the “Velcro effect” in that when the materials that have been loomed together tear apart during a fall, the remaining material appears to have a Velcro type appearance.
The fourth type of absorber was discussed in the previous section. This is the Manyard style, which has a woven interior that will tear out at a pre-determined rate. An additional problem with manyard style absorbers is they look like simple lanyards and may be used as such by those who are not trained in their use.
Energy absorbers should meet or exceed ANSI standards. Section 5.3 of the ANSI standard should be read and reviewed by those whose task it is to purchase and maintain fall protection equipment. NOTE: When purchasing energy absorbers read the manufacturers label closely. Energy absorbers manufactured for the Canadian market will allow maximum elongation of forty-eight (48) inches; those manufactured for the U.S. market will have a maximum tear out of forty-two (42) inches. Energy absorbers for both markets will appear to be identical from external appearances; you cannot use Canadian style energy absorbers in the U.S. All energy absorbers must have the ability to support 5,000 pounds after they have been activated. Which means even after they have been fully deployed to their full extent they must be able to support the above quoted weight. If they do not they will not meet the standard and should not be used. NOTE: Energy absorbers are required to limit the amount of impact force to the worker to 900 pounds. Most, if not all, will keep well below that number.
Energy absorbers can be purchased in a variety of ways. The most common is an energy absorber integrated into a six-foot lanyard. Others are sewn to three and four foot lengths to accommodate worker requirements. There are versions that have twelve-foot lengths however, these have been specifically designed for the steel industry and should only be used by those properly trained in their use. Others are integrated directly into the harness, which has merit because this ensures that workers will have the availability of the absorber immediately. It also reduces the possibility of girth hitching the lanyard. There are products on the market that allows girth hitching but these use steel rings sewn directly into the lanyard that allow the hook to secure to the ring and have reinforced areas of the lanyard to allow it to wrap around the selected anchor point.
Another type is the 100% tie off which is two equal length lanyards integrated into an energy absorber that has been so designed and engineered that upon activation, even if both lanyards are secured at different lengths, the tear out will be equalized so the worker will not be subjected to unequal or excessive impact.
Inspection, Care, and Maintenance
The decision to retire and energy absorber from service rests on a number of issues.
- Length of service. If the absorber has been well taken care of and has seen little in the way of abuse then between five and seven years will be the rule of thumb. Again, check with the manufacturer. The products produced today are much better than products produced five years ago.
- Check for tears, cuts abrasions and discoloration of the synthetic material of the lanyard.
- Deformation and damage to the energy absorber pouch. Damage in this area may impede the workings of the absorber and may even indicate a partial activation of the device. Remember: The amount of force to begin activation of the energy absorber is rated at 450 pounds. A partial fall may tear out a very insignificant portion of the device however, at this point the absorber MUST be removed from service and DESTROYED!
- Examine the hardware for burrs, deformities and proper operation. These include the hooks and ring if so equipped.
Body holding devices are designed to support the human body during and after fall arrest. For full information on harnesses refer to ANSI Z359.1. This section will provide the reader with the technical aspects and requirements of this specific type of PPE.
Body holding devices have been in service for quite awhile however, the types, styles and materials used to manufacture these harnesses has changed dramatically over the last decade. For the sake of brevity we will discuss only two styles and address the types by application. As to the material used for their construction it is safe to assume synthetic material in the form of a polyester blend is the predominant choice of manufacturers today.
1.6.1 Waist Belts
This type of belt has been used in virtually every type of industry. As of January 1, 1998 the use of a waist belt as part of a fall arrest system is illegal. Originally OSHA allowed the use of a belt if the maximum arresting force exhibited on an employee was 900 lbs. As we will learn, this is totally unacceptable and after serious examination, OSHA concurred. Are waist belts still allowed? Yes, but only in work positioning and fall restraint situations. This brings up the argument of whether belts should be incorporated into a complete fall prevention / arrest program. The general consensus is no. Full body harnesses can be equipped with all the necessary attachments making the belt redundant. All too often an employee may opt to leave a belt on rather than change out to a harness simply because they “don’t have the time.”
Medical studies have shown that the human is capable of sustaining impact loads up to 2,400 lbs. The reality is the human body cannot sustain these forces without injury. A more practical threshold is 1,800 lbs. The arguments surrounding the waist belt were muted when military studies showed the types and severity of the injuries sustained by those using belts in free fall incidents. Ruptured spleens, internal injuries, broken ribs and backs just to highlight a few. Subjecting a person to a concentrated 900lb impact in the abdominal area followed by a period of suspension guaranteed critical injury and a high probability of a fatality.
OSHA will allow a worker to be subjected to 1,800lbs of impact if they are wearing a full body harness. This primarily because of the harnesses ability to absorb the impact forces due to its elasticity and design which concentrates the vast majority of the forces where the body can best tolerate such impacts i.e. the buttocks.
After the fall the harness will allow a worker to be suspended for a much greater time than a belt and without the threat of further serious injury. How long? Twenty to twenty-five minutes with minimal discomfort. Beyond that period it is safe to say that a worker will suffer increasing discomfort however, the alternative is far less attractive.
1.6.2 Full Body Harness
The modern basic harness is constructed with synthetic materials such as Nylon, polyester or a blend of both. The material of choice is polyester because of its abrasion resistance, strength, ability to shed water and its flexibility.
While many models are monochromatic, a better choice would be those that come in contrasting colors. This allows for easy identification of the upper and lower harness sections. Straps are to be at least 1 5/8 inches wide and rated at 5,000 lbs. All attachment hardware i.e. the rings, whether they are steel or equivalent material, are to have a rating of 5,000 lbs. NOTE: There are harnesses available on the market that utilizes synthetic loops or rings instead of steel rings. These are usually found in areas were there is a concern for electrical conductivity and are often seen with the shock absorbing lanyard integrated into the ring assembly. Connecting hardware on the harnesses such as friction buckles, parachute buckles, and tongue and grommet assemblies are rated at 3,600 lbs. All harnesses are rated for 310lbs. A worker cannot weigh more than 310 lbs., this weight includes clothes and tools. If they exceed the rated weight, harness manufacturers can deny product liability. If you or any of your employees see this as a problem approach a supervisor or your supplier and/or manufacturer direct. Harnesses can be manufactured and rated for weights in excess of 310.
The biggest concern for the harness wearer other than correct application identification is FIT! An improperly adjusted harness can cause injury. It is important for the wearer to select the correct size. A harness designated as a universal fit does not automatically guarantee the harness will fit every worker in the plant. Harnesses that after being donned have excessive slop or play, are extremely hard to adjust or after adjustment have excessive material are usually the wrong size for the individual. Trying to make an improper harness fit is an extremely frustrating and time consuming exercise that will only increase an employee’s resistance to the wearing of the harness on a regular basis.
Another concern has developed with the increasing number of female workers in industries that have been traditionally male dominated. Vest style harnesses for the most part present no problem to the average male worker but the proper adjustment of this style requires that the chest strap line up across the nipple line. This adjustment may be difficult for a woman and in some cases, not possible. Chest straps worn above the bust line may increase the probability that the strap would rise up and impact the throat area if the strap were worn too high, if worn below the bust line there is a danger the strap may ride up under impact injuring the breast tissue. If it all possible a woman should be given the option of choosing a cross strap version. This style allows the straps to cross at the sternum area thereby eliminating the possibility of impacting this soft tissue area. Again, allow workers to try on various harness sizes. A harness that fits and adjusts easily will be worn. If it doesn’t, it won’t.
Fitting the harness is a matter of putting it on and making the proper adjustments. A properly adjusted harness should be snug, not tight. Sloppy fitting harnesses may be comfortable but they pose a number of dangers, even to the point of allowing the wearer to slip through or being flipped out. The Dorsal D ring or the fall arrest ring at the rear of the harness should be centered between the shoulders and high enough up the back so that the wearer can reach back over his shoulder and grab the ring so that it can be secured and centered to fit the hook or carabiner into it. A ring that is too low will be impossible to reach and in the case of a fall will cause the victim to be impacted improperly and during the period of suspension will cause the body to lean at a severe angle causing undue stress in the lower leg area. A ring that is too high will allow the hook or connector to strike the head or helmet causing annoyance and in the case of a fall, a real headache!
Chest straps on vest style harnesses should be nipple height and snug. Loose straps could allow a worker to pitch forward and literally fall out of the harness. Too tight and the harness will be bunched and uncomfortable. If the strap is too high, under impact it could slide up, too low and we could have a repeat of the scenario described with loose straps.
The most important area of adjustment is in the leg straps and sub pelvic strap. Keep in mind this is where the major impact to the body is to be centered allowing for the major muscle areas to absorb the forces being generated in a fall. The sub pelvic strap should be centered under the cheeks of the buttocks. If the strap is too high there will be little if any support mechanism to support the lower section of the body and the impact will center on the inner thighs. Leg straps should be snug and not overly tight. Loose straps will hang down and under impact will slide up rapidly causing, at minimum, severe pain to the wearer. Make sure that the straps form a “V” in the genital area. Man or woman, improperly adjusted straps here could cause severe damage to these soft tissue organs. Make sure the straps are not crossed or twisted in either case this can cause injury. It is important these straps are properly position to allow them to work properly and still allow the worker freedom of movement with a minimum of discomfort.
Rule Of thumb: Either wear the harness or take it off. A common practice is to undo the leg straps while at lunch or break. This may lead to failure to reattach the straps. The same thing can be said for chest straps. While it may seem impossible there have been instances where workers have failed to properly reconnect the harnesses with serious results.
After donning the harness and making preliminary adjustments have a friend do a buddy check and see if the harness is properly fastened and adjusted. Take the time and go through your range of work motions. You will find that over time the harness will stretch and conform to your body. Stretching and moving will help make fine tuning the harness easier. If you are working through the range of seasonal weather make sure that if you wear the harness over heavy outer clothing allow more time for adjustment. When warmer weather returns, adjust again. Many workers will keep the harness under heavy coveralls or work jackets and have slits tailored in the backs to allow the dorsal D ring to slide through eliminating the adjustment cycle.
1.6.3 Harness Styles
OSHA and ANSI do not address harnesses by application or by class. The Canadian Standards Association (CSA) does and their classification methods are what will be used to help identify the styles available on the market today.
The CSA breaks harnesses into five classes: Class A, D, E, L and P.
All Canadian harnesses have an “A” with an arrow pointing to the dorsal D ring. This arrow along with the “A” indicates the point of attachment for the restraint lanyard or the energy absorbing lanyard component. This ring, and only this ring, is to be used for fall arrest. Using any other ring will cause the wearer to suffer severe injury should a fall occur.
- Class A – A basic harness with one sliding dorsal D ring used in situations where a single fall arrest anchor or restraint lanyard is used. This harness can come in two styles, simple vest or a cross strap variant.
- Class D – This is classified as a descent harness. This harness features a D ring in the middle of the chest in addition to the dorsal ring. This harness is utilized in raising and lowering systems often found in confined space applications. It is also used for ladder climbing devices. Another application would be for rescue situations using the center ring for a rappelling device. While this use is not common, pick off rescues can be done with this class of harness. NOTE: The center ring should never be used as attachment point for fall arrest!
- Class E – Entry / Exit harness. This harness features two rings mounted on the shoulders and are used in conjunction with spreader bars or collapsible A frames. The rings may either be fixed or sliding. The use of these rings insures that a worker can raised or lowered in a near vertical position for confined space areas.
- Class L – Essentially this harness is the same as a descent control harness. The only difference is the position of the front ring, which is often placed in the midriff area. This harness is rarely seen here in the U.S. , it’s function incorporated into the Class D
- Class P – This harness features the steel rings attached to the hip area of the harness to facilitate use of work positioning devices.
In many cases you will see harnesses with multiple rings incorporating all the above classes. At this point it is imperative that employees be trained in the identification and use of the rings and the dangers in the misuse of them. Supervisors should determine the best class of harness for the workers by virtue of the task assigned. Complicated harnesses make the possibility of misuse far greater than if the employee were given the right harness for the job in the first instance.
1.6.4 Inspection, Care, and Maintenance
Manufacturers have detailed inspection and maintenance programs, which must be followed. It is very important to keep written logs of all inspections to ensure compliance with regulations.
A daily inspection is required prior to use. Annually a competent person, other than the wearer, must conduct an inspection.
Fall protection products are designed for today’s rugged work environments. To maintain proper service life and high performance, all products should be inspected frequently. Visual inspection before each use is just common sense. Regular inspection by a competent person for wear, damage or corrosion should be a part of your safety program. Inspect equipment daily and replace it if any defective conditions are found.
Harnesses can be cleaned. Washing it in cold water with a cleaner such as Simple Green in the correct proportions allows it to keep it’s flexibility by removing accumulated body oils and salts, reduces excess particulate matter and makes inspection processes easier. After washing the harnesses should be rinsed thoroughly and hung up to dry in a well-ventilated area out of direct sunlight. Check with the manufacturer for recommended cleaning solutions and cleaning procedures.
Harness / Body Belt Inspection
- Webbing – Grasping the webbing with your hands 6 to 8 inches apart. Bend the webbing in an inverted “U”. The surface tension resulting makes damaged fibers or cuts easier to see. Follow this procedure the entire length of the webbing, inspecting both sides of each strap. Watch for frayed edges, broken fibers, pulled stitches, cuts, burns, and chemical damage.
- D-Rings/Back Pads – Check D-rings for distortion, cracks, breaks, and rough or sharp edges. The D-ring should pivot freely. D-ring pads should also be inspected for damage.
- Attachment of Buckles – Attachments of buckles and D-rings should be given special attention. Note any unusual wear, frayed or cut fibers, or distortion of the buckles or D-rings.
- Tongue/Grommets – The tongue receives heavy wear from repeated buckling and unbuckling. Inspect for loose, distorted or broken grommets. Webbing should not have additional punched holes.
- Tongue Buckle – Buckle tongues should be free of distortion in shape and motion. They should overlap the buckle frame and move freely back and forth in their socket. Roller should turn freely on frame. Check for distortion or sharp edges.
- Friction and Mating Buckles – Inspect the buckle for distortion. The outer bars and center bars must be straight. Pay special attention to corners and attachment points of the center bar.
Lifelines fall into three categories: vertical, horizontal and self-retracting. All three types require an understanding of the mechanics, installation and use of these lines. In this section we will be examining and explain the criteria.
1.7.1 Horizontal Lifelines
Horizontal lifeline (HLL) systems are usually permanent systems that have been engineered for a specific environment, application and location. Over the years portable and temporary systems have been developed but these too, have specific areas of use and in all cases are limited in size and number of workers that can be attached. Permanent horizontal lines can only be designed and erected under the supervision of a qualified person i.e. a structural or mechanical engineer with an extensive background in fall protection. The amount of stress exhibited on the anchors is extreme hence the need for design and testing by qualified people. Homemade systems are immediately suspect in spite of their robust appearance.
Portable systems utilize cable or synthetic lines. Most are limited to a maximum of sixty feet in length, allow no more than two workers on it at any one time and require a minimum of thirty feet clearance. While newer versions allow a greater operational span and reduced clearances, potential users should examine the individual manufacturers products and study whether the product satisfies their needs and expectations.
1.7.2 Vertical Lifelines
Vertical lifelines (VLL) while appearing to be straightforward in their use and design are far more complex due to the components that are used to assemble them. The most overlooked and least appreciated component is also the most important, the lifeline or rope.
1.7.3 Lifeline Construction
Lifelines are synthetic in construction. The use of natural fiber ropes is not allowed and for good reason. Ropes such as manila and hemp are subject to rot, damage due to vermin, have poor abrasion properties and do not approach the strengths that synthetic ropes can offer. Rope sizes are 5/8 and 3/4 inches in diameter and incorporate an eye integrated into the terminus of the lines. The ropes are usually constructed with polyester or polyester / polypropylene blend utilizing a three-strand, laid rope design. Their rated strength is a minimum of 5,600 lbs. Polyester ropes have good abrasion resistance, are impervious to moisture and have limited stretch. The polyester blends are a little less abrasion resistant and have a lower rated strength but on the whole meet all the requirements. The difference in the two is price.
Another type of line would be a kernmantle rope. This is actually a two piece rope. The outside of the rope consists of a polyester sheath that protects the internal parts of the rope. The abrasion and moisture resistance of polyester is necessary since the internal structure of the rope consists of lineal strands of nylon. Although nylon is the strongest of synthetic fibers it has the propensity to absorb moisture that reduces it’s strength and has moderate abrasion properties. This rope is extremely strong with rated strengths as high a 16,000 lbs. however, it is elastic and will stretch under load. It requires closer inspection procedures and in comparison to the other types is expensive.
A third type is polypropylene. While almost waterproof, lightweight and inexpensive it is often difficult to work with, especially at lower temperatures, has poor abrasion resistance, mediocre strength ratings and is subject to UV damage. These ropes are constructed with the three-strand, laid rope design and considering their inherent problems constant inspection is not a luxury but a necessity.
If tasked with purchasing ropes it is important to remember the two basic rope types based on elasticity. They are either static or dynamic. Static ropes have limited stretch and are used for rescue or other tasks where the possibility of impact stresses are minimal. Static ropes are also used as vertical lifelines because they have limited stretch thereby limiting fall distance. Since these ropes have so little stretch, a rope grab should have an energy absorber attached to it or have an extremely short lanyard to limit impact load to the rope.
Dynamic ropes, such as the kernmantle as described above, have elastic properties. These ropes are used in rock and mountain climbing. Climbers do not afford themselves the luxury of rope grabs and depend on the rope to absorb the energy of their fall to ensure that attachment points in the rock are not torn free. When used as a vertical lifeline in industrial settings rope grabs used with these ropes do not necessarily need energy absorbers because the rope stretches under impact and many times the 450 lbs. of impact force necessary to engage the absorber is not reached. Keep in mind that using a rope of this type would also increase the fall distance a worker.
1.7.4 Rope Grabs
The other component in a vertical lifeline is the rope grab. Robe grabs should be mated to the rope. Some rope grabs do not work well with a specific line because of incompatibilities due to the line material or the construction design of the grab. Rope grabs fall into two basic designs, manual and automatic. In the following paragraphs we will examine these grabs in detail.
22.214.171.124 Manual Rope Grabs
Manual rope grabs must be moved and adjusted by the worker as they proceed up and down the vertical lifeline. Manual grabs utilize a one or two cam system that is spring loaded so when the ring or bar is released the cams will automatically lock onto the line. Most manual rope grabs do not have lanyards or shock absorbers integrated into their construction. This requires that the worker make the proper determination on what component to use. If the unit does have a lanyard or shock absorber sewn into it, the question of clearance comes into question.
There are a number of points to remember when working with this type of grab:
- The grab should be positioned above or in front of the worker. This does two things, it allows the worker to keep an eye on the grab, and it keeps their fall distance to a minimum. This is true whether they are in a vertical or inclined position and reduces the possibility of them seizing the grab and opening it should they slip or fall.
- Once the grab is set, it should be released and allowed to lock. Holding it in the hand is an invitation to disaster.
- Make sure the correct diameter rope is used. Too small and the cams will not hold the rope, too thick and the rope will not feed properly.
- The “UP” and arrows placed on the grab indicate the anchor. The worker needs to understand that these markers must always point to the point where the vertical line is anchored
- There are a number of styles of manual rope grabs and although this manual does not specifically endorse a manufacturer, the Miller offering has shown itself to be the best. Large enough to be manipulated with gloves, able to accept both 3/4 and 5/8-inch lines and equipped with an oversize ring for placement of lanyards makes this grab an excellent performer in comparison to the other grabs available today.
126.96.36.199 Automatic Rope Grabs
The automatic style grab allows a worker the move up and down a vertical line without touching the grab. This design works well with workers on powered swing stages and other powered devices and when a worker is constantly moving between levels. The ability move and lock automatically is based on the design and construction of these grabs. One style features an inertial cam wheel that does not rely on cam movement but rather the speed that the rope exhibits on the wheel. This completely eliminates the “death grip” problem because the grab cannot be accidentally held open. The other design operates on the typical levered cam design so that the worker must actually fall past the device to fully lock the teeth onto the rope. Both these designs work equally well, both however anticipate the worker having a clean fall. If the fall speed is slowed or impeded or the worker fails to pass the grab the cam lever may not engage or the wheel may fail to lock the rope in place. Again, if the worker is staying at a specific location for a period of time it is suggested that the worker “park” the grab above them to insure minimal fall distance. One major consideration when using an automatic grab, these types should not be used on inclined surfaces by virtue of their operation. Remember, these grabs are actuated by speed or worker movement past the grab. If this does not happen, a slow slide on a roof or other area will not activate the devices.
1.7.5 Self-Retracting Lifelines (SRL’s)
There are numerous types and styles of retracting devices on the market. They fall into two basic types, self-retracting lanyards and self-retracting lifelines.
188.8.131.52 Self-Retracting Lanyards
For the lack of a better description these devices are no more than upgraded seat belt retractors. The good points of these devices are that they are relatively inexpensive, light weight, lock up very quickly thus allowing very little free fall potential and come in a variety of equipment variations.
The deficiencies are more extensive. Because of their quick lock up speed they restrict movement and can be annoying to the point of frustration. If subjected to a fall of any height they must be disposed of immediately. Their internal workings and lanyard are routinely exposed to the environment that may adversely affect their workings and durability. Work areas such as paint shops or any environment that suffers from high particulate contaminate are suspect for the use of the devices. As they get older and become worn they acquire a symptom commonly referred to as the “dog tongue effect” whereby the device looses it’s ability to fully retract allowing the lanyard to hang as much as two feet below the main body of the device. This is a sure sign that the retractor spring has lost its strength. If not equipped with a swivel either at the main body or the point of connection there is the possibility of the line becoming twisted so as to restrict the line’s ability to retract fully. This could cause slack in the system raising the potential of free fall potential.
While there are many worthwhile applications for this unit, special attention to inspection care and maintenance become necessary and if constant replacement becomes an issue it may be time to investigate the acquisition of a sell retracting lifeline.
184.108.40.206 Self-Retracting Lifelines
Self-retracting lifelines have been in use for more than two decades and have seen marked improvement in their reliability, design and construction. Originally designed to allow an 1,800-lb. impact on a worker, they are now capable of reducing that impact to 900 lbs. or less. All the major manufacturers as well as some specialty manufacturers of safety equipment offer these devices. In the following paragraphs we will take a close look at the workings and uses of these units.
The basic internal design includes a drum containing excess line or cable, a locking mechanism comprised of spring-loaded pawls and a toothed wheel. This in turn is mated to a clutch type assembly, which acts as an internal energy absorber. Externally, there is an anchor point comprised of a handle or eye. The connecting means are usually snap hooks or carabiners.
The housing of these units are usually made of cast aluminum, steel or composite synthetics. Some units are partially sealed which reduces the possibility of foreign particles causing damage or impeding the operation of the unit. The line lengths of SLR units range from 11 feet to 150 feet in length. Lengths from 11 to 20 feet are synthetic lines of flat webbing, lengths from 20 feet and longer are 3/16 inch galvanized or stainless steel cable.
The cable or line is also equipped with a reserve section that can deploy if a catastrophic fall is experienced.
The locking mechanism is engaged by centrifugal force. The locking pawls engage when a speed of 4.5 feet per second is exhibited on the unit. Once the unit has locked a disc brake type assembly or clutch engages slowing the worker’s fall and reduces the impact forces to the worker to 900 lbs. or less. The smaller units will have two pawls, the larger ones, three. This redundancy ensures that should one pawl miss the gear the second or third will engage effectively arresting the fall.
Points to consider:
- The SRL should always be suspended directly above the worker or as close as physically possible. SRL’s that are positioned at an angle or if the worker moves too far horizontally away from the anchor point may result in a swing fall that will not allow the SRL to gain the 4.5 fps needed to lock the device. This will result in the worker being allowed to fall much farther than anticipated and will add undue stress on the SRL. Most manufacturers recommend an angle of 45 degrees or less is maintained when moving away from the anchor point of the SRL.
- Do not lay the SRL on its back or allow the cable or web line to travel across edges even with a pad. Lines that are stressed in this fashion could part under shock load if used in this manner.
- Do not tie knots in the web or block off lengths of the cable with a vise grip to provide slack in the line. In the event of a fall the speed and impact forces generated on the SRL may be enough to cause the unit to fail.
- Do not add shock absorbers or lanyard extensions to the connecting means. These units are self-contained and adding equipment in this manner will only defeat the design of the unit.
- Do not use these units on sloped surfaces or above fluids and semi solids such as slurries, grains, sand or viscous fluids. Remember, the unit needs 4.5 fps to engage and these areas described will not allow that speed to be reached.
- Do not extend the line and secure it. Allow the line to fully retract after use. Retrieval can be accomplished by use of a tag line attached to the connector. This will allow the worker access to the hook without exposing the line to contaminates or causing the retractor spring to become weak and suffer retraction memory loss. Web lines are especially vulnerable to UV damage or particulate contamination if not allowed to retract fully inside the housing.
- SRL’s should be connected to the dorsal D ring only. This is a fall protection device. Use of any other ring will result in injury.
- If the worker is using an older device not equipped with a swivel at the anchor point or the hook is static, it is advisable to obtain and use a swivel type carabiner at the anchor point. This will allow the cable or web free movement with the worker. Static devices in the past have contributed to lines being twisted and stretched as the worker moved about.
- This device is not to be used as a work-positioning device. Although these units lock up in less than two feet they are not be construed as anything but fall protection devices. This means that suitable 5,000 anchor points must be used, fall distance calculations must be done and the worker must never lock the device and lean into the line. Any movement backward, however slight, will unlock the device.
1.7.6 Inspection, Care, and Maintenance
Inspection of these devices should occur at two levels. On a “per use” basis by the worker and on a regular schedule by a competent person. Simple steps such as pulling on the device at least twice will enable the worker to check on the unit’s function and an inspection of the hook to ensure proper operation and determine if an impact has taken place on the unit by examining the impact indicator.
* Impact indicators on older units were usually found on the housing assembly in the form of a red dot or a red flag in a semi-transparent window. Units today have the impact indicator at the point of connection in the form of red bands or torn out red stitching. In some cases where the hook rotates, the hook will be seized and a red band exposed.
The line should be inspected routinely by the user especially the area closest the hook. Discoloration, abrasion marks, loose cable fibers, cuts are signals to remove the device from service or require inspection from a designated competent person. The entire line length should be inspected on a routine basis. The frequency of inspection should be predicated on the use and environment the SRL is subjected to.
The formal inspections should be done according to the manufacturers recommendation and these usually include a yearly factory inspection and re-certification. Never attempt to open these devices to repair or inspect unless qualified. Spring tension in these units is such that attempts to service them without proper training could lead to serious injury.
There are variants in the SRL family. A popular version is the winch / fall protection unit. These are often found in confined space situations and other venues that would require a worker to be lowered and raised. The salient feature of these devices is if a worker does slip or fall, the device will arrest their fall. If an incapacitating injury occurs then the attending worker can engage the winch and retrieve the worker. If the worker is required to enter into confined spaces on a regular basis it might be wise to have a secondary line on a dedicated man-rated winch and allow the fall protection to be addressed by a separate unit.
Ladders are either fixed or portable. OSHA regulations for ladders can be found in 1910.27 and 1926 Subpart X. OSHA in the 1910 section addresses ladder cages, platforms and lengths of climb. Safety devices for fixed ladders in this section may be substituted for cages and platforms were the length of climb exceeds 20 feet, especially for towers and chimneys.
1926 is a bit broader in its scope. Ladders 24 feet or greater and with a length of climb greater than 24 feet are required to have cages, wells, ladder climbing safety devices or SLR’s in addition to rest platforms. It would be prudent to read both the 1910 and 1926 sections carefully to determine what your work area requires.
It is interesting to note that OSHA is seriously considering the elimination of ladder cages as a protective device for climbers. Cages were not designed for safety but rather to allow a worker to rest during the climb. Anyone who has fallen in a ladder cage will attest to the fact the cage will not arrest the fall but will merely keep you bouncing inside the structure till you either hit the ground or become entangled in the cage structure. In either case the injuries sustained are substantial. OSHA has finally recognized this fact and a final rule is expected in the near future.
1.8.1 Portable Ladders
Using portable ladders creates other fall hazards. Proper climbing and work habits can eliminate a lot of falls.
- Inspect the ladder prior to use and do not use it if it is in bad shape.
- Make sure the ladder is fully open and locked.
- The worker should never go above the third step from the top. NEVER work on the top level of a ladder.
- Do not over extend creating an off balance situation.
- Tie off above your head to a secure anchor if possible.
When a straight or extension ladder is used:
- Inspect before use, if in doubt, throw it out
- Get help raising the ladder, and NEVER raise the ladder if the fly is extended.
- Ensure the proper angle is created before climbing (rule of thumb – every 24′ up, go 6′ out)
- Ensure the ladder extends 3′ beyond the level of the roof.
- Ensure the proper overlaps at the fly sections are maintained. It is recommended that:
- 32′ ladder uses 3′ overlap
- 32′-36′ ladder uses 4′ overlap
- 36-38′ ladder uses 5′ overlap
- over 48′ ladder uses 6′ overlap
- Ensure the feet are secure and are on even solid ground
- First person up secures the ladder against movement
- Maintain 3 points of contact at all time
- Never over extend (rule of thumb – keep belt buckle between rails at all times)
- Do not carry tools up; bring them up the ladder with a rope and bucket
1.8.2 Ladder Climbing Systems
Ladder climbing systems are found on fixed ladders and fall into two basic types, cable or rail systems. Rail systems can be either a flat or notched rail.
Ladder climbing devices require the user to use a full body harness with a front D ring. Attachment distance from the user to the device can be no more than 9 inches. This is effectively done with a carabiner. Frontal attachment is acceptable because the lock up distance for these devices is 6 inches or less and free fall is insignificant. Both the cable or rail systems work equally as well, the major differences are in price and application.
Cable systems tend to be less expensive. A galvanized or stainless 3/8-inch solid core cable. The cable can be cut to any length and attachment points placed along the length of the ladder either in the center or the side of the ladder. Narrow ladders would benefit from side placement of these devices so as not to interfere with the climbers’ ability to safely access the rungs. This will be true in the rail systems as well. The cable device is a mechanical sleeve with a cam device that seizes the cable is sudden downward movement is made. While ascending or descending the device will follow the climber. One often overlooked benefit of these devices is it restricts the rate of descent by a climber forcing them to descend in a safe controlled manner rather than attempting to “slide” the ladder. Another feature of the cable systems is their ability to detach from the cable at any point along its length. This is especially valuable when there are multiple levels and thus multiple users of the system at any one time. The user can detach the device from the cable and keep it on their person insuring that they will have it to descend the ladder. It also eliminates the problem of having a device blocking the ladder.
There have been concerns over outdoor use of cable systems especially in cold weather. Ice or snow buildup on the cable is addressed by striking the cable with a wooden handle or rubber mallet, the subsequent vibrations will shake the snow and ice from the cable. Retorquing the cable to specifications eliminates questions on whether stretch in the cable could compromise its effectiveness. A periodic check on tension will ensure proper tautness in the line.
Rail systems can be aluminum, galvanized or stainless steel. These systems are expensive but durable and are, for the most part unaffected by weather or industrial environment. They utilize a 2-inch flat rail or a notched rail system that varies in diameter. A flat rail system will lock up as quickly as a cable, a notched rail will lock up almost as fast with the exception being the device must engage a notch before arresting which means that the worker must fall to the notch. While completely safe, it can surprise someone unfamiliar with the workings of the device.
All these systems can go up and around curves such as found on water towers or arched roof as in an aircraft hangar roof. They are reliable, safe and provide a sense of security for climbers especially for those that do not climb ladders on a regular basis.
One major drawback for rail systems is their inability to detach from the system. This causes problems if the ladder is used to access multiple levels and if more than one person is on the ladder at different times and at different levels. Once a person leaves the ladder, the device is left on the rail leaving the ladder blocked. This problem illustrates the need to effectively assess the type of system that works best before a purchase is made.
We have discussed anchor points, lanyards, shock absorbers, SRL’s and a whole list of components that make up systems either as restraint, positioning or fall arrest. What we need to find out and determine is how far we these systems allow us to fall and what clearances we need to keep from striking the surface of the ground or object after the system engages.
With restraint the answer is simple. No fall therefore no clearance calculation.
Work positioning systems are allowed a maximum two-foot free fall. When setting up these systems we already know a device will allow us to fall two feet. Add in our own height and placement of the anchor and we can determine where our feet will touch if we fall.
Fall arrest systems are more complicated because of the number of components and the variables accompanied by their use.
Here are the factors that you will need to determine fall distances:
- Location of anchor point. (Shoulder height or above)
- Length of lanyard (3,5 or 6 foot)
- Maximum tear out of an energy absorber (3.5 Feet)
- Height of worker
- Stretch of Harness / Connector lengths (Hooks / Carabiners)
If the average worker is 6 foot and they use a 6-foot lanyard with the anchor point just above their heads the distance needed underneath a worker would be an average of seventeen feet. Remember too, that planning fall distances must take into account obstructions such as pipes, conduits, beams, trusses, machinery and even other workers. Hitting the ground may not be your biggest concern. The pipe you hit ten feet below you can kill you as easily as the ground thirty feet beyond the pipe.
Swing or pendulum falls are another concern. This was discussed in the SLR section. This type of fall occurs when anchor points are set at extreme angles to the position of the worker. Falls generated from the side can impact a worker against beams, walls, standpipes, rebar or steel assemblies with nearly the same force as a vertical fall. Try to keep the anchor point as close to your body position as possible. Use the 45-degree or less rule for SRL’s as a standard for all fall protection systems.
Any fall protection plan needs a rescue component. It wouldn’t do the worker any good if their fall was arrested and there was no established method available to get them down. Planning for problems will also help eliminate them. If hazards are identified it may be possible to eliminate them removing the need for fall protection and in turn, rescue concerns.
Rescue does not have to be a complicated affair. A conscious worker can easily access a ladder, cherry picker, or scissors lift and effect a self rescue.
Calling 911 is not always the answer. Many municipal services do not have high angle capabilities and in some instances qualified personnel may be engaged in other tasks. It would be wise to contact the local rescue or fire company and have them review with you their capabilities and your needs.
1.10.1 Self Rescue
If 911 cannot service you and ladders or other equipment are inadequate then self-rescue by employees becomes an option. Devices such as Rope Riders, Rope Genies, and descenders allow trained staff to lower themselves from heights and leave the affected area. These are all friction devices of one sort or another using rope, usually 1/2-inch nylon line. While all of them can be reset and used again they are, in reality, one-person escape units. These units are fairly inexpensive, portable and can be used for almost any height. All that is needed is the correct length and the proper training.
Automatic rescue units such as the RescueMatic are designed to allow an infinite number of people to use the same device repeatedly to exit a specified area. These devices run at a rate of 3.5 feet per second and require no more training than putting the rescue straps on in the specified manner. Once the worker steps off the platform or surface the machine will engage and lower the worker at a controlled of speed. Once the worker touches down, they will remove the rescue straps and allows the next worker to descend. Again, training is required for the proper use and operation of this unit.
The last option is a rescue team. This is an expensive and time consuming alternative but if workers are in remote areas removed from municipal services this may become a viable alternative. Equipment and training will need to go hand in hand. Seek advice in this area before committing to either equipment purchase or training.
OSHA standards for worker safety vary depending on application height, access considerations and more. Requirements can be as simple as demarcation of a hazardous area, or as involved as a fully integrated fall-arrest system. FLS professionals will tell you exactly what’s required for your specific application.
For a fall protection system to be safe and effective, it must be able to handle the load of deployment. FLS engineering professionals make certain safety systems are integrated responsibly, without causing damage, and that in the event of a fall, loads are distributed without compromising the integrity of the surrounding structure.
A fall protection system won’t be effective if it isn’t easily used, and if employees aren’t properly trained in its operation. FLS systems are user-friendly and we don’t consider a project complete until your employees are thoroughly knowledgeable and comfortable with its operation.
Standards and regulations are frequently updated. Equipment can require maintenance. FLS takes the guesswork out by offering annual inspections to ensure your systems are in good working order and remain compliant with the latest Federal, State and Local regulations.